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jcmarchi · 2 years ago

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With a quantum “squeeze,” clocks could keep even more precise time, MIT researchers propose

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With a quantum “squeeze,” clocks could keep even more precise time, MIT researchers propose

The practice of keeping time hinges on stable oscillations. In a grandfather clock, the length of a second is marked by a single swing of the pendulum. In a digital watch, the vibrations of a quartz crystal mark much smaller fractions of time. And in atomic clocks, the world’s state-of-the-art timekeepers, the oscillations of a laser beam stimulate atoms to vibrate at 9.2 billion times per second. These smallest, most stable divisions of time set the timing for today’s satellite communications, GPS systems, and financial markets.

A clock’s stability depends on the noise in its environment. A slight wind can throw a pendulum’s swing out of sync. And heat can disrupt the oscillations of atoms in an atomic clock. Eliminating such environmental effects can improve a clock’s precision. But only by so much.

A new MIT study finds that even if all noise from the outside world is eliminated, the stability of clocks, laser beams, and other oscillators would still be vulnerable to quantum mechanical effects. The precision of oscillators would ultimately be limited by quantum noise.

But in theory, there’s a way to push past this quantum limit. In their study, the researchers also show that by manipulating, or “squeezing,” the states that contribute to quantum noise, the stability of an oscillator could be improved, even past its quantum limit.

“What we’ve shown is, there’s actually a limit to how stable oscillators like lasers and clocks can be, that’s set not just by their environment, but by the fact that quantum mechanics forces them to shake around a little bit,” says Vivishek Sudhir, assistant professor of mechanical engineering at MIT. “Then, we’ve shown that there are ways you can even get around this quantum mechanical shaking. But you have to be more clever than just isolating the thing from its environment. You have to play with the quantum states themselves.”

The team is working on an experimental test of their theory. If they can demonstrate that they can manipulate the quantum states in an oscillating system, the researchers envision that clocks, lasers, and other oscillators could be tuned to super-quantum precision. These systems could then be used to track infinitesimally small differences in time, such as the fluctuations of a single qubit in a quantum computer or the presence of a dark matter particle flitting between detectors.

“We plan to demonstrate several instances of lasers with quantum-enhanced timekeeping ability over the next several years,” says Hudson Loughlin, a graduate student in MIT’s Department of Physics. “We hope that our recent theoretical developments and upcoming experiments will advance our fundamental ability to keep time accurately, and enable new revolutionary technologies.”

Loughlin and Sudhir detail their work in an open-access paper published in the journal Nature Communications.

Laser precision

In studying the stability of oscillators, the researchers looked first to the laser — an optical oscillator that produces a wave-like beam of highly synchronized photons. The invention of the laser is largely credited to physicists Arthur Schawlow and Charles Townes, who coined the name from its descriptive acronym: light amplification by stimulated emission of radiation.

A laser’s design centers on a “lasing medium” — a collection of atoms, usually embedded in glass or crystals. In the earliest lasers, a flash tube surrounding the lasing medium would stimulate electrons in the atoms to jump up in energy. When the electrons relax back to lower energy, they give off some radiation in the form of a photon. Two mirrors, on either end of the lasing medium, reflect the emitted photon back into the atoms to stimulate more electrons, and produce more photons. One mirror, together with the lasing medium, acts as an “amplifier” to boost the production of photons, while the second mirror is partially transmissive and acts as a “coupler” to extract some photons out as a concentrated beam of laser light.

Since the invention of the laser, Schawlow and Townes put forth a hypothesis that a laser’s stability should be limited by quantum noise. Others have since tested their hypothesis by modeling the microscopic features of a laser. Through very specific calculations, they showed that indeed, imperceptible, quantum interactions among the laser’s photons and atoms could limit the stability of their oscillations.

“But this work had to do with extremely detailed, delicate calculations, such that the limit was understood, but only for a specific kind of laser,” Sudhir notes. “We wanted to enormously simplify this, to understand lasers and a wide range of oscillators.”

Putting the “squeeze” on

Rather than focus on a laser’s physical intricacies, the team looked to simplify the problem.

“When an electrical engineer thinks of making an oscillator, they take an amplifier, and they feed the output of the amplifier into its own input,” Sudhir explains. “It’s like a snake eating its own tail. It’s an extremely liberating way of thinking. You don’t need to know the nitty gritty of a laser. Instead, you have an abstract picture, not just of a laser, but of all oscillators.”

In their study, the team drew up a simplified representation of a laser-like oscillator. Their model consists of an amplifier (such as a laser’s atoms), a delay line (for instance, the time it takes light to travel between a laser’s mirrors), and a coupler (such as a partially reflective mirror).

The team then wrote down the equations of physics that describe the system’s behavior, and carried out calculations to see where in the system quantum noise would arise.

“By abstracting this problem to a simple oscillator, we can pinpoint where quantum fluctuations come into the system, and they come in in two places: the amplifier and the coupler that allows us to get a signal out of the oscillator,” Loughlin says. “If we know those two things, we know what the quantum limit on that oscillator’s stability is.”

Sudhir says scientists can use the equations they lay out in their study to calculate the quantum limit in their own oscillators.

What’s more, the team showed that this quantum limit might be overcome, if quantum noise in one of the two sources could be “squeezed.” Quantum squeezing is the idea of minimizing quantum fluctuations in one aspect of a system at the expense of proportionally increasing fluctuations in another aspect. The effect is similar to squeezing air from one part of a balloon into another.

In the case of a laser, the team found that if quantum fluctuations in the coupler were squeezed, it could improve the precision, or the timing of oscillations, in the outgoing laser beam, even as noise in the laser’s power would increase as a result.

“When you find some quantum mechanical limit, there’s always some question of how malleable is that limit?” Sudhir says. “Is it really a hard stop, or is there still some juice you can extract by manipulating some quantum mechanics? In this case, we find that there is, which is a result that is applicable to a huge class of oscillators.”

This research is supported, in part, by the National Science Foundation.

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volumeofvalue · 2 years ago

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The Leak

BOOK REVIEWThe Leak: Politics, Activists, and Loss of Trust at Brookhaven National Laboratoryby Robert P. Crease with Peter D. Bond 2022 About the AuthorsRobert P. Crease is Professor in and Chair of the Department of Philosophy at Stony Brook University, where he has taught for more than three decades. He is the author of The Great Equations, The Prism and the Pendulum, and other books. A…

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#History

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newtonian-tragedy · 2 years ago

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It is perfectly true that Hooke who, as Curator of Experiments of the Royal Society, was supposed "to furnish the Society every day [they met once a week] with three or four considerable experiments," never enjoyed the blessing of leisure of which Newton, at least in his Cambridge years, had so large a share. Yet, it was certainly not only outward pressure that prevented Hooke from thinking out his extremely numerous and original ideas; it was just as much, or even more, the inner pressure of a feverish and ebullient mind. Let us quote once more the DNB and Professor E. N. da C. Andrade. The DNB, p. 284:

"The registers of the Royal Society testify to the eagerness with which Hooke hurried from one inquiry to another with brilliant but inconclusive results. Among those which early engaged his attention were the nature of the air, its function in respiration and combustion, specific weights, the law of falling bodies, the improvement of land-carriage and diving bells, methods of telegraphy and the relations of barometrical readings to changes in the weather. He measured the vibrations of a pendulum two hundred feet long attached to the steeple of St. Paul; invented a useful machine for cutting the teeth of watch-wheels; fixed the thermometer zero at freezing-point of water; and ascertained (in July I664) the number of vibrations corresponding to musical notes."

This characterization of Robert Hooke is not so very different from that of Professor E. N. da C. Andrade, who says (op. cit., p. 439):

"Probably the most inventive man who ever lived, and one of the ablest experimenters, he had a most acute mind, and made astonishingly correct conjectures, based on reason, in all branches of physics. Physics, how- ever, was far from being his only field: he is the founder of scientific meteorology; as an astronomer he has observations of great significance to his credit; he did fundamental work on combustion and respiration; he was one of the founders of modem geology."

And (ibid., p. 441),

"From now on [1660] we are to be confronted with the difficulty of coping with the stream of inventions, notions, brilliant suggestions, accurate observations, daring speculations and prophetic conjectures that poured from Hooke's fertile brain and contriving hands. It will be impossible even to mention them all; to classify them will be difficult; in many cases, in view of the scanty record, it will be hard to decide what exactly was done. Practically everything, however, will bear witness to a truly extraordinary inventiveness and a truly modern outlook. Sometimes Hooke is wrong, but he is wrong in a strictly scientific and not a medieval way. Very often the ideas which he tumbled out in such profusion were taken by others; sometimes his findings were reached quite independently by others, which Hooke found hard to believe. At every stage we are witnessing the workings of a mind so active, so fertile in expedients, so interrupted at every hour, at every endeavour, by the inrush of new concepts, new projects, that it is hard to disentangle his doings. Newton said that he made his discoveries by keeping the subject constantly before him and waiting until the first dawnings opened little by little into the full light. This Hooke was quite unable to do: he totally lacked Newton's powers of concentration. His mind was restless, continually disturbed by fresh ideas, but they were nearly all good, and many were of first importance."

—Alexandre Koyré, An Unpublished Letter of Robert Hooke to Isaac Newton

#robert hooke #isaac newton

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dreaminginthedeepsouth · 4 years ago

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LETTERS FROM AN AMERICAN

August 10, 2021

Heather Cox Richardson

The shocking revelations from former acting attorney general Jeffrey A. Rosen about former president Trump’s direct efforts to use the Department of Justice to overturn the 2020 election, along with the horrors of spiking Covid among the unvaccinated, drove out of the news cycle a revelatory piece of news.

Last Friday, the Bureau of Labor Statistics in the Department of Labor released the jobs report for August 2021. It was stronger than economists had predicted, and even stronger than the administration had hoped.

In July, employers added 943,000 jobs, and unemployment fell to 5.4%. Average hourly wages increased, as well. They are 4% higher than they were a year ago.

Harvard Professor Jason Furman, former chair of President Barack Obama’s Council of Economic Advisors, tweeted: “I have yet to find a blemish in this jobs report. I've never before seen such a wonderful set of economic data.” He noted the report showed “Job gains in most sectors... Big decline in unemployment rate, even bigger for Black & Hispanic/Latino… Red[uctio]n in long-term unemp[loyment]... Solid (nominal) wage gains.”

“Still a long way to go,” he wrote. “[W]e're about 7.5 million jobs short of where we should have been right now absent the pandemic. But we've made a lot of progress.”

Michael Gapen, chief U.S. economist at Barclays, told New York Times reporter Nelson D. Schwartz: “It’s an unambiguously positive report…. Labor market conditions are strong. Unemployment benefits, infection risks and child care constraints are not preventing robust hiring.”

The jobs report is an important political marker because it appears to validate the Democrats’ approach to the economy, the system the president calls the “Biden Plan.” That plan started in January, as soon as Biden took office, using the federal government to combat the coronavirus pandemic as aggressively as the administration could and, at the same time, using federal support to restart the economy.

In March 2021, the Democrats passed the American Rescue Plan, a $1.9 trillion economic stimulus package. In addition to strengthening healthcare systems to combat the coronavirus, it provides economic relief primarily to low- and middle-income Americans by extending unemployment benefits and the child tax credit; funding schools, housing, and local governments; providing help for small businesses; and so on.

Polls indicated that the measure was enormously popular. A Morning Consult poll from February showed that 3 out of 4 voters liked it, and local governments and state governors, including a number of Republicans, backed the bill.

But every single Republican lawmaker in the House of Representatives voted against the measure, saying it was too expensive and that it was unnecessary.

Since 1980, Republican lawmakers have opposed government intervention to stimulate the economy, insisting that private investment is more efficient. Rather than use the government as presidents of both parties from Franklin Delano Roosevelt through Jimmy Carter did to keep the playing field level and promote growth, modern-day Republicans have argued that the government should simply cut taxes in order to free up capital for wealthier Americans to invest. This, they said, would create enough growth to make up for lost tax revenues.

President Ronald Reagan began this trend with major tax cuts in 1981 and 1986. President George H.W. Bush promised not to raise taxes—remember “Read my lips: No new taxes”—but found he had to increase revenues to address the skyrocketing deficits the Reagan cuts created. When he did agree to higher taxes, his own party leaders turned against him. Then President George W. Bush cut taxes again in 2001 and 2003, despite the wars in Afghanistan and Iraq, and in 2017, Republicans under President Donald Trump cut taxes still further.

In 2017, Trump claimed the cut would be “rocket fuel for the economy.” Then–Treasury Secretary Steven Mnuchin echoed almost 40 years of Republican ideology when he said: "The tax plan will pay for itself with economic growth." And then–Senate Majority Leader Mitch McConnell said: "After eight straight years of slow growth and underperformance, America is ready to take off.” (In fact, while Trump’s tax cuts meant tax revenues dropped 31%, they yielded only 2.9% growth, the exact same as the economy enjoyed in 2015, before the cuts.)

Laws like the American Rescue Plan should, in the Republicans’ view, destroy the economy. But Friday’s booming jobs report, along with the reality that the Biden administration has created an average of 832,000 new jobs per month, knocks a serious hole in that argument.

It may be that the pendulum is swinging away from the Republican conviction that tax cuts and private investment are the only key to economic growth.

Today, the Senate passed a $1 trillion bipartisan infrastructure bill by a vote of 69 to 30. The bill repairs roads and bridges, invests in transit and railroads, replaces lead pipes, and provides broadband across the country, among other things. In the next ten years, it is expected to create nearly 3 million jobs.

Nineteen Republicans voted in favor of the bill. There were many reasons to do so. The measure is popular with voters, and Republicans were embarrassed by their unanimous opposition to the American Rescue Plan. Indicating a willingness to work with Democrats might also undercut the Republicans’ image as obstructionists and help to protect the filibuster (a factor I’m guessing was behind McConnell’s yes vote).

But that Republicans felt they needed to abandon their position and vote yes for any reason is a big deal. "For the Republicans who supported this bill, you showed a lot of courage,” Biden told them. “And I want to personally thank you for that."

The bill now goes to the House, which will take it up after the Senate passes a $3.5 trillion infrastructure measure through the reconciliation process, which Democrats can do with a simple majority and without Republican support. The larger package addresses climate change, child care, elder care, housing, and so on. Moody Analytics, which provides economic research and modeling, says that, if it is combined with the bipartisan bill, it will add close to 2 million jobs a year over the next ten years.

Yet, Republicans say it is a “reckless tax and spending spree.”

In contrast, Treasury Secretary Janet Yellen said: “My largest concern is not: What are the risks if we make these big investments? It is: What is the cost if we don’t?”

—-

Notes:

https://www.bls.gov/bls/history/home.htm

https://www.washingtonpost.com/business/explainer-5-key-takeaways-from-the-july-jobs-report/2021/08/06/97dff92a-f6f3-11eb-a636-18cac59a98dc_story.html

Jason Furman @jasonfurmanI have yet to find a blemish in this jobs report. I've never before seen such a wonderful set of economic data: --Job gains in most sectors --Big decline in unemployment rate, even bigger for Black & Hispanic/Latino --Redn in long-term unemp --Solid (nominal) wage gains2,735 Retweets10,265 Likes

August 6th 2021

https://morningconsult.com/2021/02/24/covid-stimulus-support-poll/

https://www.nytimes.com/2021/08/06/business/economy/july-2021-jobs-report.html

https://www.cbpp.org/research/federal-tax/the-legacy-of-the-2001-and-2003-bush-tax-cuts

https://www.npr.org/2019/12/20/789540931/2-years-later-trump-tax-cuts-have-failed-to-deliver-on-gops-promises

https://www.whitehouse.gov/briefing-room/speeches-remarks/2021/08/06/remarks-by-president-biden-on-the-july-jobs-report/

https://www.npr.org/2021/08/10/1026081880/senate-passes-bipartisan-infrastructure-bill

https://www.politico.com/news/2021/08/10/senate-passes-bipartisan-infrastructure-bill-503265

https://www.cnn.com/2021/07/28/politics/infrastructure-bill-explained/index.html

https://www.moodysanalytics.com/-/media/article/2021/macroeconomic-consequences-infrastructure.pdf

https://www.usatoday.com/story/opinion/2021/08/10/senate-passes-infrastructure-bill-bipartisan-support/5539281001/

https://www.cnbc.com/2021/08/04/yellen-says-enacting-bidens-agenda-key-to-keeping-america-as-worlds-pre-eminent-economic-power.html

LETTERS FROM AN AMERICAN

HEATHER COX RICHARDSON

#Heather Cox Richardson #Letters From An American #political #jobs #Democracy #Democrats #the economy #corrupt GOP #criminal GOP

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whatdoesshedotothem · 4 years ago

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Saturday 23 November 1839

12 25/..

fine morning F62 ½° on my bedroom table at 9 5/.. breakfast at 9 ¼ and about 9 ½ Mr. de Richter came and brought A- the 19 nos. of Demidoffs’ work on South Russia for which paid him 15/. to pay Urbin – could not get to take anything for the 6 lessons he has given 3 Russian to me and 3 botanical to A- and to me – he proposed my subscribing (instead of giving to him) the money to the horticultural society here and becoming a member and having a diploma – to pay (subscribe) 100/. per annum – I fought off this on account of the difficulty of paying annual subscriptions – he mentioned

SH:7/ML/E/23/0133

a young Russian student who, if he had not other views, would be at liberty the end of May next and might suit us as compagnon de voyage – a natural history student – aet. 20 – speaks well French and English and a little German – I said he had best bring him here without saying anything to commit either part d’avance – Mr. de R- staid till 10 ¾ - I then finished breakfast and wrote the above of this morning till now 11 ¼ - then trying on cap got second pother about it thought of going tonight chez les Goudovich – then give it up on seeing the day promising snow this evening – out at 12 5/.. – walked A- and I 3 turns together and then II one turn alone, she above an hour and I 1 20/.. hour and came in at 1 35/.. – then studying the Russian

Read book Count Panin gave me till now 3 5/.. – vid. St. James’s chronicle of September 12 to 14 p. 3 vol. 4

p. 252 Antarctic expedition quoted from the Literary gazette – the 2 ships seemed to have sailed the very beginning of September – the 2 so much alike, difficult to know one from the other – Erebus [?] 370 tons – Terror about 340 tons – in each the full complement of officers and men = 64 .:. the 2 ships = 128 – each carries 6 guns i.e. four six-pounds and two salute guns – the warming apparatus is ‘a square iron tube, above a foot in diameter, running all round the sides, and distributing a comfortable warmth to every berth in the ship’ – victualler for 3 years with fresh provisions ‘and pemmican and prepared meats in cases’ ‘the phenomena of terrestrial magnetism will be independently observed throughout the voyage; and also in connection with the new observations about to be established’ (vid. Literary gazette) ‘at St. Helena, the cape, Van Diemens land, etc. the declination, inclination, and intensity of the magnet, will thus form tables of the utmost importance towards solving this great problem. The declination instrument, the horizontal and the vertical force magnetometers, are constructed under the direction of Professor Lloyd of Dublin; and there are besides, dip circles, transits with azimuth circles and chronometers of the most approved construction there are also pendulums for ascertaining the true figure of the earth, thermometers for determining the temperature of the sea at given depths; other blackened thermometers to measure the atmospheric temperature at different latitudes; photometric sensitive paper for experiments on light; barometers to be observed during storms, white squalls, etc; glasses for sidereal observations (particularly on the variable botanical and natural history specimens; actinometers for finding the forces of solar and terrestrial radiation) hygrometers, Oslers’ anemometers,

rain gauges, electrometers, skeleton registers of every needful kind; and, in short, such means to employ, and so much to be done, that will be no great leisure for our enterprising countrymen when all these instruments are put in requisition, and their results are regularly chronicled for the information of the world’ ........... they 1st go to ‘St. Helena where Lieutenant Eardley Wilmot, of the Royal Engineers, will be left in charge of the new observatory Next, at the cape, will be landed for the like purpose, another officer. The vessels then make their way across the ocean, touching at and examining Kerguelens’ land, Amsterdam, and other islands, either known or imperfectly reported in that vast Expanse of waters. Arrived at Van Diemans’ land, the instruments, etc. for the observatory will be sent ashore, and whilst it is [?] they will cruise to various points where the scientific pursuits of the expedition are most likely to be advanced. On their return, they will start de novo in a direct southern course between 120 degrees and 160 degrees east longitude towards the Antarctic pole; and it is a singular and fortunate thing that in this direction, during the present season, a ship of Mr. Enderbys’ has discovered land on both sides of the longitude we have indicated in about 65 and 68 degrees of South latitude (c) these shores have been named Sabrina Lane, seen March 1839, and Balleny Isle, seen February 1839; and between them, as well as upon them, the efforts of the Erebus and Terror will, in the 1st instance, be employed........ they will afterwards circumnavigate the Pole, and try in every quarter to reach the highest point, whether near Enderbys’ land, discovered in 1832, or by Captain Weddells’ furthest reach, about 73 degrees in 1832.

It is between Sabrina Land and Balleney Isle, to the northward, in about latitude 50°, and East longitude 140°, that, it is expected the south magnetic pole will be found............. the vessels on the plan which divides them into 3 compartments; so that either extremity or the middle might be stove in, and yet the remainder be a safe hold for the crew (d)

(c) of these recent discoveries in the Southern Hampshire, Mr. Bates, of the Poultry, has just published an excellent chart, under the superintendence of Captain Beaufort. they appear like the pillars of a gateway, between which the expedition should pass. Editor L.G. i.e. edition of the Literary Gazette –

***

(d) the pumps fitted are those of Massies’ patent. the weather deck is also doubled with 3in. fir-plank, with fear-nought dipped in tallow, laid between them’

SH:7/ML/E/23/0134

had just written so far at 4 20/.. – then till 5 40/.. talking to A- or written a little of rough draft of letter to Mr. P- then dressed – dinner at 6 ¼ in ½ hour – then at Russian grammar till 7 ½ - off at 7 55/.. to the Orousoffs’ – princess R- better tonight – count Kutaitsoff there and prince Michel Orousoff (arrived from St. Petersburg) came and about 9 ½ countess Kutaitsoff with the 2 children from a childs’ ball – the old princess O- always kind asked us to dine there tomorrow her husbands’ birthday – Miss Delamine there as usual – we came away as they all sat down to supper – home at 10 ½ - fine day tho’ a little small crystalline snow as we walked today – R -2° = F28° tonight at 10 40/.. pm – F64 ½° on my bedroom table now at 12 25/.. tonight

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anne-lister-adventures · 5 years ago

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Sunday, 26 April 1840

8 1/4

12 35/’’

Easter Sunday O.S. breakfast over at 10 40/’’ and had had Colonel Broussiloff and Captain Tolstoy who came together very soon after we had sat down to breakfast – Had been up all night 4 hours at church in the night – And today a day of toil and visits –

Each took a cup glass of tea and a mouthful of bread and butter – Colonel B-[Broussiloff] said on my offering to pay him for the wine no! but he would pay himself – Would take a cup of tea – Gentlemanly pleasant agreeable – And T-[Tolstoy] also – A-[Ann] wondered I would admit them – they would go away better pleased as it was than as it would have been had I been A-[Ann]

Have just sent cards (received them from Mesdames Orloff and then Golovin) to Mesdames

✓Galovin Chwastoff

Braïko Latchinoff

✓Orloff Besoc

Kotzebue Mendt

Scallon

The names marked ✓ have sent cards –

‘Tis now 11 1/4 then A-[Ann] and I read prayers before we had quite done had Mr. Krusenstiern cousin to General Kotzebue who staid with us till 12 55/’’ – Agreeable gentlemanly man –

Then sat making some notes on Ispahan from Malcolm vol.[volume] 1 and reading Dubois vol.[volume] 3 route from here to Erivan and looking at the map (État Major map) till dinner at 5 in 26 minutes – Then wrote the last 4 lines – Then at map and reading again till Mademoiselle Kotzebue came about 6 and soon after Mr. ______ the Armenian who went to the top of Ararat with Professor Parrot –

Khachatur Abovian (or “Obuvian”, as Anne writes him in later pages), was the Armenian who worked as guide and interpreter for Professor Parrot when he climbed Mt. Ararat.

Vide Dubois III. 343. 31 v.[versts] from Erivan to the foot of the mountain in a direct line but 60 v.[versts] by the road – The Monastery 2 v.[versts] up the mountain – Parrot ascended in August – Left the monastery at 6 a.m. and reached the sleeping place at 6 or 7 a.m. arranged their sleeping on the rocks very conveniently – The rocks below the snow – Set off next morning at 4 and reached the summit at 3 p.m. – On the top 1 1/2 hour – Barometer at top – Pendulum at the bottom – Returned to the sleeping place that night, and next day to the Monastery – Rode 4 or 5 hours on leaving the Monastery on the ascent – No difficulties – Only the fatigue – Thinks I can do it –

Mt. Ararat seen from the Arch of Charents in Armenia. (Image Source)

Where the wind had swept off the snow and left bare ice, they made steps with an ax which took much time – No shingle it would seem – Tolerably good walking on the lava rock – Ascended Southwest – Tried South? or West? 1st and could not get up – It seemed as if there was a sort of cheminée to climb up at the last – But tiresome to make inquiries thro' an interpreter – Mr. ___ would like to go again – Will be at liberty 15 June O.S. 15/27 June for a month – 1/2 agreed to go with him – To think about it and let him know – Thought I could arrange so as to do this – They both went away after 7 –

Then walked 50 minutes on the gallery-balcony looking into our court – Then tea – Then sat reading and looking into Malcolm and at map and wrote the last 12 lines of the last p.[page] and so far of this till now 12 10/’’ – Very fine day –

Nikolai brought us each a Oeuf Béni this morning asked for his bellet – Gave it him – He is to be off on Thursday with the Post Bags – Told George he hoped I should give him something more than the 2/- per day – Our landlord sent to borrow 200/- tonight whilst I had Domna about 10 p.m. sent him 100/- in ℀ [account] of our 14 days at 2 1/2 Silver Rubles – Reaumur 12 3/4º now at 12 20/’’ tonight

[symbols in the margin of the page:] ✓c ✓c

[in the margin of the page:] the Armenian who ascended Ararat with Professor Parrot.

Page References: SH:7/ML/E/24/0090 and SH:7/ML/E/24/0091

#anne lister code breaker #anne lister #ann walker #moscow to baku 1840

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mysteriousplanchette · 5 years ago

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This dark time is a great opportunity for another themed series! Get ready for the Radio Hypnotic Crystal! For the next week, I’ll be exploring the history and evolution of these unique hypnotic devices with an able assist from the research of my peers in IAPSOP, the International Association for the Preservation of Spiritualist & Occult Periodicals. The device that would come to be known as the Radio Hypnotic Crystal was first invented and used by a notorious hypnotist and mail-order occultist, “Professor” F.T. McIntyre, and sold by his Metropolitan Institute of Sciences. Getting into the details of his notorious career would be more than this format could bear, but give him a keyword search in IAPSOP founder Marc Demarest’s “Chasing Down Emma” blog for more! McIntyre’s invention was first named the “Ocular Fatigue Producer” or “Hypnotic Ball” upon its invention in 1895, and for those familiar with the hypnotist’s classic sleep-inducing swinging pendulum as a source of focus and relaxation, you’re on the exact right track. Essentially a wood-handled glass globe filled with sand surrounding a small, pearlescent ball on a thin rod, the Hypnotic Ball was used in the same manner as the ubiquitous pendulum. McIntyre’s 1903 “Practical Instruction in Suggestion, Hypnotism & Healing” described its creation: “I found myself continually looking for some object which I could use in producing ocular fatigue. At times I would use a pencil, a knife point, or...a diamond ring. In my experiments however I found that subjects would invariably look away from a pencil point and that they would not follow the diamond with sufficient concentration of vision. I therefore determined to construct a device that would induce a condition of fatigue more rapidly than the articles mentioned. Hence—the introduction of the Ocular Fatigue Producer.” The pictured item is an original McIntyre model with an original box, and the only known surviving specimen, to my knowledge. It is now housed in the Mysterious Planchette archive. Swipe for more! #hypnosis #hypnotism #hypnotist #ocularfatigue #mesmerism #radiohypnoticcrystal #mesmerisme #occult #psychic #suggestion https://www.instagram.com/p/B9389PNFuT3/?igshid=1lhlnwy7k1jr9

#hypnosis #hypnotism #hypnotist #ocularfatigue #mesmerism #radiohypnoticcrystal #mesmerisme #occult #psychic #suggestion

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lookslikethatsallthetimewehave · 2 years ago

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Poptropica characters that might be on the autism spectrum?

My personal headcanons for Pop characters who are on the neurodevelopmental spectrum:

Children

Annie Perkins (Cryptids Island book)

Edgar (Monster Carnival Island)

Ishmael (S.O.S. Island)

Mya (Mystery of the Map)

Oliver (Mystery of the Map)

Simon Cobb (Astro-Knights Island book)

Adults

Abe (Zomberry Island)

Amelia (Home Island)

Arthur Eraser (Pencil Warrior book)

Bert Shell (Virus Hunter Island)

Cactus von Garlic (Vampire's Curse Island)

Claria (Jade Scarab Island)

Daphne Dreadnaught (Ghost Story Island)

Dr. Beev (Mocktropica Island)

Dr. Hare (24 Carrot Island)

Duck Game Worker (Monster Carnival Island)

Harold Mews (Cryptids Island)

Joe Puddy (Zomberry Island)

Kevin (Mystery of the Map)

Dr. Lange (Virus Hunter Island)

Mark Hertz (Mocktropica Island)

Mordred/Binary Bard (Astro-Knights Island)

Myron Van Buren (Survival Island)

Professor Pendulum (Time Tangled Island)

Rachel Salerno (Lunar Colony Island)

Ringmaster Raven (Monster Carnival Island)

Vince Graves (Nabooti Island)

Alright :p

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friendlyneighborhoodborg · 6 years ago

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I just did a bit of a change in aesthetic, including a new steampunk-inspired, Rube Goldberg-themed banner! Spent all tonight on it.

*Please ask for permission before using.

Picture captions transcribed below cut:

“Professor L. G. Butts got his tie caught in a Venus Flytrap and came up with his invention for lighting up the workshop. One simply has to turn the crank (A), manipulating the gear system (B). The gears lift a piece of carrot cake (C) for a hungry rabbit (D), who eagerly bounds towards it, firing the crossbow (E). The bolt will hit the target (F), moving spare rocket boot (G). When the boot’s button hits the wall, the rocket will ignite, lighting the fuse (H), which will eventually split off and drop the trapdoor (I) and weight, pulling the scissor arm (J) and pushing the valve (K) for the steam pipe. The steam will power the steam engine (L), the flywheel for which will power the heater (M), heating the tea kettle (N). When the tea’s hot, the steam will inflate a balloon (O), which will lift a hook and release a clock pendulum (P). It will knock the oil can (Q) over, pouring oil into the funnel, putting oil in the oil compartment of the lamp (R). This tops off the fuel, and the fuse we lit back at (H) will by now have traveled its length to light the wick.

When the balloon eventually pops and the kettle is free to whistle, you’ll hear the workshop has been lit, and you may enter the room with leaves, cups, and scones.”

*Inspired by the cartoons of Rube Goldberg, with a steampunk twist.

#Borg Draws #art #Rube Goldberg #Rube Goldberg Machine #tumblr banner #Steampunk

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scepticaladventure · 7 years ago

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28 Fresh Perspectives Needed 13Sep18

Introduction I have three motivations in writing this series of essays. The first is to improve my own understanding through research, contemplation and organizing my ideas by writing them. The second is to be able to share this journey with others in a plain-English format, just in case anyone is interested or amused by this (which is not the case for my wife, friends and relatives!). My third reason is the hope of provoking fresh thinking in areas that seem to me to be calling out for new insights and answers.

I think modern cosmology is in trouble. 95-98% of the Universe has gone missing and cannot be found. Cosmologists claim to understand the history of the Universe, even before the so-called Big Bang, but cannot explain the motion of stars in spiral galaxies or why the Universe seems to be expanding at an accelerating rate, or why its geometry seems to be so flat. We can’t even deeply explain the motion of a simple Foucault pendulum here on Earth. And our model for light is an unsatisfactory pastiche of conflicting ideas. Paradoxes persist. How long will it take before we agree – we seem to have lost the path, it should not be as hard as this, we have missed something, we have failed to fully understand something fundamental.

So I have gone back through the foundations of modern physics with an open but skeptical mind. It has been a fascinating journey.

Here are my conclusions: 1. Our model for light is clumsy, old fashioned, contradictory and severely limiting. It needs a fresh look. Wave-particle duality is just a label for something we don’t properly understand. 2. The aether theory isn’t dead, it is just sleeping. It ran into problems and was bypassed, shelved and ignored. But maybe Lorentz, Sagnac and others were onto something that needs a fresh and further look. 3. Special Relativity is a work of genius and uncovered some fundamental aspects of Nature. But it rests on three postulates that may not be always, everywhere and entirely valid. 4. The issue of where does inertia comes from in the first place needs some deep consideration. 5. General Relativity is brilliantly successful because it recognizes that both time and the speed of light are affected by gravity. It is also a clever and powerful model that brings a whole lot of new mathematics into play. But for all that it is just a model. 6. If you add the insights of Special Relativity and the fact that gravity slows the speed of light/time back into classical physics you can successfully model, quantify and predict all of the so-called proofs of General Relativity. This shows that General Relativity is an excellent way of looking at certain aspects of Nature, but it is not the only way of understanding Nature. 7. Restricting our viewpoints restricts our understanding and progress. We need some fresh perspectives.

The Cone Here is a parable. Consider a solid cone made out of some hard shiny material. Viewed from one end it will look like a disc. Viewed from the other end it will still look like a disc, but with some indications that it has a symmetrical three dimensional nature and maybe a pointy tip. Viewed side on it will look like a triangle, again with some suggestions of curvature but this time from side to side. Which view is correct? The answer is that all three views are correct, but none is completely correct. Insisting that one view is correct and ignoring the other views is to limit understanding of the true nature of the cone.

I think it is the same with General Relativity. Insisting that it is the only correct way of interpreting the Universe is to limit our chances of developing a deeper understanding.

The Rise of the Metric Approach to Gravity There are various ways to try to describe physics involving gravity. It is clear that four dimensional spacetime is needed and that the lessons of Special Relativity need to be included. Furthermore, the fact that gravity slows down the speed of light and the rate of time points to the need to allow for flexibility in the time dimension. So a flat Minkowski spacetime is not entirely adequate. But this is where the great divide comes in. You can choose to follow Einstein and make use of a fully curved spacetime model, or not.

If you do choose Einstein’s geometric approach then you can regard this as just a model – as Einstein himself did – or you can go further and choose to regard curved spacetime as some sort of fundamental reality. This last step gained popularity after Einstein died, promulgated by luminaries such as Misner, Thorne and Wheeler in the United States and Stephen Hawking in the United Kingdom.

Necessity for Full Spacetime Curvature? N.B. In this essay I will again be making references to a heavyweight textbook on gravity by Charles Misner, Kip Thorne and John Wheeler (MTW): “Gravitation” C W Misner, K S Thorne, J A Wheeler Freeman Press, 1970 ISBN 0-7167-0344

MTW have played a major role in promoting the idea that gravity is nothing more than spacetime curvature. Einstein’s own approach was regarded as a curiosity by many scientists for the first forty years of its life but from the middle of the 20th century it gradually assumed the ascendency. Whereas Einstein regarded his full curvature approach to be a useful tool, MTW and others reinterpreted his approach and helped to create the modern view that gravity is just an illusion created by full spacetime curvature.

MTW do not have an open mind on the subject. On p1066 they say “Among all bodies of physical law none has ever been found that is simpler or more beautiful than Einstein’s geometric theory of gravity; nor has any theory of gravity been discovered that is more compelling”. On p1067 they say “For any adequate description of gravity, look to a metric theory”. On p 421 they say “Mass-energy curves space is the central principle of gravity”. On p429 they praise General Relativity because “It describes gravity entirely in terms of geometry; most of its competitors do not”. And John Wheeler is often quoted as saying “Matter tells spacetime how to curve and curved spacetime tell matter how to move.”

Clifford M Will was a student of Kip Thorne at Caltech and later became a leading professor of physics, specializing in General Relativity. I will use quotes from his online article “The Confrontation between General Relativity and Experiment” June 2014, SpringerLink, and his overview “Was Einstein Right? A Centenary Assessment” 33 pages, 8 figures, published in General Relativity and Gravitation: A Centennial Perspective, eds. A. Ashtekar, B. Berger, J. Isenberg and M. A. H. MacCallum (Cambridge University Press), 2015. Abridged version at arXiv:1403.7377.

Will presents the Einstein Equivalence Principle and Strong Equivalence Principle in confusing ways, with each principle containing other principles. Will then says that the equivalence principles are the heart and soul of gravitational theory, “for it is possible to argue convincingly that if they are valid, then gravitation must be a ‘curved spacetime’ phenomenon.” In other words, the effects of gravity must be equivalent to the effects of living in a curved spacetime.

I think that to whether “the effects of gravity must be equivalent to the effects of living in a curved spacetime curvature” is true or not depending on what it meant by ‘equivalent’. If the author means “can be satisfactorily modeled by” I would happily agree. If the author means we live in a curved spacetime reality and gravity does not exist, then I think that he has gone too far. Further than Einstein ever went and further than is reasonable.

The Parametrized Post Newtonian Formalism The Parameterized Post-Newtonian Framework (PPN) was developed over 50 years by illustrious physicists such as Eddington, Robertson, Schiff, Nordtvedt and Will. The PPN formalism adds ten generic parameters to a basic version of General Relativity. The parameters can be adjusted so that the PPN can represent a whole variety of competing geometric models of gravity, including subtle variations of General Relativity itself. The idea is then to use experimental results to put limits on the parameters as a way of weeding out the range of theories and preventing new weeds from taking hold.

Theories subject to this treatment include Einstein’s General Relativity (1915), Whitehead (1922), one of Bergman’s (1968) scalar-tensor theories, one of Nordstrom’s theories, theories by Birkhoff (1943), Dicke-Brans-Jordan (1961, 1959), Ni (1970, 1972) and many others.

Suffice it to say that plain vanilla General Relativity complies neatly with these tests and the other models struggle.

The work by Will also covers a lot of metric theories, classified into General Relativity, scalar-tensor theories (of which the Jordan–Fierz–Brans–Dicke theory is a good example), vector-tensor theories and scalar-vector-tensor theories. Let me quote from the second of the Will references mentioned above: • A number of theories fall into the class of “prior-geometric” theories, with absolute elements such as a flat background metric in addition to the physical metric. Most of these theories predict “preferred-frame” effects that have been tightly constrained by observations. An example is Rosen’s bi-metric theory. • A large number of alternative theories of gravity predict gravitational wave emission substantially different from that of general relativity, in strong disagreement with observations of the binary pulsar. • Scalar-tensor modifications of general relativity have become very popular in unification schemes such as string theory, and in cosmological model building. Because the scalar fields could be massive, the potentials in the post-Newtonian limit could be modified by Yukawa-like terms. • Theories that also incorporate vector fields have attracted recent attention, in the spirit of the Extension of the Standard Model (of sub-atomic particles), as models for violations of Lorentz invariance in the gravitational sector, and as potential candidates to account for phenomena such as galaxy rotation curves without resorting to dark matter.

Again Will uses a range of experimental results and concludes that plain vanilla General Relativity complies neatly with these tests and the other models do not.

My problem with all this work is not its intention, but the way it is carried out. MTW, Will and Nordtvedt make up the rules, act as prosecutor, select the evidence, interpret the evidence and act as jury and judge. If they encounter a problem in a theory they allow no attempt to fix it. They simply bayonet the wounded theory, declare it dead and buried, and move on to the next.

Einstein struggled for ten years to develop his General Relativity model, with many twists and turns. He produced an initial calculation for the light bending effect that was half the final result. He argued for, then against, and finally for the existence of gravitational waves. He introduced a cosmological constant and then called it a mistake. So it may be a bit harsh and possibly premature to kill off other models at the first sign of a problem.

Models with Backgrounds The antagonism by MTW towards alternate theories of gravity and alternate interpretations of Einstein’s approach shows up in the discussion by MTW of attempts to view gravity as a standard type of field situated in a flat spacetime background.

This approach has been developed and explored by notable theorists such as Gupta, Kraichman, Thirring, Feyman, Weinberg and Deser (see MTW p436). It offers one of several routes to the field equations of Einstein’s General Relativity.

One version (Fierz and Pauli 1939) borrowed from quantum theory and envisages gravity as occurring via the exchange of gravitons – hypothetical zero rest mass particles with a spin number of 2. MTW claim that by the time this approach is fully developed the original flat spacetime has become unobservable. MTW dismiss the theory (p437) because it is silent about the emergence of the Universe from an initial singularity - the Big Bang Theory. Hence MTW dismiss a serious attempt to bring together the two pillars of modern physics because it is silent about something else that they like.

MTW start their more general discussion of models with backgrounds by stating that any flat background must be unobservable (p424). This is the same point of view put to Lorentz by Einstein in relation to Special Relativity.

Einstein did not deny the possibility of a background that may or may not correspond to a lumiferous aether. He just argued that if it cannot show up in Michelson-Morley type experiments it must be unobservable and hence not useful.

MTW praise General Relativity for being free of any ‘prior geometry’, and criticize any competitors which admit this as a possibility. I think they have a point because I think that all geometry is a man-made overlay and hence has no prior reality. In fact no reality at all except in our own minds. But I think that that agreeing that there is no prior geometry is not quite the same as agreeing that there is no background. It might just mean that the background has no prior geometry.

I think this subtle difference is vitally and fundamentally important.

In my view, Newton’s rotating bucket, the Foucault pendulum and the Sagnac interferometer all readily distinguish reference frames which are rotating or accelerating from ones which are not. The Cosmic Microwave Background does the same. Conversely, Einstein’s attempt to explain why some objects demonstrate rotational phenomena and others do not by imposing boundary conditions on his cosmological models was a failure. Einstein thought so anyway, even though it suits many modern cosmologists to disagree.

So why do MTW show such antagonism to the idea of a cosmological background? I think it might be because they conflate it with ‘prior geometry’. However, to their credit they attempt to clarify their language. On p 429 they say “By ‘prior geometry’ one means any aspect of the geometry of spacetime that is fixed immutably, i.e. that cannot be changed by changing the distribution of gravitating sources”.

So what about a background geometry that is affected by the distribution of gravitating sources in the Universe? This echoes the argument put forward by Ernst Mach towards the end of the 19th century. Einstein admired the idea so much that he dubbed it “Mach’s Principle.” (Einstein endeavored to incorporate the idea into his theories all his life, but eventually concluded that he had not been successful.) If the background is given a Machian interpretation then I think it has to be taken very seriously.

There seems to be a confused belief that the idea of a background conflicts with something that Einstein called the Principle of General Covariance. This principle states that the outcome of physical experiments does not depend on the choice of reference frame in which to view them. In other words, physics is agnostic to reference frames invented by observers for their own convenience.

This principle is entirely reasonable, but has little to do with the fact that some reference frames are more equal than others. For example, frames that are not accelerating or rotating do not contain spurious forces deflecting unattached test particles all over the place.

It is robustly true that the physical outcomes are the same whatever reference frame you chose to use – it is just that the ease of describing what is going on them is vastly different depending on the frame you happen to choose to describe them in. Choose your frame right and you do not have to invent ‘fictitious’ forces to balance the books.

An example of the type of effort that I admire is a modeling approach developed by W T Ni in 1970 and 1972 (see MTW p1070). This has a background geometry and treats gravity as a scalar field. MTW agree that the theory satisfies the equivalence principle (which version is not clear), and that the model is self-consistent and complete. But then they say “If the solar system were at rest in the ‘rest frame of the Universe’, the theory would agree with all experiments to date – except possibly for the expansion of the Universe. But the motion of the solar system through the Universe leads to serious disagreement with experiment (Will and Nordtvedt 1972)”.

The alleged fatal flaw comes from work by Will in 1971 that suggests that the force between two massive objects will depend on the way in which they are travelling through the background metric. This is calculated to create a twice-a-day fluctuation in the tides on Earth and also to tidal fluctuations within the Earth that conflicts with the experimental evidence. This leads Will to claim that the theory of Whitehead (1922) and of Ni (1972) cannot be correct. But is Will correct?

When Galileo presented his model of a spinning Earth orbiting a stationary Sun, the wise men of the day calculated that the tangential speed of the Earth’s surface could be anything up to 1600km/hour and said that Galileo’s model could not possibly be true because no bird could fly that fast in order to keep up. It was not an unreasonable point because this was in the days prior to Torricelli and hence there was not yet a concept of the atmosphere being a thin layer coating the earth with no viscous drag where it meets the vacuum of space. Likewise Will’s objection could be perfectly reasonable and clever, but nevertheless wrong.

Since General Relativity and modern physics generally cannot explain the enormous anomaly in the motion of stars in the discs of all spiral galaxies (without inventing hypothetical dark matter) there is clearly something occurring that is not well explained by the conventional paradigm. So it may be unwise to be too definite about what is right and what is wrong at this stage. What if the type of thinking put forward by Ni resolves the galaxy rotation curve crisis?

The Fabric of Spacetime? It is common to hear expressions such as “the fabric of spacetime”, and “spacetime tells matter how to move”. It is also common to see diagrams with spacetime depicted as a curved or distorted rubber sheet with dimples around massive objects forcing the path of freely moving bodies into curves and orbits.

This is a bit unfortunate. It tends to create the impression that spacetime is a real thing, an actual entity. That moving objects are deflected because they hit a bump in the road.

Spacetime is a just way of defining places and moments, lengths and times in a satisfactory way so we can describe what is going on. We do this sort of thing all the time, but we need to be careful not to get confused between our imagined constructs and actual reality.

For example, we have an agreed way of assigning lines of latitude and longitude to the surface of the Earth. This creates a two dimensional grid. But it is not real. You cannot see it, touch it, taste it, smell it or hear it. You cannot detect it with any instruments. It does not interact with matter in any shape or form. The motion of everything on Earth is oblivious to the imaginary grid that we have imagined and agreed upon for our own convenience of reference.

It is the same with spacetime. Curved or not. It is just a reference frame that we overlay onto physical reality to make it easier to talk about what is going on. If it proves convenient to use a warped geometry then use that. If some other representation is more convenient then use that one instead. It makes no difference to actual reality.

Imaginary reference frames are useful for describing physical systems. That is all. Spacetime does not exist as a thing in its own right, any more than the lines of latitude and longitude exist on the surface of the Earth. Spacetime curvature does not tell matter how to move any more than the lines of latitude and longitude tell ships and planes how to move, or ducks how to migrate. It is important not to become confused between descriptions of reality that we happen to find useful and reality itself.

When someone says “matter tells spacetime how to curve and spacetime curvature tells matter how to move” we should not take the words too literally. It would be better to remind ourselves that we have imposed an imaginary and somewhat arbitrary reference frame across the physical system we are trying to describe and that for some purposes we find it convenient to model the effects of gravity by using a warped four dimensional framework.

I know that General Relativity can be recast in terms so generic that the convenience of coordinates can be dispensed with all together. However I do not think this alters my point.

I am also familiar with the argument that goes as follows. By applying geometry to the surface of the Earth we can discover that two dimensional geometry which is locally Euclidean no longer works on a larger scale, thus revealing that the surface of the Earth is a curved manifold in three dimensional space. Similarly, applying four dimensional geometry which is locally Lorentzian on a larger scale reveals that spacetime curvature is necessary to account for physical dynamics in the presence of gravity. I would agree with this if I thought that Einstein’s Equivalence Principle was literally true. But I don’t. I think that gravity can be mimicked by a linear acceleration to a certain degree, and that it is possible to build clever mathematical models based on this fact. But is gravity, the most dominant force in the Universe, just an illusion created by a quirk of geometry? I don’t think so.

Is General Relativity Perfect? Yes, you can get rid of gravity by imagining spacetime is curved. Yes this is brilliant stuff. Yes this produces a small number of remarkable (very small) predictions that turn out to be true. And yes it is possible to build innumerable wonderful cosmological models using curved spacetime geometries. But that is not conclusive proof that the modern version of General Relativity is the only way to look at the Universe, the best way to look at the Universe, or even the most convenient way to look at the Universe.

General Relativity is very hard to use and I think the results of its over complicated mathematics throw up more questions than they answer. And while I am being heretical, I may as well produce a list of criticisms. In my naive opinion, the modern version of General Relativity: 1. is based on a Principle of Equivalence which is just a mathematical assumption 2. elevates spacetime to a status it does not deserve 3. does not explain why matter, stress and energy distort spacetime 4. does not explain the origins of linear or rotational inertia 5. does not explain why matter has mass 6. is so complicated that it enables mathematicians to come up with a whole range of solutions which have no correspondence in Nature 7. creates red herrings that waste everyone’s time 8. has not helped with the dilemmas of missing Cold Dark Matter and Dark Energy 9. has predictions which can be accounted for in other ways 10. obscures, bypasses or overshadows a lot of fundamental issues that deserve more attention.

In many ways, the proof of the pudding is in the eating. A century after General Relativity was produced, most astronomers do not use it except in special circumstances such as gravitational lensing and black holes. In day-to-day discussions they just use a post-Newtonian approximation. And although Einstein and modern ‘metricists’ seem to be averse to any ‘a priori’ geometry in the Universe, astronomers nevertheless find it convenient to have agreed reference frames for the Solar System, the Milky Way and the wider Universe. Are they are instinctively using something that has physical significance?

Spatial Curvature on a Cosmological Scale Einstein’s General Relativity model requires mass/energy to warp spacetime. Its equations involve mass/stress/energy tensor warping the 4x4 spacetime metric tensor in all of its sixteen components (six of which are duplicates due to symmetry).

Suppose there are three spacecraft at rest with respect to each other and the cosmic microwave background. Connect them by laser beams and measure the angles between the three beams. The beams form a triangle. If the interior angles always add up to 180 degrees, then spacetime is flat. If the sum of the angles is more or less than that, then space has positive or negative curvature.

As far as we can tell, on a very large spatial scale our Universe is flat. Very flat. Parallel lines in intergalactic space will never meet. But this requires a very particular value for the universal stress energy tensor. Theorists have been struggling for nearly a century to explain why this might be so. It would be a remarkable coincidence if the average mass/stress/energy in our Universe happens to be exactly the right amount for universal spacetime to have neither positive nor negative curvature on a macro scale.

So Why is our Universe so Flat? The Einstein-Friedmann-Robertson-Walker models of the Universe involve solutions for Einstein’s equations based on the assumption that the Universe is more or less uniformly filled with mass/stress/energy, a bit like a perfect fluid. The equations have solutions which have positive curvature (like a sphere in 3D), negative curvature (like a hyperbolic surface in 3D) or zero curvature (i.e. flat) depending on the energy density measured by the omnipresent mass/stress/energy tensor.

But observations show the Universe is flat. So how did the Universe come up with exactly the right amount of mass/stress/energy to arrive at this special case? Theorists have come up with all sorts of suggestions, but it is still a mystery.

I have a much simpler answer. The Universe is flat because is has always been flat and that is the only thing it can be. The non-flat Friedmann solutions are just artifacts of the model and the assumptions used in obtaining its generic solutions. Not all aspects of the solutions have to correspond to reality.

When I read the debate between cosmologists about possible values for the cosmological constant I cannot help but be reminded of the debate between medieval theologians about how many angels can dance on the head on a pin. All very clever, but maybe not very useful.

Consider the Cartesian map analogy again. It is possible to map the surface of the earth onto a two dimensional surface by allowing the lines of longitude to move further and further apart as the distance from the equator increases. This is very useful, especially when reproducing maps on paper. But it produces singularities at the north and south poles. It is no good worrying about the meaning of these singularities and what bizarre things might be happening at the poles because the singularities do not exist in reality – they are just an artifact of the mathematical approach used to build the two dimensional model.

Likewise, you can waste time worrying why the Universe is flat, or you can just accept that the non-flat mathematical solutions are an artifact of a particular set of solutions to a peculiar model of the Universe based on a peculiar approach to describing physics.

I say peculiar model of the Universe because it seems to me that the Einstein-Friedmann-Robertson-Walker models of the Universe rest on some doubtful assumptions. Friedmann was not making assumptions summarizing actual experimental observations – he was just making gross simplifications in order to be able to get a handle on the mathematics. I don’t think the Universe is anything like a homogeneous perfect fluid. The more we look the more we find macro patterns in its structure. Huge super-clusters of galaxies, filaments, voids and walls. The analogy to the particles in a fluid are the galaxies. However, unlike the molecules in a fluid, the space between the galaxies contains a lot of intergalactic dust, neutrinos and photons. Furthermore galaxies collide with each other in ways that are totally different to the ways that molecules collide in a fluid. And the list of differences goes on.

I think the large scale geometry of our Universe is so flat because it was never curved. Cosmological curvature is our idea – not Nature’s.

Conclusion Inspired by Einstein’s great work there have been literally dozens of other models of gravitation over the last hundred years or so.

At first gravitation theory was a theorist’s paradise but an experimenter’s purgatory. Since the 1960’s however, developments in space technology and astronomy have created the ability to test many aspects of this work. The clear winner has been Einstein’s original theory. So much so that many scientists regard spacetime curvature not as a model of what is going on in nature, but as a fundamental new reality.

I think this is a mistake. I think that General Relativity is a very clever and successful model, but a model none-the-less. There is plenty that we do not yet understand properly about the Universe, how it works and how it evolved. Refusing to consider alternative approaches has the strong likelihood of unnecessarily limiting our understanding and delaying the next generation of breakthroughs.

General Relativity leaves key questions unanswered, e.g. in relation to the origins of inertia and the dynamics of spiral galaxies. The fact that 98% of the Universe required by theory cannot actually be found may be trying to tell us something - we have missed something fundamental. We have got off track. Something is wrong somewhere.

The current orthodoxy is a cage to our thinking and it deserves to be rattled and shaken. And finally a message to young scientists – please do not stop asking questions and do not stop questioning what they tell you, especially if it seems fudged.

A quote from a lecture Einstein gave in 1921: “As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain they do not refer to reality.”

#science #physics #Einstein #General Relativity #cosmology #gravity #theories of gravity #hereticalphysics

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orbemnews · 4 years ago

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She Wants to Kill the Girl Boss In a start-up economy of self-described “boss babes,” Ashley Sumner wants to be known in simpler terms. While on a run near her home in the Venice neighborhood of Los Angeles in early March, Ms. Sumner was thinking about identity and the peppy phrases that female professionals use to describe themselves online: “girl bosses” and the like. “I worry about the negative impact of that,” Ms. Sumner, 32, said. “I worry that it allows investors to see founders who are women as a separate class from the rest of the founders. I worry it allows investors to write women founders smaller checks. I do believe that women need to help inspire other women but also that identity can be used as labels to separate us.” Ms. Sumner is the chief executive officer of Quilt, an audio platform for conversations about self-care topics like wellness in the workplace, PTSD and astrology. (In prepandemic days, the company organized work gatherings and group discussions in people’s homes.) She has felt marginalized in the woman section of founders’ circles. “I am always asked to speak on the female founders panel,” Ms. Sumner said. “I want to be asked to speak on the panel.” Since she is in the discussion business, she wondered if she could start one with the central question. “When is labeling in support and celebration of furthering our mission of equality successful and when is it ‘othering’ and hurting our mission?” She ran home, sat sweatily at her computer, banged out a few words and overlaid them on a photograph of herself. “I am a female founder,” she typed, then dramatically crossing out the word “female” and adding a caption that read in part: “putting my gender in front of what I am belittles what I’ve accomplished.” Ms. Sumner isn’t particularly active on Instagram or Twitter. On LinkedIn, she had never done more than repost someone else’s articles or musings. But given that platform’s focus on professional life, she thought it was a reasonable place to first share her handiwork. Ms. Sumner’s post has drawn nearly 20,000 comments, from men and women in the United States, Australia, Africa, Latin America, India and beyond; from executives, construction workers, health care employees, professors and military professionals. After reading it, Kate Urekew, the founder of Revel Experiences, a marketing firm in Boston, contacted three successful business owners she knows to ask them what they think. Each said there is not yet enough representation of women in leadership ranks to ignore the gender disparities. “In order to change things and truly achieve parity,” said Ms. Urekew, 50, “you need to have more visibility for other women.” She added: “I love that she started this discussion, it opened up my eyes to many more aspects.” In something of a rarity for a viral social media post, especially one about identity, the comments reflect a range of perspectives and are mostly civil. “That’s what we all need to hear,” one man wrote. “Too much identity politics leads to confirmation bias.” “I don’t feel we are there yet,” a woman wrote. “We are still at a point where we are trying to get equal footing, and that takes awareness, doesn’t it?” “Succeeding in the business world means you are accomplishing a great thing and in some cases outperforming a male,” a man wrote. More than 150 female founders posted similar photos of themselves, crossing out the word “female,” and then shared what was now credibly a meme on the internet. One was Antoinetta Mosley, the founder of I Follow the Leader, a consulting firm that specializes in diversity, equity and inclusion strategy, initiatives and education in Durham, N.C. “It was a little shocking at first, to see ‘female’ crossed out,” she said of Ms. Sumner’s post. “I immediately clicked to see what she said, and I thought it was really striking.” Ms. Mosley, 34, said in the unconscious bias seminars she leads, she asks people to consider the way race, gender and other traits influence narratives about people’s professional skills and how they can perpetuate inequities. “When people see me as a Black woman leader,” she said, “they are assuming that my being Black and a woman influence my leadership style.” She believes these labels can sometimes hold women back from being considered on equal footing to men. She said that being a Black woman is a significant part of her identity, but she, like most people, has far more dimensions. She believes her professional traits result most from being an athlete and the oldest of four children with driven parents. Faryl Morse, 55, who owns the footwear company Faryl Robin, was also moved to make her own post, listing the social media lingo of “Boss Babe,” “WomEntrepreneur,” “Girl Boss” and “Mompreneur.” “Let’s please stop adding these cute names to women who are ambitious and are going after their dreams with persistence,” she wrote. “It is not empowering any woman.” Ms. Morse wants other women to see her success and know that they too can aspire to own and operate a thriving business in a male dominated industry, and she believes that being a woman gives her a different and valuable perspective. “But I am not a woman founder,” she said. “I am a founder. End of conversation. Gender should not be descriptive in the world we live in today. It doesn’t define me professionally.” Rayy Babalola, the founder of the Agile Squad, a project management and consulting firm in Kent, England, was captivated by the responses on LinkedIn but says that it’s not so easy for everyone to drop the labels and forget the struggle and perseverance required to find professional success. Ms. Babalola, 30, believes that to call herself a Black woman business founder conveys that she has overcome the dual obstacles of sexism and racism. And she feels a responsibility to signal to other Black women that they too can have a path to business ownership. “Being a Black woman has affected how I have been treated, and that has pushed me to become a founder,” she said. “And you can’t be selfish,” she said. “Just because you found a way doesn’t mean that it’s OK, now you can be silent.” She thinks identifiers like “female founder” and “Black-owned business” are still important. “Until those terms stop rattling minds,” she said, they need to be used to remind the world that they remain something of a novelty and in the minority. Nikki Thompson, of Overland Park, Kan., said she never shares her opinion on social media but when she came across Ms. Sumner’s post, she couldn’t stop herself. “Labeling perpetuates the differences we should be seeking to resolve,” she wrote. As a registered nurse, Ms. Thompson’s responsibilities include continuing education training and paperwork for patients, and many forms ask about race, gender, generational demographics, religion and ethnicity. She understands that data collection is essential when it pertains to diagnosis and treatment of illness. But she questions the value of that data collection in the many other facets of daily life. (Ms. Thompson was happy to answer the question of her age — she will turn 41 next week — but noted that labeling people’s age is part of the problem.) “What if we drop the labels, maybe the biases would subside,” she said. “This is a daily thing in my career, and I think a lot about words and bias and unconscious bias and how we might decrease it.” (She also said that the pendulum can swing both ways: She has heard relatives say of her male peers, “I had a male nurse and he was very good.”) Surprised by the reaction to her post, Ms. Sumner acknowledged that many of her experiences are influenced by being a white woman, “with all the privilege that entails,” she said. “But how do I see myself? How do I identify? As a founder, and as someone who starts discussions.” Source link Orbem News #Boss #girl #kill

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theliberaltony · 7 years ago

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via Politics – FiveThirtyEight

Thursday is the first anniversary of Jeff Sessions’s confirmation as attorney general. Over the past year, he has announced that he would seek to increase the use of the federal death penalty; reversed a series of Obama-era memos that instructed federal prosecutors not to go after the marijuana industry in the states that have legalized it; and directed prosecutors to slap drug suspects with the most serious charge they can prove.

None of these policies would have seemed out of place 30 years ago. And, in fact, it’s clear that Sessions has set his sights on returning the country’s criminal justice system to the days of harsh penalties for crime and hardline drug laws. The problem: A lot has changed over the last three decades — in particular, crime and our understanding of how to fight it.

Thirty years ago, there were open-air drug markets in big cities from New York to Los Angeles, residents of those cities were robbed or even killed on public transportation, and the murder rate was near its all-time high. At the crest of the crime wave, harsher penalties for criminals like mandatory minimum sentences and expanded use of the death penalty seemed like a reasonable response to a devastating national crisis, and most Americans supported them.

But today, the crime rate is much lower than in the 1990s, and Sessions’s policies are out of step with most public opinion. Moreover, many criminologists view his strategy as a throwback that’s unlikely to significantly curb violence or drug crime.

That’s because since these policies were implemented, decades of social science research has led experts like David Kennedy, a professor of criminal justice at the John Jay College of Criminal Justice in New York City, to conclude that they don’t work well enough to justify their cost. “The evidence shows that they’re expensive, there’s enormous human damage, and they’re not actually effective in deterring crime,” he said.

Sessions has long established himself as a hard-liner on criminal justice issues: As Alabama’s attorney general, he proposed a crime bill that would have made the death penalty mandatory for a second conviction for drug trafficking. As the U.S. attorney general, he’s billed his new policies as a rejection of the “soft” strategies on crime that characterized the Obama administration, arguing that capital punishment and long sentences deter criminals and that pot is a “gateway drug” for harder substances and addiction.

There’s no question that crime did start to drop precipitously during the era of harsher penalties. And in 2010, the homicide rate hit a four-decade low, according to the Bureau of Justice Statistics. Though most experts agree that the harsher strategies alone can’t explain the decline, there’s still no consensus about why the crime rate started to drop three decades ago. Scholars do note that it was already falling before many tough-on-crime measures were widely introduced, and they have offered theories from improved policing to the roaring economic growth of the 1990s to explain the change.

Richard Rosenfeld, a criminologist at the University of Missouri-St. Louis, said Sessions deserves some credit for calling attention to the recent uptick in the murder rate, which rose for the second consecutive year in 2016 after a 25-year decline.

But Rosenfeld, who studies the causes behind crime rate shifts, and other mainstream criminal justice experts reject the notion that the Obama-era criminal justice reforms, like the decision not to pursue mandatory minimum sentences for low-level drug offenders, caused an increase in violent crime. Instead, Rosenfeld blames the increased violence in part on the drug market, with more demand for heroin because of the opioid epidemic. Rosenfeld also said that tensions between African-American communities and the police could be a factor.

And there’s even debate about whether the violent crime rate — as opposed to just the murder rate — is actually increasing. With a criminal justice outlook that seems more suited to the 1990s than today, Sessions finds himself implementing policies on sentencing, capital punishment and drug enforcement — particularly marijuana — that are out of sync with much of the country.

Prison sentences

Americans today show much less appetite for tough-on-crime approaches than they did in 1992, when 83 percent of respondents in a Gallup poll said that the country’s criminal justice system was not tough enough, while 12 percent said it was about right and only 2 percent said it was too tough.

Two years later, Congress passed a crime bill imposing tougher sentences and “three strikes” provisions that significantly increased sentences for people with two or more prior convictions. It built on a 1986 law that established the first federal mandatory minimum sentences triggered by specific amounts of cocaine. With sentences increased and no possibility of parole in the federal system for those who committed offenses after 1987, the federal prison population skyrocketed in the 1980s and 1990s, driven by longer stays for drug offenders. Roughly half of federal prisoners today are behind bars for drug crimes, and their average time served more than doubled between 1988 and 2012.

Today many Americans think the criminal system is tough enough — and that previous crime legislation may have gone too far. Gallup asked the “tough on crime” question in a handful of later polls and found that the percentage of Americans who said the criminal justice system was not tough enough had declined precipitously, although a plurality (45 percent) still thought it was not sufficiently tough. Part of the explanation may be that the opioid crisis has changed the way some Americans think about responses to drug abuse. But others speculate that Americans think the pendulum has swung too far — whether because of the expense of mass incarceration or its disproportionate effects on African-American men — and there’s now broad-based support for the reforms that Sessions dislikes. Recent polls have shown that 61 percent of Americans believe prisons hold too many drug offenders, 77 percent support ending mandatory minimum sentences, and at least 83 percent favor reforms that reduce prison sentences in some cases.

Shrinking support for a ‘tough on crime’ justice system

Share of respondents who think the criminal justice system is too tough, not tough enough or about right in its handling of crime, 1992-2016

1992 2000 2003 2016 Too tough 2% 3% 6% 14% Not tough enough 83 70 65 45 About right 12 22 26 35 No opinion 3 5 3 6

Source: Gallup

Research largely backs up this rejection of “tough on crime” sentencing policies. First, there’s the fact that most violent crime is handled at the state level, so federal policy has a fairly minimal effect on curbing it. “What happens at the national level gets a lot of attention, but it doesn’t have much of an impact on violent crime,” Kennedy said.

A 2014 National Academy of Sciences study concluded that the effect of mass incarceration on reducing crime was “unlikely to have been large.” That’s because long sentences are not a very good deterrent for crime, nor are they a particularly efficient way to incapacitate people who are threats to public safety.

Studies have shown that the certainty of being caught is far more important as a deterrent than the length of the sentence. And prison sentences in the U.S. are already so long, Kennedy said, that the possibility of spending an additional 10 or 20 years in prison just doesn’t matter to people who commit crimes — if they’re even aware of how the byzantine federal sentencing guidelines would affect them.

Some research suggests that longer stints in prison can actually result in more crime by encouraging the formation of criminal networks behind bars. The lack of economic opportunity for ex-felons can also prompt recidivism — that’s why a 2016 report by the Brennan Center for Justice recommended incarcerating fewer people and for shorter periods of time.

From a public safety perspective, the value of incarcerating people for violent crime diminishes rapidly as well because these crimes tend to be committed by young people. “Violent offenders tend to stop by the age of 30,” Kennedy said. “So if you send someone to prison at the age of 24 and they serve a 20-year sentence, that’s essentially 16 years of meaningless incarceration.”

Death penalty

The 1990s also saw a surge in the use of capital punishment. The Supreme Court lifted a death penalty moratorium in 1976, leading to the resumption of executions in 1977 after a 10-year hiatus. As death penalty cases restarted in the early 1980s and the death row population swelled, the number of state, military and federal executions snowballed, reaching a post-1976 peak of 98 in 1999.1 Since then, death penalty cases have fallen, with prosecutors less likely to ask for the death penalty and juries less willing to hand down death sentences.

Also since the mid-’90s, public support for capital punishment has fallen substantially. According to a Gallup poll conducted in 2017, 55 percent of Americans favor the death penalty for a person convicted of murder, down from 80 percent in 1994 and the lowest level of support in more than 40 years.

This seems to be due to a few factors, including the drop in the crime rate, concerns about the cost of the legal battles that precede an execution and high-profile exonerations of prisoners who had already been executed or were on death row.

Meanwhile, Sessions’s claim that capital punishment is a “valuable tool in the belt” doesn’t hold up to scientific scrutiny. Daniel Nagin, a criminologist at Carnegie Mellon University, chaired a National Academy of Sciences panel on the deterrent effects of the death penalty and found that the available evidence is “so badly flawed that it doesn’t tell us anything about whether capital punishment increases homicide, decreases it or has no effect.”

Part of the problem, Nagin said, is that it’s extremely difficult to measure people’s perception of the risk that they could receive the death penalty since it’s only carried out regularly in a handful of states. This problem is compounded on the federal level because many people may not be aware of which crimes are federal and punishable by death.

Drug enforcement

Legal marijuana has been another long-time bugbear for Sessions, and that’s also a place where the country has left him behind. At a Senate hearing on drug use in April 2016, he decried pot as “a very real danger,” adding that legislators needed “to send that message with clarity that good people don’t smoke marijuana.”

Yet states have increasingly liberalized their marijuana laws. Medical marijuana is legal for at least some diseases in 29 states, the District of Columbia, Guam and Puerto Rico, and nine states have legalized both medical and recreational marijuana use.

Marijuana is still illegal on the federal level, though, and earlier this year, Sessions revoked an Obama-era policy directive that had discouraged federal prosecutors from enforcing the law in the states where marijuana is legal. The move opens the door to a federal crackdown on marijuana growers and sellers across the country in an industry that has burgeoned quickly in part because of the lack of federal enforcement.

But public support for legal marijuana — for both medicinal and recreational uses — has ballooned over the past decade, driven partially by the marijuana industry’s success in the states that have legalized it. Sessions is even at odds with members of his own party on this issue, setting up a potential collision course with Congress if federal prosecutors begin clamping down on legal pot.

And it’s not clear that tougher enforcement of drug laws — whether it’s cracking down on legal marijuana or stepping up other drug prosecutions — will result in reduced crime. In fact, studies have shown that increasing illegal drug enforcement could result in more violence.

Efforts to figure out whether legal marijuana causes crime, either between states or around dispensaries, have been inconclusive, according to Rosanna Smart, an economist at the RAND Corp. But one recent study suggests that the availability of legal medical marijuana may be reducing violent crime along the U.S.-Mexico border by creating less demand for black-market pot.

It’s unlikely that these criticisms will deter Sessions, who is so enthusiastic about the criminal justice strategies of the 1980s and ’90s that he’s even talked about reviving D.A.R.E, an anti-drug program targeted at kids that experts now criticize. But if Sessions’s goal is to bring down crime, he’s unlikely to be successful.

“There’s no evidence that the war on drugs reduced crime,” Rosenfeld said. “We’ve learned some important lessons from those days of highly punitive responses, but now we seem to be going back in the wrong direction.”

#IFTTT #Politics – FiveThirtyEight #politics #538 #Amelia Thomson-DeVeaux

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