#Cesium Beam

[usafphantom2]

👆 aircraft, dubbed “Oxcart”, A-12 all manner of new technology was created at Area 51 to make the aircraft invisible to radar, or at least as small a radar image as could be achieved. Materials that would absorb radar, space age design and electronic counter measures were all employed.

During Project OXCART, the operation of the Lockheed A-12 reconnaissance aircraft, the CIA funded an attempt to reduce the RCS of the A-12's inlet cones. Known as Project KEMPSTER, this used an electron beam generator to create a cloud of ionization in front of each inlet. The system was flight tested but was never deployed on operational A-12s or SR-71s. The A-12 also had the capability to use a cesium-based fuel additive called "A-50" to ionize the exhaust gases, thus blocking radar waves from reflecting off the aft quadrant and engine exhaust pipes. Cesium was used because it was easily ionized by the hot exhaust gases. Radar physicist Ed Lovick Jr. claimed this additive saved the A-12 program.

Yet when President Kennedy gave A-12 Oxcart it’s mission to fly surveillance over Cuba to look for nuclear missiles being secretly installed there by the Soviet Union, the aircraft was still not quite ready. Instead they sent U-2 to Cuba. One of our SR-71 pilots flew missions over Cuba before he flew the SR 71 that would be Buddy Brown..

Researchers and scientists redoubled their efforts, but it was decided that Oxcart was still not stealthy enough. Some other way had to be found to make it all but invisible to enemy radar.Project Kemper-Lacroix was one possible solution. At Area 51, scientists came up with the idea of attaching two giant electron guns, one on either side of the aircraft. The guns would shoot out a 25-foot wide ion cloud of highly charged particles in front of the aircraft (an aircraft which was already moving at speeds above Mach 3). The ion gas cloud would further absorb enemy radar waves coming up from the ground, providing the plane with more stealth. Testing on scale models of the Oxcart aircraft showed the theory would work.

Testing the electron beam guns on the full scale Oxcart aircraft, the researchers soon discovered the radiation given off by the guns would kill the pilot.

So more engineers worked on developing an x-ray shield the pilots could wear to protect them from the radiation. But the first test pilot to wear the shield said it was too cumbersome to allow the pilots to fly the aircraft. Project Kemper-Lacroix was abandoned.

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Posted by Linda Sheffield

[healthcaremarketanalysis]

Understanding the Different Types of X-Ray Detectors in Medical Imaging

X-ray detectors are essential components in medical imaging, playing a critical role in capturing images that help diagnose a wide range of conditions. Over the years, advancements in technology have led to the development of various types of X-ray detectors, each with its unique features and applications. In this blog, we will explore the different types of X-ray detectors used in medical imaging and their significance.

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1. Film-Based X-Ray Detectors

Film-based X-ray detectors, the earliest form of X-ray detection, involve the use of photographic films to capture images. When X-rays pass through a patient's body, they expose the film, which is then developed to produce an image. While film-based detectors offer high image resolution, they are gradually being replaced by digital technologies due to their time-consuming processing and the need for chemical development.

2. Computed Radiography (CR) Detectors

Computed Radiography (CR) detectors are an intermediate step between traditional film and fully digital systems. CR detectors use photostimulable phosphor plates to capture X-ray images. After exposure, the plate is scanned by a laser, releasing the stored energy as light, which is then converted into a digital image. CR detectors offer several advantages over film, including the ability to digitally enhance images and store them electronically. However, they still require an additional step of processing the phosphor plates.

3. Digital Radiography (DR) Detectors

Digital Radiography (DR) detectors represent the latest in X-ray detection technology, offering significant improvements in image quality, speed, and efficiency. DR detectors come in two main types: indirect and direct.

Indirect DR Detectors: These detectors use a scintillator material, typically cesium iodide or gadolinium oxysulfide, to convert X-rays into visible light. The light is then detected by a photodiode array or a charge-coupled device (CCD), which converts it into an electrical signal and finally into a digital image. Indirect DR detectors are widely used due to their high sensitivity and relatively low cost.

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Direct DR Detectors: Unlike indirect detectors, direct DR detectors do not use a scintillator. Instead, they employ a photoconductor material, such as amorphous selenium, to directly convert X-rays into an electrical signal. This direct conversion process results in higher image resolution and reduced blur, making direct DR detectors ideal for applications requiring detailed imaging, such as mammography.

4. Flat-Panel Detectors (FPDs)

Flat-Panel Detectors (FPDs) are a type of DR detector and are increasingly popular in modern medical imaging systems. FPDs are available in both indirect and direct configurations, offering the benefits of high image quality, rapid image acquisition, and digital workflow integration. FPDs are lightweight, compact, and have a large imaging area, making them versatile for various medical imaging applications, including radiography, fluoroscopy, and cone-beam computed tomography (CBCT).

5. Charge-Coupled Device (CCD) Detectors

Charge-Coupled Device (CCD) detectors are used in some specialized X-ray imaging systems. CCD detectors use a scintillator to convert X-rays into visible light, which is then captured by the CCD sensor. The sensor converts the light into an electrical charge, which is processed to create a digital image. CCD detectors are known for their high sensitivity and ability to capture images with low noise, making them suitable for applications like dental X-rays and small animal imaging.

6. Complementary Metal-Oxide-Semiconductor (CMOS) Detectors

Complementary Metal-Oxide-Semiconductor (CMOS) detectors are another type of digital X-ray detector, similar to CCD detectors but with some distinct advantages. CMOS detectors integrate the sensor and processing circuitry on a single chip, resulting in lower power consumption and faster readout speeds. These detectors are compact and cost-effective, making them ideal for portable and handheld X-ray imaging systems. CMOS detectors are also increasingly used in dental and mammography imaging due to their high image quality and efficiency.

Conclusion

X-ray detectors are a critical component of medical imaging, with various types available to suit different applications and needs. From traditional film-based detectors to advanced digital systems like DR, FPDs, and CMOS detectors, each type offers unique benefits that contribute to the accurate diagnosis and treatment of patients. As technology continues to evolve, we can expect further advancements in X-ray detection, leading to even better imaging capabilities and improved patient outcomes.

Whether you're a healthcare professional or simply interested in medical technology, understanding the different types of X-ray detectors can help you appreciate the innovations that make modern medical imaging possible.

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[creativeera]

Food Irradiation: An Effective Technique To Improve Food Safety

What is Food Irradiation?

It is a technique where foods are exposed to ionizing radiation to destroy microorganisms, bacteria, viruses, or insects that might be present in or on the food. The technique uses gamma rays (from cobalt-60 or cesium-137), X-rays, or electron beams from a machine source to blast foods with ionizing energy, altering their molecular structure. History

The concept of food irradiation was first researched as early as the beginning of the 20th century. However, it gained global recognition around the 1950s when serious research was performed to establish its viability and commercial applications. Initial research showed irradiation could effectively eliminate bacteria from meats and spices without changing their visual appearance and quality. The first international conference on food irradiation took place in 1956. Since then, many countries approved irradiation of various food items like spices, herbs, onions, potatoes, fruits, and meats. How Does Irradiation Work? Here's a brief overview of how irradiation works: - Radiation sources like gamma rays or electron beams are used to generate the required radiation energy. - Food Irradiation Food items are placed on a conveyor belt or rack and passed through the radiation area at a controlled dose rate and exposure time. - The radiation energy penetrates through packaging and food physically altering DNA/RNA structures of microbes present. - At approved low doses, it does not make food radioactive but disrupts cellular functions and DNA/RNA structure of pathogens and insects, preventing their reproduction. - The end result is elimination or reduction of pathogens and insects without altering the visual or sensory qualities of foods. Advantages of Food Irradiation Reduces Foodborne Illnesses: Irradiation is extremely effective in eliminating pathogens that cause serious foodborne illnesses. It can destroy bacteria like E. coli, Listeria, Salmonella and other parasites in meat, poultry, seafood and spices. This significantly improves food safety. Lengthens Shelf Life: By halting microbial growth and arresting ripening/sprouting processes, irradiation extends the refrigerated shelf life of various produce and foods by several weeks. This reduces spoilage losses during storage and transportation. Controls Insect Infestation: Low dose irradiation is approved globally to control insect pests in grains, cereals, dried fruits and herbs. This eliminates quarantine issues and reduces post-harvest losses from insects and insect-borne diseases. Maintains Sensory Qualities: When performed at approved low doses, irradiation does not alter the appearance, texture, aroma or flavor of foods. Irradiated fruits and vegetables look and taste fresh for much longer. Sanitizes Spices: Many spices are irradiated to kill Salmonella, E. coli and other pathogens that may be present naturally or from cross-contamination during processing. This eliminates food safety risks from consuming contaminated spices. Applications of Food Irradiation Fruits & Vegetables: Irradiation preserves the quality and extends shelf life of several delicate produce including mangoes, papayas, potatoes, onions and garlic by 3-4 weeks. It arrests ripening/sprouting to prevent losses during storage and transport. Poultry: The poultry industry uses irradiation to destroy Campylobacter and Salmonella bacteria routinely present in raw chicken and turkey. This significantly reduces the risk of foodborne illnesses from consuming undercooked poultry meat. Spices: Many commonly used herbs and spices like black pepper, cumin, coriander, basil, celery are irradiated to kill pathogens and insects. It ensures the microbial safety of spices. Grains: Low dose irradiation is used globally to control insect pests in grains like wheat, rice and pulses. This eliminates quarantine issues and reduces post-harvest losses during transportation and storage.

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Vaagisha brings over three years of expertise as a content editor in the market research domain. Originally a creative writer, she discovered her passion for editing, combining her flair for writing with a meticulous eye for detail. Her ability to craft and refine compelling content makes her an invaluable asset in delivering polished and engaging write-ups.

(LinkedIn: https://www.linkedin.com/in/vaagisha-singh-8080b91)

[rajukumar8926]

Ensuring Product Safety: How Gamma Irradiation Sterilization Works 

Cobalt 60 radiation is used in the gamma irradiation process for several purposes, such as materials modification, decontamination, and sterilization. Gamma irradiation is the best option for many different kinds of materials and their packaging since it provides good penetration of dense items. Gamma radiation sterilization is among the most prevalent variations of the modern commercial radiation sterilization procedure. Below mentioned are the working process of Gamma irradiation sterilization: 

High penetrating energy:  

High penetrating energy is emitted by gamma irradiation sterilization from radioactive materials such as Cesium 137 or Cobalt 60. Even when medical and industrial products are completely sealed or packaged, the presence of bacteria and pathogens is limited and reduced to almost nothing, due to this high penetrating energy. 

Time efficiency: 

In the 21st century, the E-Beam gamma radiation sterilization technology uses time as its currency, enabling the procedure to be finished in seconds. 

Cold sterilization process: 

When gamma radiation is applied and used to sterilize desirable industrial or medical products, the product does not experience any temperature change. It can, therefore, be used with heat-sensitive objects like biological samples and medications. Cobalt-60 is currently used as the gamma radiation source in all industrial radiation processing facilities. Cobalt-60 has a reasonably long half-life of 5.27 years and comparatively high energy of its gamma rays, making it the ideal material for radiation processing. 

Chemical independence: 

There is no use of any hazardous or toxic substance during the gamma radiation sterilization procedure that could have negative effects with even the slightest callous handling. 

How does food irradiation work? 

Currently, x-rays, electron beams, or gamma rays are the three types of radiation used in food irradiators. All three approaches function in the same way. Food in bulk or packaging travels on a conveyor belt through a radiation chamber. The food travels through a radiation beam rather than coming into contact with radioactive elements. The food's bacterial or mold cells receive enough energy from the ionizing radiation to destroy molecular bonds. This lessens disease or spoiling by killing off or stopping the germs' ability to increase. 

Applications: 

Human tissue grafts, including connective tissue allografts like bone, cartilage, tendons, ligaments, dura mater, skin, heart valves, and corneas, are sterilized using gamma sterilization. These allografts are commonly used in reconstructive surgery across various clinical specialties, including orthopedics, neurosurgery, traumatology, cardiac surgery, plastic surgery, laryngology, and ophthalmology. Adhesive bandages, thermolabile medications, scalpels, hypodermic needles, plastic syringes, surgical blades, and other items are also sterilized by radiation.  

Medical X-rays and industrial radiography both operate on essentially the same principles. Similar to how X-rays in medical settings assist physicians and surgeons in identifying and localizing fractures and fissures in human bones, gamma irradiation sterilization allows for the tracking and localizing of defects and cracks in industrial materials and finished goods. 

Wrapping it up: 

Symec Engineers has completed many gamma irradiation plants in India and Abroad. Their hardworking team of design engineers, draughtsmen, workshop and administrative staff members is devoted to going above and beyond for their clients by offering them creative solutions and superior service. 

[jcmarchi]

Milestone for novel atomic clock - Technology Org

New Post has been published on https://thedigitalinsider.com/milestone-for-novel-atomic-clock-technology-org/

Milestone for novel atomic clock - Technology Org

An international research team has taken a decisive step toward a new generation of atomic clocks. By using nuclear, rather than electronic, transitions in atomic scandium, researchers at the European X-Ray Free-Electron Laser facility have made an advance that some believe will lead to a thousandfold increase in timekeeping precision. The results are published in the journal Nature.

An X-ray beam at European XFEL excites the ultra-narrow resonance of a Scandium-45 nucleus, causing it to emit nuclear fluorescence photons which enable an accurate measurement of the resonance energy. This facilitates the future use of Scandium-45 as nuclear clock with unprecedented accuracy. Image Credit: European XFEL / Tobias Wüstefeld, HI Jena / Ralf Röhlsberger

Atomic clocks have numerous applications that benefit from improved accuracy, such as precise positioning using satellite navigation. 

Atomic clocks are currently the world’s most accurate timekeepers. These clocks have used energy transitions of electrons in the atomic shell of chemical elements, such as cesium, to define time. These electrons can be raised to a higher energy level with microwaves of a known frequency. In the process, they absorb microwave radiation. 

An atomic clock shines microwaves at cesium atoms and regulates the frequency of the radiation such that the absorption of the microwaves is maximized; experts call this a resonance. The quartz oscillator that generates the microwaves can be kept so stable in this manner that cesium clocks are accurate to within one second over 300 million years.

Crucial to an atomic clock’s accuracy is the resonance width used. Current cesium atomic clocks already use a very narrow resonance, and even more accurate results are obtained using strontium lattices. In hopes of leapfrogging ahead, teams around the world have been working for several years on the concept of a “nuclear” clock, which uses transitions in the atomic nucleus rather than in the electron shells of the atom. Nuclear resonances are much sharper than the resonances of electrons, but also much harder to excite.

The team could now excite a promising transition in the nucleus of the element scandium, which is readily available as a high-purity metal foil or as the compound scandium dioxide.

“The breakthrough in resonant excitation of scandium and the precise measurement of its energy opens new avenues not only for nuclear clocks, but also for ultrahigh-precision spectroscopy and precision measurement of fundamental physical effects,” says Yuri Shvydko of Argonne National Laboratory. 

Texas A&M University’s Olga Kocharovskaya, initiator and leader of the project funded by the U.S. National Science Foundation, adds “Such a high accuracy could allow gravitational time dilation to be probed at sub-millimeter distances. This would allow studies of relativistic effects on length scales that were inaccessible so far.”

John Gillaspy, NSF program director for Atomic, Molecular and Optical Experimental Physics, said that “this advance is both exciting and timely (double pun intended).”

Source: NSF

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[some-pers0n]

uhhh pyro x pauling :)

I like em :)

I'm a "Pyro is unlabeled" kind of person, mostly because whenever I think of Pyro the last thing that comes to mind is their sexuality. Like it's almost a black void of empty space that I cannot fill. It's not even in a: "Oh I can't see them with anybody lemme hit them with me aro/ace beam". Straight up just an absence. Any sort of label doesn't feel right. So, none at all. Leading to me never really considering Pyro with anybody.

However, I do really like Pyropauling. I like the ship name "Cesium" (really cute and sweet) and I think they work well off of each other. I can see Pauling bringing Pyro on her little escapades and hiding bodies together. They're full of so much whimsy together. Love them both. Murder woman yuri the beloved.

[truphysics]

Hafele-Keating Experiment

Introduction The Hafele-Keating experiment was a test of the theory of relativity. In October 1971, Joseph C. Hafele, a physicist, and Richard E. Keating, an astronomer, took four cesium-beam atomic clocks aboard commercial airliners. They flew twice around the world, first eastward, then westward, and compared the clocks against others that remained at the United States Naval…

[uranium]

my hands are getting Blasted with cesium beams lately #umm

[aptrust]

Utc time to est

UTC TIME TO EST HOW TO

UTC TIME TO EST INSTALL

From east to west they are Atlantic Standard Time (AST), Eastern Standard Time (EST), Central Standard Time (CST), Mountain Standard Time (MST), Pacific Standard Time (PST), Alaskan Standard Time (AKST), Hawaii-Aleutian Standard Time (HST), Samoa standard time (UTC-11) and Chamorro Standard Time (UTC+10). The United States uses nine standard time zones. A new federal law took effect in March 2007 which extends Daylight Saving Time by four weeks. Eastern Standard Time (EST) becomes Eastern Daylight Time (EDT), and so forth. The names in each time zone change along with Daylight Saving Time. On the first Sunday in November areas on Daylight Saving Time return to Standard Time at 2:00 a.m. local time on the second Sunday in March. In the United States Daylight Saving Time begins at 2:00 a.m. Virgin Islands and American Samoa do not observe Daylight Saving Time. In places not observing Daylight Saving Time the local UTC or GMT offset will remain the same year round. As a result, their UTC or GMT offset would change from UTC -5h or GMT - 5h to UTC -4h or GMT - 4h. In areas of the United States that observe Daylight Saving Time local residents will move their clocks ahead one hour when Daylight Saving Time begins. Coordinated Universal Time is also known Zulu Time or Z time. The usage of UTC and GMT is based upon a twenty four hour clock, similar to military time, and is based upon the 0 degrees longitude meridian, referred to as the Greenwich meridian in Greenwich, England.Ĭoordinated Universal Time is based on cesium-beam atomic clocks, with leap seconds added to match earth-motion time, where as Greenwich Mean Time is based upon the Earth's rotation and celestial measurements. UTC+5h or GMT +5h would refer to that time zone being five hours ahead of UTC of GMT and so forth for the other time zones. In this example the (-5h) refers to that time zone being five hours behind UTC or GMT and so forth for the other time zones. You will often see time zones represented similar to UTC - 5h or GMT - 5h. Coordinated Universal Time replaced the use of Greenwich Mean Time (GMT) in 1972. Ubiq makes it easy to visualize data in minutes, and monitor in real-time dashboards.Coordinated Universal Time (UTC) is used as the official world reference for time. Hopefully, now you can convert datetime to UTC in MySQL. Here’s an example to convert EST to UTC timezone by specifying time zone names instead of offset values.

UTC TIME TO EST INSTALL

However, in this case, you will need to download and install MySQL time zones on your server. You can also specify time zones instead of offsets.

UTC TIME TO EST HOW TO

| convert_tz(order_date,'+10:00','+00:00') |Īlso read : How to Get Current Date and Time in MySQL Here’s an example to change time zone of order_date column in sales table, from UTC to EST mysql> select convert_tz(order_date,'+10:00','+00:00') from sales Similarly, you can also convert date, time, date time columns using convert_tz. By default, you need to specify original (+10:00) and new time zones (+00:00) as offsets from UTC. Here is an example to convert date time value from local time zone (GMT+10:00) to UTC(+00:00). The original and new time zones can be specified using offsets or time zone names.Īlso read : How to Convert UTC to Local time in MySQL In the above function you can specify date value as a literal string, system function or column name, its original time zone, as well as its new time zone. Here is the syntax for convert_tz convert_tz(date_value, original_timezone, new_timezone) You can easily change datetime to UTC using convert_tz function. Here are the steps to convert datetime to UTC in MySQL. In this article, we will look at how to convert datetime to UTC in MySQL. Sometimes you may need to change timezone to UTC or set timezone to UTC.

[nocturnal-stims]

Clock making stimboard for anon. Some clock facts: 

🕰️  England’s Salisbury Cathedral Clock is world’s oldest functioning clock, built in 1386.

🕰️  The NIST-F1 Cesium Fountain Clock is the world’s most accurate clock. Developed by the National Institute of Standards and Technology in Colorado, the clock will run precisely on time for the next 20 million years.

🕰️   In October 1971, Joseph C. Hafele and Richard E. Keating tested the theory of relativity by flying four cesium-beam atomic clocks twice around the world east and west. When they compared them to the clocks at the United States Naval Observatory, the clocks were no longer in sync, indicating time dilation had occured.

Sources: x x x / x x x / x x x

[youvebeenlivingfictional]

I’m Always Curious Part Thirty

Previous Part | Next Part |  Masterlist Notes: I hope everyone’s having a good week 💕

Welcome back to Pike’s POV! I hope y’all like it 😬

Warnings: Cursing and canon-typical violence/suspense(?) Summary: Christopher Pike was well and truly at a loss. 

She didn’t like this.

Pike could see that in her every gesture, hear it in every word. He saw it in the way her jaw clenched minutely when they were discussing the prospect of a manual tag; he could hear it in her dejected sigh of, “But we put our dreams away.” He didn’t know what that meant to either her or Reno, but he didn’t like the sound of it coming from either of them. Christopher Pike was well and truly at a loss. He was unfamiliar with the mission type, with the man running it, and he felt wholly unfamiliar with the Commander suiting up to pilot the attack fighter to tag the DY-100. He should not have felt so unfamiliar with the Commander. He knew her, or had known her, before. But she seemed so changed since the last time they’d been in one another’s company. That morning was something that Christopher thought about more often than he cared to admit: the memory of her waking in his arms, the sweet kisses and soft murmurs, her being summoned for a mission, telling him that she’d be back in an hour—

Christopher pulled himself from thought as he stepped onto the turbolift with Durling to head to the Bridge. The Commander’s words were still ringing in his head: “Caught the wrong end of a bat’leth.” She said it like it was something that happened every day. But then, for her and Durling, and for much of Starfleet, that had been their reality for almost a year.  “You worried?” Pike glanced over to see Durling watching him expectantly, waiting for an answer. He wasn’t sure he liked the man very much. The Commander seemed very familiar with him, but by their accounts, they had spent much of the war working with one another on such missions as the upcoming 22-9-14. Christopher had caught the look that Durling had cast the Commander when he’d introduced himself; he couldn’t help but wonder how much he knew. Perhaps he was simply aware of the fact that the Commander was previously stationed on the Enterprise. “You and the Commander seem to have things in hand,” He answered crisply, “As you’ve said, you’ve run plenty of these, I’m sure it’ll be fine.” Durling gave Pike a small nod, “Been a while for you two, huh? Seeing each other.” “Yes, it has. You were stationed together for most of the war?” “That’s right.” “For how much of that time was she a Commander?” “Not much, mostly the last leg. At that point, we were placed on separate craft. She was put in charge of a fleet of attack fighters, stationed out of Starbase 412.” “So you’re used to calling the shots,” Pike offered. Durling chuckled. “Guess so, but I’ve been under her a time or two.” He stepped off of the turbolift ahead of Pike, who watched him go with narrowed eyes. The implication was clear, and the ease of interaction between the two did lend credence to it. Christopher was not sure he liked Eli Durling. -- He had offered the Captain’s chair to Durling, who had politely declined. Instead, Durling had briefly commandeered Burnham’s station, with Burnham and Tilly hovering beside. Pike couldn’t bring himself to sit, so he stood instead, eyeing the S.S. Botany Bay. The craft was eerily silent and dark, drifting out in the ether like a whale in the open ocean. The Commander had launched from the shuttle bay only moments ago, and Pike watched the attack fighter approach. What could she possibly be thinking? 

Christopher used to be able to tell what she was thinking with a look. He knew every eye roll, brow raise, smile— They’d hardly met one another’s eyes since she’d been aboard the Discovery. When he’d seen her at Kat’s side, he could’ve sworn he was seeing a ghost. But she’d seemed so stunned in turn, had turned away so quickly— And, well… He had known that she had served on the Pinnacle for some time. He’d never been able to bring himself to reach out, a fact that had managed to escape Una’s notice until recently. And he hadn’t sought the Commander out while she was on the ship, either. There was a mission at hand, one that he was unfamiliar with and that they both needed to be focused on. 

Of course, it did not help that she was at the core of this mission. 

“How’s it looking, Commander?” The sound of Durling’s voice again drew Pike from his reverie. Her voice came through seconds later, “Like the holo, but bigger.” “...Thank you for that,” Durling answered, “Get ready for bot deployment—” “Afraid I can’t do that, Durling.” “You know I don’t like hearing that.” “You think I like saying it? Can Helm please patch through my feed?” There was a pause before the feed from the attack fighter came through. The hull of the S.S. Botany Bay was dark, slightly rusted. “Run a hull integrity test, please,” She added. Christopher could hear in her voice that she knew precisely what the outcome would be. He glanced back as he watched Michael step up beside Durling and run the calculations. “The integrity of the hull seems to be highly compromised,” Michael grimaced, glancing up at Pike. “What do you put the likelihood of an automated external tag application? I ran the numbers on the trip out, let’s see if we got the same thing,” The Commander commented from inside the ship. Christopher’s brows rose. The last time he recalled the Commander copping an attitude like that, they’d been in private; they had just returned from Koutov, and they had exchanged a fair amount of smack-talk in the gym before— “Why don’t you give me your number first,” Burnham offered. “Likelihood of a break from tag as a result of automated pressure sits at 94.772%.” “I had it at 94.771%,” Burnham reported. “Damn,” Detmer muttered. “So, Durling,” The Commander added, “I figure this is the part where you get to reach out to Admiral Cornwell for authorization of a manual tag. I’d do it, but I’m pretty sure it falls to you. You know, since you’re the commanding officer on this mission and all.” Tilly snorted, then slapped her hand over her mouth, averting her eyes as Durling glanced back at her. Pike cast the ensign a small, amused smile, fighting the urge to laugh, himself. He had known the Commander's unease with the mission since their briefing, and he could only imagine that Ensign Tilly had a handle on the Commander's feelings as well. Durling turned back to the station, fingers moving over the screen. “What happens now?” Pike asked, walking a little closer to the station. “We have to get authorization from Admiral Cornwell for a single ejection for the tag and run,” Durling answered, eyes set on the screen.  “Why a single ejection?” “The mechanism is tricky, and the longer the Commander spends out of the ship, the more risky it is—” “Captain, I’m getting a reading,” Owosekun spoke up, “There’s an unusual amount of… Debris, it looks like, coming off of the Botany Bay.” Pike frowned, striding over to the console and peering over it. He could see the pieces breaking away from the ship. His hand tightened on the back of where he’d rested it on Owo’s chair. He cleared his throat, speaking up: “Commander—” “I see it, Captain,” Was her quick answer, “Looks like it’s coming off of the cesium tanks— Durling, where are we—” “Authorization just came through. Eject at earliest convenience, tag fast, kid.” “Yessir.” Christopher leaned back from Owo’s station, letting go of her seat and turning back to Durling. “How long do you think it’ll take?” “In perfect conditions, minimal hull integrity, it takes her about 4 minutes. Something this delicate, though, it depends. Six minutes on the outside.” “Have we got a trajectory on the debris?” Pike asked. “Can you guys close comms for a few minutes? Trying to launch myself into space here,” The Commander spoke up through the mic. Byrce muttered an apology before shutting Comms. “We have a trajectory,” Detmer answered, glancing back at Pike, “The Commander and the attack fighter will be in its path in the next eight minutes.” That was a slim window. He glanced back at Durling. “The tether to her attack fighter—” “There isn’t one,” Durling shook his head, “No tether, just the Commander and a jetpack.” Pike felt a burst of fear in his chest that was unlike anything he’d felt in a long time. “She’s floating free out there?” He asked harshly. “If something were to hit the ship, it would drag her with it. She knows what the risks are, Captain, she’s done this before.” “Has she ever not made it back to the fighter?” “Once,” Eli conceded, nodding, “I don't know how they handled it, she was with the squadron at that point.” “Engaging tag,” The Commander’s voice crackled through the comm. “Copy,” Durling answered quickly. “Captain, the cesium components are picking up speed,” Detmer warned. “Suggestions?” Pike asked, looking around the bridges he grappled with his own solutions. “We could lock phasers on it,” Nhan offered. “The blasts could put the Commander in the path of the way rubble,” Burnham shook her head. “We could have the transporter bay lock on the Commander and prepare to beam her back to the ship,” Tilly offered. Durling nodded, “That could work,” As Pike turned to Detmer. “Get a lock on her signal, prepare to transport her back to the ship,” He ordered. “Aye, sir,” Detmer nodded. “Progress?” Durling asked into comms. “Working on enabling the proxy,” Came the Commander’s answer. “Work faster.” “You wanna come out here and do it?” “The cesium debris is picking up speed, your window’s closing.” “Course it is,” The Commander muttered, “This wasn’t already fun enough— I’m two minutes out.”  “Can you make that one?” Pike asked. “Only if you want the job done fast and not right, Captain.” Pike turned back to look out through the viewscreen, tucking his hands behind his back and clutching one wrist with his hand, giving it a squeeze as he watched the cesium debris drift closer. Urging her to work faster would only increase what was, no doubt, an already insane amount of pressure on the Commander. But he couldn't help the dread simmering in his stomach. He fought the urge to shift from foot to foot, to pace, if only to stop himself from taking one of the exploratory pods that he'd piloted previously and getting her out of there himself. “Where are we with the lock, Detmer?” He asked. “Locked on her signal, sir. Transporter bay’s prepared to beam her out,” Detmer reassured. Pike gave a nod of thanks, hand flexing. He could hardly see the Commander as it was— she was a speck on the hull of the Botany Bay, distant and easily missed if one didn’t know where to look. “Thirty seconds,” The Commander reported as Owo warned, “One minute.” “Window’s closing,” Durling warned, “We’re beaming you back.” “—Transporter’s been knocked offline, sir,” Detmer informed Pike worriedly, “There’s interference from the debris.” “I’m heading back to the fighter,” The Commander informed them. “Do you still have a lock on the Commander?” Pike asked. “Yes, and the transporter bay’s working to get back functionality.” Pike glanced between Detmer and Durling, waiting for any change, warning, but the first sign that he got was— “I’m in the fighter, hatch is locked,” The Commander reported, “Heading back for the Discovery.” Pike felt his shoulders relax a little for a moment, a quiet breath leaving him— until he heard alarms going off on the Commander’s side. “What’s happening over there?” Durling asked. “I’ve got heavy damage to the left warp nacelle, looks like some of that debris ripped through the unit.” “Can you make it back?” “I don’t hard I can push this thing,” The Commander admitted, and for the first time in a long time, Christopher heard a thread of fear in her voice. “Where are we with transporter bay?” He asked. “They’re at 74%,” Owosekun answered.

Pike watched with bated breath as the attack fighter began to weave its way through the debris field. He could see the sharp, jittering movements, the hairpin dives and dips it was forced to make. 

“Commander,” Burnham warned, “I’m detecting another impending detachment from the Botany Bay--”

“If you’re referring to that piece of hull breaking off, I am detecting that, too!” 

The Bridge crew watched, horrified, as a chunk of rusted ancillary hull peeled from the ship. It sailed through the cesium tank debris, sending pieces scattering toward the attack fighter. 

Pike heard the beeping of systems warnings and a hissed curse before: “I’ve got cabin puncture.”

“How bad?” Durling asked. 

“I am again asking if you’d like to come here out here yourself.”

Pike heard the flipping of switches on the other end.

“Where are we with transporters?” The Commander asked. 

“98%,” Detmer answered. 

“I’m initiating manual eject,” The Commander informed them. 

“You’re what?” Durling snapped nearly over the Commander answering, "It'll be easier for you to lock on my signal from outside of the fighter, the nacelle's heating up and I don't want to beaming in a damaged warp component instead'a me!"

“I want phasers ready on the debris and tractor beam locked on that attack fighter,” Pike warned. He vaguely registered the crew’s calls of compliance behind. 

“Detmer,” Pike warned, watching the Commander push herself out of her ship and into open space.

“Locked, sir!”

“Beam her out-- Fire!”

There was a pause, then several flashes of light as the Discovery’s phasers targeted the cesium and hull debris. 

The Bridge went quiet before Durling spoke up: “Commander… Are you in the transporter bay?” 

There was a long moment where Chris couldn’t hear anything but his heart pounding in his ears; his hands clenched in on themselves, his stomach churned in fear, and then,

“There somewhere else I’m supposed to be?” Was her answer. 

Christopher closed his eyes for a moment. He didn’t know if he wanted to smile, or yell, or put on a flight suit and give one of those tags a go for himself. 

“... Plot a course for Starbase 338,” He told Detmer; it was Durling’s next stop, where they’d be letting the man off, and possibly the Commander with him, “Owosekun, bring that attack fighter in."

He glanced back at Durling as both officers at the helm confirmed, and found the Lieutenant Commander headed for the turbolift. 

“Pollard needs to check her out,” Durling reminded him, “Coming with?” 

Christopher considered for a second, then shook his head a little. Durling gave a small nod before stepping onto the turbolift, disappearing from view. 

Christopher lowered himself into the captain’s chair, scrubbing his hand over his mouth. He needed to have a word with the Commander. He needed to have several words with the Commander, but he needed to have them without Durling around-- or Burham, or Jett, or Tilly, or anyone. Once the Commander was cleared by Dr. Pollard, once she’d had some rest, then he would ask her if she had a moment. 

And that, of course, gave him some time to work out what the hell he could possibly say to her. 

“Course set, Captain,” Detmer reported. His eyes darted to her before he nodded. 

“Hit it.” Tag list: @angels-pie ; @fantasticcopeaglepasta  ; @mylittlelonelyappreciationtoo ; @how-am-i-serpose-to-know ; @onlyhereforthefandomandgiggles ; @inmyowncorner​  ; @tardis-23  ; @paintballkid711 ; @katrynec ; @hypnobananaangelfish ; @elen-aranel ; @blueeyesatnight ; @hotchswifey

[medalmonkey]

Class 11th NCERT Ch 02 Units & measurements

Q1. There are seven base quantities in SI system. Which physical quantity has a prefix with its unit?

a) Mass

b) Thermodynamic temperature

c) Luminous intensity

d) Amount of substance

  Q2. Which of the following quantities has same unit in all the three system of units-

a) Mass

b) Length

c) Time

d) None of these

  Q3. Which of the following is not a physical quantity –

a) Time

b) Impulse

c) Mass

d) Kilogram

  Q4. Which of the following is not a fundamental quantity –

a) Luminous intensity

b) Thermodynamic temperature

c) Electric current

d) Work

  Q5. Which of the following is incorrect –

a) Direct and indirect methods are used for the measurement of physical quantities.

b) Scientific notation and the prefixes are used to simplify numerical computation.

c) A dimensionally correct equation need not be a correct equation.

d) The SI units is based on six base units.

  Q6. Which of the following is not a unit of British system of units?

a) Foot

b) Metre

c) Pound

d) Second

  Q7. Which of the following is not a unit of time?

a) Parsec

b) Year

c) Second

d) Hour

  Q8. Which of the following is not a derived unit?

a) Joule

b) Watt

c) Kilogram

d) Newton

  Q9. Which of the following is not a base unit?

a) Metre

b) Candela

c) Ampere

d) Pascal

  Q10. Which of the following system of units is not based on unit of mass, length and time?

a) CGS

b) FPS

c) MKS

d) SI

  Q11. In which year SI system of units was developed and recommended by General Conference on Weights and Measures?

a) 1951

b) 1961

c) 1971

d) 1981

  Q12. Find the odd one –

a) Calorie

b) Kilowatt hour

c) Joule

d) Watt

  Q13. Which of the following is unit-less quantity?

a) Pressure gradient

b) Displacement gradient

c) Force gradient

d) Velocity gradient

  Q14. The SI unit of pressure gradient is –

a) \(Nm{-2}\)

b) \(Nm\)

c) \(N/m\)

d) \(Nm{-3}\)

  Q15. Fathom is the unit of –

a) Speed of ship

b) Depth of ship

c) Distance of the ship

d) Speed of cyclone

  Q16. Which of the following is not unit of length?

a) Angstrom

b) Fermi

c) Barn

d) Parsec

  Q17. Which of the following is the smallest unit?

a) Millimetre

b) Angstrom

c) Fermi

d) Metre

  Q18. Which of the following instrument is not used for the measurement of length?

a) Atomic clock

b) Vernier callipers

c) Screw gauge

d) Spherometre

  Q19. Light year is –

a) Light emitted by the sun in one year.

b) The time taken by light to travel from sun to earth.

c) The distance traveled by light in free space in one year.

d) Time taken by earth to go once around the sun.

  Q20. Light year is the unit of –

a) Distance

b) Time

c) Speed

d) Intensity of light

  Q21. How many light years away is Alpha Centauri from the earth?

a) 1.29

b) 2.29

c) 3.29

d) 4.29

  Q22. Which of the following methods is used to measure distance of a planet from a star?

a) Echo method

b) Parallax method

c) Triangulation method

d) None of these

     Q23. Which of the following propertied of laser beam can be used to measure long distances?

a) It is very intense.

b) It is highly monochromatic.

c) It is an unidirectional beam of light.

d) All of these.

   Q24. What is the name of device used to measure the mass of atoms and molecules?

a) Spring balance.

b) Torsional balance.

c) Mass spectrograph.

d) Common balance.

  Q25. Which of the following is incorrect –

a) Mass is basic property of matter.

b) SI unit of mass is kg.

c) Mass of an atom is expressed in u.

d) Mass depends upon temperature, pressure, and location of the object in space.

  Q26. One second is defined as –

a) 1650763.73 periods of krypton clock.

b) 652189.6 periods of krypton clock.

c) 1650763.73 periods of cesium clock.

d) 9192631770 periods of cesium clock.

  Q27. Light from the sun reaches the earth approximately in –

a) 5 s

b) 50 s

c) 500 s

d) 0.5 s

   Q28. Which of the following is most precise instrument –

a) Meter rod of least count 0.1 cm.

b) Vernier callipers of least count 0.01 cm.

c) Screw gauge of least count 0.001 cm.

d) None of these.

  Q29. Which of the following is most precise device –

a) A wall clock.

b) An atomic clock.

c) A digital watch.

d) A stop watch.

  Q30. Which of the following is incorrect –

a) Every measurement by measuring instrument has some error.

b) A measurement can have more accuracy but less precision and vice versa.

c) Every calculated quantity that is based on measured values has some error.

d) The magnitude of the difference between the true value of the quantity and the individual measurement value is called the relative error of the measurement.

  Q31. Which of the following instrument has minimum least count –

a) A vernier callipers with 20 divisions on the vernier scale coinciding with 19 main scale divisions.

b) A screw gauge of pitch 1 mm and 100 divisions on the circular scale.

c) A spherometer of pitch 0.1 mm and 100 divisions on the circular scale.

d)  An optical instrument that can measure length to within a wavelength of light.

  Q32. Which of the following is incorrect –

a) All the non-zero digits are significant.

b) All the zeros between two non-zero digits are significant.

c) Greater the number of significant figures in a measurement, smaller is the percentage error.

d) The power of 10 is counted while counting the number of significant figures.

    Q33. Which of the following quantities has a unit but no dimensions –

a) Relative velocity

b) Relative density

c) Strain

d) Angle

  Q34. Which of the following quantities has neither units nor dimensions –

a) Relative velocity

b) Relative density

c) Angle

d) Energy

  Q35. A dimensionless quantity –

a) Never has a unit.

b) Always has unit.

c) May have a unit.

d) Does not exist.

  Q36. Which of the following pairs of physical quantities have same dimensions?

a) Force and power.

b) Torque and energy.

c) Torque and power.

d) Force and torque.

  Q37. P, Q, R are physical quantities having different dimensions. Which of the following combinations can never be a meaningful quantity?

 a) \(\frac{P-Q}R\)

b) \(PQ-R\)

c)  \(\frac{PQ}R\)

d) \(\frac{\displaystyle PR-Q^2}R\)

 Q38. Which of the following sets have different dimensions?

a) Pressure, Young’s modulus, stress.

b) EMF, potential difference, electric potential.

c) Heat, work done, energy.

d) Dipole moment, electric flux, electric field.

  Q39. What is the dimension of quantity \(\frac{El^2}{m^5G^2}\) where E is energy, m is mass, l is length and G is gravitational energy.

a)      Mass

b)      Length

c)       Time

d)      Angle

  Q40. The dimensions of Planck’s constant are the same as that of -

a)      Linear impulse

b)      Work

c)       Linear momentum

d)      Angular momentum

  Q41. Dimensional formula of heat is –

a) \(ML^2T^{-2}\)

b) \(MLT^{-2}\)

c) \(ML^2T^{-1}\)

d) \(MLT^{1}\)

 Q42. The dimensional formula of physical quantity is \(M^aL^bT^c\) . The physical quantity is –

a)      Surface tension if a=1, b=1, c=-2.

b)      Force if a=1, b=1, c=2.

c)       Angular frequency if a=0, b=0, c=-1.

d)      Spring constant if a=1, b=-1, c=-2.

   Q43. Checking the correctness of equations using the method of dimensions is based on –

a)      The type of system

b)      Equality of inertial frames of references.

c)       Principle of homogeneity of dimensions.

d)      None of these.

    Q44. The displacement of a progressive wave is represented by \(y=A\sin\left(\omega t-kx\right)\), where x is distance and t is time. The dimensions of \(\frac\omega k\) are same as those of

a)      Velocity

b)      Wave number

c)       Wavelength

d)      Frequency

  Q45. What would be the dimensions of length, if velocity of light c, Planck’s constant h, and gravitational constant c are taken as fundamental quantities?

a) \(\sqrt{\frac{ch}G}\)

b) \(\sqrt{\frac{Gh}{c^5}}\)

c) \(\sqrt{\frac{Gh}{c^3}}\)

d) \(\sqrt{\frac{hC^3}G}\)

[foxwide539]

2pm Utc To Gmt

Time Zone Converter from 2am in Utc time. Easily find the exact time difference with the visual Time Zone Converter. Find meeting times for your contacts, locations and places around the world. Convert UTC to EST time zone, calculate the time difference between Universal Time (UTC/GMT) and Eastern Standard Time (North America) (EST).

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2pm Utc To Gmt Time Zone

Coordinated Universal Time (UTC) is used as the official world reference for time. Coordinated Universal Time replaced the use of Greenwich Mean Time (GMT) in 1972. You will often see time zones represented similar to UTC - 5h or GMT - 5h. In this example the (-5h) refers to that time zone being five hours behind UTC or GMT and so forth for the other time zones. UTC+5h or GMT +5h would refer to that time zone being five hours ahead of UTC of GMT and so forth for the other time zones. The usage of UTC and GMT is based upon a twenty four hour clock, similar to military time, and is based upon the 0 degrees longitude meridian, referred to as the Greenwich meridian in Greenwich, England. Coordinated Universal Time is based on cesium-beam atomic clocks, with leap seconds added to match earth-motion time, where as Greenwich Mean Time is based upon the Earth's rotation and celestial measurements. Coordinated Universal Time is also known Zulu Time or Z time. In areas of the United States that observe Daylight Saving Time local residents will move their clocks ahead one hour when Daylight Saving Time begins. As a result, their UTC or GMT offset would change from UTC -5h or GMT - 5h to UTC -4h or GMT - 4h. In places not observing Daylight Saving Time the local UTC or GMT offset will remain the same year round. Arizona, Puerto Rico, Hawaii, U.S. Virgin Islands and American Samoa do not observe Daylight Saving Time. In the United States Daylight Saving Time begins at 2:00 a.m. local time on the second Sunday in March. On the first Sunday in November areas on Daylight Saving Time return to Standard Time at 2:00 a.m. The names in each time zone change along with Daylight Saving Time. Eastern Standard Time (EST) becomes Eastern Daylight Time (EDT), and so forth. A new federal law took effect in March 2007 which extends Daylight Saving Time by four weeks. The United States uses nine standard time zones. From east to west they are Atlantic Standard Time (AST), Eastern Standard Time (EST), Central Standard Time (CST), Mountain Standard Time (MST), Pacific Standard Time (PST), Alaskan Standard Time (AKST), Hawaii-Aleutian Standard Time (HST), Samoa standard time (UTC-11) and Chamorro Standard Time (UTC+10). View the standard time zone boundaries.

Nowadays, Greenwich Mean Time, abbreviated as GMT, is a time zone designation rather than a time standard. Time difference between time zones can be expressed by the GMT or UTC offset. In the UTC standard, there is a commitment to keep within 0.9 seconds of GMT, so that every few years a leap second is applied to UTC. Convert Time From (UTC/GMT) to any time zone. Need to compare more than just two places at once? Try our World Meeting Planner and get a color-coded chart comparing the time of day in (UTC/GMT) with all of the other international locations where others will be participating. Time Zone Converter from 2pm in Gmt time. Easily find the exact time difference with the visual Time Zone Converter. PDT UTC-7 5:00 am April 26, 2021 April 27.

2pm Utc To Gmt Date

Coordinated Universal Time (UTC)Greenwich Mean Time (GMT)Friday 05/07/21 10:57 AM UTC/GMT+00:00 Friday 05/07/21 10:57 AM UTC/GMT+00:00

United States GMT/UTC Offsets

Time Zone in United StatesExamples of places in the United States using these Time ZonesUTC Offset Standard TimeUTC Offset Daylight Saving TimeAtlanticPuerto Rico, US Virgin IslandsUTC - 4hN/AEasternConnecticut, Delaware, Florida, Georgia, part of Indiana, part of Kentucky, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, part of Tennessee, Vermont, Virginia, West Virginia and Washington, D.C.UTC - 5hUTC - 4hCentralAlabama, Arkansas, Florida, Illinois, part of Indiana, Iowa, part of Kansas, part of Kentucky, Louisiana, part of Michigan, Minnesota, Mississippi, Missouri, Nebraska, North Dakota, Oklahoma, part of South Dakota, part of Tennessee, most of Texas, and WisconsinUTC - 6hUTC - 5hMountainArizona*, Colorado, part of Idaho, part of Kansas, Montana, part of Nebraska, New Mexico, part of North Dakota, part of Oregon, part of South Dakota, part of Texas, Utah, and WyomingUTC - 7hUTC - 6h * n/a for Arizona except in the Navajo Nation which does observe daylight saving time.PacificCalifornia, part of Idaho, Nevada, most of Oregon, WashingtonUTC - 8hUTC - 7hAlaskaAlaska and a portion of the Aleutian Islands that is east of 169 degrees 30 minutes west longitude observes the Alaska Time Zone.UTC - 9hUTC - 8hHawaii - Aleutian Unofficially often referred to as Hawaii Time ZoneHawaii and a portion of the Aleutian Islands that is west of 169 degrees 30 minutes west longitude observes the Hawaii-Aleutian Standard Time Zone. Although Hawaii does not observe daylight saving time the Aleutian Islands do observe daylight saving time.UTC - 10hUTC - 9h Hawaii does not observe daylight saving time. A portion of the Aleutian Islands which observes the Hawaii - Aleutian time zone does observe daylight saving time.

Time Zone Look Up by State with Current Local Times

2pm Utc To Gmt

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[sciencenewsforstudents]

By watching how atoms behave when they’re suspended in midair, rather than in free fall, physicists have come up with a new way to measure Earth’s gravity.

Traditionally, scientists have measured gravity’s influence on atoms by tracking how fast atoms tumble down tall chutes. Such experiments can help test Einstein’s theory of gravity and precisely measure fundamental constants (SN: 4/12/18). But the meters-long tubes used in free-fall experiments can be unwieldy and difficult to shield from environmental interference such as stray magnetic fields. With a new tabletop setup, physicists can gauge the strength of Earth’s gravity by monitoring atoms suspended a couple millimeters in the air by laser light.

This redesign, described in the Nov. 8 Science, could better probe the gravitational forces exerted by small objects. The technique also could be used to measure slight gravitational variations at different places in the world, which may help in mapping the seafloor or finding oil and minerals underground (SN: 2/12/08).

Physicist Victoria Xu and colleagues at the University of California, Berkeley began by launching a cloud of cesium atoms into the air and using flashes of light to split each atom into a superposition state. In this weird quantum limbo, each atom exists in two places at once: one version of the atom hovering a few micrometers higher than the other. Xu’s team then trapped these split cesium atoms in midair with light from a laser.

To measure gravity, physicists split atoms into a weird quantum state called superposition — where one version of the atom is slightly higher than the other (blue dots connected by vertical yellow bands in this illustration). The researchers trap these atoms in midair using laser light (horizontal blue bands). While held in the light, each version of a single atom behaves slightly differently, due to their different positions in Earth’s gravitational field. Measuring those differences allows physicists to determine the strength of Earth’s gravity at that location.

CREDIT:  SARAH DAVIS

Measuring the strength of gravity with atoms that are held in place, rather than being tugged downward by a gravitational field, requires tapping into the atoms’ wave-particle duality (SN: 11/5/10). That quantum effect means that, much as light waves can act like particles called photons, atoms can act like waves. And for each cesium atom caught in superposition, the higher version of the atom wave undulates a little faster than its lower counterpart, due to the atoms’ slightly different positions in Earth’s gravitational field. By tracking how fast the waviness of the two versions of an atom gets out of sync, physicists can calculate the strength of Earth’s gravity at that spot.

“Very impressive,” says physicist Alan Jamison of MIT. To him, one big promise of the new technique is more controlled measurements. “It’s quite a challenge to work on these drop experiments, where you have a 10-meter-long tower,” he says. “Magnetic fields are hard to shield, and the environment produces them all over the place — all the electrical systems in your building, and so forth. Working in a smaller volume makes it easier to avoid those environmental noises.”

More compact equipment can also measure shorter-range gravity effects, says study coauthor Holger Müller. “Let’s say you don’t want to measure the gravity of the entire Earth, but you want to measure the gravity of a small thing, such as a marble,” he says. “We just need to put the marble close to our atoms [and hold it there]. In a traditional free-fall setup, the atoms would spend a very short time close to our marble — milliseconds — and we would get much less signal.”

Physicist Kai Bongs of the University of Birmingham in England imagines using the new kind of atomic gravimeter to investigate the nature of dark matter or test a fundamental facet of Einstein’s theory of gravity called the equivalence principle (SN: 4/28/17). Many unified theories of physics proposed to reconcile quantum mechanics and Einstein’s theory of gravity — which are incompatible — violate the equivalence principle in some way. “So looking for violations might guide us to the grand unified theory,” he says. “That’s one of the Holy Grails in physics.”

[scifigeneration]

Pairing lasers with microwaves makes mind-bogglingly accurate electronic clocks – a potential boon for GPS, cell phones and radar

by Andrew Ludlow and Franklyn Quinlan

Mating laser-driven atomic clocks like the one shown here with microwaves promises more accurate electronic devices. N. Phillips/NIST

Time and frequency standards are a key part of technologies we have come to rely on in our daily lives, from GPS navigation and cellphone networks to the electrical power grid. The importance of these systems and the constant drive to improve their performance has led to the development of atomic clocks that keep time and measure frequency with incredible accuracy.

Conventional atomic clocks use the billions-of-times-a-second vibrations of atoms like cesium to calibrate microwave signals, which are read by other devices such as GPS satellites, to keep time. The most accurate atomic clocks, however, calibrate optical signals from laser beams rather than microwaves, and they use atoms like ytterbium that oscillate even faster than cesium – hundreds of trillions of times per second.

Optical clock frequencies are so stable that it would take more than 14 billion years – the age of the universe – for one of these clocks to be off by a second. But researchers haven’t been able to feed these ultrafast optical signals at their full performance into electronic devices.

Our team of physicists and engineers, with members from the University of Colorado, University of Virginia and the National Institute of Standards and Technology (NIST), has found a way to link optical atomic clocks with microwave signals without compromising the amazing performance of the optical clock signals. The resulting microwave tracked the optical clock with a precision of under a quadrillionth of a second. A quadrillion is a thousand trillion. This yields a 100-fold improvement over the cesium fountain clock, the gold standard for microwave atomic clocks.

Keeping time

The very best microwave clock today is the cesium fountain clock, which oscillates near 10 GHz or about 10 billion cycles per second. Carefully tracking the clock cycles makes it possible to deliver a clock frequency with high stability. The best cesium fountain clocks can provide about 13 digits of precision after tracking one second’s worth of oscillations. Averaging over longer times increases the precision, and if you’re willing to wait for days or weeks you can improve the precision of the clock frequency to about 16 digits. With 16 digits of precision, it would take 300 million years for a clock to be off by a second. Microwave atomic clocks, housed in metrology institutes worldwide, are used to define the international standard for the second.

Microwave atomic clocks underlie much of today’s technology. For example, GPS measures the relative delay of timing signals from overhead satellites to determine your position. Without the nanosecond-level stability of the clocks onboard the GPS satellites, the relative timing delay among satellites would vary randomly, making it impossible to find your position accurately.

High-performance clocks are also extremely important for science. One example is very long baseline interferometry (VLBI) where microwave and millimeter wave signals are detected at observatories spread across the globe, and are combined to form images of cosmic objects. High stability clocks are needed to effectively time stamp the received signals so they can be combined in a meaningful way to form an image. A recent example of this technique at work was the first-ever images of a black hole.

Over the past decade, a number of optical clocks have surpassed the performance of their microwave counterparts. Optical clocks operate at 100s of terahertz – more than 100 trillion cycles per second – and can now provide 16 digits of precision in one second or better. In just a few hours, they can offer a whopping 18 digits of precision or more. This has opened up exciting new avenues in scientific research with atomic clocks, including the search for dark matter, testing whether fundamental constants of nature are truly constant and chronometric leveling where gravity’s effect on an atomic clock rate can be used to measure Earth’s gravitational potential. With the extraordinary performance of optical atomic clocks, a redefinition of the second now seems inevitable.

New applications become available by bringing optical-clock-level stability to microwaves.

GPS could be more accurate, positioning you to within a few centimeters rather than a few meters. Better GPS would improve the performance of aircraft auto pilots and self-driving cars. With more precise timekeeping, electronic communications like cellphone signals can transmit more information.

Radar is dependent on the frequency stability of the transmitted microwaves. With higher precision microwaves, radar sensitivity could see sizeable improvements, particularly for detecting slow-moving targets. Moving VLBI to space and outfitting it with improved timestamping could greatly increase resolution and observation time, making it possible to image more objects in the universe.

Combing frequencies

Bringing optical atomic clock precision to microwave signals was achieved with a tool known as an optical frequency comb. The frequency comb, named for its array of discrete, evenly spaced laser frequency tones, emits a train of sub-picosecond light pulses. A picosecond is a trillionth of a second.

The black rectangle (center) is a high-speed photodiode that converts laser pulses to high, super-stable microwave frequencies, bringing the incredible accuracy of optical atomic clocks to everyday electronics. Franklyn Quinlan/NIST

When the frequency comb is connected to an optical clock, the rate at which these pulses are emitted is a well-defined fraction of the optical clock frequency. Shining these pulses onto a high-speed optical-to-electrical converter makes it possible to generate a microwave signal that oscillates at a well-defined fraction of the optical clock frequency, and whose stability and accuracy matches that of the optical clock.

Armed with this level of performance, a new generation of microwave timekeeping opens the door for many scientific and technological advances.

About The Author:

Andrew Ludlow is a Lecturer of Physics at the University of Colorado Boulder and Franklyn Quinlan is a Physicist at the National Institute of Standards and Technology

This article is republished from our content partners over at The Conversation under a Creative Commons license.

[batstrangecloudcollection-blog]

Cesium Beam Atomic Clock Market to Witness Significant Rise in Revenue During the Forecast Period (2018 - 2026)

Cesium-Beam Atomic Clock Market: Introduction

An atomic clock is known as a precision clock that depends on an electrical oscillator for its operation. The electrical oscillator is regulated by the vibration frequencies of natural kind of an atomic system. The cesium-beam atomic clock is used as the primary standard of time and frequency which has a microwave oscillator that helps generate radiation in a microwave cavity. The microwave oscillator is maintained at a frequency such as a hyperfine transition which is induced in a beam passing through the cavity that contain cesium atoms. It is also known as cesium-beam atomic oscillator.

Ever-since the cesium-beam atomic clock was introduced, market players have been working towards differentiating the cesium-beam atomic clock with the help of new technologies. Attributes such as compact designs with the easy of handling being incorporated with the cesium-beam atomic clock have been major highlights of the cesium-beam atomic clock market. Moreover, the cesium-beam atomic clock has been offering a unique set of attributes and performance that meet the stringent needs of stability and accuracy for clock signals for a long time till date.

Cesium-Beam Atomic Clock Market Dynamics

The cesium-beam atomic clock market is experiencing various dynamics with respect to the sales of the cesium-beam atomic clock. With aspects such as highly accurate synchronization and maintaining nano-second time deviation, the cesium-beam atomic clock market participants are seen playing around the capabilities of the cesium-beam atomic clock. With the need for accuracy and precision, the cesium-beam atomic clock market is expected to witness greater research conducted for this need.

Precision time-keeping is gaining major significance when it comes to cesium-beam atomic clock. The significance of precision is further expected to boost the cesium-beam atomic clock market in the future. With the new products in the cesium-beam atomic clock market designed for use in space, the cesium-beam atomic clock manufacturers are working towards the benefits of atomic clocks being used in time-sensitive application that demand greater level of precision. Furthermore, the need to gain greater accuracy of defining the second has triggered the cesium-beam atomic clock market to think beyond the conventional definitions and gain greater accuracy over time-measurement.

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Cesium-Beam Atomic Clock Market Segmentation:

The global cesium-beam atomic clock market can be segmented on the basis of type and application type. On the basis of types, the global cesium-beam atomic clock market can be segmented as:

Production Frequency: 10MHz

On the basis of application, the global cesium-beam atomic clock market can be segmented as:

Navigation Military/Aerospace Others

Cesium-Beam Atomic Clock Market: Regional Outlook

The cesium-beam atomic clock market is active in the most of the emerging regions across the globe. The production of cesium-beam atomic clock is analyzed in the report with respect to regions including Europe, the United States, Japan, China, South Korea, and others.

The consumption of cesium-beam atomic clock market is however focused on a micro-level with a comprehensive country-level understanding with emphasis given to countries including the ones in Europe, France, UK, Malaysia, United States, Russia, Rest of Europe, Asia-Pacific, China, India, Japan, South Korea, North America, Canada, Vietnam, Australia, Indonesia, Germany, Mexico, Philippines, Italy, Thailand, Central & South America, GCC Countries, South Africa, Turkey, Egypt, Rest of Middle East & Africa, Brazil, Rest of South America, and the countries in Middle East & Africa region.

Regional analysis includes:

Cesium-Beam Atomic Clock Market in North America (U.S., Canada) Cesium-Beam Atomic Clock Market in Latin America (Mexico, Brazil, Argentina, Chile, Peru) Cesium-Beam Atomic Clock Market in Western Europe (Germany, Italy, France, U.K, Spain, BENELUX, Nordic) Cesium-Beam Atomic Clock Market in Eastern Europe (Poland, Russia) Cesium-Beam Atomic Clock Market in Asia-Pacific (China, India, ASEAN, Australia and New Zealand) Japan Cesium-Beam Atomic Clock Market Middle East and Africa Cesium-Beam Atomic Clock Market (GCC Countries, South Africa, Turkey)

The cesium-beam atomic clock market report is a compilation of first-hand information, qualitative and quantitative assessment by industry analysts, inputs from industry experts and industry participants across the value chain.

The report provides in-depth analysis of parent market trends, macro-economic indicators and governing factors along with market attractiveness as per segments. The cesium-beam atomic clock market report also maps the qualitative impact of various market factors on market segments and geographies.

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Cesium-Beam Atomic Clock Market: Key Market Participants

Players in the cesium-beam atomic clock market are exploring various possibilities to grab a bigger chunk of the total sales of the cesium-beam atomic clock while meeting the needs of the customers. With a focus on gaining a competitive edge, the players in the cesium-beam atomic clock market are majorly inclined towards working on harnessing the benefits associated with the cesium-beam atomic clock and its respective application.

The manufacturers are covered in this research report include :

FEI, Oscilloquartz SA, Microsemi, Kernco, Inc., Chengdu Spaceon Electronics, Chronos Technology, Casic, Orolia

Report Highlights:

The research report presents a comprehensive assessment and contains thoughtful insights, facts, historical data and statistically supported and industry-validated market data. It also contains projections using a suitable set of assumptions and methodologies. The research report on cesium-beam atomic clock market provides analysis and information according to market segments such as geographies, application and industry.

The report covers exhaustive analysis on Cesium-Beam Atomic Clock Market includes:

Cesium-Beam Atomic Clock Market Segments Cesium-Beam Atomic Clock Market Dynamics Cesium-Beam Atomic Clock Market Size Supply & Demand Current Trends/Issues/Challenges Competition & Companies involved Technology Value Chain

Report Highlights:

Detailed overview of parent market Changing market dynamics in the industry In-depth cesium-beam atomic clock market segmentation Historical, current and projected market size in terms of volume and value Recent industry trends and developments Competitive landscape Strategies of key players and products offered Potential and niche segments, geographical regions exhibiting promising growth A neutral perspective on market performance Must-have information for market players to sustain and enhance their market footprint