bgsphysicsmatters-blog

[bgsphysicsmatters-blog]

Thank you!

Hello Physics Lovers!

I just wanted to thank everyone who’s followed and enjoyed this blog over the last year! Setting up and then running Physics Matters has been really fun and I hope it has enthused you to be as excited about Physics as I am. I hope you all learnt something new and found some cool Physicsy sites!

Please continue to follow and check Physics Matters as I’m sure that the Physicists who will be running the blog after me will do an awesome job! :D

Have fun and keep loving Physics!

Elena :D

[bgsphysicsmatters-blog]

Somewhere over the rainbow...

When you shine white light at a prism, it is split into a spectrum of the 7 colours of the rainbow. This is because visible white light is made up of all of those 7 colours. When you shine the light through the prism, the different colours travel at different speeds to each other through the glass (as even though they travel at the same speed in a vacuum and air - near enough - they don’t in other substances). They are therefore bent (as one part of the light wave enters first and is slowed down before other parts of the same wave) and travel at different angles. These different angles mean they are seen out of the other side of the prism as separate colours.

The same thing happens when white light from the sun goes through raindrops, however, the light is also reflected inside the raindrop. To see a rainbow you must be able to see the shadow of your head/have your back to the sun as the sunlight will go towards the raindrops and be reflected inside the raindrops back towards your eyes allowing you to see the rainbow.

[bgsphysicsmatters-blog]

Oh wow I have wasted far too much time on this site! It is an Instagram with videos of physics related toys and curiosities. I particularly liked the refraction jewellery and the spinning top with the snake!

Elena Salmon

[bgsphysicsmatters-blog]

Ooh I found this channel ages ago when I watched a cool video about creating a crazy vortex in a swimming pool!

Elena Salmon

[bgsphysicsmatters-blog]

If you fit these criteria, then take advantage of the Institute of Physics’ free membership for 16-19 year olds! It offers you loads of perks such as access to free digital copies of Physics World magazine, receiving emails about news in the Physics community and online resources.

Even if you don’t want to be a member, the Institute of Physics holds lectures joint with the Open University which are always about topics at the forefront of modern physics. Entry is free.

Elena Salmon

[bgsphysicsmatters-blog]

This website is brilliant for aspiring physicists, especially younger ones with it’s easy to use and colourful format.

Elena Salmon

[bgsphysicsmatters-blog]

EINSTEIN!!!!

Einstein has been heralded by many as being a genius, and they would probably be right, as he single handedly changed the face of physics. Not only did his Special Theory of Relativity change the way in which physicists thought about the motion of objects which are moving in the same direction but at different speeds, but it also gave rise to his most famous equation, E=mc2, which shows how matter can be converted into energy and energy can be converted into matter.

It is, however, his General Theory of Relativity which I find to be the most wacky. In this theory, Einstein suggested that time will pass more quickly for someone on whom gravity has less of an effect - so you would be ever so slightly older if you’d lived in the mountains than if you'd lived at sea level. He also suggested that the gravitational field and space itself could in fact be the same thing. What he explained was that objects with larger masses would cause greater distortions in space-time and therefore have a greater gravitational pull on other objects. So basically, the Sun would have a greater gravitational pull on stuff than the Earth would.

It was, undoubtedly, Einstein’s willingness to ask questions and break the mould by thinking differently which allowed him to make such breakthroughs, however much this rebelliousness annoyed his school teachers. Indeed, his schoolmaster in Munich said “he will never amount to anything” - I don't think that man could have been any more wrong!

by Elena Salmon

[bgsphysicsmatters-blog]

This website has videos answering really crazy questions, like what would happen if you put your hand in front of the beam in the Large Hadron Collider? They’re really worth a watch! :D

[bgsphysicsmatters-blog]

Don’t you just hate bad hair days?

Don’t you just hate it when your hair goes wild and you can’t do anything about it?

When you brush your hair, electrons from the molecules in your hair are rubbed off onto the plastic in the hair brush/comb. As electrons are negatively charged, this gives the brush/comb a negative charge and your hair a positive charge (as the charges of the protons and electrons were balancing each other out before but now that the electrons are gone, the hair is left positively charged). On a non-humid day, as your strands of hair are now positively charged, they repel each other (like charges repel) making your hair messy.

This only works because hair and plastic do not conduct electricity and so the electrons stay where they are transferred instead of being conducted away. This doesn’t really work on humid days as the electrons are conducted by the water droplets in the air, reducing the charge of the brush/comb and deposited on the hair by water droplets, balancing out the charges.

A similar thing happens when you use a Van Der Graaf generator. As you have to stand on an insulator (e.g. polystyrene) when you are touching the generator, the charge cannot flow away into the ground and so builds up in your body… and your hair, resulting in the same effect.

by Elena Salmon

[bgsphysicsmatters-blog]

A cool Physics video channel where colourful drawings help you understand fun, and often surprising, Physics. I discovered this site a couple of years ago whilst trying to find out what Schrodinger’s Cat was and have happily wasted many hours on it since then.

Elena Salmon

[bgsphysicsmatters-blog]

The Madman’s Daughter

You will have heard of many computing pioneers such as Bill Gates, Alan Turing and Steve Jobs, however, you may not have heard of Ada Lovelace. Ada was the first computer programmer, despite living in the first half of the nineteenth century - about 100 years before modern computers were invented.

Ada was the daughter of the infamous poet Lord Byron (who was described as being 'mad, bad and dangerous to know') from his short-lived marriage with Anne Milbanke. Her parents separated when she was a month old and her mother, Anne, with whom she grew up, insisted that Ada learn Maths and Science so that she wouldn’t become a poet like her father who Anne now believed to be insane.

From when she was a teenager, Ada had a strong friendship with the Mathematician Charles Babbage with whose prototype of his Difference Engine (which could be used as a calculator) she became greatly interested in. A fully functional Difference Engine was only built later - this was between 1989 and 1991 under the Curator of Computing at the Science Museum in London and it can still be seen there today.  When he came up with the idea for his Analytical Engine which, had it been built, would have been the first computer and would have been powered by steam, Ada helped him.

When an article was written about Babbage’s concept of the Analytical Engine by an italian mathematician, Ada set about to translate it, with Babbage asking her to add extra notes to his article as she understood the machine so well. Her article ended up being over 3 times longer than the original article and it included programmes which could be added into the Analytical Engine’s punch card system - the first computer programmes to ever be published. She even envisaged how the machine could be used for other purposes that Babbage had never considered, such as for creating music. This was way ahead of her time as the machine had never even (and still has not) been built. Her notes went on to inspire Alan Turing in his work on computers and helped lead him to the concept of Artificial Intelligence which he imagined when creating the Turing Test.

By Elena Salmon

[bgsphysicsmatters-blog]

Alan Turing: A Man Before His Time

Alan Turing is famed for his life-saving work at Bletchley Park during World War 2 on trying to break German codes encoded by the Enigma machine. He invented the Bombe, a machine which could be used to help break the code - an amazing feat when computers had not yet been invented (it is argued that the Bombe was the first one) and when there were approximately 158 million million million different ways the Enigma could have encoded the message (with a different one often being chosen each day). The Bombe, however, was not his only achievement.

He was a man before his time, indeed in 1936 he published a revolutionary paper imagining a machine which all you had to do was give it a set of instructions and it would carry out your demands. This became known as the Universal Turing Machine and the idea that you could get one machine to be able to do multiple different things by giving it instructions is the concept behind modern computers.

Later, he envisaged a machine - a computer - which could mimic the human brain. He invented the Turing Test, which he published in 1950, a test designed to prove whether a machine had been developed which could be mistaken for human in its mental capacity. This was a seemingly crazy idea at the time when computers had only just been invented and were still in their very infant stages.

In many parts of his life he was ahead of his time - not only in his work. Tragically, he was arrested in 1952 due to his homosexuality and agreed to taking a harsh chemical treatment instead of going to prison. In 1954 he was found dead from cyanide poisoning at the age of 41. Whilst the official report called it suicide, whether his death was indeed suicide, an accident or a government conspiracy is still argued today. In December 2013, he received a royal pardon which cleared him of the charges against him, however, this was too late to save him or his brilliant mind.

By Elena Salmon

Above is shown the plaque from the Alan Turing Memorial in Sackville Park, Manchester, England.

[bgsphysicsmatters-blog]

Stephen Wolfram did a Physics degree and later went into Computer Science. He is now an entrepreneur and CEO who is trying to make a model of our universe with computers, from as simple rules as possible.

[bgsphysicsmatters-blog]

Where would we be without the world wide web?

The world wide web was invented by Tim Berners-Lee in 1989 for the purpose of sharing data from experiments instantly with scientists around the world. He was working at CERN, which you will probably have heard of as being where the particle accelerator the Large Hadron Collider is housed. The LHC is famed for being not only the world’s largest accelerator but for also proving the existence of the Higgs Boson in 2012. The invention of 1989 had an integral part in this as so much data is created from LHC experiments that it has to be sent to physicists from all around the world to be analysed.

CERN made the software for the world wide web freely available to the public in 1993 and it is astounding to think how much progress it has made. Indeed, it is surprising (at least it was to me) how recently this was as the internet is such an integral part of our lives today - you are probably even reading this article via the internet. The invention of the internet revolutionised our lives and made finding information easier than ever before and this is proof that Physics can lead to discoveries that have major impacts on our lives.

...This is the first article in a series about major figures in computing, which has an integral part in modern Physics.

By Elena Salmon

[bgsphysicsmatters-blog]

Absolute Zero: the coolest concept in the Universe

What is heat? The answer to this question may not be as obvious as you might think…

Let’s use the example of a hot cup of tea since the film of Alice Through The Looking Glass has just come out:

When you have a hot cup of tea, it will cool down as it sits in a room, as the room temperature is less than the temperature of the tea. This is because the tea is hotter, but what does this actually mean?

Everything is made up of particles, including the tea, the teacup and the surrounding air. The particles in the tea have been supplied with energy - because, when the water was boiled, energy was supplied to the water by the heating element in the kettle - so they will be moving around quickly; in Physics terms, they have gained kinetic energy. When the higher energy particles in the tea collide with the particles in the teacup, they transfer some of their energy to the teacup’s particles, making the particles in the teacup vibrate more because they have more kinetic energy. The same thing happens when particles in the air collide with the teacup and the tea (at the top of the cup) - some of the energy from the teacup’s and the tea’s particles will be transferred to the air’s particles giving them more kinetic energy and therefore making the air “hotter” too. As the tea loses heat to the teacup and the air, it’s particles have less kinetic energy (and so are moving slower) meaning that the tea is cooler.

As we now know that an object’s “heat” is how much its particles move about, we can imagine cooling an object down so that its particles have no kinetic energy and so are completely still. This theoretical state is called Absolute Zero and scientists have calculated that the temperature that this would occur at would be about -273℃.

Thus, theoretically, we can cool an object to Absolute Zero by just slowing down its particles until they don’t move or vibrate. However, experimentally (in a laboratory) this is very unlikely, especially as there are always forces acting on particles . This means that a very  high precision is required to balance these forces to leave an overall force of zero (to make the size of forces in opposite directions equal so that they have no overall effect on the motion of the particle).

Earlier, we discovered that in order to cool an object we might put it in a place that is colder than the object, but how can we do that if we don’t know of anywhere cold enough (at less than Absolute Zero) to put the object in? And we know that we can’t have anything colder than Absolute Zero as how can you slow particles down when they are already stationary (as they would be at Absolute Zero)? You just can’t (at least not that I’ve ever heard of)!

Some Physicists have managed to get very close to Absolute Zero, however, with the Nobel Prize for Physics in 2001 going to a group of Physicists who had managed to achieve a temperature of “a tenth of a millionth of a degree above absolute zero��* which is frankly astounding. How close to Absolute Zero do you think scientists will get in the future?

by Elena Salmon

(*Here I quoted the 2001 information for the public about this prize which can be found at this web address: https://www.nobelprize.org/nobel_prizes/physics/laureates/2001/popular.html)