Accelerate – Spring 2024

Table of Contents:

2023 Physics Highlights (page 3)

People:

Laplace’s Demon (pages 4-5)

Why you Should Know About Chien-Shiung Wuthe Physicist Oppenheimer Failed to Mention (pages 6-7)

Space:

Are we Alone in the Universe and Why are we Here Today? (pages 8-9)

Are White Holes a Solution to the Information Paradox? (pages 10-12)

Technology:

Artificial Intelligence - What are its Current Applications and What is Holding it Back? (pages 13-15)

Superconductivity and MAGLEV Trains (pages 1618)

The ‘Hum’ Throughout The Universe

Scientists finally got their break in June 2023 when they detected low frequency gravitational waves produced by colliding supermassive black holes When black holes orbit each other they emit waves which stretch and compress space-time that in turn alter the timing of pulsar signals (pulsars are dead star which emit regular bursts of energy) which can then be observed by very sensitive detectors such as NANOGrav in North America. “What we’ve essentially done is hack the entire galaxy to make a giant gravitational wave antenna,” Stephen Taylorastrophysicist at Vanderbilt University - said.

Does Antimatter Fall Up?

The recent experiment Alpha-G at CERN had some disappointing results They captured anti-hydrogen atoms before releasing them to see whether they would fall up or down As it turns out, antimatter, just like normal matter, falls downwards when experiencing a gravitational field Why did they do this experiment if they suspected this all along? Well, if the result had been that antimatter falls up it could have solved one of the big mysteries in the universe - why is the observable universe only made of antimatter? Furthermore, there is something to be commended about the technical achievement of this experiment since antimatter is infamously difficult to deal with.

Groundbreaking Results From JWST Help Us Understand The Beginning Of The Universe

The James Webb Space Telescope has provided more questions than answers about the universe Multiple bright red objects have been identified by the JWST which are supermassive galaxies from the beginning of the universe It was previously thought that at early times all objects would be constantly colliding with each other and hence galaxies of such a size were not yet achievable “This could potentially change the framework of cosmology itself” claims astronomer, Caitlin M Casey

The First X-Ray Image Of A Single Atom

Saw Wai Hla and Volker Rose at the Argonne National Laboratory in US used a metallic tip to increase the precision of X-ray imaging from 10,000 atoms to just 1. The reason this was not possible before was because the X-ray signal produced by an atom is very weak and so conventional detectors are not sensitive enough to detect them By adding a sharp metallic tip to 1nm above the sample this allows electrons to tunnel from the sample to the tip creating a current unique to each element Scientists hope this technique will have many applications in environmental science tracing toxic materials even at very low levels

2023 Nobel Prize In Physics - The Study Of Electron Dynamics In Matter

Pierre Agostini, Ferenc Krausz and Anne L’Huillier revolutionise methods for studying one of the atom’s constituents - the electron Electrons move extremely rapidly in atoms meaning that a camera just as fast is needed to capture its movements They managed to create flashes of laser light that were only attoseconds in length (that’s 0 000000000000000001 seconds!) This will have exciting new applications in the future from electronics to medicine.

Can We Conjure Energy From Thin Air?

Martin Martinez and team prove Masahiro Hotta’s theory on quantum energy teleportation from 2008 which seems to break the laws of thermodynamics! By lowering two carbon atoms to the lowest quantum energy state and entangling them with radio pulses they managed to send information from one to the other via an intermediary particle without energy transferring between them The process took only 37 milliseconds in the lab, if energy had travelled over these physical distances it would have taken a whole second. Scientists hope this will have many useful applications from advanced experiments to basic science.

The Next Step To Integrating Humans And Technology

Researchers in Sweden have discovered a work around for the mismatch between rigid electronic substrates and soft tissues - just grow the electrodes inside livin tissue instead! The team inject a gel into the body which contains enzymes to break down metabolites (end products of metabolism such as amino acids, sugars and lipids) in the body and trigger enzymatic polymerisation of organic substances in the gel to create soft and stable conducting electrodes The process has already been tested and proven successful in zebrafish and leeches

The Oh-My-God Particle Has A Cousin

The OMG particle, discovered in 1991, is an ultra-highenergy cosmic ray that has 100 quintillion times the photon energy of visible light which is 10 million times more powerful than the Large Hadron Collider. This may sound frightening but don’t fear - it’s roughly equivalent to a basket ball travelling at 28 m/s. The recently detected particleAmaterasu, named after the Japanese sun goddess - has 3/4 of the energy of the OMG particle and was discovered by the Telescope Array Project, Utah. Weirdly, this ultra-highenergy cosmic ray came from the Local Void which is a seemingly empty patch in the universe

LaPlace’s Demon

By Jessica Hindin, UVI

Determinism: the doctrine that all events, including human action, are ultimately determined by causes regarded as external to the will. In short, everything we think, do or say has already been decided upon. It is a concept which has fascinated philosophers and physicists alike since it was initially proposed during the sixth and seventh centuries BCE The question of whether we inhabit a world of chance and decision pioneered by our own free will or one that adheres to predestined plans is not one that can be answered simply Some argue that it is not one that can be answered at all Even so, attempts have been made to propel us towards an explanation

One such attempt is that of Laplace’s Demon. Proposed by French scholar Pierre-Simon Laplace in 1814, Laplace’s Demon is a thought experiment designed to prove the theory of determinism using a scientific basis. Originally scribed in Laplace’s book (A Philosophical Essay on Probabilities), it explains that if one were to possess detailed knowledge of everything in the universe in an instance, one could use that data to describe the past and accurately predict the future. Determinism follows the logic that the present directly causes the future, and was directly caused by the past This suggests that having attained complete knowledge of the present, the past and future will also be revealed; it utilises the assumption that determinism is reality to prove its existence However, as there is no known being in the universe capable of gathering and analysing such extensive information, Laplace referred to this creature as a ‘demon’.

Since Laplace’s Demon was initially published, it has become subject to both support and criticism. Considerable issues have been discovered with the theory as our understanding of the world has advanced. Perhaps the largest inconsistency is due to quantum mechanics. The experiment states that the demon would require access to complete and detailed knowledge of the universe This would, on the deepest level, be the locations and velocities of all atoms and subatomic particles within them The problem with this is that subatomic particles do not obey the laws of classical mechanics, but instead quantum mechanics, making them entirely unpredictable (as they operate

within probabilities). Heisenberg’s uncertainty principle states that one cannot know both the position and velocity of a particle, as certainty of one increases uncertainty of the other does so too. Laplace’s Demon completely violates this rule.

Another limitation of Laplace’s Demon lies in the second law of thermodynamics - entropy. Entropy is a concept associated with a state of disorder, and it is understood that the entropy of any system will always increase with time. This eventually leads to thermodynamic irreversibility Laplace’s Demon uses the present to reverse-engineer the past, but according to the idea that the situation will become more and more disrupted over time, it should be impossible to accurately restore ideas of a former state

entropy, InternetEncyclopaedia of philosophy, https://iep.utm.edu/entropy/,[Accessed15th February2024]

The final factor that invalidates Laplace’s Demon is - in a sense - itself. From the idea that a demon has complete knowledge of the universe, it logically follows that this demon must also have complete knowledge of itself This self awareness gives the demon a form of free will in that it could choose to act in a way that opposes its own predictions Whether or not it chose to, the demon would always have the ability to, and therefore possesses free will, disproving determinism If the demon was completely outside of the system and the universe (hence unpredictable), it would be unable to accurately determine the happenings inside the universe due to having no interactions with it.

In conclusion and due to the scientific advancements detailed, Laplace’s demon can simply not exist. However, that does not stop the theory from being an intriguing way of considering the possibilities of free will and determinism, or a useful base from which we can further explore their probabilities and consequences

References:

González-Fierro, Laplace’s Demon And The Scientific Method, 2017, https://miguelgfierro com/blog/2017/laplacesdemon-and-the-scientific-method/, [Accessed 19/12/2023]

[Anon], Laplace’s Demon, The Information Philosopher, https://www.informationphilosopher.com/freedom/la places demon.html, [Accessed 22/12/2023]

Why You Should Know About Chien-Shiung Wu - the Physicist Oppenheimer Failed to Mention

By Ines Escobar, Year 10

Chien-Shiung Wu (1912-1997) acquired the nickname of ‘the First Lady of Physics’ for her pioneering contributions to modern science. Her experiments transformed our knowledge of nuclear physics and Beta Decay (the process by which a particle in the nucleus of an atom changes form) and were the first to disprove the theory of parity conservation in weak subatomic interactions. Hence, she is often described as the leading female physicist of her time, although many people have never heard of her as a consequence of her exclusion from the 1957 Nobel Prize

Chien-Shiung was raised in Eastern China and attended a school which was run by her father; he was a believer in girls’ education, which was unusual at the time. It was also fairly uncommon for women to show curiosity in science. Nevertheless, she eagerly followed her passion and went on to graduate from the National Central University in Nanjing and the Zhejiang University in Hangzhou. In 1940, she received a ph.D. at Berkeley for research studies which aimed to determine the properties (such as yields, half-lives and decay modes) of the individual members of several fission chains. By this time, the Second World War had begun and Wu could no longer communicate with her family Because of the Communist takeover in China, she would never see her parents again

After the Second World War, Wu’s colleagues Tsung Dao Lee and Chien Ning Yang proposed that the theory of the law of conservation of parity (the notion that a mirrored version of this world would also behave in a mirror-image way) didn’t apply to weak interactions in particle physics. Their suggestion was consistently ignored until Wu’s experiments demonstrated that identical nuclear particles do not invariably act in the same way. Lee and Yang won the 1957 Nobel Prize for their theory but Wu, who had facilitated their breakthrough, received none of the credit she was due.

Wu’s disappointing exclusion from the Nobel Prize was the mirror-image of Ida Noddack; while Wu was dismissed because her role was purely experimental,

Noddack, who had originally put forward the theoretical principle behind nuclear fission, was denied the 1944 Nobel Prize in Chemistry due to the absence of experimental input. It therefore holds that gender prejudice might have been at the root of these injustices. Over time, Professor Wu became an increasingly vocal proponent of gender equality in the scientific sphere and beyond, demanding an equal salary to her male colleagues

“I wonder whether the tiny atoms and nuclei, or the mathematical symbols, or the DNA molecules have any preference for either masculine or feminine treatment," Wu said at a conference on women in science

Wu continued to make major contributions to her field for the rest of her career, working at Columbia University. Her research advanced the understanding of blood and sickle cell anaemia and in 1963, her experiments validated the proposed conservation of vector current in nuclear beta decay. By the end of her life, she had received an impressive array of honours, including the Wolf Prize in Physics, the National Medal of Science, the Comstock Award and the first female presidency of the American Physical Society, to name but a few

Acc. 90-105 - Science Service, Records, 1920s-1970s, Smithsonian Institution Archives

It is worth noting that Wu also made contributions to the Manhattan Project, having joined in 1944 (although she did not appear in the Oppenheimer movie). This was a secret operation aiming to construct the first atomic bombs during the Second World War and resulted in two bombs being dropped in August of 1945: one on Hiroshima and one on Nagasaki. To begin with, Wu worked to help develop the process for separating uranium metal into U-235 and U-238 isotopes by gaseous diffusion; obtaining uranium-235 would be essential to the fuelling of the bomb on Hiroshima She then undertook work concerned with radiation detection and when the B Reactor at Hanford mysteriously malfunctioned, Wu determined the cause This reactor would then provide the Plutonium used in the atomic bomb dropped on Nagasaki

Devastatingly, the bombs are thought to have caused the deaths of around 250,000 civilians. Many people have attempted to justify the Manhattan Project, saying that it was necessary in order to end the war, thus preventing other deaths. However, intercepted Japanese communications suggested that they were close to surrender. In addition, the fear that Germany had almost created a nuclear bomb of their own was groundless So, was Wu evil? Had she hoped that the bombs would have a purely demonstrative purpose? In any case, Chien-Shiung Wu was a scientific mastermind who boldly fought against sexism and antiAsian racism, paving the way for the next generation of empowered physicists

References:

Anon.], ‘9 Scientists Who Didn’t Get the Credit They Deserved’, Oxford Royale, no date, http://www.oxford-royale.com/articles/9-scientistsdidnt-get-credit-deserved/ [Accessed 22/12/2023]

Leon Lidofsky, ‘Chien-Shiung Wu, 29 May 1912.16 February 1997’, Proceedings of the American Philosophical Society, 145:1 (2001), 1-11. [Anon.], ‘Chien-Shiung Wu’, Museum of Natural History, no date, https://oumnh ox ac uk/learnchien-shiung-wu [Accessed 23/12/2023]

The Editors of Encyclopedia Britannica, ‘ChienShiung Wu’, Britannica, no date, https://www britannica com/biography/ChienShiung-Wu [Accessed 23/12/2023

Ronald K. Smeltzer, ‘Chien-Shiung Wu’, Atomic Heritage Foundation, no date, https://ahf.nuclearmuseum.org/ahf/profile/chienshiung-wu/ [Accessed 23/12/2023

Joanna Scutts, ‘The Manhattan Project Scientist Who Fought for Equal Rights for Women’, Time, (2016), https://time.com/4366137/chien-shiung-wuhistory/ [Accessed 24/12/2023

[Anon.], ‘B reactor’, The Hanford Site, no date, https://www hanford gov/page cfm/BReactor [Accessed 24/12/2023

Tom Metcalfe, ‘What Was the Manhattan Project?’, Scientific American, (2023), https://www scientificamerican com/article/whatwas-the-manhattan-project/?scrlybrkr=555b7

da0#:~:text=The%20Manhattan%20Project%20wa s%20a,that%20are%20%20still%20%20e vident%20today. [Accessed 24/12/2023

George Iskander, ‘The Manhattan Project Shows Scientists’ Moral and Ethical Responsibilities’, Scientific American, (2022), https://www.scientificamerican.com/article/themanhattan-project-shows-scientists-moral-andethical-responsibilities/ [Accessed 24/12/2023]

Are we Alone in the Universe and Why are we Here Today?

By Ysabel De Burca, Year 11

Are we alone in the universe? Such a simple question with such a confusing answer. When you hear that there may be other life forms your mind probably flashes to images of aliens with spaceships and tractor beams, epic star wars battles being waged across the galaxy. Ideas ranging to infinity and beyond. However the reality is far from it. Delve into this article which explains the possibility of life within our own solar system

The recipe for life:

Before we begin our search for life we must first understand what conditions we are looking for that could potentially harbour it One such key ingredient in our recipe for life is liquid water. Almost all biologists would agree that water is a building block for life. The water must be able to be found in its liquid state as well as the solid and gaseous forms. This can sometimes be determined by whether or not the planet is within the star's habitable zone, a zone where liquid water could be found. The heavier a star the further away the habitable zone will be. For example, Earth is right in the centre of our solar system's habitable zone, which could be the reason why liquid water is found so readily on the surface of our planet Closer to the sun, though still within the habitable zone lies Venus We know that Venus once had liquid water on its surface but due to its proximity to the sun and a runaway greenhouse effect it has lost its liquid water It is a similar story for Mars The planet is at the furthest edge of the habitable zone, and also supposedly contained liquid water upon its surface. However due to its distance from the sun most of its water now exists as ice at the poles, icy dirt, thin clouds and a small amount as liquid water in the ground. As we search for worlds that may harbour life it is important that we look for liquid water.

Europa:

Continuing on with our journey, I would like to take you to a place where there may be life in the backyard of our very own world Only roughly 628 3 million km away from earth is one of Jupiter's moons Europa At

first you might be wondering as to why I have taken you to this specific moon out of Jupiter's 78 others, surely life should exist upon a planet like our own. Well what makes this moon so special is not where it is but what it contains. Beneath the icy crust of Europa there is a massive salty ocean.

Despite the rock hard crust there still may be water one day on Europa’s surface Jupiter has a strong gravitational field strength due to its massive size And so exerts a force upon Europa Deforming the outer layer This would allow the salty ocean material to reach the surface of the moon Even so with the water released from the icy crust we still need other material to allow life to form The forces that manipulate the moon’s shape will additionally allow for ocean water to seep into the rocky interior of the planet. This will then be heated by the core and chemically react with the rock, filling the water with minerals and organic carboncontaining compounds. The water would flow back through the cracks in the rocky interior allowing it to reenter the ocean. This process could supply the moon’s water with the building blocks for life, and provide food for simple organisms. The possibility of life within our own solar system, especially beyond the habitable zone, is astounding In October of 2024 NASA plans to launch its Europa Clipper spacecraft in order to investigate the possibility of life on this moon, the clipper is scheduled to enter orbit in 2030 However, Europa may not be the only moon to potentially have life on it

EuropaClipper,ExploringJupiter’s Icy Moon, EuropaUp Close, NASA, https://europa.nasa.gov/whyeuropa/europa-up-close/,[Accessed17/02/2024]

Titan:

Orbiting Saturn, lies Titan. The second biggest moon in the solar system, Titan, is the only one known to have a dense atmosphere Like Earth, Titan’s atmosphere is primarily nitrogen It is also the only other world known to have an Earth-like cycle of liquids, the liquids evaporating, condensing, raining from the sky and flowing back into the moon’s standing lakes, rivers and seas similarly to the Earth’s water cycle The moon’s surface is sculpted by liquid hydrocarbons, with any bodies of liquid made from methane and ethane Again in this image from Cassini it shows the methane clouds in Titan’s sky and higher up closer to the north pole you can see some hydrocarbon lakes. In various images taken by Cassini we can see that the glint of a sunrise has been reflected off something, potentially one of these hydrocarbon lakes. It is believed on Titan that ice acts as rock, because the moon is so far out from the sun. Additionally, if the world ends up being volcanically active scientists think that water would play the role as lava The moon is also thought to have an ocean of water beneath its crust With this liquid on its surface and the subsurface ocean the moon is an amazing candidate for life Within the water of the ocean would exist slats and ammonia already providing it with other compounds for life to use Although there isn’t any liquid water on the moon's surface, the liquid hydrocarbons could still harbour life as we have never seen it before. This is why in June of 2027 NASA plans to launch a rotorcraft lander Dragonfly, estimated to arrive on the moon's surface by 2034, to further investigate the possibility of life on this world.

Enceladus:

Remaining in the Saturnian system we come to Enceladus. Roughly as wide as 1/7th of the Earth’s Moon it is one of the few worlds to have a liquid water ocean In 2005, NASA’s Cassini spacecraft discovered that Enceladus sprays its ocean out into space Samples taken from this sprayed water scientist have determined that it contains many chemical ingredients that are needed for life It is suspected that these chemicals come from hydrothermal vents deep beneath Enceladus’ icy shell These hydrothermal vents would not be unlike the ones here on earth. Enceladus’ spray of icy particles creates Saturns’ E ring with the particles spreading out as it orbits Saturn. However some of these particles will settle back down onto the moon’s surface adding to Enceludus’ whiter appearance. The bright white colour reflects lots of sunlight so the moon’s surface is extremely cold (-201oC). However with its global ocean and hydrothermal vents beneath the surface the world might not be as inactive as we once thought

The possibility of life outside our solar system:

Although this article has had a greater focus on the possibility of life within our own solar system, there is extensive research that goes into finding other solar systems and each one's possibility for life. Currently there are 5,241 confirmed exoplanets (planets that orbit other stars) with over 3916 other planetary systems, who’s to say that we won't find life on any of these other worlds.

Conclusion:

I would like to reiterate the fact that the search for life is a complex topic, the search may be never ending And so we should be grateful that our civilised lives exist Earth is 4 5 billion years old, intelligent life has only existed on it for a fraction of that time We are so incredibly lucky that we have our unique lives Our existence here on earth is so impossibly rare that we must take care of it as well as the world around us

References:

Brennan P., Exoplanet Exploration, Planets Beyond Our Solar System, NASA, https://exoplanets.nasa.gov/, [Accessed 17/02/2024]

Are White Holes a Solution to the Information Paradox?

By Alessandra Diotallevi, UVI

What is the information paradox?

In a sentence, the information paradox questions what happens to information as a black hole evaporates.

Let’s dig into this statement a bit further.

Firstly, what do we mean by information? Each particle in the universe has a unique ‘fingerprint’ that, if known, allows us to (theoretically) reconstruct objects even though they may have been destroyed beyond recognition So the information we are referring to is in the quantum scale and describes the properties of particles such as spin, velocity and position. A key property of information is that, just like energy, it cannot be created or destroyed.

Black holes are formed when stars of a certain mass collapse into an extremely dense and small point. Due to this they bend space-time significantly meaning that beyond the event horizon, not even light can escape and time around a black hole seems to travel extremely slowly from the perspective of a distant observer This means that from such a perspective an object approaching a black hole would appear to take infinitely long to cross the event horizon and disappear, whereas from the perspective of the object itself there is no discernible change in how time is experienced When an object enters a black hole (crosses the event horizon) all of its information and energy (or mass for they are one and the same) is pulled in by the black hole’s gravity.

Despite often learning that nothing can escape a black hole, this is not entirely true. In 1974 Stephen Hawking discovered a phenomenon which he dubbed Hawking radiation that describes how a black hole evaporates over time causing the horizon to shrink; it is important to note that the interior of the black hole does not shrink and it can continue to accrue matter and grow The process of evaporation involves pairs of particles that are constantly coming in and out of existence via matter-antimatter annihilation and pair production Hawking predicted that when pair production happens around a black hole the positive mass particles (matter) have enough energy to escape the event

horizon and the negative mass particles (anti-matter) get sucked in and decrease the mass of the black hole. However these escaped particles (which have a mass so can therefore also be thought of as energy) seem unrelated to the information that entered the black hole so energy/mass is escaping but what about information? If the black hole horizon eventually disappears because all the energy has evaporated into the universe then has the information been destroyed? Herein lies the paradox

There seem to be a handful of different solutions to this problem, white holes being my favourite which is why I have chosen this topic However some of the others include: information being encoded in the energy escaping, information being released in an explosion right at the end of the black hole’s life or being compressed into an infinitely dense point that remains even after the black hole is long gone.

What are white holes and how are they formed?

Einstein’s theory of general relativity describes the interactions in the universe - what happens to time and space around a mass Schwarzschild’s solution to Einstein’s field equation describes the effect of time dilation as seen from afar when approaching an extremely dense object (i e a black hole)

Let’s picture the black hole as a funnel where the rim is the event horizon and the collapsing star is at the bottom of the narrow tube.

Einstein’s equations predict that over time the inside of a black hole narrows and lengthens (but is not infinite!) However when the distortion of space-time is so extreme the equations stop working This is the point we call a singularity and not, despite commonly thought, the centre of the collapsing star because at 10

that point the equations still work So if the zone where the equations stop working (the singularity) is not at the centre of the black hole then where is it? The answer is: in the future. It happens when the funnel is so narrow that it reaches the Planck scale and is essentially a line where “space has collapsed, time is finished”.

It is important to address this misconception as well as another since they will help us to understand where white holes come from The second misconception is about how we think about/perceive time Many of the laws of physics, including General Relativity, are symmetric in time and space The Schwarzschild solution to Einstein’s equation only considers time flowing in one direction - however what would happen if time flowed in the other direction? We could get a white hole, so actually white holes and black holes are different solutions to the same equation, time is just progressing in opposite directions.

What are some other comparisons between white and black holes?

Whilst black holes consume and compress everything around them, white holes spew energy, matter and information out into the universe.

They both have an event horizon however this is the point of no entry for a white hole rather than the point of no return

Inside a black hole it narrows and lengthens but in a white hole it shortens and widens

Strangely they both appear the same to a distant observer - as in it seemingly takes forever to reach the horizon and then disappear The time dilation is due to extreme distortion of space-time in both instances but the disappearance is either the object entering the black hole or getting destroyed by outgoing matter from the white hole.

The process of forming a white hole starts with the collapse of a massive star to form a black hole. Eventually the compression of the black hole is halted by a quantum property of space called granularity (just as grains of light are photons there are also grains of space) as a black hole could not be squeezed smaller than the size of the individual grains of space This implies that the contraction actually stops before we reach the singularity (hence why it is in the future) as the smallest possible grains are the Planck length and the singularity is only beyond this point What happens

next if collapse is no longer possible?

The black hole quantum leaps (much like how an electron leaps between orbitals/shells when emitting light but on a much more radical scale) via the tunnel effect into a white hole. A quantum transition of this scale is known as loop quantum gravity (leaping from one configuration of space to another).

How do white holes solve the paradox?

The first thing to consider is how likely is it that a black hole will transition into a white hole?

As the horizon shrinks it becomes very small compared to the large volume inside which has still been taking in mass and lengthening and narrowing. This means that the probability of a quantum leap becomes very large. However after the leap has occurred the white hole will not have the energy to increase in size so it remains small (and therefore more stable) emitting weak radiation until it vanishes.

The diagrams on the previous page explain the path of energy and information as the black hole transitions into a white hole. The vertical arrow on the left hand side indicates the passage of time.

1.

Energy enters the black hole and is then lost via Hawking radiation (positive energy when the positive mass/matter particles escape). The negative energy are the antimatter particles which decrease the mass of the black hole and annihilate its energy. This means that only a small amount of energy ever reaches the white hole horizon.

2.

Information, once passing the horizon, remains inside until after the quantum leap.

The issue with black holes was that although energy/mass and information enter, only energy/mass escapes via evaporation which causes the black hole’s horizon to shrink and the information can’t escape. However if black holes transformed into white holes the information and remaining mass/energy would ‘fall out’ of the white hole easily, thus solving the paradox.

References:

TED-Ed, Hawking’s black hole paradox explained - Fabio Pacucci, [YouTube], https://www.youtube.com/watch?

v=r5Pcqkhmp_0, [Accessed 20/01/2024]

Rovelli C., White Holes, Milton Keynes: Penguin Random House UK, 2023

Artificial Intelligence - What are its Current Applications and What is Holding it Back?

By Marianna Verster, UVI

What is Artificial Intelligence?

A branch of computer science dealing with the simulation of intelligent behaviour.

How does it work?

Artificial Intelligence works with neural networks. Neural networks are modelled off human neurons which fire electrical impulses upon being triggered by a stimulus

How A I neural networks work: they take inputs in the form of numbers, accumulate them and with enough activation, like triggering a neuron, the computer will compute an output similar to a neuron firing an impulse.

AI machine learning works through classification. The goal for machine learning is to classify things from each other from seeing them. Basic Applications of AI classification systems are: spam filters, analysing sentiments from tweets and many other functions such as object recognition computer ‘vision’. When feeding data for machine learning, the learning process has two phases in which the data fed into the system is split into two The two phases are training data phase and testing data

1

Training phase - used to learn - human teacher classifies first half of data then feeds the labelled data into the machine

Neural Networks and Bias:

Neural networks represent the knowledge of the computer. This consists of I - algorithms (instruction) and J - algorithms (judgement). I - algorithms act as a computational recipe , while J - algorithms put this into practice.

A point of consideration is that whilst I - algorithms are just following exact instructions computed in by a human, J - algorithms make biased decisions based on these instructions and can perpetuate this bias in a way that could unfairly affect predictions This could be the fault of the programmers, however it could also be external factors such as the A I responding to a negative feedback loop without it being corrected

WenzelM, ReducingAlgorithmic Bias ThroughAccountabilityandTransparency,Medium, https://medium.com/swlh/reducing-algorithmic-bias-through-accountability-and-transparencyb7dc210df678, [Accessed15thFebruary 2024]

2

Testing phase - feed other half of data into the machine classifier and see how it classifies data compared to the human teacher, then tweak classifier if it is not validated by the human teacher’s data.

Baheti P, Train TestValidation Split: HowTo & Best Practices, V7, https://www.v7labs.com/blog/trainvalidation-test-set, [Accessed 15th February 2024]

For instance, in 2015 it was unearthed that Amazon’s recruiting algorithm was biased against women As it was based on the candidates hired over the past 10 years with most of the candidates being men, the algorithm subsequently favoured men over women as it responded to a negative feedback loop. In the end the recruiting algorithm has to be scrapped due to the A.I. penalising qualifications that included the word ‘’women’s’’. There are many other instances of this bias coming through in algorithms, from facial profiling apps to predictive policing , often being biased against racial minorities. Though this bias is not the computer’s own work but a reflection on bad data fed in by people who programmed the system, it has real world consequences and can diminish human trust of Artificial Intelligence

The Big Question: What are the current applications of A.I and what is holding them back?

There is a whirlwind of conflicting opinions on where we currently stand in the age of Artificial Intelligence.

In several instances knowledgeable people, or even the A.I.s themselves are claiming to have reached a point of sentience, contradicting public knowledge and causing a storm of debate in the media.

In August 2021, Google Engineer Blake Lemoine who had been testing the company’s chatbot LaMDA was convinced after 1 month that it was sentient with the robot claiming that it knew how to be sad, content and angry and had a “very deep fear of being turned off”.

Though these claims have been discredited by most experts on the matter, the media sensation caused by this has raised the question as to just how much the public really knows about the progress being made in Artificial Intelligence. The expenses required to develop A.I is the main reason for its concealment, however given the ethical and philosophical issues tied into the development of artificial intelligence, the ignorance of the public on this matter is a major cause for concern in the future. Michael Wooldridge, a professor of computer science at the University of Oxford, who has spent the past 30 years researching A.I., finds it “troubling that the development of these systems is predominantly done behind closed doors and that it’s not open to public scrutiny in the way that research in universities and public research institutes is,”. Perhaps the concept of Artificial Intelligence being sentient currently belongs in the world of science fiction but the progress in this field is showing no sign of stopping. Jeremie Harris, founder of AI safety company Mercurius warns, “AI is advancing fast – much, much faster than the

public realises – and the most serious and important issues of our time are going to start to sound increasingly like science fiction to the average person.”

A.I’s current applications and implications:

Possibly the most widespread use of Artificial Intelligence at the present is recommendation systems which push content for a specific profile based on their search history. To build this system, you require browsing history, customer behaviour, and implicit data. Data mining and machine learning skills are necessary to produce the most suitable product recommendations based on customers’ interests. You will also need to program in R, Java, or Python and leverage artificial neural networks.

Currently this is done very effectively by Google as they are enabled to collect a mammoth amount of data from their users for optimal function, far more data than most of its users are aware of or should feel comfortable with.

The YouTuber Arun Rupesh Maini, known as MrWhoseTheBoss, upon checking the data google has on him, revealed that Google stored data from not only his search history but also Google photos, conversations with Google assistant and could pinpoint every location he had been to on Google maps. Through these tracking platforms that most people are unaware of there is a very dangerous potential for misuse of people’s data. Through this application of A.I. people are at great personal risk if their Google account is hacked. With sensitive

Tangen Jr.O, Is GoogleStreetView aninvasion of privacy?, DW, https://www.dw.com/en/do-you-think-that-google-street-view-is-an-invasion-of-privacy/a18822186,[Accessed15th February 2024]

information such as where people live and their relationships, the people who control this data have a hold over people’s lives. Despite this data collection having potentially beneficial uses such as locating or preventing criminal or terrorist threats, furthering this system could do more harm than good in the future as peoples’ dependence on technology increases.

References:

YouTube Originals, How Far is Too Far? | The Age of A.I., [YouTube], https://www.youtube.com/watch?

v=UwsrzCVZAb8&list=PLjq6DwYksrzz_fsWIpP cf6V7p2RNAneKc&index=2, [Accessed 15/02/24]

YouTube Originals, Will a robot take my job? | The Age of A.I., [YouTube], https://m.youtube.com/watch?

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Superconductivity and MAGLEV Trains

By Alessandra Diotallevi, UVI

What is a superconductor?

A superconductor is a material that, when cooled to a very low temperature, becomes superconducting. This phenomenon causes the material to have additional properties. Firstly, the material has no electrical resistance and therefore if a current is supplied it can flow for an infinite amount of time Secondly, all magnetic fields are expelled from the material (a k a The Meissner Effect which is discussed in more detail later on) Finally, they produce much stronger magnetic fields when used as electromagnets (soft metal core surrounded by a coil of wire that when a current is passed though, becomes a magnet)

How is superconductivity achieved?

Electrical resistance in a metal conductor is caused by electrons colliding with positive ions in a lattice structure as they flow through it. If the temperature of a material is lowered then the ions vibrate less strongly meaning that less kinetic energy is transferred from the electrons to the ions during the collisions so there is less resistance (and scattering) So, logically, one would think that to obtain zero resistance you reduce the temperature until the kinetic energy of the ions is zero

However, Heisenberg’s uncertainty principle, ΔxΔp >= h/(4π) , is such that all particles always have some motion since no quantum object can have precise values of position and momentum at the same time (if it was stationary the momentum would be zero and we could determine the position, therefore both values are known). So how do we obtain zero resistance?

All fundamental particles in the universe can be divided into 2 groups - fermions and bosons; spin is a property of these particles related to their momentum. Fermions (e g electrons) have a half spin and make up all matter in the universe They obey the Pauli exclusion principle which states that only one fermion can occupy each energy level at a time Bosons (e g photons - energy packets of electromagnetic radiation) are responsible for the four fundamental forces of the universe and have an integer spin Unlike fermions, multiple bosons

can exist on one energy level at the same time.

When electrons pass through an ionic lattice they repel each other (as they both have a negative charge) but are attracted to the ions (as they have opposite charges). These interactions distort the lattice creating regions with a higher positive charge This increase in positive charge density attracts more electrons and this attraction is sufficient to overcome the repulsion between electrons causing them to join into a combination called a Cooper pair Although electrons are fermions, when they form Cooper pairs they now behave as bosons which allows multiple Cooper pairs to occupy a single energy state, for example the lowest energy state. When multiple bosons, cooled to a low temperature, occupy the lowest quantum energy state (ground state) the substance is called a Bose-Einstein condensate (BEC). Since the Cooper pairs are already in the lowest possible energy state when they flow through the lattice and collide with ions they lose no energy therefore causing zero resistance, achieving superconductivity.

For the Cooper pairs to remain intact the temperature must be below a certain value, this is known as a material’s critical temperature (Tc), so that there is not sufficient energy to break them apart This value is very close to absolute zero (0 Kelvin = -273°C) however there is lots of interesting work being done investigating room-temperature superconductors

The Meissner Effect and Levitation:

The Meissner effect is when all magnetic fields are expelled from a superconducting material. To explain how this works let’s first consider a magnet on top of a metal disc where the temperature is greater than Tc. Above this critical temperature the magnetic field produced by the magnet can penetrate the metal so the magnet remains on top of the metal.

If we decrease the temperature such that T < Tc the metal becomes superconducting and something unusual happens The magnet begins to levitate This is because an eddy current (a localised circular electric current induced in a conductor by a varying magnetic field) forms in the metal This eddy current creates another magnetic field within the metal that is a mirror image of the one created by the bar magnet. Therefore within the material the magnetic field lines ‘cancel out’ and the field from the magnet is expelled.

Since the magnetic fields are mirror images of each other this means that like poles are facing each other so there is a repulsion between the magnet and the superconductor. An equilibrium forms due to the repulsion acting upwards and the gravitation pushing downwards causing the magnet to levitate

How do MAGLEV trains use superconductors?

Superconductors have many interesting uses such as magnetic confinement in plasma fusion generators, electrical transmission cables and MRI scanning

However countries such as Japan have utilised superconductors to engineer magnetically levitated trains, allowing stronger magnetic fields to be created for a more efficient system When designing such trains there are 3 main factors to consider: propulsion, levitation and guidance

To propel the train along the tracks there is a series of electromagnets (arranged so each electromagnet has the opposite pole to the two next to it) along each side of the train. They are made from superconducting materials so that once an initial current is supplied the current will continue to flow forever until the circuit is broken. In the sides of the tracks there is another series of electromagnets supplied with an alternating current, however these are not superconducting so the amount of energy supplied can be controlled When two south poles align in the train and the tracks they will repel each other; yet the south pole on the train is also attracted to the north pole in the tracks ahead of it, pushing the train forwards The polarities in the tracks are then reversed so the process can repeat, creating a net force forwards The rate at which the polarities change controls the speed of the train.

To levitate the train there is a series of unpowered figure 8 coils of wire on either side of the tracks To simplify the mechanism let’s consider a pair of superconducting magnets (one on each side of the train) as a bar magnet moving parallel to the tracks. If the bar magnet was to travel aligned with the centre of each coil the voltage induced in the top and bottom loops would be equal therefore there would be no

effect on the bar magnet On the other hand, if the bar magnet was below the centre the voltage induced in the bottom loop of the figure 8 would be greater than the one in the top loop The difference in strength means a net current flows through the loop causing a south pole to be produced on the top loop and a north pole on the bottom loop (if we are looking at the north pole of the bar magnet). These fields will now interact with the bar magnet to lift it upwards (due to the attraction and repulsion between them) until it is in the centre again.

Furthermore, by connecting opposite figure 8 loops, if the bar magnet was too close to the right then the magnetic field produced in the bottom loop of the coil on the right would be greater than the bottom loop of the coil on the left side of the tracks. This would cause the bar magnet to be repelled from the right hand side until it reached the centre and the magnetic fields are equal again. This process of guidance is also known as lateral stability and is the final objective of achieving a MAGLEV train.

Britannica, The Editors of Encyclopaedia, eddy, Encyclopaedia Britannica,

https://www.britannica.com/science/eddy-fluidmechanics, [Accessed 14/11/23]

Department of Materials Science and Metallurgy, University of Cambridge, Superconductivity, Discovery and properties,

https://www.doitpoms.ac.uk/tlplib/superconducti vity/images/timeline.svg [Accessed 13/11/23]

References:

PhysicsHigh, meissner effect explanation (basic), [YouTube],

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v=NVeAmKUbXvA&t=125s, [Accessed 13/11/23]

Arvin Ash, (3 April 2021). How do Superconductors work at the Quantum Level?, [YouTube]

https://www.youtube.com/watch?

v=vruYFOlM1-Q, [Accessed 14/11/23]

Lesics, (16 June 2021), The Fastest train ever built | The complete physics of it, [YouTube],

https://www.youtube.com/watch?v=XjwFSTGtfE&t=0s, [Accessed 14/11/23]