Fortnightly Science News Digest - 30/09/12

Landau levels revealed: using scanning tunneling spectroscopy, physicists at University of Warwick revealed the first image of Landau's prediction for the homonymous levels. Those were predictions that made Landau win the Physics Nobel Prize in 1930, but we were only able to picture them now. Landau predicted that in a clean system, the electrons would take on the form of concentric rings. Interesting how this could also be used to give a definition of kilogram (which is still debated) as the spaces between the rings could be as universal marker for weight, being dependent on electron's mass.

Ig Nobel honours ponytail physics

'Meteors' sighted in skies across UK

Off-Peek: Radio Telescopes Edge In on Plasma Jet Spewing from Massive Black Hole


P.S.: as you might have noticed this was posted ridiculously late and it is missing description for most of the news. I apologize for the first, and about the second: from now on I decided to only write something about the first news and just post links about other major news. This is to keep the FSND feature alive as I will not have as much free time now. I just started a PhD, have mercy on me!

A picture of us all

The thing I like the most in writing science news is that the majority of the news is good news. Think of scientific research. It can only bring progress, and most of it is directed towards discovering things we can do and not things that we cannot do.

Sometimes, though, there are bad news. Exactly a month ago the first man that stepped on the moon died. A pioneer, or better, the pioneer of lunar exploration had complications after heart surgery and left us with one of the most remarkable achievements of humans, not just on the world, but on the universal scale. This is a gift not only appreciated by people in the USA, which launched the Apollo 11 expedition, but by the entire world, and consequently everyone mourned his death.

He did not like to be in the spotlight for his biggest achievement and he dropped his career as pilot (and astronaut) after his big mission. However, he did not stop from looking at the future as he started teaching in the University of Cincinnati in the department of Aerospace Engineering.

If you want to know more about his life, there are plenty of sources, and I would suggest you to do it, as it was a very interesting one, for sure, regardless of his longest trip.
What I am going to talk about here is about one of my favorite pictures of Neil:

Buzz Aldrin on the Moon. You really want to click on this picture to enlarge it.

You might be asking yourself if I it is a typo or not. And you are right, the most visible astronaut in the picture above is Buzz Aldrin, but if you zoom on his helmet's visor, you will notice a familiar reflection:

Zoomed-in visor showing reflections

And this landscape in the reflection is what makes me love this picture.
That is the reflection of Neil Armstrong, right in the middle, taking the picture of Buzz.

It is amazing to think about the trip photons had to undertake in order to form this picture. Coming from the sun, traveling through a distance of 149980571 kilometers, at around a billion km/h, roughly taking 8 minutes, to end up hitting Armstrong's suit.

In all the possible direction they could have been reflected (or absorbed, finishing their trip), they got reflected towards Buzz Aldrin's helmet. Instead of going through the visor, into Buzz's eyes, or (more rarely) being absorbed by the visor itself, they got reflected back exactly towards Neil. In particular, they got reflected towards his camera, and having passed the lens and all the components of the camera smoothly, finally they met their fate getting absorbed by the film, which is now letting us seeing the amazing pictures of men on the Moon.

But that is not all. There are at least other two amazing facts in this picture.

The first, being the "halo" around Buzz's shadow.
If you see the picture of the reflection from the visor, you will notice that the lunar grounds look lighter around Buzz's shadow. An interesting fact, which helps explaining the phenomenon, is that the halo of light is not seen in the original picture (unzoomed) where Buzz's shadow can be seen unreflected.

That is because it is an optical illusion, commonly called opposition effect. It does not just happen on the Moon, as seen here, but the high concentration of regolith on the moon increases the strength of the effect.
The opposition effect happens when the observer (or photographer) is pointing at the opposite direction of the light source (the sun). As regolith has high retroreflective properties, the zone which opposes the sun will reflect much more light and will then be brighter.
All of this, reflected back to us thanks to Buzz's helmet.

It was not just enough having Neil's reflection and a reflected opposition effect, as the picture includes something even more astounding.

Mankind in a shot

All of us are in the pictures as well, as the visor also reflects the Earth in the sky. Highlighted in the picture above, we are all there, on the pale blue dot. I can safely say that this is the only human-made picture which includes the whole of humanity (Michael Collins is in the module, which is also reflected by the visor, on the right) and in general, a picture which includes every living organism known to us.

I need to say it again: I love this picture, and I hope you can fully understand why, now. I will conclude with a touching quote about this very photo, from Buzz Aldrin, which can surely express better than me the beauty of this shot:

"As I walked away from the Eagle Lunar Module, Neil said 'Hold it, Buzz', so I stopped and turned around, and then he took what has become known as the 'Visor' photo. I like this photo because it captures the moment of a solitary human figure against the horizon of the Moon, along with a reflection in my helmet's visor of our home away from home, the Eagle, and of Neil snapping the photo. Here we were, farther away from the rest of humanity than any two humans had ever ventured. Yet, in another sense, we became inextricably connected to the hundreds of millions watching us more than 240,000 miles away. In this one moment, the world came together in peace for all mankind."

Buzz Aldrin - Apollo, Through the Eyes of the Astronauts

The curse of Productivity

It's now clear to me why I eat later and later, and become nocturnal

Fortnightly Science News Digest - 15/09/12

The Ulam spiral: when arranging numbers in a spiral, highlighting prime numbers,
they produce the (yet not fully understood) pattern showed above

Deep connection between prime numbers proved:  “If Mochizuki’s proof is correct, it will be one of the most astounding achievements of mathematics of the twenty-first century.” says Dorian Goldfeld, a mathematician at Columbia University, New York. Mathematician Shinichi Mochizuki of Kyoto University, Japan claims to have proved the abc conjecture. It was one of the unsolved problems in number theory. The abc conjecture needs the concept of radicals to be understood. A radical of a number $n$, $rad(n)$ is the multiplication of the prime numbers dividing $n$ (e.g. $ 360 = 2^3 \cdot 3^2 \cdot 5$, then $rad(360) = 2 \cdot 3 \cdot 5 = 30$). The abc conjecture then states that, given three integers $a$, $b$, and $c$, such that $a+b=c$, the number $ \frac{rad(abc)^r}{c} $ is always greater than 0 for any $r>1$. The proof of this theorem is split between 4 papers and is based on many others, so it might take a while to verify, but Mochizuki was known for his deep mathematics proof and provides lot of confidence. The proof of this theorem will not only help solving similar problems in future, but also solves many other problems, such as the famous Fermat's Last Theorem.

First visible-light evidence for gravitational waves:  before this discovery, an evidence for the general theory of relativity in strong gravitational fields was the measurements of binary pulsars' (a bright x-ray source) periodicity. This was achieved measuring the shrink in the period of revolution, given by the loss of gravitational waves. For the first time, the model including Einstein's general relativity has been tested in a pair of white dwarves, which has spectrum in the visible light and a significantly lower mass. Direct detection of gravitational waves could be possible with an ambitious experiment involving building an interferometer into space with arms separated a million kilometers, but connected through lasers.

Proximity-induced high-temperature superconductivity using Scotch tape:  Scotch tape is proving to be a good friend to physicists, lately. After the discovery (following a Physics Nobel Prize in 2010) of an easier production of graphene, using Scotch tape, by Andre Geim, a research group from University of Toronto discovered another use of Scotch tape. High-temperature superconductivity is a property of a few materials only, which allows them to show superconductive properties at room temperature, without overheating and losing energy. Cuprates show this property, but were believed to be impossible to be incorporated as superconductors. Then, other techniques, as proximity effects were used to induce superconductivity (from Cuprates) into semiconductors, but this requires the two materials to be close in nearly perfect contact. Cuprates cannot be fabricated that way (chemically), hence here comes the tape: the team used it to tape glass slides and Cuprates to topological insulators, known to have semiconducting properties as a whole, but to be very metallic on the surface. This induced semi-conductivity into the the topological insulators, making it a first. These semi-conductors can be used to improve energy efficiency in quantum computation.

Heisenberg's uncertainty might not be that uncertain:  the Heisenberg's uncertainty principle is one of the biggest pillars of quantum mechanics. A team from University of Toronto built a new experiment involving entangled photon pairs in order to try to determine the "indeterminacy" of quantum mechanics. Heisenberg is still right, but the quantitative aspect of the uncertainty was never singularly tested. According to results, the "outcome" blurred out less than expected.

Of Einstein's genius

This man oozes brainpower. Maybe not in this picture, though.

The real genius in Einstein's work is in the fact that he discovered a fundamental property of the universe from only a few assumptions.
He set the speed of light as constant in different frames of reference and developed the mathematics of Lorentz transforms further to come up with one of the most beautiful theories in physics.

While usually in physics direct evidence and data is studied to deduce a phenomenon, he inductively derived his theory having no evidence at all. He made his own axioms and derived everything again from them. And the best part is that it worked, at least in theory. Despite a few physicist immediately recognized his genius, his theories were not completely recognized by the scientific community at the beginning, especially when the paper for his theory of Special Relativity presented no references. Einstein's reasoning was outside the lines, but sharp, nonetheless, and it proved no mistakes.

Evidences for his special theory of relativity started to come up only much later, around 1932, with the Kennedy-Thorndike experiment testing the dependence of the speed of light on the velocity of the measuring device.
Direct evidences of the general theory of relativity are still feeble, even though it is now a firmly accepted theory.

No, it is not photoshopped

The difficulty in testing this theory (linked to the difficulty to discover it) lies in the fact that we need astronomically strong gravitational fields in order to detect the space-time fabric and its tiny ripples: the gravitational waves. I did not use the word astronomical by chance, as the best empirical evidences come from deep space. Usually quasars (active galactic nuclei), which are very far, but bright x-ray sources, are used as indirect test for the theory of general relativity, as their ginormous gravitational field can bend light. Pictures of galaxies behind quasars could be worked out from their light being bent right into our eyes (or telescopes), forming "rings" of light around the quasars.

A more direct evidence of general relativity would be detecting its evident result: gravitational waves. Unfortunately, these waves are far less energetic than anything we can imagine, making it easy to let them disappear into the much higher and chaotic background of radiation. Experiments exist trying to achieve the impossible through interferometers, but a much more concrete evidence, at least for now, is presented by binary pulsars.

Not the most scientifically
accurate gif I could find,
but surely the coolest.

Binary pulsars move into space and their gravitational field emits gravitational waves, which is a leak of energy from the system. Everything, in fact, emits gravitational waves, but for small (less heavy, to be precise) objects their emission is undetectable. As energy is leaking from the binary system of pulsars, their period of revolution will get slightly slower than usual and with enough time passed, this accumulated time will get significantly big to be measured. This is not a direct evidence, as the energetic leak that slows the period down is not necessary given by gravitational waves, but that is the only phenomenon we know that could cause it, for now, and Einstein's model works really well when applied to these bodies, so it is still evidence, even if indirect.

When I started writing this post, it was meant to be an introduction to one big recent news in science in one of the FSND series. I was so excited writing about how marvelous Einstein's theories are that it got too long and I decided that it would easily be a blog post on its own.

The news regards the recent first visible-light evidence of gravitational waves from a pair of dwarf stars, and I'll now leave you in a pointless cliff-hanger (pointless as the news is already out elsewhere) as I will talk about it in the next Fortnightly Science News Digest on 15 September.

Forthnightly Science News Digest - 31/08/12

Neil, tired but happy after the "walk" on the moon, in the Eagle lunar module still landed on the Moon

Neil Armstrong is dead:  Neil did not survive after complications of an operation on blocked coronary arteries, on 25 August 2012. The man that set the first step on the moon, announcing the famous line: "That's one small step for [a] man, one giant leap for mankind" survived 82 years, but did not live in the shadow of his big mission. Before working in space and going to the moon, he was between the top pilots in the world. After, he decided to teach in Cincinnati University, continuing to inspire young students into the wonders of aeronautics. The news of his death saddened not just the US, but the whole world.

Fermilab proposes plans for neutrino experiment:  having served the world of particle physics thanks to its Tevatron, a proton-antiproton collider, Fermilab is proposing a new big experiment. Tevatron closed due to lack of funds and the advent of the bigger LHC at CERN, Geneva. Fermilab proposed a new neutrino experiment five months ago, which budget would have been 1.9 billion dollars. Due to the amount of money required, they were asked to rework their plans and on the 28th of August, they proposed a new plan, requiring only 789 million dollars. The new experiment would be called Long-Baseline Neutrino Experiment (LBNE) and would research on one of the most mysterious particles: neutrinos, its oscillations (between three of his families: muon, electron and tau neutrinos) and differences between neutrinos and anti-neutrinos, which could shed some light on the CP violation, a fundamental law which could explain why more matter than antimatter exists in the universe.

Ice cover in arctic seas reaches new low:  a satellite survey by NASA reported that ice cover in the arctic seas reached a new low on August 2012, taken from a sample of recordings since 1979. It is also expected to be lower on September. Scientists at NASA say the increased sea ice lost is due to the increased temperatures last year. The survey recorded a surface of 1.58 million square miles, from 1.61 million square miles in September 2007. Professor Peter Wadhams, from Cambridge University, reported to BBC News that models and calculations show that the arctic sea could become ice-free by 2015 or 2016. The alarmist view of the professor has been criticized in the past, but this new measurement could show hints toward this prediction. The ice cover getting thinner is a positive feedback system - which accelerates when it starts - as warmer temperatures caused by less ice in the seas allows the generation of storms which destroys more ice and accelerate its melt. The implications of ice-free artic seas are serious, as lack of ice would decrease the reflected light by the planet increasing temperatures even further, and causing permafrost to melt, which would release copious amounts of methane, a powerful greenhouse gas.

NASA plans new mars mission:  just after a few weeks from the launch of Curiosity, the new mars rover, NASA announces plans a 425 million dollars lander which scope would be drilling into the red planet to probe its mantle, crust and core. The analysis of the interior of Mars would help understand how it evolved from the stage of incandescent ball of magma. Earth's interiors have been unveiled analyzing seismic activity, but the structure of the other rocky planets (Venus, Mars and Mercury) is mostly unknown. Mars is big enough to have developed a crust, mantle and core, but does not show the expected tectonic activity.