Hi <<First Name>>. Thanks for reading the first issue of my newsletter!
This is Eleni, a particle physicist with a quest. Last year I left my job at a research institute with the "quest" of seeing if it is possible for a researcher to work as freelancer. Avant-garde, I know. Then I spent the next months travelling slowly and working on my laptop on a solar physics analysis with public data, which I named "being a nomad scientist". No income during that time, in case anyone wonders, but more decent cocktails, tea and installations of instant messengers than my previous average.
Now I write from my hometown, Athens; a current summary of the aforementioned analysis is found here. And how is the quest going? The renegade study is under journal review, and parachuting to ask for collaborations hasn't borne definite fruits yet, so I'd say we are close to being 1-1. Hopefully in next months' updates I will have tricks of success to share!
But let us jump to last month's top news and then some.
eleni@chapette.net
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March '18: The latest in ph-word
Moriond and B-anomalies
Physics of elementary particles has two rounds of global-reach conferences, the winter and the summer ones. The "Rencontres de Moriond" is the winter star, held annually at the Italian ski resort town La Thuile. Here is the place of the announcement of new results, hot from the long hours of work during the dark months and the battles for who will represent their experiment in such high-profile events ;)
Nowadays the majority of research comes from the experiments at the Large Hadron Collider -which look for physics outside the Standard Model, the big framework describing elementary particles as we know them today- and from the experiments looking for particles that could be the mysterious dark matter. Now, the way particle physics works is that you either see something new in your measurements; or you usually don't, in which case you "constraint its properties" as you collect more and more data and it still doesn't appear (often you constraint the possible mass that a hypothesized new particle could have). This year, like all the last ones, the Moriond updates can be summarized in one sentence: the Standard Model keeps getting confirmed. That's one small discomfort for the workers in the field, but a giant triumph for mankind (as the Standard Model is one of its crowning intellectual achievements and stuff).
Mostly for the record though, there is a discrepancy between the measurements and the theoretical expectation which attracted some attention at Moriond, the "B-anomalies". These come from the LHCb experiment, which looks at quarks of one kind turning into another while throwing around either electrons or muons (those particles often called "heavy electrons"). Muons seem to appear less frequently than the Standard Model says, and if this persists then there might be something about the weak nuclear force. These discrepancies are rather small but do appear in five different sub-atomic processes and they've been noticed for a few years now; there is only one thing that will eventually say whether they are a coincidence or not: more measurements by LHCb.
EDGES 21cm
But in observational cosmology, things are different. The field looks unstoppable. And a new VIP announced itself last month: the 21cm absorption line by the EDGES experiment.
The EDGES people found a way to see the dent from the light of the first stars, which we can agree is pretty cool in itself. But as if this wasn't cool enough, they found that the universe at that moment in time was even cooler than expected; no, really. Also, they didn't look by pointing a telescope at a particular star or even galaxy, but instead basked in the faint very old light that baths the sky in all directions (because this is the 21st century, baby).
As the universe was cooling down, 400,000 years after the big bang it would finally stay still long enough for electrons and protons to form hydrogen atoms - the first atoms. From that point on, chunks of hydrogen gas would go about their job of slowly falling together to form stars, while some stray hydrogen atoms would continue cooling down and some ambient light would travel around carefree.
Fast forward 170 million years. Stars form and their first light starts shining. Now, certain frequencies of the starlight could flip the electrons in the stray hydrogen and lower the energy that the atoms have. However, there is still ambient light bumping on them, getting absorbed and giving them back the energy they lost. This situation would go on until the stars started warming the hydrogen gas and stopped this subtle process.
So, what is the dent from the first starlight? A minuscule drop in the ambient light in that specific frequency. And this is what this small experiment in Australia looked for and saw, the imprint of the "21 cm" frequency of light as it traveled to us through space and time for the next 13 billion years.
As a cosmic bonus, the temperature of the stray hydrogens can be measured from how much the light dropped (by the way I'm glad that I'm only retelling the story after somebody else spent months working out the math). And here is the second highlight, because just as the people on the EDGES saw the sign of the first stars ever and were busy feeling enthusiastic, they had to stop and feel surprised: the hydrogen temperature they measured is about twice lower than expected.
This gave rise to several discussions already, but the original achievement itself is reason enough to party, while waiting for some other experiment to repeat it before diving into finer speculation.
The "ambient very old light" is more often known as cosmic microwave background, introduced nicely by this gentleman.
The EDGES article is here - with a neat summary on the right and an acknowledgement to the Aborigines owning the experiment's site at the bottom.
Interstellar GPS
Lastly in March, a galaxy was weighted and found to not contain any of the infamous dark matter, which can be big news for understanding a little more about it, although some re-checking would be good first. And in starry-eyed news, an orbital GPS started operating - only that it doesn't use signals from satellites but from neutron stars instead (because it should start feeling like the 21st century, baby).
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That's Gemma Arrowsmith, a comedian with shows that blend uniquely science enthusiasm with social critique. Gratefully many of her sketches are found on her channel. Like the one with Beauty Tips for Female Cosmonauts.
("Remember when cosmonaut Yelena Serova was asked how she would look after her hair in space? Or when astronaut Sally Ride was asked 'do you weep when things go wrong on the job?'")
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Serendipity
There is one case where the two most prestigious (in arbitrary order) prizes in physics have been collected by the same person, Andre Geim. In 2000 he won an IgNobel for levitating a live frog, and in 2010 he won a Nobel for coming up with the super-material graphene, by peeling scotch tape off carbon.
However, the most significant IgNobel in physics might arguably be the 2002, for showing that beer froth obeys the mathematical law of exponential decay and using this to differentiate between beers.
A personal fav though is the 2012 in neuroscience, for showing that with complicated instruments and simple statistics one can detect brain activity even in a dead fish.
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Now in real-life travel tips...
Juan Carlos Algaba is an astronomer in Seoul National University working on active galactic nuclei - central regions of galaxies which are blasting with energies that cannot be explained only by stars, but involve the presence of a supermassive black hole!
- Juan Carlos, you come from Valencia, in Spain. What would you recommend a tourist who is also a science fan to do or see there?
Valencia is the home of the "Ciudad de las Artes y las Ciencias" (City of Arts and Sciences), an entertainment-based cultural and architectural complex that includes "L'Hemisferic", an eye-shaped planetarium, the "Principe Felipe Science Museum", shaped like a whale's skeleton, "L'Oceanogràfic", an open-air oceanographic park, and the Palau de les Arts Reina Sofía, an opera house and performing arts center, among others. The designs are clean and futuristic and have served as the filming location for the 2015 film Tomorrowland and some episodes of the British science-fiction television programme Doctor Who.
- Will you share a few words about a cool project or discovery that you've worked on?
One of the most surprising feature of these active galactic nuclei is that sometimes they present jets. In short, it's the way the super massive black holes have to deal with all this stuff that they cannot swallow at once. Before it can fall inside the black hole's event horizon and be trapped forever, some material can escape such fate by interacting with the strong magnetic fields and be ejected away in the form of jets. It's like a gigantic aurora reaching distances 10 times the host galaxy. But how these jets are accelerated and shaped is still a mystery. In a recent work, I analyzed a sample of these jets very near the gravitational influence of the black hole and found that they look almost parabolic. This is against 50-years assumption of conical shapes, and may have implications on how the galaxy itself plays a role in shaping these jets, and the way the jets and the stars and gas of the galaxy interact.
Of course we are not happy to investigate only the surroundings of these supermassive black holes. We want to have a look at these black holes themselves! A world-wide project - the Event Horizon Telescope - is connecting telescopes around the world to synthesize a virtual telescope as large as Earth, which will have enough resolution to observe for the first time the largest black holes as seen from Earth: the one in the centre of our own galaxy, the Milky Way, and the one in a nearby active galactic nucleus, M87. Our group in Korea is working in synergy with the Event Horizon Telescope to complement the data and results.
- Many thanks!
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That special person in your life? You know whom, the one who will also enjoy the Ph-word? Be kind enough to share the sign-up link with them:
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