Science News Feb 8 (Patreon)

[This is a transcript with references.]

Welcome everyone to this week’s science news. Today we’ll talk about how to look inside a nuclear reactor with muons, eight new signals that came up in a search for extra-terrestrial intelligence, why Germany wants to bring back direct current, the plausibility of climate goals, what air pollution does to your brain, how to stab a potato with paper, a scalable quantum simulator, a glass sphere that imitates the sun, true stories that are more engaging than false stories, and of course, the telephone will ring.

Looking inside a nuclear reactor isn’t all that difficult. Coming back to tell someone about it is a different story. This is why the most radioactive parts of a nuclear reactor have thick shields. Unfortunately, this doesn’t only prevent the radiation from leaking out, it also prevents you from looking inside. Not even X-rays go through these shields. But a group of French researchers has now taken a three-dimensional image of a nuclear reactor with muons.

Muons are the most abundant particles in cosmic ray showers, so they rain down on us constantly. They are basically heavier versions of electrons, but since they are heavier, they are more difficult to stop, which is why they can go through thick shields.

The researchers in this study used those cosmic muons to take images of a decommissioned nuclear reactor, the Marcoule G2 reactor in France. The thing has been sitting around since the 1980s and is waiting for the French to figure out what to do with it. It’s a cylinder about 34 metres long and 20 metres in diameter.

For this study, they used four telescopes to measure the muon flux from 27 different directions for about three days each. The data you get from this is how many muons are absorbed along each path. This can then be used to reconstruct a 3-dimensional image, which worked amazingly well.

Muon imagining is non-invasive and non-destructive, and has previously been used for several other purposes, such as to look inside a pyramid or magma chambers below volcanoes. It was also used after the Fukushima accident, to help determine the locations and amounts of fuel remaining in the damaged reactors. But this is the biggest and most detailed 3-d reconstruction to date. It could one day make an important contribution to nuclear safety and allow imaging other inaccessible and dangerous areas such as my mom’s attic.

It’s not hard to imagine aliens with four arms or carbon shielding, but apparently it’s hard to imagine aliens that don’t send radio signals. 125 years ago, Nikola Tesla thought he’d detected a radio signal from Mars, which, guess what, was never seen again. But ever since then, researchers and citizen scientists likewise have searched for suspicious electromagnetic signals that might give away intelligent life. The SETI Institute, which has been at the forefront of alien detection technology since 1984, has now announced that artificial intelligence helped them find eight interesting new targets.

The data they looked at is a whopping 150 Terabytes of radio signals. They come from 820 stars recorded by the Green Bank Telescope in West Virginia. The data had previously been searched but no alien messages were found. The new search conducted by the AI now found several radio signals that had the computer raise an artificial AI-brow. The suspicious sources include variable stars and binary systems, but also normal stars on the main sequence. The signals were all narrow-band transmissions, which had an artifact, known as doppler drift, that one expects from a moving transmitter. Taken together, these factors suggest the signal is not of natural origin.

The group did further observations on these eight sources, but disappointingly enough they looked entirely normal. So, no aliens this week, sorry.

The German industry wants to bring back direct current and is taking first steps to make it happen.

One of the most epic fights in science ever was certainly the “war of currents” between Thomas Edison and Nikola Tesla over the way of using electricity. Edison advocated direct current, DC for short, that flows in only one direction, whereas Tesla pushed for alternating current, AC for short, that switches back and forth in direction.

Tesla won that argument, partly by arguing that alternating currents are less likely to roast innocent people, but mostly because of economic reasons. Alternating currents are less lossy when transferred over long distances, so Tesla’s system scaled better. Which is why, if you today plug a device into a socket, you’re getting an alternating current that reverses its direction 50 or 60 times a second, depending on where you live.

But an alliance in Germany, wants to bring back a direct current grid to be used by power intensive industry and possibly research centres. This “Open Direct Current Alliance” consists of 39 parties, that’s 33 companies, including Audi and Siemens, and 6 research centres. After a three-year research project, they launched their initiative at the end of January.

The reasoning behind this idea is that solar panels and wind turbines generate direct current and many devices run on direct current. Converting it back and forth leads to losses that can be prevented by just designing a system that sticks with direct current to begin with. In addition, the cables used to transmit direct current require half as much copper as AC lines.

I wonder what Tesla would have made of this.

Hi Nikola, Well, what do you think?

A large, interdisciplinary team of researchers has released a cheerful report saying it’s too late to limit global warming to 1 point 5 degrees as mandated by the Paris Agreement.

The 230 pages report looked at both the physics of climate change, but also at the social changes necessary to limit warming. In their own words, they focus on plausibility not feasibility. So, unlike most other reports who settle on stating it’s technologically possible to do one thing or another, this report also considers what is socially possible.

They assess the changes that have already taken place, such as moves away from the use of fossil fuels and the enacting of legislation to promote green technologies, as well as what’s needed in the future to hit the targets set by the Paris agreement. 

The verdict is bad news. The social drivers of decarbonization, they say, are “incremental and temporary”. Climate action pledges remain “insufficient and uncertain” and beset by financial obstacles. The report points out that it’s become more difficult for nations to meet their climate targets due to the economic stress of the COVID pandemic and the consequences of the ongoing Russian invasion of Ukraine. They conclude that it’s not plausible we’ll limit warming to 1 point 5 degrees.

There is a little bit of good news, in that they note that climate movements and lawsuits are driving social change, but in a nutshell, it’s too little too late. This conclusion is depressing but let’s be honest, not particularly surprising. Indeed, I’d say it’s depressing exactly because it isn’t surprising.  On the other hand, we’ll all save on our energy bills once we can cook eggs on the pavement.

If you’re looking for a reason to keep the window open in the office this summer, show this to your boss. A study has found that air pollution increases how often chess players make mistakes.

The study, published in the journal Management Science, looked at the games of 121 chess players across three seven-round tournaments that took place in Germany in 2017, 18, and 19. The researchers placed air quality monitors in the game rooms to pick up temperature, carbon dioxide concentration, and particulate matter, that’s the small particles emitted by car engines and burning wood. They then compared 30 thousand of the players’ moves against those suggested by the Stockfish computer chess engine.

The results show that an increase in airborne fine particulate matter of just 10 microgram per cubic metre of air is enough to increase the chance of a player making a sub-optimal move by more than 25 percent. And not only this, the errors also became worse by more than 10 percent. The dip in performance was exacerbated by time pressure, as some matches were played with a time limit placed on the first 40 moves, and players made their worst moves just before their 40th, when the time budget was nearly spent.

Professional chess players have already made their next move and have begun monitoring the air quality while they play.
Korean researchers have developed a paper straw that can be used to stab a potato.

The group of scientists from the Korean Research Institute of Chemical Technology coated paper with a thin layer of biodegradable plastic to obtain a material that won’t get soggy and yet naturally degrade. Yet another small step in our fight against plastic pollution and hostile potatoes.

A universal quantum computer that can execute algorithms is a long way off. Meanwhile, physicists are trying to build specialized devices that solve one problem at a time, known as “quantum simulators.” Researchers from Stanford University have now made a proposal for scaling such a simulator up that might prove influential.

Some things are really difficult to calculate on a conventional computer, for example air flow around an object. This is why engineers use wind tunnels.  It’s a controllable replication of the real thing, a simulation. A quantum simulation does the same thing for an object with quantum properties. 

The most obvious thing you might want to do is to simulate the interactions between atoms in a material, not with atoms, but with larger quantum things. The properties of materials come from the behaviour of the electrons. We know the equations that describe this behaviour, but they’re just too difficult to solve.

The new Stanford simulator is a micrometre-sized device that mimics certain interactions between atoms, so it simulates a system that’s usually a factor 1000 or so smaller. The device is made of combinations of metals and semiconductors that keep the electrons flowing in just the right way to mimic the real thing.

In this first experiment, they simulated the interactions between only two quantum objects. But they explain in their paper that it should be possible to combine more of these simulators and eventually to even build a lattice. This could enable them to simulate material properties that are currently beyond the computational capacity of any conventional computer.

Hi Mark, Congratulations on the sudden jump in stock prices!

Wait until they find out that women have nipples!

Talk soon, bye.

Scientists from UCLA have shot microwaves at a glass sphere to understand what’s going on inside the sun, in what is basically a table-top simulation that may go on to defeat supercomputing centres.

The sun is a big hot ball of plasma, and understanding its dynamics has remained challenging even as computing power has increased. Back in January, the sun released a series of huge, X-class flares. They luckily didn’t come directly at us, but they still caused some radio blackouts across the Pacific. This space weather, as it’s called, can be particularly dangerous at high altitudes where it can affect satellites and significantly increase the radiation dose on passenger flights.

It’s not only events like this which scientists don’t understand, they also haven’t quite figured out how the solar cycle works. The number of sunspots changes with a period of about 11 years, and the magnetic field of the sun changes with it. Indeed, the magnetic field flips entirely over in these 11 years, repeats the same thing upside down, and then flips back up. Kind of like doctors trying to decide whether coffee is good or bad.

But the solar cycle isn’t perfectly regular and there seem to be longer cycles superimposed on it. Scientists believe that all these processes are largely driven by big overturning circulations in the plasma, but no computer simulation seems to get it all right.

In the new study, which was just published in Physical Review Letters, the scientists used a rotating glass sphere three centimetres across. They shot microwaves at it to heat it up. The microwaves generate sound waves that are constrained in the glass similar to how plasma waves are constrained in the sun. The researchers were able to identify convective cycles in their measurements that agree well with the theoretical expectations.

Now, this experiment has one important difference to the sun, besides the size I mean, which is that magnetic fields were absent, so at this point it can’t tell us much about the solar cycle, but maybe they’ll figure out how to include this in the future.
 
Mister President,

I entirely agree. You can’t let the Chinese get away with a balloon. Next thing you know they’ve got nukes and will fly to the moon.

You have my full support.

“No other evil we know is faster than rumour, thriving on speed and becoming stronger by running.” So wrote Virgil 2000 years ago. It might seem that not much has changed since, except that we’ve found some new ways to spread rumours. But a new study has found that, amazingly enough, true stories are sometimes more engaging than false ones, at least on Reddit.

The study from Ohio State University  looked at almost 10 million comments made from 2016 to 2018 on the social news aggregation site reddit. They found that the mere act of fact-checking a post, whether the result was that it was true or false, led to more engagement. Fact-checked posts that were found to be true in turn received more comments, and conversations went on for longer.

This study stands in contrast to the results of a 2018 study which found that false news spread faster on twitter, which supports the conclusion that algorithmic design is relevant to what people share. I talked more about this in my recent video on social media.

So Reddit is more discerning than Twitter? You heard it first on YouTube.