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Science News July 5
🕑 Added 2023-07-05 15:01:00 +0000 UTC[This is a transcript with links to references.]
Welcome everyone to this week’s science news. Today we’ll talk about the first evidence that time ran slower in the early universe, how to catch light, what astronomers think about the new starlink satellites, a breakthrough in quantum computing reported by Microsoft, what helps against tinnitus, better cooling for qubits, the Euclid Mission, laser scans of Ukrainian art, a metasuit, and of course the telephone will ring.
Astronomers from the University of Sydney have found evidence that time ran slower in the early universe.
You have probably heard of cosmological redshift, which means that light from faraway galaxies is shifted to the red as it travels towards. This happens because the universe expands as the light travels. But this isn’t the only effect of the expansion of the universe. Another effect is that when we look back in time, we see everything happening slower. It’s called “Cosmological Time Dilation”. Indeed, the two things go together.
Think about it this way, if you have a wave, you could use each crest of the wave as a tick of a clock. Now if the wave shifts to the red, it stretches, and those time markers move apart. So, the clock ticks slower. It’s a direct consequence of Einstein’s theory of general relativity.
In the new paper now they report that they have seen a systematic slow-down in the variability of quasars that is compatible with cosmological time dilation. Quasar is short for “Quasi-stellar object”. They’re supermassive black holes that sit in galactic centres and accrete matter. The matter gets very hot and leads to a lot of radiation that makes quasars very bright.
For their analysis, the astronomers used a sample of 200 quasars at different distances from earth. They sorted them into four different samples, depending on their emission characteristics, and then looked for systematic shifts in quasar variability that correlates with distance. That way, they were able to infer that about twelve billion years ago, time in the universe ran five times slower than today.
What does it mean that time ran slower in the early universe? Did people back then jump in slow motion?
No, cosmological time dilation is purely an observational effect. It’s about how events from back then look to us. If you’d lived back then, you wouldn’t have noticed people jumping any differently than today.
This is the first time cosmological time dilation has been experimentally confirmed. Previous studies didn’t find it, so I guess this result will be hotly discussed in the coming months. Though I’d argue that you can observe cosmological time dilation in your supermarket: the farther back in line you are, the slower it goes.
Physicists have figured out how to catch light, at least theoretically. While you might be picturing a beam of light locked up in a jail cell somewhere, that isn’t exactly what they mean. They mean that they’ve figured out what properties a material must have so that light gets stuck in some places.
It’s a fascinating phenomenon discovered in the 1950s, in which random motion leads to localization. It’s known as “Anderson Localization” named after Phillip Anderson, one of the recipients of the Physics Nobel Prize in nineteen seventy-seven.
Physicists have observed that this phenomenon indeed localizes light, but so far only in two dimensions, so in flat sheets of material. They’ve never seen it in three dimensions, and indeed it’s remained somewhat controversial whether it’s even possible.
Part of the problem is that to demonstrate Anderson localization, you have to show that the amplitude of the light decays exponentially away from the localization spot. This is very difficult to do experimentally.
In the new study now, the researchers teamed up with a company that specializes in 3D simulations. This allowed them to run a calculation that previously took multiple days in thirty minutes. They found that the best material to freeze light is random packings of overlapping conductive metallic spheres. Metals have long been overlooked for this purpose because they tend to absorb light rather than trap it, but the team was able to calculate their way to this solution.
The next step is now to try and catch light in the real world, not just in a computer simulation. And once they’ve caught it, they’ll marinate and grill it.
A group of astronomers has looked at the new generation of Elon Musk’s Starlink satellites to figure out how much they ruin astrophotographs. And they have some good news.
Starlink might have a bright future as the next big thing in internet connectivity, but astronomers haven’t been too happy about that. The company’s first generation of satellites ruined countless observations by earth-based observatories with lines cutting through images. They’ve also shown up in an increasing number of images taken by the Hubble telescope. The issue is that the satellites fly in low orbits, and around sunset and sunrise they reflect light very efficiently.
The issue is partly preventable by making the satellites less shiny, and Musk put his people on the case. They’ve equipped the second generation of Starlink satellites with paints and covers that absorb rather than reflect light. And they have thought of a way to orient them so that the remaining reflections go into outer space rather than down to earth.
According to a series of measurements by amateur astronomers that just appeared on the arXiv, the new Starlink satellites are indeed up to 10 times fainter than their predecessors.
However, they also found that while the Generation two Starlinks are less bright when they’re settled on their orbit, they’re brighter than the first generation as they get there, when they deploy, and when they’re adjusting their orbits.
Also, the Generation 2 Starlinks that are currently out in space are just a few small test satellites. SpaceX intends to launch as many as seven thousand five hundred somewhat larger satellites in the coming years. There are many other companies who have plans to also put satellite fleets into orbit. According to some estimates we might end up having a hundred thousand up there by the end of the decade.
Ah, who could this be?
Hello,
Hi Elon, what a surprise.
Astronomers complain too much. They should have given you the cosmic photobombing award!
I think you should just go with it. “Sign up to Starlink, Ruin a scientist’s day”, It’ll work like a charm.
You’re welcome.
Researchers at Microsoft claim that they’ve taken a first step towards the creation of noise-resistant quantum computers.
The major problem with today’s quantum computers is that the quantum properties which they need to calculate are incredible fragile and get destroyed easily. Companies try to limit noise by cooling devices in cryogenic fridges to near absolute zero, like this huge super-refrigerator that IBM is building.
Another way to limit noise is to try and use quantum states that are resistant to noise because they are topological. That they are topological means that the quantum behaviour is encoded in the entire configuration of the state, but these properties are conserved, which is why noise can’t easily destroy them.
It’s called “Topological Quantum Computing” and Microsoft has tried a particular approach that uses Majorana modes.
In the new paper that was just published in PRB, they say that they’ve successfully created such Majorana modes. They used a thin semiconducting wire coupled to superconducting aluminium and claim they have convincing evidence for majorana modes on the end points of the wire. This device still needs to be cooled to 20 milliKelvin or so, but if they are right, this finding could make it much easier to scale up quantum computers.
But as usual, things aren’t as simple as they appear. A different group at Microsoft claimed already in 2018 to have successfully produced Majorana modes. But the paper was questioned by other scientists and retracted in 2021.
The issue is that other researchers have shown that there are more things going on in these wires, and some could appear like the tell-tale signs of Majorana modes. To address this criticism, this time around, the company used more stringent tests.
As a consequence, the new paper ended up being 56 pages long, so it’ll probably take some time for other researchers to go through it. But we’ll keep you up to date, so stay tuned.
Sometimes a permanent ringing is just your ex who can’t let go, but what are you to do if it’s ringing directly in your ear, twenty-four seven? A team of Brazilian scientists now says that your best option may be lasers.
It's called tinnitus, the experience of hearing constant or intermittent sounds without any apparent cause. It affects as much as one in ten people and it can be incredibly disturbing.
I had tinnitus for a couple of months, and I feel extremely lucky that eventually it went away almost entirely. Though like my ex, it sometimes reappears when you don’t expect it.
For the new study that was recently published in the Journal of Personalized Medicine, they recruited about 100 people and divided them into ten groups, each of which received different procedures that are commonly used for treating tinnitus. That included laser acupuncture, a drug that’s used to treat migraine, Ginkgo ointments, vacuum therapy, and low-level laser stimulation of internal parts of the ear. They also tried out various combinations of these.
In the end they found that laser acupuncture and low-level laser stimulation were the most effective at making people report fewer effects of tinnitus. Exactly why it works they don’t know, but they believe that the laser clears blockages and stimulates cell growth. If the laser’s big enough, it also helps with your ex.
An international team of physicists and engineers has bathed quantum circuits in liquid Helium and found an absolutely astonishing noise reduction.
The biggest problem with the current quantum computers is that their units of computation, the qubits, must be cooled to almost absolute zero to reduce noise, because noise leads to decoherence, that’s a loss of quantum effects. If it’s any warmer than just a few millikelvin, the qubits don’t have the quantum properties required for the calculations. Currently, qubits are cooled by sticking quantum chips into refrigerators where they are held in a vacuum on top of a very cool surface. But this makes it very difficult to diffuse energy.
For the new study that was just published in Nature Communications, the researchers instead bathed a tiny quantum circuit in Helium-3. That’s an isotope of helium which stays liquid even at near-absolute zero temperatures. They showed that this way they were able to dramatically lower noise in the quantum circuit. It works amazingly well. In this figure you see the noise spectrum. The red and blue dots show how it drops to the left, that’s at low temperature. It’s a reduction by more than one thousand times
They think the Helium-3 baths was so effective because it latched onto atomic defects in the material and drew excess energy away. This finding might allow for bigger and more complex quantum computers in the future.
And we have more cryogenic news this week. A group from Trinity College Dublin suggests that we deep freeze cells from all species, so whoever is left after we’re done wrecking the planet can repopulate it. And in case you’re wondering what could possibly go wrong, there’s the college that sues for damages, saying a cleaner turned off the lab freezer and destroyed their entire research.
The European Space Agency’s Euclid mission launched on Saturday. Its goal is to learn more about the nature of dark energy and dark matter by creating a three-dimensional map of the universe. Euclid should be able to see galaxies up to 10 billion light years away from us. Astrophysicists hope that the new data will allow them to better reconstruct how structures form, and to infer how dark energy and dark matter behave.
Named for the ancient Greek mathematician who established the basis of geometry, the Euclid mission’s most important parts are its two telescopes. The black camera on the left is a visible-wavelength camera called the VISible instrument, or VIS for short. The other, gold-covered camera is a near-infrared spectrometer named the Near-Infrared Spectrometer and Photometer, or NISP, which will allow researchers to learn more about the chemical properties of what they’re looking at.
The mission took off on the back of a SpaceX Falcon 9 rocket. The plan is to position it one point five million kilometres away from us, at the Sun-Earth Lagrange point 2, where it’ll sit alongside other instruments like the James Webb Space Telescope.
A French engineer has teamed up with a Ukrainian architect to create 3D models of historical sites in Ukraine. They hope to preserve at least virtual replica of architecture and artworks and to document the destruction of the ongoing war.
The team volunteered for UNESCO, that’s the cultural agency of the United Nations. They have already created 3D images of various historical sites across the country, including a three hundred-year-old cathedral and a library that dates back to 1902.
They use a combination of laser scans that allows them to measure distances in three dimensions and high-resolution photographs. The laser data can be used to assign depth to the otherwise flat photographs, allowing them to construct an accurate 3D model. According to UNESCO, the war has already damaged or destroyed more than two hundred and fifty historical and cultural sites.
I recently had a 3D scan of my teeth which, according to my dentist, are also endangered by destruction, so maybe UNESCO will set their eyes on those next. They’re certainly taking cultural preservation into an entirely new dimension.
Student researchers from ETH Zurich are taking the next logical step after virtual reality headsets: a full-body “metasuit” which allows users to better interact with virtual environments.
The metasuit uses lightweight, artificial muscles called hydraulically amplified self-healing electrostatic actuators, HASEL actuators, for short. They’re kind of like zip-lock bags that expand or contract when stimulated by electric currents. They can be worked into clothing for a full-body metaverse immersion. You definitely want that, right?
Using these HASEL actuators, the suit can both be moved by signals sent to it, or sense movements and send out signals. This means in the metaverse, the suit can both track you, say, making a motion like throwing a baseball, while also simulating you being hit by a baseball that someone else has thrown. The suit might also have uses outside the metaverse. For example, by providing muscle stimulation to Parkinson’s patients or for tracking movements in the film industry.
If you want playing baseball to feel real, maybe you could just, I dunno, really play it?
Hello?
Hi Mark,
Researchers in Brazil put fibre optics cables into pants. Ah, maybe if they did that in Germany, it wouldn’t take decades to bring fibre optics to our house.
Oh, to track movements. Of course.
Yes, you should most definitely get a pair and call them smarty-pants that’s very clever.
You’re welcome!
Comments
Regarding the slower early universe. I obviously have an incorrect idea about this. Doesn't this paper's conclusions conflict with the fact that the CMB aligns with predictions of the early contracted universe's temperature? It seems that this paper's time dilation conclusion produces problems for the CMB and age of the universe age estimates. PS. I can conceive that time would run slower then than now due to the greater mass density of the universe, what effect would that have on age estimates and this time dilation conclusion?
Is time speeding up due to our frenemy Entropy?
