Interesting science stories.

Aridas

Crazy Little Green Dragon
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Occasionally, I come across interesting little science things that I don't really feel like making a new thread to poke at, so I'm making this thread as somewhere to share random cool or potentially interesting things.

For example,

Mechanically robust lattices inspired by deep-sea glass sponges

A significantly stronger and more resilient lattice form than the usual cross hatch.

And...

On Venus, mysterious traces of gas tease the possibility of extraterrestrial life
Scientists are scouring the galaxy for "biosignatures" that could provide evidence of simple forms of life. They didn't expect to find one on our solar neighbor.

Phosphine gas in quantities that are currently only explainable via the presence of life, in short. As an aside, after that news broke, Russia decided to claim that Venus is a Russian planet.
 
“Holy Grail” Metallic Hydrogen Is Going to Change Everything
The substance has the potential to revolutionize everything from space travel to the energy grid.

Potentially dramatically better rocket fuel and more useful superconductor.

Metallic hydrogen could potentially enable rockets to get into orbit in a single stage, even allowing humans to explore the outer planets. Metallic hydrogen is predicted to be “metastable” — meaning if you make it at a very high pressure then release it, it’ll stay at that pressure. A diamond, for example, is a metastable form of graphite. If you take graphite, pressurize it, then heat it, it becomes a diamond; if you take the pressure off, it’s still a diamond. But if you heat it again, it will revert back to graphite.

<snip>

Metallic hydrogen has also been predicted to be a high- or possibly room-temperature superconductor. There are no other known room-temperature superconductors in existence, meaning the applications are immense — particularly for the electric grid, which suffers for energy lost through heat dissipation. It could also facilitate magnetic levitation for futuristic high-speed trains; substantially improve performance of electric cars; and revolutionize the way energy is produced and stored.
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The article is from 2017. "Metallic hydrogen is predicted to be “metastable”". "The next step in terms of practical application is to determine if metallic hydrogen is indeed metastable."

So what's happened?

Hmm. Metallic_hydrogen#Claimed_observation_of_solid_metallic_hydrogen,_2016WP

Apparently not much. ;)
 
Gord_in_Toronto said:
The article is from 2017. "Metallic hydrogen is predicted to be “metastable”". "The next step in terms of practical application is to determine if metallic hydrogen is indeed metastable."

So what's happened?

Hmm. Metallic_hydrogen#Claimed_observation_of_solid_metallic_hydrogen,_2016WP

Apparently not much. ;)
Click to expand...

To quote from that...

In February 2017, it was reported that the sample of claimed metallic hydrogen was lost, after the diamond anvils it was contained between broke.[45]

In August 2017, Silvera and Dias issued an erratum[46] to the Science article, regarding corrected reflectance values due to variations between the optical density of stressed natural diamonds and the synthetic diamonds used in their pre-compression diamond anvil cell.

In June 2019 a team at the Commissariat à l'énergie atomique et aux énergies alternatives (French Alternative Energies & Atomic Energy Commission) claimed to have created metallic hydrogen at around 425GPa using a toroidal profile diamond anvil cell produced using electron beam machining[47]

Experiments on fluid deuterium at the National Ignition Facility, 2018

In August 2018, scientists announced new observations[48] regarding the rapid transformation of fluid deuterium from an insulating to a metallic form below 2000 K. Remarkable agreement is found between the experimental data and the predictions based on Quantum Monte Carlo simulations, which is expected to be the most accurate method to date. This may help researchers better understand giant gas planets, such as Jupiter, Saturn and related exoplanets, since such planets are thought to contain a lot of liquid metallic hydrogen, which may be responsible for their observed powerful magnetic fields.[49][50]
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Thanks. Not much, yeah. Not nothing, though, and it's not saying anything about predictions being wrong, so I'm still rating it as something with potential, at the moment.
 
The Great Zaganza said:
I only want a Space Elevator.

Is that too much to ask for?
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Got $10 Billion laying around to invest?

I say investment, though, because...

But it could reduce the cost of putting things into orbit from roughly $3,500 per pound today to as little as $25 per pound, says Peter Swan, president of International Space Elevator Consortium (ISEC), based in Santa Ana, California.
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That leaves enough leeway that it could make up the cost pretty quickly, provided sufficient payload capacity.
 
Has it been established that a space elevator would actually be possible to construct using materials we already know how to make? The last I heard, it was more speculative than that, requiring e.g. very long carbon nanotubes that are theoretically possible but not presently manufactured.

Ah, yes, the linked article says exactly that: 'That [making long graphenes] can’t be done yet, he says, adding that “it will be possible in the very near future."'
 
Space elevator claims are mostly total loony-tune lies.

Peter Swan said:
Kaku isn’t exaggerating. A space elevator would be the single largest engineering project ever undertaken and could cost close to $10 billion to build.
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Total bollocks to claim 10 billion now. The same article claims current launch costs are $3,500 per pound. 10 billion is then just what it would cost to launch the materials for the first elevator. This assumes the elevator itself would be free. What possible justification is there for that? The materials needed don't currently exist. Materials that are currently cited as "coming close" now don't even remotely come close, usually don't come close in multiple ways, and any reasonable extrapolation of their cost exceeds 10 billion dollars. At the moment you have to absurdly generous with these extrapolations to even get down in to "just" billions of dollars for the materials.

Peter Swan said:
But it could reduce the cost of putting things into orbit from roughly $3,500 per pound today to as little as $25 per pound, says Peter Swan, president of International Space Elevator Consortium (ISEC), based in Santa Ana, California.
Click to expand...

Loony toons. I've looked at these claims before. You can only justify that cost per pound if the elevator is nearly free and most of the cost is the energy to lift the payload to orbit. These low cost projections have a ton of unreasonable assumptions built in to them.

Most near term claims for early space elevators call for ten ton payloads reaching GEO in a week. At $25 per pound that would be $5 million per week. It then takes 40 years to recoup the $10 billion investment cited in this article. And that, of course, requires that it be free to operate. The claims of space elevator proponents just do not stand any sort of scrutiny.

Rockets actually do have a clear path to getting down to double digit per pound costs. And no new technology required. It's all a matter of supply and demand. The $3,500/pound cited by the article I quoted above has already been beaten by a factor of 3. The $25/pound that the article promises for some unlikely future elevator is the design goal of the SpaceX Starship*.

Even if SpaceX doesn't meet that goal, it's still clear that the goal can be met and it's just a matter of someone demonstrating a need that justifies an assembly line approach to building rockets.

* Someone might nitpick that I'm comparing a rate to LEO against a rate to GEO. But since once is based in reality and the other is based in fantasy and/or outright lies, I contend it's still a worthwhile comparison.

https://en.wikipedia.org/wiki/Space_elevator_economics#Costs_of_current_systems_(rockets)
https://en.wikipedia.org/wiki/Super_heavy-lift_launch_vehicle#Comparison
 
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This one is a decade or so old now, but it's cool because it's both obvious and counterintuitive in it's scale.

There is enough ice in Greenland to raise sea levels ~6.5 meters or a little over 20 feet globally. There is so much ice that the force of gravity it exerts pulls the oceans towards Greenland. If this ice melts, therefore, the water being pulled towards Greenland will recede and within ~2000 miles of Greenland sea levels would actually fall and right at the Greenland coast sea levels could fall as much as 50 meters or ~160 feet.

https://www.sciencemag.org/news/201...et-could-actually-lower-sea-level-some-places

http://nautil.us/issue/33/attraction/why-our-intuition-about-sea_level-rise-is-wrong
 
lomiller said:
This one is a decade or so old now, but it's cool because it's both obvious and counterintuitive in it's scale.

There is enough ice in Greenland to raise sea levels ~6.5 meters or a little over 20 feet globally. There is so much ice that the force of gravity it exerts pulls the oceans towards Greenland. If this ice melts, therefore, the water being pulled towards Greenland will recede and within ~2000 miles of Greenland sea levels would actually fall and right at the Greenland coast sea levels could fall as much as 50 meters or ~160 feet.

https://www.sciencemag.org/news/201...et-could-actually-lower-sea-level-some-places

http://nautil.us/issue/33/attraction/why-our-intuition-about-sea_level-rise-is-wrong
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The argument seems on its face to be possible. I'm certainly not qualified to comment. But it does not take into account the speed of melting with respect to that of isostatic rebound North America is still experiencing earthquakes from the melting of the glaciers at the end of the last Ice Age (about 9,000 years ago).

I visualize a super slow tsunami. Rising oceans from the melt over decades followed, over the course of centuries, lowering due to the effect in question.
 
Here's a cool one I found:
http://www.collectspace.com/news/news-111320a-2020so-surveyor-centaur-stage.html

Apparently a rocket stage launched in 1966 has returned to a temporary orbit around earth, but will be leaving again soon. They figured out it was a rocket stage by calculating its backward trajectory.

The animation of its orbit is pretty cool. You can see as it approaches earth that it passes in front of the moon. This slows its orbit down, allowing it to be captured into an earth orbit. But as it comes in for a second pass, it trails the moon, so the moon's gravity accelerates it, and it escapes again. 3 body orbital mechanics are not simple.
 
Gord_in_Toronto said:
The argument seems on its face to be possible. I'm certainly not qualified to comment. But it does not take into account the speed of melting with respect to that of isostatic rebound North America is still experiencing earthquakes from the melting of the glaciers at the end of the last Ice Age (about 9,000 years ago).

I visualize a super slow tsunami. Rising oceans from the melt over decades followed, over the course of centuries, lowering due to the effect in question.
Click to expand...

I gave a rough description, but the actual calculations were for instantaneous melting and did include isostatic rebound.
 
lomiller said:
I gave a rough description, but the actual calculations were for instantaneous melting and did include isostatic rebound.
Click to expand...

So how long to meet a steady state? Instantaneous isostatic rebound does not sound like a good thing. ;)
 
Hmm.

Aging process in live animal tissues not just halted, but reversed

I think that potential human immortality is probably still quite a ways off, but this has potential to help in ways that weren't available before, at the least. To take a snippet -

Sinclair and the rest of the team expressed OSK in mice with glaucoma and in other mice with plain old advanced age, and by doing this, they were able to reset the retinal ganglion cells back to young cells, with all the markers and behavior of young cells (telomere length, DNA methylation, etc.) These cells regenerated and restored vision in these kinds of mice.

Previous research has been able to arrest the progress of optic nerve damage associated with glaucoma or old age, but never to reverse it.
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Deepmind's AlphaFold2 has apparently "solved" portion folding.

I don't think it's as simple as that, but it seems they've made some major breakthroughs that could have implications for biomedical research, synthetic biology, and probably other things I'm not thinking of.

My VPN won't connect at the moment so I'm not able to find an article on the subject, but I did have a window open with a YouTube video of Lex Fridman talking about the subject:

https://www.youtube.com/watch?v=W7wJDJ56c88

I would appreciate it if someone else interested found an article on the subject, but my VPN should be working sometime soon so if not I'll post something in the next day or two.

I did see an article titled something like "AlphaFold2 has not solved protein folding", so while this sounds like an important step, like most things of this nature it's also probably being overhyped in the media somewhat.

ETA: Well, that was fast. My VPN connected. So here's a link to an article on nature.com:
https://www.nature.com/articles/d41586-020-03348-4
An artificial intelligence (AI) network developed by Google AI offshoot DeepMind has made a gargantuan leap in solving one of biology’s grandest challenges — determining a protein’s 3D shape from its amino-acid sequence.

DeepMind’s program, called AlphaFold, outperformed around 100 other teams in a biennial protein-structure prediction challenge called CASP, short for Critical Assessment of Structure Prediction. The results were announced on 30 November, at the start of the conference — held virtually this year — that takes stock of the exercise.

“This is a big deal,” says John Moult, a computational biologist at the University of Maryland in College Park, who co-founded CASP in 1994 to improve computational methods for accurately predicting protein structures. “In some sense the problem is solved.”
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Aridas said:
"Artist's bracket" fungus helps turn wood into ... a generator of electricity

Not a powerful generator, of course, but even a small bit for a short time can work just fine as a trigger.
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Imagine something that produces vibrations as a side effect of what it does. Like a diesel or petrol engine. You could put these things around it, not only will this dampen the vibrations, but generate electricity as well.

You could use this also in conjunction with springs in cars.
 
rjh01 said:
Imagine something that produces vibrations as a side effect of what it does. Like a diesel or petrol engine. You could put these things around it, not only will this dampen the vibrations, but generate electricity as well.

You could use this also in conjunction with springs in cars.
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Possibly. I don't think that I saw anything in the article about the durability of the wood when prepared, though, and durability would be very important if it were to be applied in vehicles or any other constant use situation, I think, before getting to any space concerns.
 
This was a bit of an interesting story -

Superbugs have two new nemeses: the chestnut tree and LEGO

Alternative approach to reducing danger from infections - preventing the bacteria from releasing toxins, which makes it much cleaner for an immune system to clean them up, with a fun little lego construct doing the job of a much, much more expensive piece of equipment as part of narrowing down the actually effective substance in play.
 
Myriad said:
Has it been established that a space elevator would actually be possible to construct using materials we already know how to make? The last I heard, it was more speculative than that, requiring e.g. very long carbon nanotubes that are theoretically possible but not presently manufactured.

Ah, yes, the linked article says exactly that: 'That [making long graphenes] can’t be done yet, he says, adding that “it will be possible in the very near future."'
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No, we are currently no-where near the necessary materials. And US$10B is 1-2 orders of magnitude lower than the real costs.
 
catsmate said:
No, we are currently no-where near the necessary materials. And US$10B is 1-2 orders of magnitude lower than the real costs.
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I believe the maths shows we have materials of sufficient strength to biuld a space elevator.

On Mars. Which I believe presents a bit of a moon issue.
 
Myriad said:
Has it been established that a space elevator would actually be possible to construct using materials we already know how to make?
Click to expand...
catsmate said:
No, we are currently no-where near the necessary materials.
Click to expand...

I believe carbon nanotubes and graphene have the theoretical required strength, and we can make them.

But there's two problems, which may not be surmountable (at least any time soon). First is that the quantities required are ginormous, and we don't know how to make nanotubes or graphene in such huge quantities.

The second is that while these materials have the required strength at the microscopic level, we aren't going to be making multi-kilometer long nanotubes (as an example). So we would need to stitch together much shorter lengths of the stuff. And we can do that. But the strength of a bunch of stitched together nanotubes isn't the same as a bunch of continuous nanotubes. We don't know how strong we can make a collection of these things. I don't think what we can make now is strong enough.
 
3point14 said:
I believe the maths shows we have materials of sufficient strength to biuld a space elevator.

On Mars. Which I believe presents a bit of a moon issue.
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Clarke came up with a rather scary solution to that one. Engineer it so that it has an appropriate lateral oscillation mode with the right frequency and an antinode in the right place so it simply bends out of the way each time Phobos goes by.

Dave
 
Dave Rogers said:
Clarke came up with a rather scary solution to that one. Engineer it so that it has an appropriate lateral oscillation mode with the right frequency and an antinode in the right place so it simply bends out of the way each time Phobos goes by.

Dave
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I wonder if that's even necessary.

Phobos's orbit is equatorial, meaning its orbital plane matches the equatorial plane. If you build your space elevator at a distance away from the equator, then your elevator won't be in the equatorial plane. You will have to deal with the fact that the elevator won't be quite vertical, but you only need a few degrees of tilt to get out of Phobos' path.
 
Ziggurat said:
I wonder if that's even necessary.

Phobos's orbit is equatorial, meaning its orbital plane matches the equatorial plane. If you build your space elevator at a distance away from the equator, then your elevator won't be in the equatorial plane. You will have to deal with the fact that the elevator won't be quite vertical, but you only need a few degrees of tilt to get out of Phobos' path.
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I think it's going to have to weave back and forth across the equatorial plane at that point. It can't stay on the same side all the time.
 
3point14 said:
I think it's going to have to weave back and forth across the equatorial plane at that point. It can't stay on the same side all the time.
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It can (and will) if the base is to the side of the equator.

Putting the base at the equator is the simplest option because it makes the cable vertical. But it isn't strictly required. Consider the most extreme case: but the base at the pole, and have the cable start out running horizontal. It's obviously much harder to do that way, but the cable wouldn't come near the equator.
 
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