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submitted 1 day ago by cm0002@lemmy.world to c/science@mander.xyz
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[-] Chrobin@discuss.tchncs.de 8 points 12 hours ago

I'm noticing in these comments that the tech bros that want to solve climate change by magical technological advances instead of using what we have had an interesting effect: some people on the other side have grown tired of the real technological advances that would actually help.

[-] secretlyaddictedtolinux@lemmy.world 24 points 19 hours ago

what an incredible achievement. rome wasn't built in a day and real.science takes time and effort. so much effort by these scientists!

[-] Shyfer@ttrpg.network 12 points 17 hours ago

I'm so used to hearing that this technology is 10 years away, or whatever the old adage was, that i can't believe we've been seeing actual progress on this front in the last few years. Maybe it will actually happen eventually!

[-] CanadaPlus@lemmy.sdf.org 7 points 14 hours ago

Well, there's been incremental progress all along. I remember reading about milliseconds being a big accomplishment at some point.

Also, it's pretty heavily dependent on the exact plasma in question. One hot enough to do lots of fusion will probably be different, so this isn't the finish line. Relevant XKCD.

[-] Loss@sh.itjust.works 2 points 17 hours ago

It just took someone without a profit motive

[-] gandalf_der_12te@discuss.tchncs.de 17 points 22 hours ago

I'm studying Physics at the moment and Prof. gave us a printout of a textbook last week stating that the internal of the sun generates approximately 150 W / m³ on average. That's about as much as a compost pile, so, not very much. The sun only generates enormous amounts of power because it's so huge. In other words, reproducing fusion on Earth might actually not be very efficient.

[-] Chrobin@discuss.tchncs.de 6 points 12 hours ago* (last edited 12 hours ago)

I'm pretty sure the reason for that is that the sun is actually mostly not hot enough to do nuclear fusion, but has to instead rely on quantum tunnelling. This makes the fusion rate much, much lower. Now while this is good, because otherwise, the sun would burn up far too quickly and kill all of us, it also explains the low power, or energy per time.

Source: Doing my master's in cosmology.

[-] Duamerthrax@lemmy.world 7 points 17 hours ago

Look up the etymology of the word "sophomore".

[-] _stranger_@lemmy.world 27 points 22 hours ago

Found this article

https://www.abc.net.au/science/articles/2012/04/17/3478276.htm

And it looks like it's saying that the energy produced by nuclear fusion (which happens in the relatively small core) divided by the entire mass of the sun, gives you that low number.

Terrestrial fusion power plants are aiming to be sun cores, so that all the hydrogen they put in gets fused, and not just a few atoms here and there.

[-] CleoTheWizard@lemmy.world 18 points 20 hours ago

Why do people assume that scientists don’t sanity check themselves? Genuine question, no offense to the OC here.

[-] cazssiew@lemmy.world 14 points 19 hours ago

"guys, I know we've been working on this for decades, but I've been going over this first-year textbook, and I have some bad news..."

[-] Grandwolf319@sh.itjust.works 8 points 18 hours ago

Cause maybe they assume scientists are hyping things up like VCs for AI.

In a dishonest world, the honest would be mistrusted more.

[-] CanadaPlus@lemmy.sdf.org 2 points 14 hours ago

It's low in the core too, just not quite that low.

How does nobody else here know that we're talking about artificially fusing some blend of deuterium or tritium? The sun fuses ordinary hydrogen at this point in it's evolution - that's why it's a nice slow 10 billion year burn.

[-] CanadaPlus@lemmy.sdf.org 1 points 14 hours ago* (last edited 14 hours ago)

Different kind of fusion. Don't forget hydrogen bombs have been around for decades, right? They're just not very controlled and harnessable.

To the sun's credit, it's 4.5 billion years in and it's still got plenty of juice left to go.

[-] Blackmist@feddit.uk 18 points 1 day ago

I feel like little fusion has kind of missed the boat. It's been "just a few decades away" since I was in school, and that's a good while ago now.

We can already get limitless clean energy from the real sun.

[-] GaMEChld@lemmy.world 45 points 23 hours ago

Here's why it's been so long:

[-] _stranger_@lemmy.world 26 points 22 hours ago* (last edited 22 hours ago)
  1. We should do both

  2. There is no two.

[-] Loss@sh.itjust.works 5 points 16 hours ago

A) solar energy isn't clean, and it's the exact opposite of environmentally friendly; it's just that current power sources are so much worse it looks good by comparison.

B) fusion cannot ever be profitable. The fuel for it is the most common on the planet, if not the universe, requires no special refining, and can't be made artificially scarce. A post fusion world is a post energy industry world. It's the practical end of what currently owns the US and other countries.

This has drastically reduced funding for it and has blocked advancement for decades. This project among others in China have no profit motive, they are trying to accomplish a goal without caring how they can become rich off it. If fusion energy is possible, it'll be done in China.

[-] booly@sh.itjust.works 2 points 2 hours ago

The fuel for it is the most common on the planet, if not the universe, requires no special refining

It is true that regular hydrogen (with 1 proton and no neutrons) fuses in the Sun, first to deuterium (2 protons combine into a nucleus that immediately decays a bunch of radiation and becomes a proton and neutron), then another hydrogen proton to create helium-3 (2 protons, 1 neutron), then two helium-3 nuclei fuse to create 2 hydrogen protons and a stable Helium-4 nucleus (2 protons, 2 neutrons).

But nobody on earth is trying to accomplish fusion through that difficult pathway. We don't have the ability to create the pressures and heat to ignite that reaction.

The way all of these fusion projects are trying to achieve are deuterium (1 proton, 1 neutron) plus tritium (1 proton, 2 neutrons), to form Helium-4 (2 protons, 2 neutrons) plus a neutron and a bunch of energy. That is a reaction that human technology can ignite. So all the research goes into this particular reaction.

And for that, tritium is exceedingly rare. We can make it as a byproduct of fission reactors, from lithium.

[-] Chrobin@discuss.tchncs.de 5 points 12 hours ago

As far as I know, the current plans for fusion require deuterium and tritium. Whole deuterium can be easily obtained from water, tritium is a bigger problem. Its replacement, helium-3, is also not really frequent on earth.

[-] NatakuNox@lemmy.world 22 points 1 day ago
[-] CanadaPlus@lemmy.sdf.org 2 points 14 hours ago

Literally has tons of the same kind or reactor, and Europe is working on one that might actually do practical things.

[-] CheeseNoodle@lemmy.world 8 points 21 hours ago* (last edited 21 hours ago)

Living in the UK I suspect you have the same problem we have. Plenty of people capable of doing all the impressive shit China is doing (science, infastructure, whatever) and all of them being starved of funding as all the money dissapears into gigantic blackholes of backroom deals where huge amounts of money are spent on vague things that never seem to materialize or even be adequately explained; but whatever they are they sure do generate enormous profits for the cronies of whoevers currently in power.

[-] Shyfer@ttrpg.network 3 points 17 hours ago

Well at least here we can pretty easily see where the money goes by looking at the billions of dollars given to Israel and the military.

[-] kmaismith@lemm.ee 3 points 19 hours ago

My country is in this comment and i don’t like it

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[-] rbesfe@lemmy.ca 21 points 1 day ago

Someone needs to bash these scicomm journalists over the head until they stop using the words "artificial sun"

[-] barnaclebutt@lemmy.world 11 points 1 day ago

Also, where's the study? Is it even peer reviewed?

[-] MothmanDelorian@lemmy.world 7 points 22 hours ago

Good job scientists!

[-] SplashJackson@lemmy.ca 15 points 1 day ago

Forget artificial suns, let me tell you right now how to make an artificial moon:

  1. Be a robot.
  2. Pull down pants.
  3. Bend over.
  4. Point robo-crack towards recipient
  5. Artificial Moon.
[-] x00z@lemmy.world 2 points 19 hours ago

Maybe they miss the sun because of all the smog in the air.

[-] RubberElectrons@lemmy.world 6 points 1 day ago

Meh, net gain is the point, long cycles well be useful for production. Useful, eventually. Cart before the horse, otherwise.

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this post was submitted on 21 Jan 2025
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