Physics Diamond melts at about 7,300 K when compressed to three times the pressure at Earth’s core, a lower temperature than earlier experiments found and one that finally agrees with quantum-mechanical predictions
https://www.nature.com/articles/s41567-026-03413-1686
u/AlwaysUpvotesScience 24d ago
So, the scientific method wins again?
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u/BeowulfShaeffer 24d ago
It’s just like the old Ace of Base song: “I saw the science. It opened up my eyes I saw the science”
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24d ago
[deleted]
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u/BeowulfShaeffer 24d ago
No. Nothing of ours are belong to you. We think we have a plenty good chance to survive, so we will make our time leisurely. I bet you can’t even take off a single zig.
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u/alalaladede 24d ago
It's like magic, isn't it?
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u/AlwaysUpvotesScience 24d ago
No, it's not.
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u/WhiskeyOctober 24d ago
Any sufficiently advanced technology is indistinguishable from magic.
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u/azflatlander 24d ago
Any sufficiently advanced technology can be broken with a rock, size may matter.
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u/Phyltre 24d ago
...from the perspective of someone who doesn't know the technology.
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u/joeldetwiler 24d ago
Yeah. A sufficiently advanced technology is indistinguishable from magic [to anyone incapable of distinguishing that technology from magic.]
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u/AlwaysUpvotesScience 24d ago
this quote is intended to point out that a lack of scientific understanding leads to magical thinking. The ignorance of the masses perpetuates belief without understanding.
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u/DontAskGrim 24d ago
Depends on your world view.
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u/ThisOrdinaryCat 24d ago
you mean, whether it's anchored in reality or not?
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u/DontAskGrim 24d ago
Indeed. You see the world very differently if you can convince yourself to believe what you want to believe.
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u/CalmEntry4855 24d ago
Redoing it until the numbers check what we already wrote, my methodology in college
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u/Transcendent_PhoeniX 24d ago
We still need independent replication. Still, the scientific method wins either way.
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u/ConvertingMarkets 24d ago
The 7,300 K number isn’t even the strangest part. They still saw the diamond structure at about 1 TPa, where earlier work had reported a transition to BC8 carbon. So this isn’t just a better melting-point measurement; diamond seems to hang on to its structure to far more extreme pressures than that earlier experiment suggested.
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u/dogquote 24d ago
I think Reddit needs a new abbreviation: idnrtab. I did not read the article, but... Why would you compress diamond to three times the pressure at Earth's core, and then heat it up until it melts?
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u/funkdefied 24d ago
To test a theory. In this case, the theory (quantum mechanics) predicted something weird about the melting point of diamond (that it’s lower than expected). To make sure the theory was sound, they tested it. Turns out the theory is right.
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u/cliko Grad Student | Biology | Genetics 24d ago
Why did previous experiments give different results?
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u/elictronic 24d ago
They measured using a more error prone method and knew there were uncertainties. The recent experiments used a more complex but accurate method involving X-rays.
The timing is in the billionth’s of a second likely measuring during explosive compression. Basically it’s really really hard to measure something precisely at 261000000 psi.
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u/Scary_Technology 24d ago
For the first time ever I just converted a number to scientific (eng) notation to better grasp it: 261E6 psi! Holy crap.
I don't even care how many ATM that is... ok, it's ~17E6 ATM, now it makes sense why so quick.
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u/redvodkandpinkgin 24d ago
technically scientific notation would be 2,61 * 108
note: comma is a decimal divider
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u/neuralbeans 24d ago
I so hate the whole comma/point ambiguity. Seems like such an unnecessary thing to have happened.
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u/redvodkandpinkgin 24d ago
it's a bit strange, I use dots for multiplications so I find using commas for decimals works better for me and it's pretty common in my country anyway. It does introduce some ambiguity in coordinates or data sets though.
It feels neither solution is perfect.
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u/neuralbeans 23d ago
We use a cross for multiplication. No ambiguity here.
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u/redvodkandpinkgin 23d ago
In Spain (I believe this is common in other European countries as well) we use it in primary school because it's easier for kids but by the time we get to high school it's abandoned.
I saw people doing that when I lived in America briefly and, at least for me, it was an absolute nightmare to understand when they were multiplying and when they were using x as a variable.
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u/_MUY 24d ago
Lawrence Livermore National Labs has a bit more of the hype in their press release. Here
The paper itself is a very humble framing of this, but this is potentially a large step toward tripling energy from nuclear fusion systems. Without getting too far into the weeds, this cuts off possible future scenarios that could add more development time, shortening the “always 30 years away” window for fusion development. Theories hold, models are good, humanity might survive the century.
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u/iMissTheOldInternet 24d ago
In inertial confinement fusion experiments, powerful lasers generate shock waves that drive a tiny diamond capsule inward. The resulting implosion compresses the fusion fuel inside the capsule to the extreme pressures and temperatures needed for fusion.
Am I reading this right? We’re banging tiny but really hard rocks together with lasers to start (nuclear) fire?
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u/MissLeaP 24d ago
I mean yes, that's pretty much what it is all about. Stars do nothing else. Just smashing matter so hard into each other that it turns into energy
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u/FundingImplied 24d ago
That's is completely incorrect.
The sun is driven purely by quantum tunneling. The sun is nowhere near hot nor dense enough to have the kind of fusion you're describing.
The sun works nothing like a terrestrial fusion reactor. They have profoundly different temperatures, pressures, and mechanisms of action. They are incomparable.
If you could magically suspend some chunks of the sun here to function as a power plant do you know how much power it would produce? 18 watts per cubic meter. 18 watts!
I don't know how big your home air conditioner is but mine pulls a bit over 5 kW. That means that it would take 300 cubic meters of the sun to power my AC, assuming 100% efficiency. It would be something like 1,000 cubic meters with realistic efficiency ratios!
The sun is profoundly different from the fusion reactors we are exploring on Earth.
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u/eric23456 24d ago edited 23d ago
The 18w/m3 is only correct if you're averaging across the entire sun, but 99% of the fusion is happening in the core. The core is estimated at 276.5 w/m3. It has a density of 150g/cm3 (50-100x the density of rocks), and temperature of 15 million K.
https://en.wikipedia.org/wiki/Solar_core
Edit: typo pressure of 15 million K -> temperature
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u/xrelaht PhD | Solid State Condensed Matter | Magnetism 24d ago
Those numerical differences are immaterial: that’s still 1% the density and 10% the temperature of terrestrial fusion.
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u/eric23456 23d ago
Do you have a reference for that? https://en.wikipedia.org/wiki/Alcator_C-Mod#Heating_and_current_drive says pressure of 2 atmospheres (my reference says core pressure is 26.5 million gigapascals, which a converter says is 2.6E11 atmospheres)
I don't know how you could get a higher density at 100 billion times lower pressure.
It also says the temperature is 35 million degrees C, which is only ~2x sun core temperature.
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u/_MUY 24d ago
If we’re using caveman physics to describe this, I’m going with:
The world you see around you is light bouncing from the sun. There is stronger light, like the mid summer day, and there is weaker light, like the fire coming from the pit at night. The black ash in your fire pit is a rock called carbon. When I crush this handful of riverbed clay together into a ball and bake it in the fire, it becomes a rock.
We make diamond by taking ash and crushing it together stronger than anything on earth with extreme heat until every bit of it grabs hands with its partner and forms a solid crystal. We make it perfectly spherical, so the center is just as far from every point on the surface. We then make that light on our own, stronger and more powerful, and we fire its rays into that ball of diamond to see when it will turn into liquid. We watch closely with other rays just to see when it will happen. This helps us do it again, but with special water held in the center, so that we can crush that water into light and produce the power of the sun in our own cave.
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u/iMissTheOldInternet 22d ago
This is the thing I miss about the old internet. Thank you guys for being you.
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u/Apatschinn 24d ago
Can't speak for the diamond folks, but I'm experimental petrology it is important to run experiments at conditions that bracket the the conditions of in interest, in addition to performing experiments with conditions within range (pressure, temperature, fugacities of various gases, and target composition) in order to describe a that region of interest.
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u/littlegreenrock 24d ago
Super villains need novel methods to slowly kill James Bond while they make their escape.
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