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US Department of Energy: Fusion Ignition Achieved

energy.gov

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Re: US Department of Energy: Fusion Ignition Achieved

#611

Post by dr_dshiv »

gretch wrote: post #480
steam_raven wrote: post #451

Earlier quoted context omitted.

We have calcium in our bones, iron in our veins, carbon in our souls, and nitrogen in our brains. 93 percent stardust, with souls made of flames, we are all just stars that have people names" Nikita Gill

I understand this is a poem that is focused on artistic expression and not scientific accuracy, but I find the line about “carbon in our souls” to be out of place. I guess the rest of the poem is incidentally correct (when not abstract)

Sure, the word “soul” comes from the proto Germanic “saiwiz” (for sea or ocean).

But not because “you are like a drop in the ocean,” but because “you are like an ocean in a drop.”

The idea of soul can be objectionable when it is based on an immortal being or on a vitalist life-force (like “anima” of the Latin). But it seems fine when it is based on the psyche (like the “Psuche” of the Greek).

I embrace taboo words like soul because they 1. are common 2. are useful for referring to things that seem pretty important (like avoiding soulless companies or products or buildings) and 3. are challenging to my normal (scientific) understanding of the world.

Still, I’d be more comfortable if the poem referred to the “carbon of our souls” rather than “carbon in our souls.” Hmm…

Re: US Department of Energy: Fusion Ignition Achieved

#612

Post by SiVal »

eklitzke wrote: post #262
spullara wrote: post #165

Earlier quoted context omitted.

If you look at the mass before of their fuel, 1 deuterium atom + 1 tritium atom: 2.01410177811 u + 3.01604928 u = 5.03015105811 u vs the mass of the fusion products of 1 helium atom and 1 neutron: 4.002602 u + 1.008 u = 5.010602 u You'll notice that even though we started with 5 neutrons and 2 protons and ended up with the same number there was some additional binding energy that is unaccounted for in the new configu…

Tangentially related, but I think this is an interesting fact, all the atoms in our universe/galaxy/solar system with a mass up to that of iron are formed in the core of stars in stellar fusion. Hydrogen fuses into helium, and as a star nears the end of its lifetime you get heavier elements like lithium, carbon, and so on. Under normal stellar fusion no elements heavier than iron will be produced, and iron is only el…

Iron is always spoken of as the dividing line, but I'd like to know whether iron is exactly on the line, on one side (which?), or it depends. IOW, does fusion of iron atoms release energy (hydrogen side of the line), absorb energy (uranium side of the line), neither, or either (depending on conditions)?

Re: US Department of Energy: Fusion Ignition Achieved

#613

Post by twojacobtwo »

LarryMullins wrote: post #559
boc wrote: post #450

Earlier quoted context omitted.

Quoted post unavailable.

Your "honest feedback" is nothing more than naked insults. Sillysaurusx is right. The "impossibly complex" matter is actually quite simple, Q=1 is little more than a psychological milestone, not some sort of technical tipping point where further progress becomes easier. And they haven't even gotten to Q=1 unless you buy into the justifications they give for dodgy accounting of the energy they put into it. The "imposs…

Just as a note, since I made the same mistake initially, the person you're replying to didn't make the post from which you are quoting "impossibly complex".

It seems, to me, that boc was criticizing the unnecessarily dour tone of sillysaurusx's previous comment and not the technical aspect of the achievement.

The whole thing seems to come down to whether one interprets the announcement as an attempt to deceive the public at large or simply a celebration of a milestone that many in the fusion research community have been trying to achieve for a long time. I can understand it being interpreted both ways, but I think the more charitable interpretation is that science reporting, in general, doesn't usually properly explain the levels of nuance of various achievements and, as such, something that is genuinely exciting for those in the community is not necessarily as exciting for those outside of it - which comes across as deceptive.

Re: US Department of Energy: Fusion Ignition Achieved

#614

Post by govg »

phtrivier wrote: post #248
chasd00 wrote: post #149

Earlier quoted context omitted.

> Who are our modern J. Robert Oppenheimer, Enrico Fermi, Richard Feynman, Edward Teller, John Von Neumann, and Stanislaw Ulam? they're working on getting you to click on an ad

They can't exist any more for structural reason. This generation was classically educated, without TV or social media in their childhood. They spent the time we're wasting on HN reading _books_ and following the discipline their elders learned in WWI. They had plenty of occasions to tinker. I claim the brains of those generation was structurally different from ours, and we're talking about the best minds of this gene…

I mean, sure. But at the same time they were constrained by the tools of their time, had no internet for instant information access and spread, and scientific collaboration has never been at a higher level than it is now. There's no reason to believe that people who grow up with instant lookup and massive computational power will somehow be less capable than people whose only tools were pen and pencil. What is possible now couldn't even be dreamed of back then.

Re: US Department of Energy: Fusion Ignition Achieved

#615

Post by nkrisc »

lr1970 wrote: post #448
nkrisc wrote: post #325

Earlier quoted context omitted.

Mass and energy are equivalent. You're using X energy to reduce the mass of your fuel and converting that mass into Y energy. When X The reason nuclear fusion is such a desirable goal is because it only takes a relatively small amount of mass to convert into a relatively large amount of useful energy, and the mass (the fuel) is relatively easy to obtain. Like all energy generation, it's converting one type of energy…

> Mass and energy are equivalent. Mass is energy at rest, hence equivalence with exception of massless particles like photons that have zero mass and non-zero energy. Also, photons travel with the speed of light in vacuum and cannot be found at rest in any frame of reference. Modern physics is fun, isn't it? P.S. Neutrinos were thought to have zero mass as well, but according to the Standard model they have mass.

Yeah, my explanation is very much simplified.

Re: US Department of Energy: Fusion Ignition Achieved

#616

Post by guelo »

gretch wrote: post #480
steam_raven wrote: post #451

Earlier quoted context omitted.

We have calcium in our bones, iron in our veins, carbon in our souls, and nitrogen in our brains. 93 percent stardust, with souls made of flames, we are all just stars that have people names" Nikita Gill

I understand this is a poem that is focused on artistic expression and not scientific accuracy, but I find the line about “carbon in our souls” to be out of place. I guess the rest of the poem is incidentally correct (when not abstract)

You could define soul as the fuel engine for life, which is basically burning carbon. As long as that furnace is functioning you're alive == you have a soul.

Re: US Department of Energy: Fusion Ignition Achieved

#617

Post by px43 »

Robotbeat wrote: post #187
BeetleB wrote: post #148

Earlier quoted context omitted.

Can solid state lasers produce the high energy needed here?

Yes. https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy#M...

I'm not really seeing any convincing numbers there. Mercury lasers seem to only be 10% efficient. I get that this is better than the lasers that were just used at NIF, but that still seems pretty far from useful.

Re: US Department of Energy: Fusion Ignition Achieved

#618

Post by kortilla »

ClumsyPilot wrote: post #499
kortilla wrote: post #420

Earlier quoted context omitted.

It has nothing to do with funding. SpaceX had far less than NASA. For another example from a different angle, the military has limitless supplies of funding but innovates even less than NASA.

You are comparing company that makes trucks with a company that makes precision scientific instrumers, and you are declaring that truck companu is more efficient per kilo of produce. this is stupid. Nasa develops nuclear reactors, landed on titan and has reached pluto. Spacex vehicle has never left the Earth-moon system.

Lol “spacex makes trucks”. Way to throw on the anti-Musk blinders and completely ignore the back-half of the comment and misunderstand the first half.

Also, spacex has launched outside of the earth-moon system. It was a roadster

Re: US Department of Energy: Fusion Ignition Achieved

#619

Post by ftlio »

mynameisvlad wrote: post #553
ClumsyPilot wrote: post #499

Earlier quoted context omitted.

You are comparing company that makes trucks with a company that makes precision scientific instrumers, and you are declaring that truck companu is more efficient per kilo of produce. this is stupid. Nasa develops nuclear reactors, landed on titan and has reached pluto. Spacex vehicle has never left the Earth-moon system.

SpaceX is not Tesla. It's disingenuous to call SpaceX a "company that makes trucks". Just like NASA, they also make precision scientific instruments. They're the first privately funded mission to the ISS and run a massive satellite constellation. They may not have the same accomplishments as NASA, but they're far from a "company that makes trucks".

The analogy is apt in at least defining a separation between the overall complexity of what SpaceX produces compared to NASA, to say something of how the two different models of R&D work, but maybe off in degrees as you discussed.

"NASA makes precision scientific instruments and SpaceX makes precision scientific instruments that have higher tolerances with a higher focus on throughput, and there are rapidly diminishing returns in how much funding can be used to close the gap" is probably the right take if not as fun.

Re: US Department of Energy: Fusion Ignition Achieved

#620

Post by eropple »

SiVal wrote: post #612
eklitzke wrote: post #262

Earlier quoted context omitted.

Tangentially related, but I think this is an interesting fact, all the atoms in our universe/galaxy/solar system with a mass up to that of iron are formed in the core of stars in stellar fusion. Hydrogen fuses into helium, and as a star nears the end of its lifetime you get heavier elements like lithium, carbon, and so on. Under normal stellar fusion no elements heavier than iron will be produced, and iron is only el…

Iron is always spoken of as the dividing line, but I'd like to know whether iron is exactly on the line, on one side (which?), or it depends. IOW, does fusion of iron atoms release energy (hydrogen side of the line), absorb energy (uranium side of the line), neither, or either (depending on conditions)?

As I understand it, iron is the first element that absorbs energy under fusion, and therefore won't fuse further. Could be wrong, though.
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