The physics are known to work and have been demonstrated decades ago in a different engineering context (i.e. weapons).
https://en.wikipedia.org/wiki/National_Ignition_Facility#/me...
Credit: Mark Herrmann/LLNL
From this article: https://physicstoday.scitation.org/do/10.1063/PT.6.2.2022121...
Clear qualitative difference.
Additionally, this is laser energy, but the lasers aren’t used directly. They produce X-rays which are the ones that actually drive the ablative implosion of the fuel pellet. If you used X-rays directly, the gain value would be MUCH higher… I think by that measure, they would’ve achieved Q=1 back in 2013?
Note that hey COULD use the lasers directly to drive implosion but haven’t yet. The Hohlraum/X-ray/indirect method I think produces more consistent lighting on the target, and is more analogous to the operation of an H-bomb, which is partly what this entire process is intended to replicate. They may do future experiments to try direct drive, in preparation for actually using this as a power production method and improving the efficiency dramatically… in combination with far higher efficiency modern lasers, this could enable Q high enough for net electricity production.
A real plant would need target yields 100 to 1000 times larger, with all the engineering issues that would entail.
It's so unlikely even under the sun's massive gravitational and heat that the power output is about 270W/cubic meter-- compare to human metabolism or an energetic compost pile, which is over 1000W/cubic meter.
We actually have to do a whole lot better than the sun, under far less favorable conditions-- to have practical fusion for energy generation on Earth. Inertial confinement fusion ignition (and to a lesser extent, thermonuclear weapons) strongly suggest this is possible.
The fact that black holes exist does not mean that we can spin one up to harvest it's hawking radiation for power. It's not just an engineering problem. That's not what that phrase means.
A bomb? Already done.
A fusion reactor? We’re still light years away from anything of the sort. This is only one tiny tiny step there, and we’ve got miles to go.
EDIT: Being down-voted, why? Previous steps to actually develop a power plant around NIF-like inertial fusion were cancelled in order to focus on achieving ignition first: https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy
For sure, you can’t even consider the possibility of a fusion power plant without the core reaction producing power. That they figured out how to do the energy equivalent of getting the coal to actually light (finally!) in this context, is indeed useful.
But it is a tiny, tiny step towards an actual working fusion power plant.
And it does nothing to fix the economic issues here in competition with all the other energy sources, which matters.
Igniting that bit of ‘coal’ took near 100x the energy we got out of it. It was essentially putting it in a giant blowtorch, and then getting excited when it finally got lit and burned. That we previously only got half smoldering was indeed a problem! And that it finally lit is indeed cool.
it also took an extreme amount of thought, precision, investment, etc. to do it once.
Meanwhile, solar plants in the area were churning out billions of kwh.
No one needs to talk about delaying solar deployment, obviously that would be stupid. No one should be arguing for that, I certainly am not, and trying to do this whole thing where we attack genuine advances just because they aren’t the thing we prefer is super counterproductive to progress. Shameful to do that, no matter how common it is on social media.
This was built as a machine to test fusion, not to generate electricity. It did that, and doing so is a significant advance.
It’s sparking fire in a very specific synthetic scenario which maybe could be useful in making a specific type of fusion reactor.
It’s a critical step, yes, in development of that type of reactor, if we wanted to do so. Currently there is no reason to believe we’d find it worthwhile to do.
But there are literally hundreds more steps just as critical with no known solution, that are likely just as hard before we could actually have net positive energy even in a lab for such a reactor. Even if we found the economics would pan out.
That’s why I’m saying it’s a small step and we’ve got miles to go - because we do.
You’re pointing out some of the next small steps.
But those won’t get us to even having the energy balance positive on paper.
making lasers 100x more efficient for one being a notably hard problem, from a physics perspective. Probably even harder than IC fusion. The planned upgrades to lasers will help, but not enough to be close to a positive energy balance.
If the ‘first 90% takes 90% of the time’, we’re now at 2% of that first 90%. But everyone is hyping it up as we just completed it. Which is not true at all.
Honestly, it sounds like a Hail Mary funding push to try to get a new project funded or stop the lab from being shut down.
You want to use lasers to initiate some fusion, you can do that using a tabletop laser lab (although magnetic confinement and big voltages is much simpler).
So this is the first machine where we're sure: it wasn't fusion caused by lasers, it was fusion caused by neutron pressure! Where did that neutron pressure come from? From other atoms fusing!
Note also that the sun does NOT do this. Fusion inside the sun is powered by falling atoms converting their falling energy first into heat then into singular fusion events, which essentially explode and throw a lot of atoms back up. Then the cycle begins again. Fusion inside the sun is a self-limiting reaction, which is why stars don't just blow up once, but "burn" over a long time. All the fusion inside the sun really does is slow down gravity for a little bit, then immediately stop. Gravity is producing the heat from the sun.
The reaction is initiated by the lasers.
You can’t actually use a hammer to initiate it at any useful scale because hammers can’t create the appropriate pressures and temperatures to initiate the process at the scale needed to produce a useful energy output. Which is why the lasers.
So no, the lasers are not immaterial at all.
We still have no idea if we'll ever be able to engineer this thing to produce commercially useful energy. And we probably never will, for all interesting values of "never", the challenges are simply so massive.
The problem is the engineering of how to actually do it in a useful way. They have made some progress towards that but it's still extremely unlikely that laser based fusion will ever work as a power source because: a) they're still two orders of magnitude from break-even from the input side, and b) they don't have a practical way of capturing the energy that's produced at all as far as I understand it.
None of that has changed.
The way to capture the energy and make it into electricity was studied here: https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy
But it had been premature before they achieved ignition. You don’t build a boiler before you even have been able to spark a flame.