For Questions That Don't Merit Their Own Thread

[JoeSchmuckatelli]

Good News Everyone! 

Fusion milestone: fusion power now only 20 years away! 

https://www.nbcnews.com/science/science-news/fusion-power-milestone-reached-briefly-sustained-reaction-rcna13690

Quote

 

Researchers at the National Ignition Facility at the Lawrence Livermore National Lab in California were able to spark a fusion reaction that briefly sustained itself

...

“We’re very close to that next step,” said study lead author Alex Zylstra, an experimental physicist at Livermore

 

 

 

 

[K^2]

1 hour ago, JoeSchmuckatelli said:

Fusion milestone: fusion power now only 20 years away! 

Seeing how it has been ten years away for pretty much my entire life, I'm a little concerned hearing this.

[JoeSchmuckatelli]

1 hour ago, K^2 said:

Seeing how it has been ten years away for pretty much my entire life, I'm a little concerned hearing this.

IKR?  But the researcher said 'maybe decades' which forced me to choose the minimum plurality 

[Spacescifi]

2 hours ago, K^2 said:

Seeing how it has been ten years away for pretty much my entire life, I'm a little concerned hearing this.

 

Ha.

I am of the opinion that they could just detonate a nuke in a vacuum chamber and use magnetic and inertial confinement and lasers all together to keep the reaction going. Or any other method that might.

 

Might not work, but won't know till you try.

 

Nukes are also fusion... we have had them for decades lol.

Edited January 28, 2022 by Spacescifi

[K^2]

1 hour ago, Spacescifi said:

Might not work, but won't know till you try.

No. No, we can definitely know without trying. Smallest nukes we got are in low kT ranges, and there is no confinement that can withstand that kind of energy release. The temperatures involved are too high for any matter to stay unionized, let alone solid, by orders of magnitude.

1 hour ago, Spacescifi said:

Nukes are also fusion... we have had them for decades lol.

And nukes that involve fusion are even more powerful yet, as we use a fission nuke to ignite these. Definitely not worth trying.

[Spacescifi]

6 minutes ago, K^2 said:

No. No, we can definitely know without trying. Smallest nukes we got are in low kT ranges, and there is no confinement that can withstand that kind of energy release. The temperatures involved are too high for any matter to stay unionized, let alone solid, by orders of magnitude.

And nukes that involve fusion are even more powerful yet, as we use a fission nuke to ignite these. Definitely not worth trying.

 

I beg to differ.

 

In space nuked do much less damage in vacuum.

The same would apply in a vacuum chamber, you just need a big chamber and uber powerful magnets to hold the plasma from spilling all over.

 

This may be beyond our abilities, but I do not think physics disallows it either witu sufficient magnetic field strength and chamber size.

Edited January 28, 2022 by Spacescifi

[Gargamel]

1 hour ago, Spacescifi said:

 

I beg to differ.

 

In space nuked do much less damage in vacuum.

The same would apply in a vacuum chamber, you just need a big chamber and uber powerful magnets to hold the plasma from spilling all over.

 

This may be beyond our abilities, but I do not think physics disallows it either witu sufficient magnetic field strength and chamber size.

Getting my popcorn ready for this one.   

[K^2]

1 hour ago, Spacescifi said:

The same would apply in a vacuum chamber, you just need a big chamber and uber powerful magnets to hold the plasma from spilling all over.

And the X-Ray radiation from a black-body source millions of degrees hot?

Also, why don't you do an estimate of the magnetic field necessary to overwhelm the magnetic pulse generated by the nuclear blast itself?

Take it from somebody who actually used to do nuclear physics professionally, these aren't these kinds of magnitudes. You are proposing an equivalent of trying to stop a locomotive with a wet newspaper. Not a pile of them, just one paper.

[JoeSchmuckatelli]

1 hour ago, Gargamel said:

Getting my popcorn ready for this one.   

You and me both.

 

[kerbiloid]

8 hours ago, JoeSchmuckatelli said:

Researchers at the National Ignition Facility at the Lawrence Livermore National Lab in California were able to spark a fusion reaction that briefly sustained itself

http://large.stanford.edu/courses/2015/ph241/chung1/

They did it!

3 hours ago, Spacescifi said:

In space nuked do much less damage in vacuum.

Then pusher plates don't work.

[monophonic]

2 hours ago, K^2 said:

And the X-Ray radiation from a black-body source millions of degrees hot?

Also, why don't you do an estimate of the magnetic field necessary to overwhelm the magnetic pulse generated by the nuclear blast itself?

Take it from somebody who actually used to do nuclear physics professionally, these aren't these kinds of magnitudes. You are proposing an equivalent of trying to stop a locomotive with a wet newspaper. Not a pile of them, just one paper.

May I propose autogravitational confinement? Use enough of the fusion fuel that the gravitational pull of the fuel itself will keep the fusion process confined. It might be necessary to build this in space to minimize interference from the Earth's gravity. Then we would need to transmit the generated power via radiation. Might need large fields of receiver arrays to keep the volumetric intensity of the beam safe to birds and aircraft that happen to pass through.

[kerbiloid]

Just now, monophonic said:

May I propose autogravitational confinement?

Of the Xray photons?

They call it kugelblitz.

[Gargamel]

24 minutes ago, kerbiloid said:

Of the Xray photons?

They call it kugelblitz.

And we’re into Type III civilizations.  

[monophonic]

18 minutes ago, kerbiloid said:

Of the Xray photons?

They call it kugelblitz.

An inactive layer of fuel surrounding the fusion reaction should handle those sufficiently. That would automatically supply the reaction with new fuel as it is consumed, which is a nice bonus.

Here, I dug up some concept art for you so you might better understand  my proposal:

 

4 minutes ago, Gargamel said:

And we’re into Type III civilizations.  

Type Zero might be close enough.

[kerbiloid]

47 minutes ago, monophonic said:

An inactive layer of fuel surrounding the fusion reaction should handle those sufficiently. That would automatically supply the reaction with new fuel as it is consumed, which is a nice bonus.

Here, I dug up some concept art for you so you might better understand  my proposal:

Yes. 

They call such things "stars". They contain the pressure of fusion by self-gravity.

[monophonic]

40 minutes ago, kerbiloid said:

Yes. 

They call such things "stars". They contain the pressure of fusion by self-gravity.

Now you got it! 

[K^2]

2 hours ago, monophonic said:

May I propose autogravitational confinement?

I'm sad that people don't seem to get this one. 

[Gargamel]

53 minutes ago, monophonic said:

Now you got it! 

But we’re looking to do this on earth’s surface. 

[K^2]

39 minutes ago, Gargamel said:

But we’re looking to do this on earth’s surface. 

I mean, you can still use Earth's gravity. Subterranean nuclear tests create nice, warm, pressurized cavities. You can definitely extract energy from that. Is that going to be efficient? No. You'll get more energy from a conventional nuclear reactor built from just the fissile materials used in the primary than you would by blowing up the secondary with and trying to harness the heat. And forget about sustained power from something like this. But if you really, really wanted to extract electric power from a nuclear blast, that's how you do it.

Likewise, in a nuclear-pulse drive, you can extract heat from the pusher plate to power various systems on your ship. It's just a tiny fraction of the nukes, but it should still be plenty for life support etc.

So it's not that getting a bit of power from a nuclear bomb is a bad idea. It's just the part about using it to light sustained fusion.

[kerbiloid]

1 hour ago, Gargamel said:

But we’re looking to do this on earth’s surface. 

We need a manageable gravitational constant to vary it locally, in a chamber.

(As happilym the gravitation plays no role at all in subterranean explosions, so we can freely omit them.)

[JoeSchmuckatelli]

6 hours ago, K^2 said:

I'm sad that people don't seem to get this one. 

Okay - to be fair, it took me a moment.  I started to read it, thought he wrote 'anti-gravitational confinement' rolled my eyes, then went back to read it again and saw it was auto-gravitational and my spidey-sense finally kicked in.  I did have to work out what that would look like, in space, and the light finally came on!

It's like the first time I started complaining to my kids about them being exposed to dihydrogenmonoxide in their school.  I told both of them to ask the science teacher for a safety sheet.

(They did not really appreciate it at the time, but we laugh now)

So @monophonic gets two points for teaching me a new one!

Edited January 28, 2022 by JoeSchmuckatelli

[Kerwood Floyd]

14 hours ago, K^2 said:

The temperatures involved are too high for any matter to stay unionized

Which union represents matter?    Has the union complained to the labor relations board about this?

[K^2]

4 hours ago, Kerwood Floyd said:

Which union represents matter?    Has the union complained to the labor relations board about this?

It's the Coulomb Potential Union. Generally, they prefer to remain neutral, but sometimes things can get polarized. They also have strict rules about not working under conditions of anything over a few thousand Kelvin, so if that ever happens, things tend to disintegrate rather fast.

Also, thank you for pointing it out. Knowing that spelling of un-ionized vs union-ized is ambiguous is my favorite factoid of the day.

[Kerwood Floyd]

3 minutes ago, K^2 said:

It's the Coulomb Potential Union. Generally, they prefer to remain neutral, but sometimes things can get polarized. They also have strict rules about not working under conditions of anything over a few thousand Kelvin, so if that ever happens, things tend to disintegrate rather fast.

Also, thank you for pointing it out. Knowing that spelling of un-ionized vs union-ized is ambiguous is my favorite factoid of the day.

Well played, sir!

[JoeSchmuckatelli]

Would a terrestrial planet of the same diameter as the earth in orbit around a higher metallicity sun-like star than the sun be likely to be more massive? 

 

(i.e. Is that how metallicity works - if the star is similar but has higher metallicity, would we expect a higher percentage of heavier elements in the planets - such that a similar volume =higher mass?)