Discussion of metallic hydrogen propulsion split from another thread.

[Chilkoot]

32 minutes ago, Dragon01 said:

I draw the line at insisting Kerbals, or any other unreal thing, is real.

I'm curious about your take on the implementation of:

• Reaction wheels
• Solar generation
• Battery power density per unit weight
• The speed of light

Do you apply realism mods for all of these including about a half-dozen other non-realities that are tweaked solely for the purpose of gameplay?

Let's be 100% crystal clear here:  while this game represents some fun and important aspects of the engineering and physics behind space exploration, it is in no way an accurate simulator and never has been.

[Guest]

10 minutes ago, Brikoleur said:

I got to ask you this @Dragon01: are you a high-pressure physicist? If not, what are your qualifications regarding this question? 

I am a physicist, and I was fiddling about with material science before switching over to biophysics (to end up mostly doing biology as of recently, funnily enough). The problem with those alloys is that they're not what you want for rocket fuel. They're being investigated for superconductivity. The reason is that anything you mix in adds heavy atoms (bad for Isp) and make metallic phase transition occur at a lower pressure. That causes the energy stored inside to plummet. A metallic hydrogen alloy, even a metastable one, will not be all that useful as a rocket fuel. You'd need either the pure MetH2 or a very slightly doped form, which is unlikely to prove metastable at this point. We're not trying things at random, there is sufficient theoretical literature to make such a conclusion.

I'm not ruling out metallic hydrogen being useful for something. However, I am saying that this something will not be energy storage for rockets. One of its alloys might be a high temperature superconductor, for example. That said, I am definitely of the opinion that we simply do not have enough to start teaching Kerbal-loving kids about this sort of thing. As I said in the other thread, we either know if it doesn't work, or we don't know anything. There's a more detailed discussion in a thread linked a page or so back.

Just now, Chilkoot said:

I'm curious about your take on the implementation of:

• Reaction wheels
• Solar generation
• Battery power density per unit weight
• The speed of light

1. Nerf (and rename to Control Moment Gyros). They're far too powerful in stock. People should learn to use RCS for turning.
2. Nerf, it's far too easy to slap some random solar panels and call it a day (until the night comes, that is  ). Probe design is a joke right now, there's almost no thought going into it compared to LVs. Give us some big blanket panels and alternate power options to compensate.
3. Rework of the batteries is sorely needed. Anyone who ever did RC drones knows these things are heavy. It would actually make for a much better gameplay, too, KSP1 electrical system is rather tacked on, in general.
4. You control either the crew or the AI inside the probe. Duh. And if you mean what happens when you reach speed of light, well, you're well outside the parameters by that point (and, in a few seconds, the Kerbal universe).

Also note, there's nothing that MetH2 specifically brings to the table. All these four things are quantitative differences. Stop equating them with a qualitative difference.

[Superfluous J]

7 hours ago, Brikoleur said:

Not in the least.

I do find this entire discussion completely pointless however.

It just hammers home the brilliance of calling the fuel in KSP "Liquid Fuel" instead of specifying anything.

Call MetH2 "MetaFuel" and everybody's* happy.

*Read: Not everybody

[Guest]

Well, it's certainly better to mark this as outright fiction. It'll stick out like a sore thumb, but at least you're not spreading myths. However, coming up with an alternative drive, such as the NSWR, to fill that spot would be far more satisfying.

[Dirkidirk]

4 hours ago, KerikBalm said:

Well if they explicitly say it is electron beam ICF... then yea, if its instead a more generic ICF engine, I am fine with that.

It seems clear that ICF can work, but it may need to be at a very large scale.

Its a hard engineering problem, but some form of net energy from fusion is possible. We don't have anything right now with a power output less than an exploding nuke, but we do have ways of getting net energy from fusion.

I'd rather have them be vague than wrong.

If all they get wrong is the minimum engine size, I am ok with that.

I am not ok with metallic hydrogen, given the current state of the research, with only very bad predictions from the 1970's to go on (they got the pressures required spectacularly wrong, why put any stock in their other predictions, when there isn't a shred of experimental evidence that agrees with or supports those predictions?)

Scratch that.

You know something else that *probably* does work but *might* not, or do not do

http://www.icarusinterstellar.org/e-beam-icf-for-daedalus-reconsidered/

1 hour ago, genbrien said:

the point is: its still a game
they try to make it realistic in many ways, but call it anyway you want: its a game to have fun

Yee

1 hour ago, MechBFP said:

Metallic Hydrogen is real science though. So in order to use it as a fuel those Kerbal fuel tanks just hold it at 600 Gpa using Kerbal skin and bones as structural support.

Problem solved.

 

Even more yee

[Guest]

It’s actually a shame... they put out a vid which is what people have been begging for for a long time and I guess there will always be something people aren’t happy with. 
 

Here’s hoping for more updates in the near future. And here’s hoping modders will be able to fix the game for everyone’s tastes.

[Dirkidirk]

1 minute ago, Dale Christopher said:

It’s actually a shame... they put out a vid which is what people have been begging for for a long time and I guess there will always be something people aren’t happy with. 
 

Here’s hoping for more updates in the near future. And here’s hoping modders will be able to fix the game for everyone’s tastes.

But the Torch Ships MAAAN! 

[mcwaffles2003]

10 hours ago, Dragon01 said:

 That said, I am definitely of the opinion that we simply do not have enough to start teaching Kerbal-loving kids about this sort of thing. As I said in the other thread, we either know if it doesn't work, or we don't know anything. There's a more detailed discussion in a thread linked a page or so back.

If you're concern is largely about spreading disinformation to kids coming into the field then I think you missed where the educational aspect of KSP was. 

In all of KSP we never really learned about the material science of different fuels aside from thrust = power and ISP = efficiency. Largely the education came in the form of the introduction of basic Newtonian mechanics, mostly in orbital mechanics. I really don't think having a likely imaginary fuel is going to harm the educational experience any more than insisting that long term space habitation isn't hazardous via life support and radiation (since kids these days might actually end up going to space). 

10 hours ago, Dragon01 said:

Well, it's certainly better to mark this as outright fiction. It'll stick out like a sore thumb, but at least you're not spreading myths. However, coming up with an alternative drive, such as the NSWR, to fill that spot would be far more satisfying.

I would enjoy having more engines like this in the game and if they are absent I will certainly download the mod that includes them. 

 

As far as any concern I have for the game itself goes, my only concern is that it provides a stable platform for all of us to make the game we want out of it. Be that raw factual science or utterly fictional, to the present or the distant future, among one planet or among many across multiple systems, by myself or with some friends. I just want it to be fun enough that more would like to join without sacraficing the challenge 

Edited February 22, 2020 by mcwaffles2003

[NoMrBond]

13 hours ago, Dragon01 said:

No, I'm citing one experiment (it didn't fail, just produced a result you don't like) as disproving a theory (from the 70s, cited in your citation) which predicted metastability in those conditions. Which is exactly what it did. Other theories do not predict metastability at 0GPa, even the one you cited. I should also note, these are theoretical results. They didn't actually discover anything, they predicted metastable forms. Whether hydrogen assumes these forms under any pressure at all is an open question (it doesn't seem to). Recent theoretical work doesn't seem to predict metastabiliy in an usable range. I don't have access to the 70s papers, but given what they could do at the time, the result was most likely something like "well, looks like it might be metastable, hopefully all the way to 0GPa". Basically, the idea that MetH2 would work in a rocket is based on extrapolation of old, inexact theoretical calculations. It was a nice thing to hope for, but not something to bet on.

Like? A hypothesis is something to be tested (to destruction if necessary, as this one was), not a puppy or a flavour of ice-cream.

I am open to the possibility that advances in science, materials and engineering might one day provide a answer, as has frequently been the case throughout history

[Guest]

6 hours ago, Dragon01 said:

You'd need either the pure MetH2 or a very slightly doped form, which is unlikely to prove metastable at this point.

So in your view the question isn’t quite settled yet either. Thank you for admitting that even if it weakens your argument. I wish you had been less categorical about it to start with — as you said, spreading misconceptions about science is pernicious, and presenting a question as definitively settled when in fact it is still open is spreading a misconception.

With that though I am definitively out of this discussion. As I said earlier, I find it pointless, and moreover I take exception to the way you present your view of KSP as primarily a hard science educational tool as superior, more valid, or more representative of KSP players than my view of it as a lighthearted but challenging game of design involving rocket parts from Jeb’s junkyard and bouncy little green guys, with orbital mechanics a side benefit.

[kerbiloid]

Googled "MetH2".
Now I see how will these spaceships get speedy...

6 hours ago, Dale Christopher said:

they put out a vid which is what people have been begging for for a long time and I guess there will always be something people aren’t happy with. 

They are trying to metallize hydrogen in their shed with a mechanical press and air compressor, to prove the concept.

***

Does the atomic radius of hydrogen affect the possibility of the metastability?
What if we partially replace electrons with muons to make the hydrogen denser? Can it then become metastable?
Notice, that its atomic mass (so, ISP) stays same, and we can gain cold fusion as bonus.

Edited February 22, 2020 by kerbiloid

[mcwaffles2003]

3 hours ago, kerbiloid said:

What if we partially replace electrons with muons to make the hydrogen denser? Can it then become metastable?

Muons have a 2.2 microsecond lifetime, so I dont see how that would be possible

[Guest]

Just now, mcwaffles2003 said:

Muons have a 2.2 microsecond lifetime, so I dont see how that would be possible

Probably the same lifetime as metallic hydrogen in a fuel tank so seems like a good match.

[kerbiloid]

7 minutes ago, mcwaffles2003 said:

Muons have a 2.2 microsecond lifetime, so I dont see how that would be possible

I see, but as they are talking about superdense matter, maybe some lite version of that is possible
https://physics.stackexchange.com/questions/88346/possibility-of-stable-muonic-structures

Upd.
Let me suggest a name for the metallic muonohydrogen fuel: Dwarfonium

Edited February 22, 2020 by kerbiloid

[Guest]

2 minutes ago, kerbiloid said:

I see, but as they are talking about superdense matter, maybe some lite version of that is possible
https://physics.stackexchange.com/questions/88346/possibility-of-stable-muonic-structures

Hmm, they can keep their exotic matter drives, I just want to do hydrolox or metholox stuff anyway :p

[Incarnation of Chaos]

13 minutes ago, mcwaffles2003 said:

Muons have a 2.2 microsecond lifetime, so I dont see how that would be possible

When they replace an electron in a orbital they become stable, but that's besides the point. By the time you could reliably generate Muons then you're well past the point metallic hydrogen as a propellant is even a consideration; you're using antimatter at that point or Muon-Cataylized fusion torchships.

[mcwaffles2003]

Just now, kerbiloid said:

I see, but as they are talking about superdense matter, maybe some lite version of that is possible
https://physics.stackexchange.com/questions/88346/possibility-of-stable-muonic-structures

From your link:

Quote

Muonic atoms should be stable in electron-degenerate matter (white dwarf material) as long as the Fermi energy is more than mμ−memμ−me.

http://astronomy.swin.edu.au/cosmos/E/Electron+Degeneracy+Pressure

Quote

 

Electron degeneracy occurs at densities of about 10⁶ kg/m³.

https://en.wikipedia.org/wiki/Metallic_hydrogen

Quote

In March 1996, a group of scientists at Lawrence Livermore National Laboratory reported that they had serendipitously produced the first identifiably metallic hydrogen^[18] for about a microsecond at temperatures of thousands of kelvins, pressures of over 100 GPa (1,000,000 atm; 15,000,000 psi), and densities of approximately 0.6 g/cm³

 

We're gunna need some more pressure

Maybe we can harvest the material from the surface of white dwarfs :|

I just want to say... I love this forum. It's been a while since I was in my stars class or my particle physics class and going back over all this kind of material I haven't seen in forever is fun

[kerbiloid]

2 minutes ago, mcwaffles2003 said:

Maybe we can harvest the material from the surface of white dwarfs :|

I've suggested here long ago to build a scoop near a neutron star, in a natural magnetic accelerator. It's a pity we don't have any close to the Sun.

Edited February 22, 2020 by kerbiloid

[mcwaffles2003]

Just now, kerbiloid said:

I've suggested here long ago to build a scoop near a neutron star orbit, in a natural magnetic accelerator. It's a pity we don't have any close to the Sun.

White dwarf might be slightly easier to work with since it only has ~ 3.5E5 times earths surface gravity vs 1E11 with a neutron star

[kerbiloid]

1 minute ago, mcwaffles2003 said:

White dwarf might be slightly easier to work with since it only has ~ 3.5E5 times earths surface gravity vs 1E11 with a neutron star

And we have Sirius B, just 8.6 ly from here.
Don't know about the metallic hydrogen, but that's what we really need to visit instead of Centauri.

[kerbiloid]

(It's offtopic in this thread, but it's too little to have its own).

It's also a pity that, treating as normal the metallic hydrogen, KSP completely ignores the controversial hafnium bomb as a mid-class engine propellant.

https://en.wikipedia.org/wiki/Hafnium_controversy

[Incarnation of Chaos]

3 minutes ago, kerbiloid said:

(It's offtopic in this thread, but it's too little to have its own).

It's also a pity that, treating as normal the metallic hydrogen, KSP completely ignores the controversial hafnium bomb as a mid-class engine propellant.

https://en.wikipedia.org/wiki/Hafnium_controversy

Very off-topic content ahead!

Spoiler

I have a fictional story iv'e been (Attempting) to write for several years; long story short the main protag uses a free-electron laser on his ship to excite an entire sphere of Hf -178m^2 to create a massive gamma-ray burst in order to move the plot forward. This is because it was the only way i could think of to semi-realistically shift the FEL into these wavelengths, and even then it's not that easy.

 

[KerikBalm]

6 hours ago, Brikoleur said:

So in your view the question isn’t quite settled yet either. Thank you for admitting that even if it weakens your argument. I wish you had been less categorical about it to start with — as you said, spreading misconceptions about science is pernicious, and presenting a question as definitively settled when in fact it is still open is spreading a misconception.

I think you are misinterpreting what he said. There is no modern prediction of metastable mH. There is no experimental evidence of metastable mH.

Its like an athiest taking the position "I don't believe in god", vs the position "I believe there is no god". The latter being an affirmative claim with a burden of proof. Until such time as there is a reason to believe in metastable metallic hydrogen, we should not believe it exists.

An intellectually honest person wouldn't even say that they are certain there is no teapot orbiting between Earth and Mars... yes I am referring to Russel's Teapot:

https://en.wikipedia.org/wiki/Russell's_teapot

No intellectually honest person can claim that Russel's Teapot claim is definitively false, but one is well within reason to reject the claim as being "unlikely to prove metastable [true]at this point."

Until any evidence has been given for the possibility of a mH engine, it is reasonable to reject it. The burden of proof is not to show beyond a doubt that it is impossible. If that is the burden of proof, then we can just add in nearly whatever fantasy drive we want, with nearly whatever technobabble explanation that we want.

[MechBFP]

1 hour ago, KerikBalm said:

Until any evidence has been given for the possibility of a mH engine, it is reasonable to reject it.

Since evidence has been given, that evidence being the mathematics that say it should be possible, that means it is unreasonable to reject it. Correct?

After all, I have yet to see anything that proves the actual math is wrong, just experiments that haven’t worked out.

[DStaal]

2 hours ago, MechBFP said:

Since evidence has been given, that evidence being the mathematics that say it should be possible, that means it is unreasonable to reject it. Correct?

After all, I have yet to see anything that proves the actual math is wrong, just experiments that haven’t worked out.

The math also works for antigravity, FTL travel, warp drives, reversing an explosion, etc.

There was a slight chance in the math that it would be meta-stable.  That stability has not been seen in the metallic hydrogen made so far.  (Though we haven't made much of it - still it was something they were specifically looking for and interested in.)