Discussion of metallic hydrogen propulsion split from another thread.

[Guest]

Just now, XLjedi said:

Argh... thems a lot of text and numbers; and we are but simple pirates.

So how fast does it go?

About 1% of the speed of light, given a mass ratio of about 2.7. If you remember the fission fragment rocket, this has a similar exhaust velocity, but with NTR-level thrust.

[XLjedi]

Just now, Dragon01 said:

About 1% of the speed of light, given a mass ratio of about 2.7. If you remember the fission fragment rocket, this has a similar exhaust velocity, but with NTR-level thrust.

Pffft…  might as well get out and push. 

I'll just meet you at the next star in multiplayer after the game ships.

[MechBFP]

29 minutes ago, Dragon01 said:

Emphasis mine. This doesn't mean it won't have any interesting properties, but the days of MetH2 as a miracle rocket fuel are over.

You do realize this doesn’t apply, because it’s not referring to meta-stable metallic hydrogen (which doesn’t exist yet, or maybe ever), right?

Edited February 20, 2020 by MechBFP

[Guest]

The only way MetH2 was going to be viable as a rocket fuel was metastability. That's literally the only way it would make sense. Otherwise, you've got yourself a diamond anvil as a fuel tank, and your MetH2 engine becomes a glorified cold gas thruster. There are better ways to store energy.

Also, not to be entirely negative, BLACK SOLAR PANELS!  Now, this is an example of Star Theory doing the Right Thing. I've been waiting for that one a long time. 

Edited February 20, 2020 by Guest

[MechBFP]

2 minutes ago, Dragon01 said:

The only way MetH2 was going to be viable as a rocket fuel was metastability. That's literally the only way it would make sense. Otherwise, you've got yourself a diamond anvil as a fuel tank, and your MetH2 engine becomes a glorified cold gas thruster. There are better ways to store energy.

Also, not to be entirely negative, BLACK SOLAR PANELS!  Now, this is an example of Star Theory doing the Right Thing. I've been waiting for that one a long time. 

It’s no longer Star Theory apparently. Check the other news post. No name for the new dev group yet it seems.

[Guest]

I'll keep calling them Star Theory until they come up with a new name.  We've got to call them something. 

Edited February 20, 2020 by Guest

[Dirkidirk]

21 minutes ago, XLjedi said:

Pffft…  might as well get out and push. 

I'll just meet you at the next star in multiplayer after the game ships.

 

23 minutes ago, Dragon01 said:

About 1% of the speed of light, given a mass ratio of about 2.7. If you remember the fission fragment rocket, this has a similar exhaust velocity, but with NTR-level thrust.

somehow the guys at Icarus interstellar made one that can go to 8.6% of the speed and slow down at the destination star system, without the use of a magnetic sail.

https://i4is.org/reaching-the-stars-in-a-century-using-fusion-propulsion/

[Guest]

What I linked is an engine, not a spacecraft. You can make it go 8.6%c, or much higher as a matter of fact, just by packing more propellant. 

I went with mass ratio of 2.7, because it's reasonably close to e, and if your mass ratio is e, then your dV equals your exhaust velocity (which helps you put it in perspective). A mass ratio of e is, in fact, rather small.

Edited February 20, 2020 by Guest

[Dirkidirk]

 

On 2/20/2020 at 1:01 PM, Dragon01 said:

What I linked is an engine, not a spacecraft. You can make it go 8.6%c, or much higher as a matter of fact, just by packing more propellant. 

I went with mass ratio of 2.7, because it's reasonably close to e, and if your mass ratio is e, then your dV equals your exhaust velocity (which helps you put it in perspective). A mass ratio of e is, in fact, rather small.

oh, ok.

Edited October 26, 2020 by Dirkidirk

[theJesuit]

2 hours ago, MechBFP said:

It’s a game, not an engineering simulator built for Elon Musk. 

Are you sure about that?

Actually maybe Elon could make more moolah by packaging up SpaceX design simulator with green people 

[Danilo Coelho]

3 hours ago, Dragon01 said:

Very disappointed by all the talk of metallic hydrogen. It doesn't work. It's done, busted, dead, nailed to the wall and buried six feet under. Please, just quietly ditch this and repurpose the assets, because that thing is an embarrassment. It's not "an unsolved engineering problem", it's bloody impossible. It's depressing to see them being so passionate about a debunked idea and so much science going into figuring out how something nonexistent would look. This will never be a thing in reality. Metallic hydrogen just isn't metastable.

Nerrrrrrrrd

[NoMrBond]

4 hours ago, Dragon01 said:

Very disappointed by all the talk of metallic hydrogen. It doesn't work. It's done, busted, dead, nailed to the wall and buried six feet under. Please, just quietly ditch this and repurpose the assets, because that thing is an embarrassment. It's not "an unsolved engineering problem", it's bloody impossible. It's depressing to see them being so passionate about a debunked idea and so much science going into figuring out how something nonexistent would look. This will never be a thing in reality. Metallic hydrogen just isn't metastable.

If you go back through history everything we use, do and even take for granted in modern life was considered ‘impossible’ before it suddenly wasn't

Talk over wires? impossible!

A machine which can calculate? Impossible!

Rocks falling from the sky? Impossible!

Talk without wires? impossible!

Split the atom? Impossible!

Heavier than air flight? Impossible!

Learn what the stars are made of? Impossible!

Flying faster than the speed of sound? Impossible!

Send something into space? Impossible!

Entangle particles at a quantum level? Impossible!

Find planets around other stars? Impossible!

Detect gravity waves? Impossible?

 

Maybe the exact method, type, preparation or use depicted in the game might not come to pass but saying there will never be metallic hydrogen or a functional equivalent thereof just ignores that history is full of unreasonable people ignoring what other people tell them is impossible

Edited February 20, 2020 by NoMrBond

[Guest]

1 minute ago, NoMrBond said:

If you go back through history everything we use, do and even take for granted in modern life was considered ‘impossible’ before it suddenly wasn't

Sorry, but that's a load of weapons-grade BS. Not only you're wrong on all counts, you're missing the whole point. None of the things you stated were proven impossible, and the only people stating that were just about as ignorant as you are right now, or, at best, conflating "impossible" with "infeasible". What you described were engineering problems. Metallic hydrogen propulsion is not that. The only relevant example is splitting the atom, and quite frankly, nobody actually had the capability to try that when they named it. Once the capability came, atoms were quickly proven divisible. Now, imagine this didn't work, and atoms really were elementary particles. That's where MetH2 is now. We made it, and it fell apart. End of the story. No amount of wishful thinking will change that.

Try: 
Move a massive object at a speed above the speed of light.
Use a bladed propeller to push off from aether.
Extract liquid heat in pure form.
Walk off the edge of Earth. 
Cure diseases by balancing humors. 

Go find me an instance of any of this ever having a change of happening. Well, metallic hydrogen propulsion, courtesy of the article I linked a few posts back, had joined this list recently. As much as you might wish it was possible, or could become possible through some kind of magic, it won't. The data is solid, and there's not enough hysteresis to use that for propulsion. Hydrogen just doesn't act that way, so it's time to scrap the concept and move on. The devs wished KSP2 to be grounded in science, and well, scientific theories are sometimes disproven.

[MechBFP]

@Dragon01 you assume it’s disproven because it hasn’t been successfully made yet. How does that prove anything?

Maybe the pressure has not been high enough yet, maybe it’s only meta-stable at higher than 1 atm pressures but within realistic storage pressures, perhaps its only meta stable when combined with other elements under pressure.

Virtually nothing has even been tested yet, yet you claim it has been proven false?

Better go tell all those researchers I guess.

[Guest]

37 minutes ago, MechBFP said:

@Dragon01 you assume it’s disproven because it hasn’t been successfully made yet. How does that prove anything?

But it has been made already. It isn't metastable. If you ask any serious researcher currently working on it, they're not hoping for metastability. If it was metastable at realistic bulk storage pressures, we'd have known already. That does not mean it's worthless to jack the pressure up further, but it's not for making rocket fuel. There are many interesting properties it could have, and it'll tell us about interior of Jupiter and Saturn, where those kinds of pressures occur naturally.

At some point, you'll all have to accept that metallic H2 aren't going to happen. That's why KSP2 can't have them. They shouldn't give people hyped up for a future that we know will never come to be. Let people forget metallic H2 propellant, and get them on NTRs, fusion propulsion, solar sails, MPDs and all the other cool technology that doesn't require breaking physics.

[MechBFP]

18 minutes ago, Dragon01 said:

But it has been made already. It isn't metastable. If you ask any serious researcher currently working on it, they're not hoping for metastability. If it was metastable at realistic bulk storage pressures, we'd have known already. That does not mean it's worthless to jack the pressure up further, but it's not for making rocket fuel. There are many interesting properties it could have, and it'll tell us about interior of Jupiter and Saturn, where those kinds of pressures occur naturally.

At some point, you'll all have to accept that metallic H2 aren't going to happen. That's why KSP2 can't have them. They shouldn't give people hyped up for a future that we know will never come to be. Let people forget metallic H2 propellant, and get them on NTRs, fusion propulsion, solar sails, MPDs and all the other cool technology that doesn't require breaking physics.

Once again, please provide these sources that prove it “breaks physics”. I have yet to see any. 
The only thing you have proven is that (what is believed to be) pure metallic hydrogen converts back once the pressure has been lowered in that particular study, in that particular test, in those particular conditions.
That is hardly a smoking gun that it is impossible to be created in any fashion what so ever.

I agree that creating absolutely perfect theoretical metallic hydrogen is likely impossible, as is engineering *anything* to meet the theoretical limits of anything.

 

Edited February 20, 2020 by MechBFP

[XLjedi]

31 minutes ago, Dragon01 said:

At some point, you'll all have to accept that metallic H2 aren't going to happen. That's why KSP2 can't have them. They shouldn't give people hyped up for a future that we know will never come to be. Let people forget metallic H2 propellant, and get them on NTRs, fusion propulsion, solar sails, MPDs and all the other cool technology that doesn't require breaking physics.

It's too late for me... 

I've already bought into the feasibility of Mystery Goo.  Pretty sure that's why Toys-R-Us went outta business; they were just sellin the stuff to anyone straight off the shelf!  NASA had to step in to shut it all down...  and then Space Force was formed to make sure it doesn't get outta control like that again.

 

 

[Guest]

26 minutes ago, MechBFP said:

That is hardly a smoking gun that it is impossible to be created in any fashion what so ever.

OK, so what's your evidence towards it working? The theoretical predictions that started the whole metallic hydrogen thing were highly speculative in first place, and so far, experiments had failed to reproduce that prediction, and it seems that particular model was incorrect. I am not aware of any theoretical studies indicating that it might yet be possible under some funny conditions. Metastability was a long shot in first place, predicted to exist exactly because of unique properties of hydrogen atom. Any additions, aside from reducing the specific impulse quite steeply (everything is heavier than hydrogen), do not help with that. 

We have zero evidence for it. Depending on your interpretation, we may or may not have evidence against it.That is not enough to go around telling people it's the drive of the future. The theory that predicted it being metastable in the "normal" metallic phase was incorrect. If you want to hope that it's just a quantitative error and not qualitative one, well, you can hope, but it's not very probable. It's far more likely that it simply isn't metastable.

Edited February 20, 2020 by Guest

[MechBFP]

You must really hate Star Trek I take it?

[NoMrBond]

1 hour ago, Dragon01 said:

Sorry, but that's a load of weapons-grade BS. Not only you're wrong on all counts, you're missing the whole point. None of the things you stated were proven impossible, and the only people stating that were just about as ignorant as you are right now, or, at best, conflating "impossible" with "infeasible". What you described were engineering problems. Metallic hydrogen propulsion is not that. The only relevant example is splitting the atom, and quite frankly, nobody actually had the capability to try that when they named it. Once the capability came, atoms were quickly proven divisible. Now, imagine this didn't work, and atoms really were elementary particles. That's where MetH2 is now. We made it, and it fell apart. End of the story. No amount of wishful thinking will change that.

Try: 
Move a massive object at a speed above the speed of light.
Use a bladed propeller to push off from aether.
Extract liquid heat in pure form.
Walk off the edge of Earth. 
Cure diseases by balancing humors. 

Go find me an instance of any of this ever having a change of happening. Well, metallic hydrogen propulsion, courtesy of the article I linked a few posts back, had joined this list recently. As much as you might wish it was possible, or could become possible through some kind of magic, it won't. The data is solid, and there's not enough hysteresis to use that for propulsion. Hydrogen just doesn't act that way, so it's time to scrap the concept and move on. The devs wished KSP2 to be grounded in science, and well, scientific theories are sometimes disproven.

Your position requires believing that our current understanding of metH2/mH2 is both perfect and complete and no further advancement will ever be made, which in my view makes the comparison to the stated cases entirely apt

Have we made all possible forms of metallic hydrogen, do we understand all those forms completely, in every permutation and condition? No, so on what basis can we steadfastly and absolutely extrapolate from our extremely limited understanding of metallic hydrogen that it is not and will always be impossible?

[Guest]

No, because it isn't claiming to be teaching anyone anything (except an odd moral of the story). Star Trek is pure fantasy. KSP2, on the other hand... well, just watch the video if you have any doubts. The devs make a big, big deal about sticking to real science... while working off what is basically a recently invalidated model. I do hate all the peddlers of pseudoscience and quackery. If the devs wanted to add cold fusion to KSP2, I'd react the exact same way.

Just now, NoMrBond said:

Have we made all possible forms of metallic hydrogen, do we understand all those forms completely, in every permutation and condition? No, so on what basis can we steadfastly and absolutely extrapolate from our extremely limited understanding of metallic hydrogen that it is not and will always be impossible?

See a few posts up, then think a little about it: why, exactly, would hydrogen be metastable in first place? The answer is, of course, there was a somewhat far-fetched, but valid theory that predicted such behavior. This theory had been disproved, because we're not seeing metastability where it said we should.

This sort of thing is not the normal way for anything to behave, and depends on certain unique properties of hydrogen. It turned out not to work like this. Those scientists are not poking around and see what they can find. They're testing a scientific theory that someone calculated. Point me to a theory that correctly predicts the recent discoveries and allows for metastability somewhere else, and you can have your MetH2. I'll wait. 

Edited February 20, 2020 by Guest

[ElJugador]

15 minutes ago, Dragon01 said:

No, because it isn't claiming to be teaching anyone anything (except an odd moral of the story). Star Trek is pure fantasy. KSP2, on the other hand... well, just watch the video if you have any doubts. The devs make a big, big deal about sticking to real science... while working off what is basically a recently invalidated model. I do hate all the peddlers of pseudoscience and quackery. If the devs wanted to add cold fusion to KSP2, I'd react the exact same way.

See a few posts up, then think a little about it: why, exactly, would hydrogen be metastable in first place? The answer is, of course, there was a somewhat far-fetched, but valid theory that predicted such behavior. This theory had been disproved, because we're not seeing metastability where it said we should.

This sort of thing is not the normal way for anything to behave, and depends on certain unique properties of hydrogen. It turned out not to work like this. Those scientists are not poking around and see what they can find. They're testing a scientific theory that someone calculated. Point me to a theory that correctly predicts the recent discoveries and allows for metastability somewhere else, and you can have your MetH2. I'll wait. 

You need to relax and realize those findings were made very, very recently. ST has probably been working on metallic hydrogen while being totally unaware of whatever it is is making you so certain it's useless as rocket propellant.

[Guest]

Yes, I realize that. If you want to teach science, however, you absolutely need to stay on top of those things. MetH2 was a risky shot. Yes, they're not scientists, but they are taking upon themselves a mission to show people the future of spaceflight (they said as much in the video). This sort of thing is severely needed, but it has to focus on things that, you know, actually work. The general public is already clueless and misinformed about science in general. Feeding them myths won't improve this. Generally, when a scientists tells you something can't work and a game dev tells you it can, most people will believe the dev (silly as it might be). This is why we need devs and so on to say the same things scientists do. KSP2 could do a lot for nuclear propulsion in particular (KSP1's NERV already has people asking "hey, that thing's awesome, why don't we have that?") and power. That is the future of spaceflight.

[ElJugador]

17 minutes ago, Dragon01 said:

Yes, I realize that. If you want to teach science, however, you absolutely need to stay on top of those things. MetH2 was a risky shot. Yes, they're not scientists, but they are taking upon themselves a mission to show people the future of spaceflight (they said as much in the video). This sort of thing is severely needed, but it has to focus on things that, you know, actually work. The general public is already clueless and misinformed about science in general. Feeding them myths won't improve this. Generally, when a scientists tells you something can't work and a game dev tells you it can, most people will believe the dev (silly as it might be). This is why we need devs and so on to say the same things scientists do. KSP2 could do a lot for nuclear propulsion in particular (KSP1's NERV already has people asking "hey, that thing's awesome, why don't we have that?") and power. That is the future of spaceflight.

For my part, I just dislike how they focused far too much on the metallic hydrogen and gave everything else short shrift, especially torchdrives... those beasts deserve better than a vague throwaway line.

[NoMrBond]

10 minutes ago, Dragon01 said:

See a few posts up, then think a little about it: why, exactly, would hydrogen be metastable in first place? The answer is, of course, there was a somewhat far-fetched, but valid theory that predicted such behavior. This theory had been disproved, because we're not seeing metastability where it said we should.

This sort of thing is not the normal way for anything to behave, and depends on certain unique properties of hydrogen. It turned out not to work like this. Those scientists are not poking around and see what they can find. They're testing a scientific theory that someone calculated. Point me to a theory that correctly predicts the recent discoveries and allows for metastability somewhere else, and you can have your MetH2. I'll wait. 

You're citing one failed experiment as a complete and irrevocably closed door for an entire area of study

A single hypothesis regarding metH2/mH2 meta-stability didn't work out, so science moves on to the next, like so;

Jeffrey M. McMahon at the Department of Physics & Astronomy tested Diamond, β-Sn and Cs-IV types of met-H2 in 2017, and found that Cs-IV type stayed metastable until 250GPa while the later conformations started breaking down ~300GPa.  While these particular forms are probably not practical but forms which are metastable were discovered.  The paper is called "On the possibility of metastable metallic hydrogen" by Craig M. Tenney, Keeper L. Sharkey, Jeffrey M. McMahon; arXiv:1705.04900 [cond-mat.mtrl-sci]