Discussion of metallic hydrogen propulsion split from another thread.

[kerbiloid]

5 hours ago, OHara said:

 Probably there is a reasonable alternative at the Atomic Rockets page but it is large and I am unfamiliar.

Every useful thing has been already invented before.

 

[Guest]

8 hours ago, OHara said:

Okay, I suppose you're considering this context to be physical metastability.   So the the dry-ice form of CO₂  would be analogous.  But usually the physical phase change from solid to gas requires energy input.

But metallic hydrogen, as probably found at the core of Jupiter, certainly has different chemical bonds than the low-pressure form of H₂.  Those H-H bonds are happy to form, and in forming the release that huge amount of energy.  That's why I was thinking it more analogous to chemical monopropellant like 2H₂O₂→2H₂O + O₂ 

It's kind of borderline, but all literature on metallic hydrogen that I've seen talked about it in terms of physical metastability. I suppose that's due to how it's formed, and the fact it only ever involves hydrogen atoms. Chemical propellant is different, and I've never saw the term "metastable" used to describe HTP. It does decompose quite readily, but chemists generally use different terminology for that. Also, despite being touchy, it has its own phase transitions to solid and gas, although if you try to get the latter by heating it, you'll have a bad time. Hydrogen doesn't, the metallic phase is definitely more on the physical side.

BTW, physical change from solid to gas can very much involve energy output. Phase transition needs not to be caused by temperature. You can also use pressure to induce it, like with metallic hydrogen, and in that case, energy will be tied up in the material to bring it into a solid state. Of course, releasing the pressure will immediately cause the energy to be released. There are some metastable ice forms that will not release all of it at once, but they just turn into different kinds of ice.

Quote

I would guess the game-idea is to have off-Kerbin resources that enable interstellar engines, but the developers may very well have substituted something else for metallic hydrogen long ago, and we probably wouldn't know yet.

FYI, metallic hydrogen is far from being an interstellar engine, and from the devs' comments, its performance isn't all that high. They described the engines as being between advanced nuclear options and the NERVA-derived one we have in KSP1. In context of the other engine choices, it's pretty low down the ladder.

Edited October 8, 2020 by Guest

[kerbiloid]

Enough dense metallic hydrogen gives a blackhole engine.

[Deddly]

Reading up on this from various sources, I see that diamond is referred to as metastable. I thought metastable meant "stable provided it is subjected to no more than small disturbances". In that case, how can diamond be metastable, since it will never revert to carbon?

[OHara]

34 minutes ago, Deddly said:

how can diamond be metastable, since it will never revert to carbon?

I think that is the more common case where people say 'metastable'.  You could turn diamond to carbon if you heat it enough.  My father's job was to do the reverse, for industrial cutting diamonds.

At ambient pressure, graphite is a re-arrangement of the carbon atoms that has slightly less thermodynamic free energy than diamond, so the thermodynamics allows diamond to spontaneously rearrange into graphite, but not the other way around.  The fact that this rearrangement is so awkward, and  the energy difference so small, that diamond lasts forever at normal temperature is another important fact, and the usual word for that is 'metastable'.

The other metastable materials that spring to mind are white tin (the useful form) and martensite in knife steel, where the metastable form lasts a lifetime unless bend it back and forth to give the atoms an easier way to rearrange. 

[Guest]

4 hours ago, Deddly said:

Reading up on this from various sources, I see that diamond is referred to as metastable. I thought metastable meant "stable provided it is subjected to no more than small disturbances". In that case, how can diamond be metastable, since it will never revert to carbon?

Diamond is an odd case, because it is technically metastable, but the energy barrier between it and the actual lowest energy form is huge. It's one of the very few materials which exhibit such behavior, and the only one with energy barrier this big. Funnily enough, the actual difference between energy levels of diamond and graphite is quite small. Technically, for a material to be metastable, it only needs to have a state which is not, globally, the lowest energy one possible, but it is separated from it by higher energy states. The barrier doesn't have to be small. In fact, aside from diamond, there are some steels in which it's present, but quite large.

In most cases, metastability looks like the situation with pure tin below 13.2 degrees. Below this temperature, white tin is metastable, and will spontaneously change to gray tin, which becomes more likely the colder it gets, or if white tin is in contact with gray tin. Upon reheating above that temperature, it turns back.

Edited October 8, 2020 by Guest

[KerikBalm]

On 8/5/2020 at 4:44 AM, Dragon01 said:

I think they would care, if they only heard about it. Marketing and/or PR is probably keeping them in a bubble (just look at how consistently any direct refutation of metallic hydrogen is eradicated from the KSP2 board). It's been a while since they had a true, interactive session with the community.

Well, to be fair, these discussions do get rather heated* and do go heavy into the science, so I understand why threads may be moved or closed. And the lack of contact with the community in general is not MH specific.

* The reason that these discussions get heated, is because time and time again, for over a year now, people jump into a discussion without reading the previous posts, and post already refuted points, again and again and again, ad nauseum. This naturally leads to frustration, bueing curt with them, and flaring of tempers.

Its hapenning again. Just look

[please do not single people out for condemnation]

This post above does not add anything new to the discussion, completely misses the point (as has been pointed out time and time again) - no the question is not how to get there (PS, we've gotten there), and shows an ignorance of the subject in general.

I'm not going to bother typing a response to the content of that post, and will instead direct him to read the previous threads, everything in there has already been addressed, and the post ads absolutely nothing new to the discussion.

On 10/6/2020 at 10:49 PM, kerbiloid said:

As they brought the unnecessary MeH, they should add also the Cavorite.

[...]

Also a tank of Phlogiston would be great, to heat the Metal Hydrogen without engines-schmengines.

excellent suggestions of other examples to use other than aether propellors and pixie farts for propulsions based on outdated theories/things that can't be 100% disproven.

[please don't single people out for condemnation]

No it can't. Do you want to say that a Phlogiston rocket would also work "in theory", because you apparently don't care if its an old and disproven theory?

For elaboration on why "it can't", read previous posts and threads, I'm not going to go fetch all the links again or spend even more time because you couldn't do proper research.

 

Seriously, these threads are pointless. I'd prefer that a thread is simply locked and pinned to the top so its visible.

Its really just useless to have a thread that goes in circles.

If I may summarize this thread:

1) Post showing why MH won't work

2) post saying "but what about A"

3) Post refuting A

4) post saying "but what about B"

5) Post refuting B

6) post saying "but what about C"

7) Post refuting C

8) post saying "but what about D"

9) Post refuting D

10) post saying "Ok, but what about A"

11) Go back to 3) 

Continue for page after page, month after month, and now year after year.

Really, there's nothing productive happening in these threads.

Pin it, Lock it, forget about KSP2 as no news has come recently, and maybe get agitated over what happened to star theory.

Edited October 8, 2020 by Vanamonde

[kerbiloid]

Thanks.
Though, I would call this not "disproven theories", but "Old Times Romantics Propulsion".

Let me also remind the Chunk of Dark Matter from one of unfortunately outdated mods.
Once you detach it, it starts attracting everything around, so you can theoretically orbit around it in atmosphere or throw it forward to be attracted.

(It was still working in 1.8, but unfortunately unlikely can be redistributed for the license reasons).

[Guest]

[snip (moderator removed quote)]

To be fair I said I was late to the party.

Also please be careful with what you type. It can offend people (it didn't for me.)

Edited October 8, 2020 by Guest
moderator removed quote

[KerikBalm]

3 minutes ago, The Doodling Astronaut said:

To be fair I said I was late to the party.

Also please be careful with what you type. It can offend people (it didn't for me.)

Well, that's kind of my point. "People post already refuted points, again and again and again, ad nauseum ... This naturally leads to frustration, being curt with them, and flaring of tempers."

I acknowledge that I was not very tactful - neither trying to be polite nor rude. Fatigue has set it, and these discussion have not been productive debate in a long time.

 

[Bej Kerman]

6 hours ago, Dragon01 said:

Quote

I would guess the game-idea is to have off-Kerbin resources that enable interstellar engines, but the developers may very well have substituted something else for metallic hydrogen long ago, and we probably wouldn't know yet.

FYI, metallic hydrogen is far from being an interstellar engine, and from the devs' comments, its performance isn't all that high. They described the engines as being between advanced nuclear options and the NERVA-derived one we have in KSP1. In context of the other engine choices, it's pretty low down the ladder.

I'd say it's pretty compact and is pretty much at the top for any interplanetary vessels.

[Deddly]

9 minutes ago, KerikBalm said:

Well, that's kind of my point. "People post already refuted points, again and again and again, ad nauseum ... This naturally leads to frustration, being curt with them, and flaring of tempers."

This is no different from discussions in long-running mod threads that occur when someone says something like "When is this updated to <my version of KSP>?" or "Can you add this to CKAN please?" or "I found a bug" when these have already been responded to umpteen times previously in the thread. We can't expect people to read everything that's been written in every thread they respond to. The way to deal with it is to respond patiently that it is already covered in the thread. If a person cannot do that without being short tempered about it, the correct thing to do is to not respond at all. 

[KerikBalm]

2 minutes ago, Deddly said:

This is no different from discussions in long-running mod threads that occur when someone says something like "When is this updated to <my version of KSP>?"

Generally, those sort of posts are looked down upon.

Quote

"Can you add this to CKAN please?"

If its the same request, over and over again, you'd call them a troll.

Quote

The way to deal with it is to respond patiently that it is already covered in the thread.

Which I did for months on end, you really think that this is how conversations should go?

People doing 30 seconds of "research", and then making a post that requires several minutes to refute at a minimum?

Its like responding to Flat Earthers. Your failure to do the research does not obligate me to be patient with you. I can tell a flat eather that they are wrong without responding to every already disproven FE point, how many times do you explain that, no, perspective does not work that way, before you aren't willing to anymore.

Does that mean FE claims should go unchallenged? Antievolution claims? etc?

[Deddly]

18 minutes ago, KerikBalm said:

your failure to do the research does not obligate me to be patient with you

No, but the forum rules do. But now we're getting off topic.

[Guest]

4 hours ago, KerikBalm said:

Well, to be fair, these discussions do get rather heated* and do go heavy into the science, so I understand why threads may be moved or closed. And the lack of contact with the community in general is not MH specific.

* The reason that these discussions get heated, is because time and time again, for over a year now, people jump into a discussion without reading the previous posts, and post already refuted points, again and again and again, ad nauseum. This naturally leads to frustration, bueing curt with them, and flaring of tempers.

Its hapenning again. Just look

This post above does not add anything new to the discussion, completely misses the point (as has been pointed out time and time again) - no the question is not how to get there (PS, we've gotten there), and shows an ignorance of the subject in general.

I'm not going to bother typing a response to the content of that post, and will instead direct him to read the previous threads, everything in there has already been addressed, and the post ads absolutely nothing new to the discussion.

excellent suggestions of other examples to use other than aether propellors and pixie farts for propulsions based on outdated theories/things that can't be 100% disproven.

No it can't. Do you want to say that a Phlogiston rocket would also work "in theory", because you apparently don't care if its an old and disproven theory?

For elaboration on why "it can't", read previous posts and threads, I'm not going to go fetch all the links again or spend even more time because you couldn't do proper research.

 

Seriously, these threads are pointless. I'd prefer that a thread is simply locked and pinned to the top so its visible.

Its really just useless to have a thread that goes in circles.

If I may summarize this thread:

1) Post showing why MH won't work

2) post saying "but what about A"

3) Post refuting A

4) post saying "but what about B"

5) Post refuting B

6) post saying "but what about C"

7) Post refuting C

8) post saying "but what about D"

9) Post refuting D

10) post saying "Ok, but what about A"

11) Go back to 3) 

Continue for page after page, month after month, and now year after year.

Really, there's nothing productive happening in these threads.

Pin it, Lock it, forget about KSP2 as no news has come recently, and maybe get agitated over what happened to star theory.

Except this post was moved back here in the KSP2 section precisely because "it's plausible!" "No it's not" was not the whole debate.

[Vanamonde]

Please get back to the subject, and while there, don't single people out as examples of bad conduct. Even if you're right, it just makes people mad and lowers the tone of the forum. Those remarks have been removed. 

[Entropian]

Ok, just, people.  Calm.  Down.  So far as I can see, over the last year (I lurked long before I registered) the MH debate has 2 sides:

1. Metallic Hydrogen is not plausible because of X, Y, and Z.
2. Metallic Hydrogen is plausible because of potential advances in technology in the future, etc, etc.

Arguing over this is pointless.  It has already been shown that, overall, the people who think MH is plausible are sticking to their opinions, and the people who think MH is not plausible are sticking to their opinions.

If this stays in the game, it seems MH will become something people may ban in their challenges, shame others for using, and many more unpleasant things.  Obviously, this is a hotly contested topic among users, so, why don't you guys just try to work together and find something else that can replace MH instead of going in circles debating something that seems to be going nowhere?  @Dragon01 already pointed out that a liquid-core NTR has near-identical statistics to what a theoretical MH engine would have, and there may be other engines that also have the same characteristics.

At this point, does it even matter if MH is viable?  It seems that there will always be the arguments "Yes it is!" and "No it isn't!" debating to have it in the game or not.  At this point, I would think that the cost of arguing over this has far outweighed the benefits/detriments of having MH in the game.  Just find common ground, and find a replacement!  Work together instead of against each other!

Probably I should also link to this:

I have tried to make this post as neutral as possible.  Please don't interpret this as being on one side of the argument or another.

[Guest]

The problem is, that, in fact there are three debates going on in this thread, more or less in parallel:
1. Is metastable metallic hydrogen scientifically plausible?
2. Should metallic hydrogen be in KSP2?
3. Should question 1 matter when it comes to question 2?

A lot of harm had been done by lumping any attempts at discussing 2 into a thread originally about 1, leading to those discussions being muddled. 3 being a point of contention for some doesn't help, and in fact is the source of all the trouble. However, i shall point to another thread, where community weighed in on 3, and "yes" is clearly the favored answer, when put in more generic terms:

For the record, my position on the three:
1. Scientific evidence (links in sig) had disproven the theory that led us to believe metallic hydrogen might be metastable. Absent any other evidence, we have no reason to expect it to be.
2. No, it shouldn't, because the answer to 3 is yes and to 1 is no.
3. KSP2, as an educational game about science, should act responsibly and not include any technology based on disproved and fringe theories, and especially not on outright bad science.

[mcwaffles2003]

3 minutes ago, Dragon01 said:

For the record, my position on the three:
1. Scientific evidence (links in sig) had disproven the theory that led us to believe metallic hydrogen might be metastable. Absent any other evidence, we have no reason to expect it to be.
2. No, it shouldn't, because the answer to 3 is yes and to 1 is no.
3. KSP2, as an educational game about science, should act responsibly and not include any technology based on disproved and fringe theories, and especially not on outright bad science.

I agree, and with that a new question comes up. If metastable metallic hydrogen is not a viable rocket fuel but the engines specs served as a useful, or even a borderline necessary feature, what can suitably replace it?

There are candidates for this role that are more plausible, based on yet unfalsified hypotheses, that would not stir up the more hard sci-fi fans while still providing all the benefits that those who were undisturbed by the implausible nature of metastable met-H wanted as a gameplay mechanic. So can can we just put metastable met-H away in a box and just replace it with a more realistic alternative so we don't have to have the heated bickering? Other than its stats, which are not wholly unique to only this engine, why does metastable met-H have to be in the game?

[Guest]

30 minutes ago, Entropian said:

Ok, just, people.  Calm.  Down.  So far as I can see, over the last year (I lurked long before I registered) the MH debate has 2 sides:

1. Metallic Hydrogen is not plausible because of X, Y, and Z.
2. Metallic Hydrogen is plausible because of potential advances in technology in the future, etc, etc.

Arguing over this is pointless.  It has already been shown that, overall, the people who think MH is plausible are sticking to their opinions, and the people who think MH is not plausible are sticking to their opinions.

I think that it doesn't really matter, KSP 2 devs have probably researched enough to say that yeah we can put this in the game. You can be completely ignorant of the parts and just never use them. That's the greatness of KSP, you have different ways to play the game.

[Incarnation of Chaos]

8 minutes ago, The Doodling Astronaut said:

I think that it doesn't really matter, KSP 2 devs have probably researched enough to say that yeah we can put this in the game. You can be completely ignorant of the parts and just never use them. That's the greatness of KSP, you have different ways to play the game.

They obviously haven't, because otherwise they would've pulled the engines from the game and issued a statement. But not a single statement has been made.

[Guest]

Just now, mcwaffles2003 said:

I agree, and with that a new question comes up. If metastable metallic hydrogen is not a viable rocket fuel but the engines specs served as a useful, or even a borderline necessary feature, what can suitably replace it?

Liquid core NTR.  Stated multiple times, it's particularly nice because it's almost an exact match. Vapor core would also work in the same niche, it's a related technology. Both of them are plausible designs relying upon established science, with performance very close to proposed metallic hydrogen engines. They could be used for landing, and they could have high thrust.

Just now, The Doodling Astronaut said:

I think that it doesn't really matter, KSP 2 devs have probably researched enough to say that yeah we can put this in the game. You can be completely ignorant of the parts and just never use them. That's the greatness of KSP, you have different ways to play the game.

This is exactly what I'm talking about. You are mixing three things together. In addition, your trust in KSP2 devs is the biggest reason I see for not featuring metallic hydrogen. If you trust them to do their research, so will others, and they will be misled. You can only ignore bad science if you know what it is, and what someone who first hears about metallic hydrogen from KSP2 should do?
1. KSP2 devs have not researched enough to say that. Their decision was made when the crown evidence was not yet available. Their knowledge is now outdated.
2. You want metallic hydrogen in KSP2, and that's your most crucial point.
3. You're also saying that what real science says doesn't really matter, because people can just ignore bad science.

This confusion is why we're getting so many "flat earther" discussions. Someone who wants metallic hydrogen starts out by saying "it's possible, science says so", and, after being proven wrong (links to that end in sig), switch tracks to "it doesn't matter, because KSP is just a game". The argument stops being about science and starts being about the nature of KSP2. Which, I might add, tends to be interpreted in self-serving way, particularly when someone feels science gets in the way of his fun. That is despite metallic hydrogen ultimately adding nothing to the game, that couldn't be done with nuclear rockets.

[Guest]

Just now, Incarnation of Chaos said:

They obviously haven't, because otherwise they would've pulled the engines from the game and issued a statement. But not a single statement has been made.

I mean, it's their game.

[mcwaffles2003]

2 minutes ago, The Doodling Astronaut said:

I mean, it's their game.

Sure, but what does saying that add to the conversation? By this reasoning do we have no right to make an objection to anything? Would you say the same if intercept came out with an update that said the game is now moving towards being a management game and rocket flying will be taken from the center stage?

This is plain out dismissiveness to a counter point for no reason other than to keep ones opinion unchanged.

[Incarnation of Chaos]

7 minutes ago, mcwaffles2003 said:

Sure, but what does saying that add to the conversation? By this reasoning do we have no right to make an objection to anything? Would you say the same if intercept came out with an update that said the game is now moving towards being a management game and rocket flying will be taken from the center stage?

This is plain out dismissiveness to a counter point for no reason other than to keep ones opinion unchanged.

Exactly^

And who is he to draw the line between an honest critique and BS? Between well-intentioned discussion and "Offensive"?

Who are ANY of us to draw that line? The mods will step in if the thread goes off the rails, but anything else is fair game.

I do agree with a previous post though; there's plenty of information out there and this thread is just going in circles. However; hopefully it being on KSP2 subfourm will bring more visibility.