Discussion of metallic hydrogen propulsion split from another thread.

[kerbiloid]

If the shown was actually KSP-2 rather than reskinned KSP-1 or some devs' experiments, the MeH is already implemented and unlikely they would throw it out.

So, if KSP-2 gets released, the true nerds should anyway ignore this Despicable MeH and wait/make a realistic mod, like KSPI-E is; while others anyway don't see difference.

When Loki was inventing the metastable metallic hydrogen, his intention was to instigate dissension among Kerbals users. It looks like he succeded.

The only actual question is: whether KSP-2 will ever get released have any alternative to the Despicable MeH, to avoid using it, or it will be an abyss between low and high rocketry, and the game will turn into a cartoonish mockup of KSP.

Edited October 8, 2020 by kerbiloid

[DStaal]

17 minutes ago, 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.

The fact that they have made no statements about engines since the original statement that started this whole discussion isn't really evidence either way at this point: It just means they aren't making statements on what's under development.  They could have scrapped it the next day, they could be ignoring this whole discussion, they could be debating it internally - we don't know, and we don't have any evidence one way or the other.  They aren't obligated to say *anything* on the topic until the game is actually released - and even then all they have to say is 'these engines are powered by technology X', not why they chose technology X - and if X isn't MMH, why they changed their minds or when.  There's no reason to infer anything based on what they haven't said at this point.

[Incarnation of Chaos]

Just now, DStaal said:

The fact that they have made no statements about engines since the original statement that started this whole discussion isn't really evidence either way at this point: It just means they aren't making statements on what's under development.  They could have scrapped it the next day, they could be ignoring this whole discussion, they could be debating it internally - we don't know, and we don't have any evidence one way or the other.  They aren't obligated to say *anything* on the topic until the game is actually released - and even then all they have to say is 'these engines are powered by technology X', not why they chose technology X - and if X isn't MMH, why they changed their minds or when.  There's no reason to infer anything based on what they haven't said at this point.

The lack of a statement means we have no reason to think they've done anything other than continue making pretty purple plumes. You're correct that we can't just assume that they haven't changed plans also.

But i find this confidence that "They've done their homework" rather disturbing especially in the face of overwhelming evidence to the contrary. Which was my main point.

[DStaal]

Just now, kerbiloid said:

If the shown was actually KSP-2 rather than reskinned KSP-1 or some devs' experiments, the MeH is already implemented and unlikely they would throw it out.

On the other hand, it would be the work of about 30 minutes to change the configs over to something else, if they wanted to just reuse the models most likely. 

[Incarnation of Chaos]

Just now, DStaal said:

On the other hand, it would be the work of about 30 minutes to change the configs over to something else, if they wanted to just reuse the models most likely. 

Rename them, change the plumes, fuel types, and add some thermal management. A couple hours work to turn them into NSWR's or something similar at the most.

[kerbiloid]

Just now, DStaal said:

On the other hand, it would be the work of about 30 minutes to change the configs over to something else, if they wanted to just reuse the models most likely. 

To unobtanium, as there is now another such substance like metastable MeH.

[DStaal]

Just now, Incarnation of Chaos said:

But i find this confidence that "They've done their homework" rather disturbing especially in the face of overwhelming evidence to the contrary. Which was my main point.

That I'll agree with.

[SOXBLOX]

I find it pointless to argue over flavor text. The only things important to gameplay are the stats of the engine. If the devs want mmH, I'm happy. If not, I'm still happy. <snip>

Also, KSP2 is not a science textbook. It is a game, which happens to incorporate some science. If something in the unimportant flavor text is not 100% perfect, deal with it. Or don't play.

Edited October 9, 2020 by Geonovast

[Geonovast]

Some content has been removed.  We all have different opinions on what's important in the game.  It's ok to disagree, but it's not ok to demean what's important to others.

[mcwaffles2003]

4 hours ago, SOXBLOX said:

I find it pointless to argue over flavor text

So you can't think of an example of a propulsion mechanism you would be opposed to?

4 hours ago, SOXBLOX said:

The only things important to gameplay are the stats of the engine.

Isn't that a bit extreme? Also, blatantly untrue... You would be 100% happy with replacing the kerbals with lifelike people?

4 hours ago, SOXBLOX said:

Also, KSP2 is not a science textbook. It is a game, which happens to incorporate some science.

 

This is just dismissive to the point underlying. If this is your rationale then to what extent are blatant untruths allowable? For instance would you be fine with a campfire blower engine?

It incorporates a hair dryer blowing down on some enflamed logs at the bottom of a tube held up by chicken wire. It can replace the flea engine.

4 hours ago, SOXBLOX said:

If something in the unimportant flavor text is not 100% perfect, deal with it.

Who here is arguing for 100% perfect?

4 hours ago, SOXBLOX said:

Or don't play.

My word sir, such vehemence, much passion, wow.

Spoiler

 

Edited October 9, 2020 by mcwaffles2003

[Guest]

56 minutes ago, mcwaffles2003 said:

Who here is arguing for 100% perfect?

It may not be asking for 100% perfect but sure it is that the KSP community is the only one in which metallic hydrogen has become such a hated and controversial argument over some very recent studies that are very difficult to find if you don't already know them.

On most other spaceflight enthusiast communities you'll find at most a "if it's metastable" remark.

This is far from the thing requiring the biggest suspension of disbelief in Kerbal, we've just arbitrary decided that all the other concessions and errors don't matter for *reasons* while somehow metallic hydrogen is a big deal.

You can strap a garden chair on top of an engine and a tank and send Jeb on a 20 years long mission without problem and the community is totally ok with that (to the point of wanting to preserve that kind of gameplay) but suddenly if the description of the engine used is not scientifically accurate it's a tragedy.

[mcwaffles2003]

2 minutes ago, Master39 said:

This is far from the thing requiring the biggest suspension of disbelief in Kerbal, we've just arbitrary decided that all the other concessions and errors don't matter for *reasons* while somehow metallic hydrogen is a big deal.

You can strap a garden chair on top of an engine and a tank and send Jeb on a 20 years long mission without problem and the community is totally ok with that (to the point of wanting to preserve that kind of gameplay) but suddenly if the description of the engine used is not scientifically accurate it's a tragedy.

I think this is mostly due to a mix of the obviousness of believability and game mechanics. For instance, the 1/10th scale requires densities of materials to be  10x greater or for the gravitational constant of the universe to be 10x that of our universe. But if the game was based in RSS barely anyone would make it to orbit when in the KSP world it seems most at least accomplish that. The example you've provided is wholly unbelievable in context of it reflecting reality and also has it's gameplay benefits in giving more freedom to the player, though I'm personally of the opinion to including stock life support as optional, mostly as a starting point for modders to coalesce around and standardize, but that's a different topic and I digress.

In the case of mH I just dont see why it can't be changed to something more reflective of reality if its specific occurrence has no effect on gameplay when adding an actually possible engine can spark intrigue and inspire curious minds to look deeper into the subject. Otherwise in the case we have now, you go to learn about mH, as many of us here have, and find that it no longer has any evidence to warrant the possibility of its existence in a usable metastable state and your curiosity comes to a sad dead end.

[Guest]

7 minutes ago, mcwaffles2003 said:

I think this is mostly due to a mix of the obviousness of believability and game mechanics. For instance, the 1/10th scale requires densities of materials to be  10x greater or for the gravitational constant of the universe to be 10x that of our universe. But if the game was based in RSS barely anyone would make it to orbit when in the KSP world it seems most at least accomplish that. The example you've provided is wholly unbelievable in context of it reflecting reality and also has it's gameplay benefits in giving more freedom to the player, though I'm personally of the opinion to including stock life support as optional, mostly as a starting point for modders to coalesce around and standardize, but that's a different topic and I digress.

Honestly this is exactly the kind of *reasons* I was thinking about while writing my reply, the subtle balance of being unrealistic enough to be unbelievable is absolutely something completely arbitrary.

 

12 minutes ago, mcwaffles2003 said:

In the case of mH I just dont see why it can't be changed to something more reflective of reality if its specific occurrence has no effect on gameplay when adding an actually possible engine can spark intrigue and inspire curious minds to look deeper into the subject.

Because literally no one else has still corrected years of treating it as the "holy grail of rocket propulsion". Why should the Devs throw away months of development time to meet higher standards?

I'm more worried about the possible damage to the gameplay done by a hurried removal than the inexistent risk of "misinformation" about what at the end of the day is just another fictional tech in a (hard) sci-fi game.

 

22 minutes ago, mcwaffles2003 said:

Otherwise in the case we have now, you go to learn about mH, as many of us here have, and find that it no longer has any evidence to warrant the possibility of its existence in a usable metastable state and your curiosity comes to a sad dead end.

No, your curiosity would just bring you to one of the countless what-ifs that people often loves to discuss about in the spaceflight community, just one that happened to be considered more slightly more seriously for slightly more time than average.

[Deddly]

It's true, it's not easy to stumble across these papers. 

And remember: it is not yet certain that they have created metallic hydrogen. If that is not yet certain, neither are their conclusions that it is not metastable. 

I will say it once again because this is far more important than whether or not KSP 2 includes pseudoscience: until it is backed up by multiple peer-reviewed studies, no single study can prove anything. This is so important to understand, because in this day and age, individual studies are being used to disseminate fake news like climate change denial. This kind of thing is dangerous misinformation, not the fact that metallic hydrogen is used as rocket fuel in KSP2. 

[MarsUltor]

8 hours ago, mcwaffles2003 said:

This is just dismissive to the point underlying. If this is your rationale then to what extent are blatant untruths allowable? For instance would you be fine with a campfire blower engine?

It incorporates a hair dryer blowing down on some enflamed logs at the bottom of a tube held up by chicken wire. It can replace the flea engine.

To be fair, when KSP literally describes parts as being found on the side of the road, or in a junkyard, your example of a “campfire blower engine” isn’t far fetched. I think you’re putting the science way ahead of the game, and taking the hard science way more seriously than the game ever intended. While I get your perspective, interstellar travel isn’t a thing... so, it’s all just different levels of speculation at this point, some more grounded in demonstrable physics than others, but still on the fiction side of science-fiction.

 

6 hours ago, mcwaffles2003 said:

Otherwise in the case we have now, you go to learn about mH, as many of us here have, and find that it no longer has any evidence to warrant the possibility of its existence in a usable metastable state and your curiosity comes to a sad dead end.

[snip] I remember learning all sorts of scientific facts that blew up my childhood preconceptions about how the universe works... you know what I did? I became I scientist. Sure, the game presents a lot of actual science, but it in no way presents itself as a prophetic game... and in no way presents itself as anything more than a game. While it has educational components, these are in the form of thrust, orbital mechanics, etc... but the game takes liberties to make for a more playable experience; for example, if you think asparagus staging works in real life, I hate to break it to you but... it doesn’t! So if you’re arguing over the fundamental physics of an impossible fuel source, but not concerning yourself with the physical impossibility of creating pumps that would allow for asparagus staging to be possible, please get off of the soap box.

Edited October 10, 2020 by Vanamonde

[mcwaffles2003]

1 hour ago, MarsUltor said:

but the game takes liberties to make for a more playable experience; for example, if you think asparagus staging works in real life, I hate to break it to you but... it doesn’t! So if you’re arguing over the fundamental physics of an impossible fuel source, but not concerning yourself with the physical impossibility of creating pumps that would allow for asparagus staging to be possible, please get off of the soap box.

Umm wow, you're extremely rude... But it's funny you call asparagus staging impossible because it isn't, it's a matter of practicality and safety in real life not physics. But please, do go on... Can you explain why asparagus staging is impossible for us non scientists out there? (I guess being an RA at a particle accelerator doesn't go far these days)

[Vanamonde]

Back off the tempers, please. 

[Entropian]

1 hour ago, MarsUltor said:

for example, if you think asparagus staging works in real life, I hate to break it to you but... it doesn’t!

Actually, it does.  It's just usually inconvenient and mass inefficient to do so, and it also requires pretty darn powerful turbopumps.  It's already been proven that you can just split up the job to multiple 'pumps.  Bernoulli hates those long pipes.

EDIT: @mcwaffles2003 a particle accelerator?  Which one?  Sounds pretty interesting.

Edited October 10, 2020 by Entropian

[mcwaffles2003]

20 minutes ago, Entropian said:

EDIT: @mcwaffles2003 a particle accelerator?  Which one?  Sounds pretty interesting.

Facility for Rare Isotope Beams (FRIB) at Michigan state uni. To be honest though I left a while after I graduated and am trying to get back into school for a degree in teaching once COVID is over. Scientist life turned out to be way clickier than Id ever imagined and begging for grants every day doesn't sound fun. 

[Incarnation of Chaos]

Just now, mcwaffles2003 said:

Facility for Rare Isotope Beams (FRIB) at Michigan state uni. To be honest though I left a while after I graduated and am trying to get back into school for a degree in teaching once COVID is over. Scientist life turned out to be way clickier than Id ever imagined and begging for grants every day doesn't sound fun. 

You did heavy isotope research?

[mcwaffles2003]

11 minutes ago, Incarnation of Chaos said:

You did heavy isotope research?

I actually worked with the team building the new accelerator. Used to be a cyclotron but those being so outdated the facility wanted to replace it with a linear accelerator. Did a lot of metal testing, simulated mag. fields in srf cavities,  and other bits n bobs. Asked everyone around me about their research though which was always fun but were getting off topic

Edited October 10, 2020 by mcwaffles2003

[Incarnation of Chaos]

3 hours ago, mcwaffles2003 said:

I actually worked with the team building the new accelerator. Used to be a cyclotron but those being so outdated the facility wanted to replace it with a linear accelerator. Did a lot of metal testing, simulated mag. fields in srf cavities,  and other bits n bobs. Asked everyone around me about their research though which was always fun but were getting off topic

Oh wow, and you're correct. Just a bit of curiosity on my part.

[KerikBalm]

[snip]

On 10/8/2020 at 12:45 PM, 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.

As has been repeatedly explained: 2 is exactly analogous to arguing that future technology can make water exist as a liquid in a vacuum. This is an inherent material property, and the argument is basically that we can throw out our currently established laws of physics in the future.

On 10/8/2020 at 1:19 PM, 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. 

This has been repeatedly mentioned, and public statements by Nate when asked about it indicate that this is not the case. Research of the literature yourself can also show that this cannot possibly be the case.

Edited October 10, 2020 by Vanamonde

[magnemoe]

4 hours ago, mcwaffles2003 said:

Umm wow, you're extremely rude... But it's funny you call asparagus staging impossible because it isn't, it's a matter of practicality and safety in real life not physics. But please, do go on... Can you explain why asparagus staging is impossible for us non scientists out there? (I guess being an RA at a particle accelerator doesn't go far these days)

Aspargus staging or cross feed would be possible, it was planned for the UR series of Soviet rockets and for first concepts of falcon heavy. 
The reason why its not used with heavy style rockets is that tanks is an much lower fraction of the dry mass than in KSP. 

[Guest]

Actually, UR series didn't involve "true" Asparagus. Instead, they used a peculiar setup with a stack of three tanks in each of the boosters. Each booster had an additional tank on top, which contained either fuel or oxidizer. Two such boosters (one with fuel, one with oxidizer) fed into one stack of central tanks. The additional tanks were mounted above the main stack tanks, which simplified the propellant transfer somewhat. Such configuration was also proposed for one of evolved Saturn variants, with propellant tanks for the main stack mounted on top of giant SRBs.  

Also, asparagus staging doesn't have nearly as much benefit in either KSP or RL as pre-atmo overhaul KSP experience had led people to believe. It was a must in the old souposphere days, but today, it's not nearly. 

12 hours ago, Deddly said:

And remember: it is not yet certain that they have created metallic hydrogen. If that is not yet certain, neither are their conclusions that it is not metastable. 

True, but remember about Occam's razor. We only have a few studies that might have created metallic hydrogen... and quite a few more, earlier ones, which are pretty certain they didn't create it. Those, too, count as evidence disproving the underlaying theory that postulates a metastable state, because this theory also predicted that metallic hydrogen would form at about 2.4GPa. We do not have direct evidence against metastability, but our evidence against the theory in question is pretty solid. IIRC, some of the relevant papers should be in the bibliography of the ones linked in my sig, if you can't access that, I'll try to dig it up later (links should be somewhere in this thread).

Anyway, if we were to reject that theory, we would, by Occam's razor, be left with no reason to believe metallic hydrogen would be metastable. This would put metallic hydrogen metastability in the same category as Alcubierre drive - not explicitly forbidden (until we can prove one of the alternate theories, at least), but not supported by experiments, either. IMO, this is not enough to put it in KSP2.

This is how modern science works, BTW. We're not prodding about in the dark. Theorists construct mathematical models that make predictions, and experimentalists verify those predictions. If the latter find the theory got it wrong, that theory must be rejected and a new one (or a competing one) be introduced to take its place. If a theory had been proven incorrect past a certain point (in this case, a given pressure), you cannot use it for points even further out, just like Newtonian physics only become less and less correct as v approaches c. It is very rare for an observation to be made that would not conform to any available model, if only theorists have been cranking them out far faster than experiment can be run to verify them.  

Edited October 10, 2020 by Guest