Discussion of metallic hydrogen propulsion split from another thread.

[KSK]

Just now, KerikBalm said:

The one I have in mind has the kernals pre heated so that only a small prick or disturbance from the outside ruptures them and releases their energy. No need to heat with a heat source on the ship.

This can outperform mH, because the corn will be genetically modified.

Sounds like a plan. Hey - you could hang a big net out the back of your spacecraft to capture the exhaust and recycle it as snacks.  

[KerikBalm]

@KSK Right, but it doesn't neutralize the thrust, because of quantum manipulation at the cellular level by the corn.

No one can prove me wrong, because I can fall back on hard solipsism.

[StrandedonEarth]

18 minutes ago, KSK said:

Sounds like a plan. Hey - you could hang a big net out the back of your spacecraft to capture the exhaust and recycle it as snacks.  

2 minutes ago, KerikBalm said:

@KSK Right, but it doesn't neutralize the thrust, because of quantum manipulation at the cellular level by the corn.

No one can prove me wrong, because I can fall back on hard solipsism.

 

Edited February 24, 2020 by StrandedonEarth

[Weighates]

    As far as I know no claims of creating Metallic Hydrogen have passed peer review so there is a good chance we haven't even created it yet.  Can we please stop trying to use non verified experiments as proof of anything.  

[Guest]

@KerikBalm
Just don’t attempt to eat popcorn directly from the exhaust nozzle XD
Headline: Rocket Scientist Dies Under Curiesque Circumstances.

Edited February 24, 2020 by Guest

[KerikBalm]

11 hours ago, Weighates said:

 Can we please stop trying to use non verified experiments as proof of anything.  

Fine, the burden of proof still lies on those who claim mH can be metastable, otherwise my popcorn drive should be included too.

Also, to be clear:

Metallic hydrogen alloyed with alkali metals has been confirmed. These become metallic at lower pressures (around 200 GPa), and are not metastable.

Claims of metallic deuterium formed from shockwaves (as opposed to static pressure allowing for long duration observations) seem ot be accepted. That nothing remains metallic after the peak pressure from shockwaves shows that it wasn't metastable under those conditions.

There are now 2 independent claims of metallic hydrogen in the 425-495 GPa range. The first one (2017) with the higher value was criticized on a number of technical issues. One was that their measurement of the pressure (thus their pressure claims), was too high, and theire pressure measurement method was flawed. If this criticism was valid, that would mean the achieved pressure was lower than 495 GPa. The pressure achieved doesn't affect the claim to have mH or not (although if the real pressure was like... 200 GPa, that would cast doubt, as it was known that pressure was too low). Their machine broke, and the putative metallic hydrogen was gone (not metastable, if it existed).

This 2nd one (2019) makes a claim in a similar pressure range (425 GPa, instead of 495 GPa), with a very similar method, and so far seems to be more widely believed. Sure, we'd like to see more data, But it seems roughly in agreement in the previous one. One could say it confirms the previous results.

Confirmed metallic hydrogen alloys are not metastable at lower pressure.

Accepted transient metallic hydrogen isotopes formed by transient pressure do not remain metallic.

The last 2 claims of metallic hydrogen via static pressure roughly agree with each other, and do not demonstrate metastability.

Models that agree with the confirmed observations, and the new claims ,do not predict metastability.

You are vastly understating the state of the evidence.

 

It would be great if our models were wrong, the most recent experiments had flaws, and metallic hydrogen was metastable... that would be awesome... but we shouldn't believe it or act like it is true just because we want it to be true.

Edited February 25, 2020 by KerikBalm

[magnemoe]

21 hours ago, StrandedonEarth said:

 

That one would work, you blow on the sail the wind is reflected backward creating trust. 
Mythbuster tested it, its obviously more effective to blow backward and boats with aircraft propellers are uses in swamps there putting the propeller in the water have an high chance of damaging it. 

[Weighates]

11 hours ago, KerikBalm said:

 but we shouldn't believe it or act like it is true just because we want it to be true.

    On this we can agree.   I personally highly doubt that solid metallic hydrogen is metastable at atmospheric pressures.  My critique is about people saying that's been experimentally proven which it has not been.  The 2017 study especially had a lot of criticism from the high pressure physics community about whether they had even achieved metallic hydrogen.  I haven't heard much about the 2019 study since it was published.  I have linked 2 articles below about this topic.   One is about the debate of the 2017 experiment with current models of how metallic hydrogen is expected to behave and it touches on metastable metallic hydrogen.   The second outlines the possibility of two phase III structures of metallic hydrogen.  

https://aip.scitation.org/doi/10.1016/j.mre.2017.10.001

https://journals.aps.org/prb/abstract/10.1103/PhysRevB.94.134101

 

   On a personal note I wasn't thrilled with them including metallic hydrogen but I don't understand how it's getting more hate than a "torchship".   Maybe that has the magical popcorn drive KerikBalm invented.

[kerbiloid]

11 hours ago, Weighates said:

but I don't understand how it's getting more hate than a "torchship

Because why do they call the magic popcorn "metastable metallic hydrogen"?

[Superfluous J]

On 2/24/2020 at 4:35 AM, fragtzack said:

 

"There is no reason for any individual to have a computer in his home."

Wow, good thing folks didn't believe this guy who was one of the founders of early computing. 

While I too chuckle at that one, it was 100% correct at the time.

It'd be like quoting "The Red Coats are coming" and snidely remarking about how they're not.

[kerbiloid]

1 hour ago, 5thHorseman said:

While I too chuckle at that one, it was 100% correct at the time.

It would stay correct for all times if the microchip development was a bit slower than the optical fiber lines in 1970s.

If in 1970s they had optics, nobody except geeks would be making personal computers. We would just rent working stations from the local internet providers.

Edited February 26, 2020 by kerbiloid

[KerikBalm]

15 hours ago, Weighates said:

On a personal note I wasn't thrilled with them including metallic hydrogen but I don't understand how it's getting more hate than a "torchship". 

#1) Until the most recent video, I wasn't sure what they mean by a torchship. The ICF fusion drive could meet some defiitions of a torchship. To me, I would consider a torchship to be any brachistichrone trajectory capable drive that has an internal reactor that needs significant cooling radiators, even if its only getting 0.1 m/s/s.

#2) Its an endgame tech, and thus most of the gameplay in "progression mode" is done without it, and it seems all the game challenges would be designed to be solvable without it. In contrast they make it seem like the game pushes you into using metallic hydrogen to progress, and have mH as the next step up from LFO (I really hope there's an alternate nuclear tech pathway forward)

#3) It is likely to be perceived by the audience a much more futuristic and speculative tech, whereas they seem to portray mH as a settled near future tech

#4) We know making and storing antimatter is possible (its a matter of scale or production and storage though), antimatter gets you a torchship... although you still have huge engineering limits with regards to the ridiculous power output that would require 99.9 (who knows how many 9 s are needed after the decimal)% efficiency to prevent waste heat from vaporizing the engine/craft.

2 hours ago, 5thHorseman said:

While I too chuckle at that one, it was 100% correct at the time.

It'd be like quoting "The Red Coats are coming" and snidely remarking about how they're not.

What I chuckle about is that @fragtzack's citation undermines his whole point. Here's a quote from his citation: "Olsen admitted to making the remark, even though he says his words were taken out of context and was referring to computers set up to control houses, not PCs.^[12] According to Snopes.com, 'the out-of-context misinterpretation of Olsen’s comments is considered much more amusing and entertaining than what he really meant, so that is the version that has been promulgated for decades now'."

I still don't have a computer controlling my home, and don't know anyone who does... unless you consider a simple thermostat, or timers on blinds.

15 hours ago, Weighates said:

I have linked 2 articles below about this topic.   One is about the debate of the 2017 experiment with current models of how metallic hydrogen is expected to behave and it touches on metastable metallic hydrogen.   The second outlines the possibility of two phase III structures of metallic hydrogen.  

https://aip.scitation.org/doi/10.1016/j.mre.2017.10.001

https://journals.aps.org/prb/abstract/10.1103/PhysRevB.94.134101

Strange that the first link has a title of "Public debate on metallic hydrogen to boost high pressure research". The abstract talks about how debate is good publicity: "We briefly review this debate, and extend the topic to show that this disputation could be an opportunity to benefit the whole high pressure community."

The review is pretty good though. They note: "DS referred to Ref. [14] for the justification of recoverability of MH. This could be wildly optimistic. Actually, an exploration of the possible energy barriers in MH at ambient pressure with accurate modern density functional theory (DFT) and NEB method unfortunately revealed that MH could be highly unstable at ambient pressure [15]."

I checked Ref. [14], its the 1972 paper... there hasn't been a paper since 1972 predicting metastability. The 1972 prediction is worthless, because it was also predicting mH would form at pressures over an order of magnitude lower than it does, showing the prediction was fundamentally flawed when it comes to determining when H would be metallic. The newer predictions that accurately reflect observations predict it to be highly unstable.

Your link also mentions a point I was already thinking of bringing up "Quantum mechanics tells that every material can come into metallic state under high enough compression, which should also be the case for hydrogen." - now most elements are already metals, but you can take a look at the lighter elements normally considered "non-metals" like hydrogen.

There's also metallic Oxygen and metallic Nitrogen, for instance. They are easier to study. Metallic Oxygen only requires 96 GPa. Nitrogen needs 125 GPa.

In neither case do we observe metastability. We now know of numerous experiments compressing non-metals enough to turn them into metals. We haven't once observed them remaining metals upon pressure release. We have no reason to think Hydrogen will.

https://en.wikipedia.org/wiki/Solid_oxygen#Metallic_oxygen 

https://eurekalert.org/pub_releases/2018-07/caos-csa070618.php

And FYI, your second link does not even discuss metallic hydrogen, it discusses solid molecular hydrogen.

[fragtzack]

Are   monkey's funny when  throwing MH monkey discussions

 

 

 

[KerikBalm]

@fragtzack So basically, you've got no arguments and nothing to discuss, but want to just post ridicule? You want to fling poo? 

Your last post adds nothing to the discussion.

[Guest]

On 2/26/2020 at 9:12 PM, KerikBalm said:

...whereas they seem to portray mH as a settled near future tech

Yer, I specifically remember seeing something where one of the devs says it’s only an unsolved engineering problem...

[Dirkidirk]

On 2/25/2020 at 1:37 PM, Weighates said:

   On a personal note I wasn't thrilled with them including metallic hydrogen but I don't understand how it's getting more hate than a "torchship".   Maybe that has the magical popcorn drive KerikBalm invented.

go to "torch ships" on atomic rockets. It shows many plausible forms of propulsion for torch ships that are probably in ksp2.

 

as for metallic hydrogen, there might be a way to keep it at high pressures using intense magnetic fields or there Might be a way to make it metastable with another compound or element mixed in. or a combination of both. 

Spoiler

or not ¯\_(ツ)_/¯

 

Edited February 27, 2020 by Dirkidirk
memes

[kerbiloid]

As the metallic hydrogen is temporarily unavailable, maybe it's a time to discuss also metallic deuterium and kelium-3?

[Guest]

7 hours ago, kerbiloid said:

As the metallic hydrogen is temporarily unavailable, maybe it's a time to discuss also metallic deuterium and kelium-3?

Ok but the exhaust has to look like this: 

because I have a feeling there’s a snowballs chance in hell of the devs throwing away their artwork to fit the science =/

[Guest]

I just saw this in my feed  @_@ watching it nao

oh... they only mention metallic hydrogen for a few second >.>

Edited February 28, 2020 by Guest

[kerbiloid]

2 hours ago, Dale Christopher said:

they only mention metallic hydrogen for a few second >.>

Because it doesn't live longer.

[KerikBalm]

20 hours ago, Dirkidirk said:

as for metallic hydrogen, there might be a way to keep it at high pressures using intense magnetic fields or...

The thing is if its not metastable, the technology is essentially the same as a compressed air can rocket...

Magnetic fields also wouldn't work, then the force is transferred to the magnetic coils. When they need to keep the pressure at 420 GPa or so, that is a lot of force. A better option would be some sort of carbon nanotube weave tank.... but even that won't work, since the pressure would be too high if the carbon nanotubes were right up against the mH. It would compress to diamond. You'd need a thick layer of diamond, held together by a carbon nanotube exterior. I did the calculations once, the mass fraction would be ridiculously bad. I suppose it might be possible to have a layer of some other metal pushed against the mH, using magnets to get some distance (so 400 GPa at the center could be like 10 GPa at the magnets), and then using carbon nanotubes to hold the magnets in place. Your mass fraction will still be very very bad, and won't be outperformed by even Kerlox.

[kerbiloid]

They should find a way to make the metallic hydrogen expansion statistically improbable.
Then they can hold it without tanks like a metallic snowball.

[Guest]

With so much effort just to contain the fuel in the tank you might as well just use antimatter. It might even be easier 0_0

(let’s face it, the only thing that made this attractive as a fuel is if it was inherently stable. If it’s not stable it’s a dead end basically.)

Edited February 28, 2020 by Guest

[KerikBalm]

1 hour ago, Dale Christopher said:

let’s face it, the only thing that made this attractive as a fuel is if it was inherently stable. If it’s not stable it’s a dead end basically.

Exactly, as I said:

"The thing is if its not metastable, the technology is essentially the same as a compressed air can rocket..."

And if the idea of just a high tech compressed air can being superior to Methalox and NTRs sounds ridiculous to you, you aren't alone.

[kerbiloid]

1 hour ago, kerbiloid said:

They should find a way to make the metallic hydrogen expansion statistically improbable.

1 hour ago, Dale Christopher said:

With so much effort just to contain the fuel in the tank you might as well just use antimatter. It might even be easier 0_0

They should find a way to gather virtual nucleons from the vacuum quantum foam and use it.

Then they can make it metallic if they want, but why?