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Confronting the Credibility Gap for Crewed Exploration of Mars

caseyexaustralia.blogspot.com

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Re: Confronting the Credibility Gap for Crewed Exploration of Mars

#5
post #2

"And then you have the EM/reactionless drive, which is less efficient than a Hall effect thruster, and also impossible." I could sense this was coming, and I stopped reading here.

For those of us who aren't experts in the physics of theoretical space travel, care to share why?

Re: Confronting the Credibility Gap for Crewed Exploration of Mars

#6
post #2

"And then you have the EM/reactionless drive, which is less efficient than a Hall effect thruster, and also impossible." I could sense this was coming, and I stopped reading here.

For those of us who aren't experts in the physics of theoretical space travel, care to share why?

It violates conservation of momentum (i.e. why solar sails work).

This is a pretty big problem with any evidence purporting that it does work because it requires a massive reinterpretation of our understanding of existing physical laws: i.e. it's mechanism of operation has to simplify to existing theory in such a way as to also explain why the effect is undetectable at the staggeringly high resolutions of measurements we've been making of other physical constants for decades now.

This is a big ask. This is a huge ask.

Re: Confronting the Credibility Gap for Crewed Exploration of Mars

#7
post #6

Earlier quoted context omitted.

For those of us who aren't experts in the physics of theoretical space travel, care to share why?

It violates conservation of momentum (i.e. why solar sails work). This is a pretty big problem with any evidence purporting that it does work because it requires a massive reinterpretation of our understanding of existing physical laws: i.e. it's mechanism of operation has to simplify to existing theory in such a way as to also explain why the effect is undetectable at the staggeringly high resolutions of measurement…

As far as I can tell, the quote given by fapjacks is saying that the reactionless drive is impossible. Note that it is in a paragraph that begins "The other major kind of shonky coverage covers mythical propulsion..." (I had to look up 'shonky', but it is consistent with the above reading.)

Re: Confronting the Credibility Gap for Crewed Exploration of Mars

#8
post #6

Earlier quoted context omitted.

For those of us who aren't experts in the physics of theoretical space travel, care to share why?

It violates conservation of momentum (i.e. why solar sails work). This is a pretty big problem with any evidence purporting that it does work because it requires a massive reinterpretation of our understanding of existing physical laws: i.e. it's mechanism of operation has to simplify to existing theory in such a way as to also explain why the effect is undetectable at the staggeringly high resolutions of measurement…

There is a big difference between "does violate" and "appears to violate".

The orbital motion of Mercury "violates" Newtonian gravity. There are other examples but I'm not trying to make a history lesson. I just want to point out, that science moves forward by impartial investigation of EVERYTHING. It's misguided to assume we know all and that there cannot be some thing we don't understand.

I'm as sceptical as anyone else about the EM Drive, but I want to understand "what the heck is going on with this thing that appears to move" more than I want to dismiss it as "not possible and obviously flawed because $ABC"

There are plenty of possible ways the drive could operate, and if it does work, it has the potential to significantly advance several fields of physics in a way no less valuable than other large expensive "hope this works" experimental physics experiments that no one is complaining about.

Re: Confronting the Credibility Gap for Crewed Exploration of Mars

#9
post #6

Earlier quoted context omitted.

It violates conservation of momentum (i.e. why solar sails work). This is a pretty big problem with any evidence purporting that it does work because it requires a massive reinterpretation of our understanding of existing physical laws: i.e. it's mechanism of operation has to simplify to existing theory in such a way as to also explain why the effect is undetectable at the staggeringly high resolutions of measurement…

As far as I can tell, the quote given by fapjacks is saying that the reactionless drive is impossible. Note that it is in a paragraph that begins "The other major kind of shonky coverage covers mythical propulsion..." (I had to look up 'shonky', but it is consistent with the above reading.)

Correct - Casey believes that the drive is impossible, given our understanding of physics. Given his background and credentials, I'm happy to defer to his opinion on the matter, over my own optimism.

Both he and I are firm believers of the scientific method though, so if researchers can show it experimentally then that's where the fun really begins. To my knowledge, the experiments until now have been fairly poor, with barely significant results (on the edge of noise).

Re: Confronting the Credibility Gap for Crewed Exploration of Mars

#10
post #6

Earlier quoted context omitted.

It violates conservation of momentum (i.e. why solar sails work). This is a pretty big problem with any evidence purporting that it does work because it requires a massive reinterpretation of our understanding of existing physical laws: i.e. it's mechanism of operation has to simplify to existing theory in such a way as to also explain why the effect is undetectable at the staggeringly high resolutions of measurement…

As far as I can tell, the quote given by fapjacks is saying that the reactionless drive is impossible. Note that it is in a paragraph that begins "The other major kind of shonky coverage covers mythical propulsion..." (I had to look up 'shonky', but it is consistent with the above reading.)

I'm pretty sure that fapjacks believes that the reactionless drive is possible, and all of the "No, this is silly" folks are just contrarian deniers who are holding back progress.

Gotta love starry-eyed futurology people.

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