Author Topic: Why "new physics" will not yield new propulsion ideas or technology.  (Read 14438 times)

Offline Supergravity

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A space elevator might not be a form of propulsion as such, but it would still be damn useful, and would represent an engineering breakthrough, not a physics one. Any number of developments in fusion technology could reduce journey time to Mars to weeks.
It's debatable if the practical problems of the space elevator can ever be solved, but at this time, it's an engineering problem. It's consistent and allowed under the laws of quantum mechanics simply for the reason we can manipulate the materials at the scales where quantum effects start to dominate classical effects. My assertion is that the scales where quantum gravity effects dominate pure quantum effects will never be accessible to engineers, so there's no point in speculating about the practical possibilities of such effects.
« Last Edit: 06/16/2013 02:19 AM by Supergravity »

Offline JohnFornaro

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For example, general relativity has almost been around for a century, and it hasn't given us much for practical application...

Come on!  We got da bomb!  And they're so practical!  Plus, ya gotta admit that so what if it is now classified as nuclear physics.  It's "practical" applications came about from instantiating a "practical" device using a bit of "relativity".

Seriously, not a bad post.  First one, huh?

Just add the qualifier "probably" in front of the term "never".

I personally think that the rabbit hole doesn't stop at the quantum level.  My tag line confirms this belief.

OP's post is full of contradictory statements. We may never have the energy budget or knowledge to do the things you say are impossible, but many are consistent with relativity.

You place too much importance on his use of the word "never" as if he posed "never" as a fact.  It is simply his opinion.  So I don't see too much contradiction.

It may be that there is a power curve to the energy budget as you briefly outline.  You do have to admit that the energy levels needed to manipulate stuff at the quantum level for people's practical transportation uses, are much, much higher than our current fascination with fossil fuels.

Look at how much energy goes into the giant atom smasher at CERN, and how much mass they end up manipulating.

While, as Chris Wilson points out, "It's very hard to know the consequences of what you don't know", it's also easy to point out the practical HSF consequences of what we do know:  Chemical propulsion.  Electric propulsion.  Maybe solar sails.
Sometimes I just flat out don't get it.

Offline cordwainer

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Well a better understanding of new physics doesn't stop or start at the quantum level, either. A better understanding of physics and chemistry at the molecular level could yield some propulsion benefits as well. Meso-particle mass drivers are one example. Thermo-power wave might have propulsion benefits if it can be scaled up. A better understanding of foams and gels might allow better storage of chemical propellants. Giganto-magnetism and Mini-magnetospheric phenomena could increase the efficiency of mag-tethers and mag-sails.

Offline Sohl

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If we could find a way to turn one pound of lead into pure photons, we'd have a source of energy on a scale far beyond the nuclear energy we currently know.

Wait, which would have more energy, a pound of lead or a pound of feathers?   ;)

Offline sanman

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Here's another article on the "warp drive" stuff, for what it's worth:

http://www.technewsdaily.com/18427-warp-drives-wormholes-ftl.html

Offline su27k

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For example, general relativity has almost been around for a century, and it hasn't given us much for practical application other than a correction for GPS.

Ironically the warp drive idea circulating in FTL propulsion circles is based on general relativity, so while "new physics" may not yield new propulsion ideas, we could get FTL by getting a better understanding of "old physics".

Offline Nilof

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For example, general relativity has almost been around for a century, and it hasn't given us much for practical application other than a correction for GPS.

Ironically the warp drive idea circulating in FTL propulsion circles is based on general relativity, so while "new physics" may not yield new propulsion ideas, we could get FTL by getting a better understanding of "old physics".

...which is to some extent new engineering rather than new physics.

I think stuff like increased understanding of condensed matter physics could lead to new propulsion technologies. For example, something similar to the metastable Helium drive. Or a chemical rocket that uses something akin to a fuel cell instead of the combustion chamber + de laval nozzle that we are used to.
For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v.   Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Offline llanitedave

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We don't need new physics.  We just need better applications of the physics we have.
"I've just abducted an alien -- now what?"

Offline Robert Thompson

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