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Questions about Nasa's space drive answered

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Re: Questions about Nasa's space drive answered

#22
post #15

Earlier quoted context omitted.

As far as I can tell it wouldn't matter what the cause of the apparent effect is. Not requiring reaction mass is what makes it interesting.

What? Of course the apparent affect matters. If the underlying physical principles can be understood, there is a possibility of increasing its efficiency for larger throughput. And if the underlying process isn't understood, there is no way to rule out something that isn't actually producing thrust or some other fluke. Finally, the whole point of science is to discover things. Not make magic :|

I don't mean to suggest it wouldn't be of interest. As you point out it would be of paramount interest to discover the physics behind it. The Pioneer Anomaly, however, was very very small indeed. This effect appears to be many orders of magnitude greater.

Re: Questions about Nasa's space drive answered

#23

Deep breaths. Probably experimental error. Extraordinary claims require extraordinary proof... God DAMN this is exciting.

Indeed. As to the whole "we don't actually understand how it works" - we still can't make up our minds as to how wings work, so this isn't overly novel. Sure, we can explain the outcome, but whether it's Navier-Stokes or Bernoulli or something else, we can't make up our minds. I suspect this will be similar for a long while - although puts physics hat on I think this is likely a relativistic temporal quantisation eff…

  > ... we still can't make up our
  > minds as to how wings work, ...
Interestingly, I recently spoke to an aerodynamicist and mentioned this, and I was severely lectured. In the follow-up he mellowed a little, but I suspect the "we" in your statement refers to laypersons who don't have advanced training in aeronautics, and yet claim to understand about flow pressure, Bernoulli, etc.

I've been convinced that the people who genuinely work with these things and study them properly, actually do know how wings work. You may not, I may not, the mythical "man on the street" may not, but there are people who really, really do.

Re: Questions about Nasa's space drive answered

#24
post #19

Earlier quoted context omitted.

The principle problem to be overcome with this tech is going to be cooling - both for the power source and for the drive. It's going to require radiators the with a stonkingly huge area and Peltier shunts, unless we come up with a cunning means of dumping excess heat - potentially turning it into more energy to drive with, even, using the seebeck effect.

Isn't space pretty cool?

Space is mostly empty. There's nothing much to dissipate heat into.

Cooling is always a problem in space.

Re: Questions about Nasa's space drive answered

#25
Photons (i.e EM fields) have no mass, but do carry momentum and can transfer it to charged particles (i.e. the solar sail). So if the drives uses EM field to transfer momentum to the quantum vacuum particles, wouldn't that upset the net-zero energy balance of the quantum vacuum? I though the particles are popping in and out of existence, hence net-zero energy?

Re: Questions about Nasa's space drive answered

#26

Earlier quoted context omitted.

Indeed. As to the whole "we don't actually understand how it works" - we still can't make up our minds as to how wings work, so this isn't overly novel. Sure, we can explain the outcome, but whether it's Navier-Stokes or Bernoulli or something else, we can't make up our minds. I suspect this will be similar for a long while - although puts physics hat on I think this is likely a relativistic temporal quantisation eff…

> ... we still can't make up our > minds as to how wings work, ... Interestingly, I recently spoke to an aerodynamicist and mentioned this, and I was severely lectured. In the follow-up he mellowed a little, but I suspect the "we" in your statement refers to laypersons who don't have advanced training in aeronautics, and yet claim to understand about flow pressure, Bernoulli, etc. I've been convinced that the people…

No, I've a masters degree in Physics, and did several research projects on turbulent/laminar flow. We have a detailed understanding of a variety of theories which correctly represent the lift effect experienced on a body moving through a flow, yet none of them do it perfectly or completely. We can implement the technology well, but not without the aid of wind-tunnels and brute-force computer simulations in order to validate our designs - had we a perfect mathematical understanding of lift - we would not need to.

Another example from Physics - quantum mechanics. We can describe the properties of a QM system, its outcomes based on inputs, the probabilities of states - yet we have not got the blindingest clue as to how it works. We have theories, but again, none are perfect - for instance see the Pilot Wave formulation of QM, which implies a deterministic universe, and isn't wrong, but isn't generally accepted - even though it describes QM systems well, for what little of it has been formulated in the last century.

Re: Questions about Nasa's space drive answered

#27
post #19

Earlier quoted context omitted.

The principle problem to be overcome with this tech is going to be cooling - both for the power source and for the drive. It's going to require radiators the with a stonkingly huge area and Peltier shunts, unless we come up with a cunning means of dumping excess heat - potentially turning it into more energy to drive with, even, using the seebeck effect.

Isn't space pretty cool?

In a sense, yes. But space has no medium to convey heat so you can't get rid of it by convection or diffusion. Getting rid of heat in space is hard and a big issue for spacecrafts.

Re: Questions about Nasa's space drive answered

#28
post #19

Earlier quoted context omitted.

The principle problem to be overcome with this tech is going to be cooling - both for the power source and for the drive. It's going to require radiators the with a stonkingly huge area and Peltier shunts, unless we come up with a cunning means of dumping excess heat - potentially turning it into more energy to drive with, even, using the seebeck effect.

Isn't space pretty cool?

It's damnably cool!

And extremely hot (100C + in near-earth orbit) in the sun, and -273 in the shade - with nothing to conduct heat away - meaning that you can only emit heat as EM radiation (photons).

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