I just read about this in New Scientist. Even if the article had gone into detail regarding the physics, I couldn't have followed it. A brief synopsis:
A method of propulsion has apparently been devised based on resonating microwaves in a waveguide. Microwaves are created within a chamber by a magnetron. No photons need to escape from the device. Rather, the resonating radiation imparts unequal forces on the different walls of the chamber as the photons bounce back and forth, causing a net force in one direction. It seems that the engine will be at least as effective as an ion drive, with the added bonus that it needs no propellant. It may even generate enough force to accelerate itself (and a good bit more) at 1G, allowing it to hover (with some well-chosen high-temperature superconductors). Seems to good to be true to me, but what do I know?
Here's somewhere to start. Please give me your opinions.
No, not according to this (IMHO) better article linked to by the first.
http://www.theengineer.co.uk/Articles/266633/Defying+gravity.htm
I feel sceptical about this, but knowing what I do about energy and matter, I'm not totally sceptical:
"Shawyer explained that if these forces were the result of a working fluid, there would merely be a mechanical strain in the waveguide walls. But as the working fluid is replaced by an electromagnetic wave at close to the speed of light, Newtonian mechanics are replaced with the special theory of relativity..."
Maybe. I'm not saying this will work, but I'm not totally sceptical because we tend to think of momentum as a property of a moving mass. But that's not quite the right picture because a massless object like a photon has momentum. You can take a high energy photon and use it to make an electron and a positron. The energy/momentum of the photon is translated into mass, which means the conservation of momentum isn't totally rock solid.
Maybe. I'm not saying this will work, but I'm not totally sceptical because we tend to think of momentum as a property of a moving mass.
But that's not quite the right picture because a massless object like a photon has momentum.
You can take a high energy photon and use it to make an electron and a positron. The energy/momentum of the photon is translated into mass, which means the conservation of momentum isn't totally rock solid.
You see, that doesn't seem to apply to the Universe as a whole. The Universe is not only expanding, but the expansion is accelerating; the energy for this expansion apparently comes from nowhere. And how the galaxies which are expanding away from us at an accelerating rate have conserved momentum is another matter. Not to menton the thorny question of where the matter and energy of the the Universe as a whole came from in the first place.Conservation of energy and momentum are rock solid.
You see, that doesn't seem to apply to the Universe as a whole. The Universe is not only expanding, but the expansion is accelerating; the energy for this expansion apparently comes from nowhere.
And how the galaxies which are expanding away from us at an accelerating rate have conserved momentum is another matter.
Not to menton the thorny question of where the matter and energy of the the Universe as a whole came from in the first place.
Whoa, guys, I don't consider a photon to be massless.
I've said it before, there's been a lot of debate in physics about mass
Agreed; however that one anomaly turns out to be the Universe itself, which is a bit difficult to explain away at the moment.Well, no, we just don't know where it comes from, or whether our observations on the matter are leading us to the right conclusions. Everything points to conservation of momentum and energy being correct, so don't let one anomaly ruin the good data.
Right; we can look at the expanding universe as being homogenous, and as long as the momentum balances overall momentum is conserved.If you sum it all up, I rather think it will add up to zero, all things considered. So what do you think actually exists?