Where and why do you guys keep on coming up with perpetual motion? It is stated quite clearly that it requires electric power to operate. While it does not require a stored fuel in the true sense of the word, it still requires power to run and the tests so far show that much more energy is need than the equivocal thrust produced. So if all of that is the case where is the perpetual motion.
Robert At 12:33 PM 8/6/2014, you wrote:
On 06/08/14 14:47, Keith Henson wrote:On Wed, Aug 6, 2014 at 1:41 AM, Peter Fairbrother <zenadsl6186@xxxxxxxxx> wrote:On 06/08/14 05:47, Troy Prideaux wrote:As we've concluded here many times in the past, rockets don't care how fast they're going with respect for the surroundings. More energy or more Isp per given mass ratio = better performance as per the rocket equation. It does matter a lot with air breathing propulsion, but not with rockets or for that matter the technology of current discussion.I think maybe it does matter with this technology - if it doesn't then it would be a perpetual motion machine, and even less likely to work.Then the laws of physics, at least as they apply to this technology, would have to be variable depending on velocity. Then the question becomes velocity with respect to *what*?What indeed, which is where the previous conversations about Michelson-Morley, Lorentz invariance, and so on come in.Purely from an informational point of view (ie, looking at how does the drive know what the velocity zero is, while ignoring how it interacts with it), as far as I can see there are at most two possibilities.The first and in my opinion by far the most likely (but only because the other is even less likely!) possibility is zero velocity relative to the big bang; which is also a zero relative to the mass in and/or of the universe; and for practical purposes is very close indeed to the rest frame relative to the cosmic microwave background.The last is something which we can actually measure; we are travelling at 369±0.9 km/s in the direction of galactic longitude l = 263.99±0.14°, b = 48.26±0.03 relative to that rest frame.The second possibility comes from General Relativity and is sort of similar in terms of being a summation of the effects of all the mass in the universe, but it takes local matter more into account. For various reasons I think it's very unlikely indeed but I thought I'd mention it as, like the rest of these speculations, it is not impossible, assuming the rest of physics is correct but incomplete.I was amused by a comment on a recent discussion of power satellites about how this would make transporting the parts to GEO easier. If this is real, it's the future energy source, forget power satellites.Yep.Unless of course it does vary depending on velocity ... in which case it isn't a perpetual motion machine, and is somewhat less implausible.-- Peter FairbrotherKeith-- Peter Fairbrother