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Comment Re: Experimental engines (Score 1) 70

I guess I should have learned by now, that the level of physics knowledge of Slashdot users ends at Newton, and they have unshakable faith in him. Ultraviolet Catastrophe is probably an alien term to many of them. But yet somehow they buy into the ideas of "dark matter" and "dark energy". I really don't have the patience or time to squabble on here. If anyone has a serious interest in this, and can plough through tons of posts by actual physicists on the matter, I will direct them to the forums, and the website.

I am posting to Delt0r's comment, because it's one of those which is not anonymous, but I mean this to cover all of the putdowns I have received.

Comment Re:We need a world-wide effort in space (Score 1) 70

Solar panels work when you're got a fair amount of solar radiation to use. That's only really the case in the inner solar system (or the inner part of any star system). For other places, nuclear is needed. Fission fuels will be far more plentiful on the inner, 'rocky' planets - in our system, that's as far as the inner asteroid belt. outer, gas planets will have more deuterium and tritium, useful for fusion. Until fusion gets working properly, we're stuck with fission. That's ok, for now.

Comment Re:Experimental engines (Score 1) 70

I can see why they're being cautious. I just wish they were a little less so. I never claimed any conspiracy, and even though the results were difficult to believe at first, and there continues to be doubt, no other explanation for the observations has been adequate. So, better experiments are performed. That's what's happening now. Because of all of the flak that the idea has, much of the work goes on in quiet.

If you're looking for a possible explanation, here is one:

Comment Re: Experimental engines (Score 1) 70

Note my slashdot id#: I've been here for a while. I've been using this nick for thirty years. Oh, maybe you have a real ID as well, but don't want to get downgraded for your choice of vocabulary and your tone.

Whatever. Here's the science you don't deserve. It's possible the EMdrive function is due to the Unruh effect.

Comment Re:We need a world-wide effort in space (Score 1) 70

I would like to see much more spending on space projects. But a global federation pooling resources will not be efficient. Firstly, space programs are very expensive so only very large or rich nations can afford them. There are many different possible designs for a star-ship like craft, it is impossible to get everyone working on a single design. US efforts during WW2 caused great economic difficulties for the people, and were barely sustainable. I would not want to put the nation or the world through that type of suffering again.

What is needed, is broadly-based support for intensive research into technology to help us expand off of Earth. We need the social and economic conditions which create a large number of people with the necessary skills for these jobs. I see none of this at present. We had better hope for the genius of the very few who are interested and able to do the work.

Comment Re:We need a world-wide effort in space (Score 1) 70

What exactly are you proposing, and why? 1) Why do you want to attach chemical and ion engines to the ISS? to maintain its orbit? to move it to a new one? We can already do that; it's not a big deal. It's just expensive. 2) pressurized space (the interior of spacecraft) is very expensive. Agriculture requires a lot of space. It is simply not practical to start these orbiting greenhouses until other problems are solved. The generation of electricity from a potato is very inefficient. Photovoltaic cells do a far more efficient job. 3) If you are talking about using biodiesel for rockets from the Earth's surface to orbit, biodiesel is not nearly powerful enough to reach orbit. If you are talking about utilizing wastes from human processes in orbit for rockets, this is very bad - we need those chemicals and they're expensive to bring up from Earth! This is why ion engines are attractive in orbit: they expel very little matter as opposed to chemical rockets. The EMdrive doesn't expel any matter at all, so it's even better.

Comment Re:Experimental engines (Score 1) 70

The EMdrive is still being worked on. There are private, and secretive, efforts to develop it, in addition to NASA research at Eagleworks. They're building test apparatus which eliminate any possibility of error from gravity, heating, etc. But they're working with very low electrical power, so the thrust they're dealing with is miniscule. There's a theory that thrust is not linear, and that the maximum efficiency is at an electrical power of 50kW, and that it's a LOT of thrust. My *hunch* is that there are groups working with EMdrives which are tens of kW, but not superconducting (but as high Q as a room-temperature RF cavity can get)...just to see what happens. Working with superconductors is difficult and expensive. The commercial superconductor industry is developing MgB2 technology for high-field magnets used in MRI, fusion, and particle accelerators, and once some of this fabrication expertise is gained, I believe that we'll see EMdrive using it. I'd give a rough estimate of 4-5 years. I don't see hi-temp (cuprate, etc) superconductors in this application for some time.

The revolution of a practical EMdrive will disrupt the propulsion industry, which may be one of the reasons NASA is putting such little money into the projects which are the subject of this article.

Comment Re:Scientists (Score 1) 203

I agree, in that if the only difficulty with high-TC superconductors was burnout (assuming burnout happened after the time needed to conduct the experiment), then it would be worth constructing. But that's not the problem. The problem is that the high-Tc superconductors are ceramics, and getting them annealed at the proper dimensions and smoothness is difficult. An insufficiently constructed RF cavity of this type wouldn't burn out, it just wouldn't function with sufficient efficiency to properly demonstrate the capabilities of the EMdrive.

Compared with the difficulties of working with other materials, machining the RF cavity out of niobium titanate is not difficult. Maintaining the near absolute-zero temperature necessary for it to superconduct would be a problem, in that much liquid helium would be consumed - and not just because of the penetration of outside heat, but also because of heat generated internally when the device is used: any imperfections in the RF cavity's construction or the frequency and shape of the signal applied would end up causing part of the power to be lost to heat. However, if the device was at least sufficiently well constructed so that the heat generated was little enough to be compensated for in the cooling system, then the magnitude of the EFdrive's acceleration should be strong enough be readily observable, and well in excess of any thermal effects which might otherwise overwhelm the EMdrive effect.

Comment Re:THIS. ISN'T. SCIENCE. It's SCIENCE-FICTION (Score 2) 203

Wow, such anger, much distortion! It HAS been replicated. there IS published experiments, peer reviewed. Are Tajmar and Fielder not respectable enough for your tastes? Some people, which may include 'gavron', call themselves physicists but are really just engineers who took some physics in college, and now don't want to think that there's so much more physics that they have to learn. There are huge frontiers in physics, but there are usually are abstract and at one end of the scale or the other: cosmologic or subatomic. This area of exploration is human-scale, potentially disruptive, and that makes some old farts nervous.

Comment Re:Summary (Score 1) 203

Unruh effect may be responsible for the EMdrive effect, and also may explain why galaxies don't fling themselves apart, without the need for bizarre concepts such as 'dark matter' and 'dark energy'. The problem with Unruh's theory is that we have lacked the ability to test it, until, perhaps, now - with the EMdrive. See this paper by McCulloch:

Comment Re:Scientists (Score 1) 203

Eh, don't like your characterisation of 'mental masturbation', but I'll skip over that and agree with other things you have said. In particular, the superconducting part.Niobium is old-school, and has to be cooled so close to absolute zero that it is expensive and cumbersome. That being said, it should be sufficient for a test of an emdrive - if thermal effects can be properly addressed. Magnesium diboride does not require quite as low a temperature, but is still difficult to get into the ultra-smooth, ultra-precise shape that a high-Q RF cavity needs to be. The cuprate superconductors, with their much less strenuous cooling requirements, are even more difficult to deal with, and superconductivity in them is destroyed under intense magnetic fields. The newest superconductor, plain old Hydrogen sulfide, only superconducts under extremely high pressure, and I don't see how that it's even remotely practical because of it.

No sum up: Please do use niobium now (niobium titanate) for an EMdrive. I believe that the Magnesium diboride (MgB2) fabrication methods will soon (in a year or two) be sufficiently advanced for use in an EMDrive, especially if there is more attention (money) put into the project if the niobium EMdrive is successful. Don't wait for other superconducting technology to mature before designing a practical EMdrive.

ASHes to ASHes, DOS to DOS.