calbiterol

If I have a spacecraft that has only so much conventional fuel for a conventional rocket and also has an ion engine, could I have it burn the rocket fuel off, and then continue in acceleration with the ion engine? I know that ion engines can accelerate until they run out of fuel or reach near the speed of light, and I don't see any reason why the above scenario couldn't happen... But I wanted to see what everyone else thought. Thanks in advance.

Aha! I found the page that had the "how to" on geomagnetic propulsion. It was in the FAQ section of the site above:

Don't worry about it, Jacques - think of it this way: you can talk in English better than a lot of Americans can, our current president included! I should mention, your English is quite good - to the point that I thought you were a native-English speaker, because your only error on the first post was using the French form of hydrogen, which is perfectly understandable. Plus, you are multilingual, which is more than a lot of Americans can say about themselves. It really is frustrating how incredibly selfish and America-centered most Americans are - but what can one do? Viele Amerikaner sind doof! I liked your saying, I'll have to remember that one. Course, I'll totally butcher the pronounciation, but it's the thought that counts. And your ability to take corrections as everyone should take them - by using them to learn from mistakes - is something I wish I could be better at. Next time, if I notice an error, I'll be sure to be nicer about it - just like I would want someone to kindly correct me if I messed up my German, or any other language for that matter. But more on the subject, it does make a lot of sense, but I don't think I could quite bring myself to give up the big bang and dark matter. It will be interesting to see what some of the telescopes under development find, because some of them are powerful enough to see so far away, and therefor so far back in time, that they can show what happened less than a millisecond after the big bang - assuming, of course, that it ocurred.

I simply didn't use any. However, there's plenty of other electrolysis threads in SFN - search for "electrolysis water" using the search button - and it seems that NaOH is extremely efficient and doesn't react much, as well as car battery acid (sulphuric acid). I used (semi)carbon electrodes from pencils. Note that these contain large amounts of clay that will, eventually, take place in the reaction. They work for playing around, but for heavy-duty electrolysis, go for platinum or pure carbon. You can grab the electrodes from batteries; they're carbon and work quite well.

To be terribly honest with you, we simply don't know enough about superconductors to say that. It isn't currently practical, though, as room-temperature superconductors have not yet been found. However, this idea is under heavy research in some circles. I've wondered a few times whether the magnetic field of a superconductor could be "exploded" (in size) with the same concept that M2P2 (mini magnetosperic plasma propulsion, a NASA concept, maybe with independent contracts - google it, or search space.com for it) uses to expand conventional magnetic fields. So, needless to say, I've done some research. By the way, if you want to do more research, the process is called geomagnetic levitation in the more technical circles. This post is a little long, but bear with it - you might find a lot of the information to be useful. Not to be offensive, and mezarashi, please don't take this as a dig on you, because it isn't, but youth has nothing to do with anything. I know a few 17-year-olds who are significantly smarter than a lot of 45-year-olds. Never underestimate the abilities of youth. It's one of my pet peeves. Again, not to be offensive, but this is... Incorrect. The phenomena that you referred to (loosely) is called the Meissner Effect. First off, if you induce a current in a superconductor in the same way as a conventional conductor or semiconductor, you will most likely destroy the superconductivity of the superconductor. In other words, it's kaputt. Superconductors have a very high resistance to external magnetic fields. That said, it's possible to levitate magnets in this way. And by the way, there's nothing "apparent" about the floating effect - it does, in effect, levitate. Now, back to the situation. Quoted from wikipedia - superconductors: If you follow the link to wikipedia's superconductors page, you'll find a picture of a magnet demonstrating the Meissner effect - by levitating. It's a very interesting and informative page. If you're interested in superconductors, it's a good resource to start out with. Well' date=' implementing superconductors, and sometimes the Meissner effect, in such trains has been done. Yes, it's wikipedia again, and you'll probably have to read (or scan) the whole thing to find out about the current incarnations of it, but it's there. Also, it has been proposed to make a transatlantic vacuum tunnel that operates on this principle - with supersonic trains, I might add. Quite simply, this is easy enough to implement, because you have two strong magnetic fields in oppostition. The earth, on the other hand, has a very weak field when you refer to something so small as an orbital craft. As lepidoptera said, if you had something with a magnetic field as large as the earth itself (I'm not sure if lepid put it that way, but as far as I understand, that's the limitation in that respect, not the actual size of the craft), there would be such an opposition. However, a craft such as this doesn't have to be as large as the earth - it's just got to have a strong enough magnetic repulsion with the relatively weak field of the earth to bear its own weight. I forgot/misplaced the link to the site I found that details this process - if anyone discovers a site that says how this would be possible, please send the link. Anyways, it's theoretically possible. Small scale electronics? Do you call experimental fusion reactors (in the process of being built)' date=' nearly ALL MRI machines, massive amounts of research, and millions of other everyday applications simply [i']small-scale electronics?[/i] There are many little-known applications for superconductors, but there will be so many more when room-temperature superconductors become available. These are the el Dorado of many research facilities, the pot 'o gold at the end of the rainbow. Many things will be possible with these, including lossless powerlines, among other things. And we may yet see geomagnetic levitation. And I too hold much hope for the future, but politically, a lot of things have to change. But that is a debate for another time and another thread, especially since I've written a novel in this post. Sorry 'bout that. Some links: Here's a relevant page from the site of an R&D company that includes geomagnetic levitation in its current research. Here's another good page.

I assumed he meant full-size. If you're talking about model airplane-size, flyboy, then it isn't quite as dangerous, or as complicated, especially if you do a PDE (pulse detonation engine), like H2SO4 was talking about.

Out of curiosity, flyboy, are you basing that on knowledge, or just speculating? Also, howstuffworks has two great articles for this thread: How nukes work How e-bombs work

Oops. Somehow I missed that part. My bad. Still, taken out of context (like on the front page, where you can't see what forum it's in), it's still a little vague, at least to me. I didn't intend to sound offended or offensive, and I did base that complaint off of one assumption - that Jaques is a native English speaker, or learned chemistry in English, which can be attributed to the fact that I am an American, and all Americans are ethno- and geo-centric people that can hardly comprehend even the idea of learning multiple languages, much less that element names might be different in them. So, for that, I sincerely apologize, especially since I already knew that many languages use the Latin names for elements (like Kalium for what most Americans would call Potassium). Sorry Jacques, my bad. Again. I liked the article though, it was interesting - but I have to say, I enjoy the idea of there being such a thing as dark energy and dark matter out there. But that's just my opinion.

In my defense, I would say something like this or this would be rather complex and difficult to build. And I don't think that building one out of a turbocharger qualifies as making one from scratch, which is how your question was phrased. Almost any schematic you find is going to be that kind.

Why would you want them? Making a true turbojet requires incredibly complex engineering and manufacturing, and amateur ones can be extremely dangerous.

Or, alternatively, do rocky planets tend to migrate towards their sun(s) as well?

Even though you posted this in the Astronomy and Cosmology forum, it probably would still have been a good idea to clarify "molecular hydrogene" (and sorry if it's expecting too much of me, but it's 'sposed to be "hydrogen") and instead say, "molecular hydrogen in space.

That blows anything on the market out of the water. To be specific, that can play games (well, ones that don't invoke a state of processor neurosis - like, for example, Doom 3, which is way to processor demanding), function as an mp3 player, a personal organizer (just like a palm pilot), has USB (so it can, in theory, connect to a wireless network) and run a linux OS. I think that was about the idea that I had. Can't think of much else. Like a mini-tablet pc.

The green crap might have something to do with chlorine gas, but I have never used NaCl as an electrolyte, nor do I know that much chemistry, so I have no solid basis to that - it's just an "educated guess."

wouldn't happen to know if there are motherboards that are about 15 centimeters square (15 x 15) or a bit larger, would you?

While I'm on the subject, do cooling systems have to be on the chip? In particular, could the chip be in a supercold atmosphere (like with a liquid nitro cooling system) without direct contact with the cooling system, without running the risk of overheating?

It depends on the system you have set up. Is it in an air-tight box with only liquid nitrogen and the superconductor?

Can anyone recommend a power efficient, small, mobile motherboard for an AMD Mobile Athlon 64 3400+ (2.2 ghz) processor? It'll be running some form of Linux. Thanks in advance.

Yeah, I knew that, but I wasn't going for a portable system, but rather a kind of PalmPilot on steroids.

PS2 has a 300 mhz processor. That rules it out. [Edit: Gamecube is 485 mhz. Bare minimum for me is 733 (xbox speed). That rules out everything but a custom made system. Bummer. Any ideas about how to make xbox games run on computers (the original disks)? Aside from software emulators?

Well then, found some pics and some information. The motherboard is "seven or eight inches square" [http://www.vanshardware.com/articles/2001/november/011116_Xbox/011116_Xbox.htm] and is connected via special links to various accessories. Given that the whole thing is specialized, it does not appear to be practical (or space friendly - a seven-ich handheld would be... huge) to use it as a PDA on steroids. That means it's on to the PS2 and Gamecube. After that, it's down to custom-built.

That's one of the ones I just guessed on. PM me about the clue for #2. Think about it first, long and hard. The indians. 101 times, 4 days. If it still eludes you, PM me.

Yep, same one. Read my previous post a few more times, play with the words, play with the numbers, and think indians. Then talk crap to the indians. Tell them about something that they don't think exists. The'll help you out - they even speak perfect English.

That's what I was talking about. Install linux to a boot cd. Instant freedom. I'm doing this for next year. It's going to be fun to replace my school's restricted suckiness with Linux. Hopefully, it'll work.

Oh here's another idea, install linux to a CD and boot from it. And/or, firefox on a thumb drive.