calbiterol

Not true. Not ALL electronics are fried by magnetic fields, just most. I also think I heard something about magnetic sheilding somewhere. What's the point? It's dirt cheap. Raw materials won't get fried. Getting into orbit can be done manually. If computer control really is necessary on the way down, then manufacture it up in the sky - or, alternatively, salvage the heat shield and just let the module burn up in the atmosphere. If the object is to get to a colony, then that's that. Otherwise, you'd have to construct a descent module. This isn't something that could be made tomorrow. By the time it could be ready, there most likely would be a way to manufacture electronic components in space. If it really is an issue, then send up electronics in a cheap conventional rocket, but use something like this as a heavy lifter. This kind of thing would really pave the way for space-based manufacture. Why spend many millions of dollars on sending something up in one piece when you could send it up in pieces and manufacture it in space for almost nothing? [Edit: NOOOOOOOOOOOOOOOOOOOOOOOOO!!!! I've been beaten to the punch line AGAIN! (Continues slow-motion yelling) NOOOOOOOO! Here's where we differ. I would say that my way is better, because it uses NO rocket fuel. It's got its disadvantages, yeah, but it's almost free (only costs I could see would be maintenance, etc) and it's simple. Simple is often best. No offense taken.

*Bump.* C'mon, somebody's got to have some idea of how these things work...

Yes, the magnets would probably destroy most electronic equipment. But first, the module wouldn't need any to function. If you were concerned about not making it into orbit, then you could always have a person onboard there to deploy a parachute in an analog way, without electronics. As far as biological cargo (in other words, humans) and other non-magnetically-sensitive materials, it'd be a dirt-cheap (comparatively, even including startup costs) way to get into orbit. As far as a heat shield goes, it might not be needed on the way down. First, you could feather it like SpaceShipOne. Or, alternatively, you could either reassemble the module in orbit for a descent, or you could go down facing the same way as when you came up.

I've long been pondering the effectiveness of an alternative system to rockets as a means to get into Earth Orbit. Escape Velocity is generally defined as about 9.0 kilometres per second and is the velocity at which an object will escape the pull of Earth's gravity and obtain orbit. So here's my alternative system. It uses a massive gravitational and magnetic accellerator to throw something into orbit. It would work like this - you have a *VERY* long U-shaped tube that is wide enough to fit a module/projectile within it (Just like this picture). Wound around this tube are many, many electromagnets. Past the electromagnets are fixed magnets. The module (which is dimagnetic) is first situated at the top of one side of this U-tube. The fixed magnets should keep it floating in the center of the tube, not touching any of the walls. The module is then released, and gravity pulls it down. In addition to gravity's pull, each electromagnet surrounding the tube is "switched on" when the dimagnetic module passes the center of that electromagnet. These electromagnets are supplied power by capacitor banks, with one capacitor bank for each electromagnet. When the module gets to the bend in the U, it is gradually pushed back upwards and towards the sky - this time, however, the magnets are doing a lot more work, accelerating the module even further, despite the fact that it is working against gravity. Could something like this be used to catapult something into orbit? The power costs would be massive, yes, but I thought about that, too. But first, the structural engineering side of it. Something like that would have to be massive. To accomodate for the structural pressures of building something so tall, you could either A, submerge it in water, B, bury it in Antarctic ice, or C, bury it underground. Either way, the primary ways of drawing power would be geothermal and solar. Clean and effective. Maybe the whole thing could be made into a vaccuum chamber, ridding the tunnel of air friction and preventing the devastating effects of a sonic boom. The only problem then is, how do you get the module out of the tube if the tube is sealed? Maybe what could be done is to give the module a pretty good seal with the sides of the tube (without touching the sides), and after dropping the module, open a hatch behind it - letting air pressure accellerate the module even more. Then, when it gets to the top of the other side of the U, either a hatch opens (more like... explodes) to let it out (but timing would be near impossible), or it punches through glass, or... Aha, an even more effective way - the seal is simply blown up with explosives, reducing loss of momentum and allowing it to wait 'till last minute to break the seal. Anyways, what do you think?

Cadmus. If I had a box that was opaque to ALL of the spectrum, visible and invisible (to human eyes), then what would be in the box? If there were NO photons in the box, what could possibly be in it? Dark. In other words, an absence of light. Take a lesson from someone who often takes things way to seriously - you're overanalyzing. P.S. NO light passes through the earth. Like Macroscopic, I hope I'm misinterpreting you here.

Yeah, here's one. Back a few years ago, I had a science teacher who was really incredibly dumb, to put it very, very nicely. Here's an example: If anyone in the class was loud or unruly, she would send that kid into the hall. So one day, she stuck her elbow into a jelly doughnut. By the time she had realized that her arm was in a jelly doughnut, she'd sent half of the class into the hall for laughing. The sad part is, that was a *good* day.

Actually, as far as things tend to go, Uranium is relatively easy to enrich. A mild budget could do it, with chemicals readily available from a chemistry store - in a way completely different from the "Radioactive Boy Scout" did. Check out the arcticle at http://www.popsci.com/popsci/generaltech/article/0,20967,1017201,00.html .

Thanks, that'll help a lot.

Sounds like it could be a milestone. Using the same process, it might be possible to make viruses that correct any number of things - viruses, tumors, alzheimers, etc. Or, use them to modify your DNA. Perhaps an end to plastic surgery, beginning of DNA modification and superhumans?

I'm in the planning stage of building a wind tunnel, and I think I have it about down - except for one "minor" detail. How do I make the air that is passing through my wind tunnel visible, so that I can see how aerodynamic the things that I'm testing are? Does smoke work for this?

Mars is generally considered to be a magnetically dead planet, meaning its core is solid (cooled) and it has no magnetic field, correct? Is there any way to restart this process? Maybe a detonation in the core? Hypotetically... Just wonderin'.

I have to agree with Nevermore there. Anyways, so far we have food/water, shelter, love, laws, and a means of keeping time as requirements for a modern society. Would they be in that order? And are there any others?

I, like Coquina, really like the way you talk about them - not as a pet, rather as a non-human companion. I have a question though - did you ever have to worry about pottytraining it? Cause that could be a pain to clean up...

What has happened to natural selection? I don't mean this at all in an evolutionary way, or I would have posted it in a different forum, but... Arg! This is perhaps the time when natural selection / survival of the fittest would do the most good! It's still around in nature, sure - but have we, as a species, progressed too far for our own good? Is cheating evolution really a good thing? Sometimes I wonder... People can be so stupid and destructive sometimes. Maybe we should just make artificial selection. You know, do it ourselves - in a "moral" way - maybe send the people who deserve to stick around to Mars or something, so that they don't have to deal with Earth's problems. Then let them be their own civilization. In a hundred years, maybe they'd be a superior race! I guess this whole thing is just venting about all the annoying, stupid, and incredibly and disgustingly idiodic (wow... that was redundant) people that I see all too much of. High school. Ugh. Can't wait to get to college.

Can someone please explain this to me? I don't quite get it. I get that you are shining two laser frequencies onto a material that is not a line, and that the two frequencies may combine to give the sum and the difference of the two frequencies, and that when the sum equals the difference, it is called second-harmonic generation. I don't really get the rest of it...

Okay, thanks. [Edit: Can you explain this? I'm not very knowledgeable about physics, but I pick up on things fast. I get the general gist of that, but not the full meaning, and I'd like some help figuring out what it means.]

Aha! So that's what that meant. It makes so much more sense now.

So let's say I want to make a double parabolic mirror (like the one at http://www.optigone.com/ ) that recreates a virtual image of a three dimensional object. That in itself wouldn't be too incredibly challenging. It's also entirely possible to do so. But is it possible to enlarge the virtual image using nothing but the shape of the parabola(s)? Or, if not, then the parabolas and a lens? While I'm on the subject, how do those devices work? I know that they just reflect the image back up to a different focal point, but what is the physics behind it? Specifically, how is the virtual image created, and where are the focal points of the parabolas?

Ai'ight. I think I get it now. 3 questions though: first, how do you excite through multiple energy levels? Do you use more power, or just sustain what power you had? Also, are there any other gasses that have the same effect that hydrogen does? And is there any way for me to determine these kinds of things (like hydrogen electrons only being able to drop one level at a time, the spectra emitted during each drop, etc)?

Atheist, können Sie bitte mir helfen? Mein Deutsch ist nicht so gut, und so kann ich nicht alle von TUD verstehen. Danke sehr.

Cadmus, sorry. I was just trying to stop the flaming. Your idea was a good one, and a very valid point. [Edit: Uh... I'm sorry' date=' I have absolutely no idea what you mean by that. Can you explain? ']

Cadmus, that was a little of the pot calling the kettle back. Now you're both at it. Why can't we all just get along? Seriously though, please stop flaming.

I should have specified that I meant a modern society. However, this includes third-world countries, so technology may or may not be an issue.

So, it's possible (in theory) to bump an electron up to a higher energy state with a photon in the nonvisible spectrum, yes? Is it possible that the same electron could, in theory, emit a visible photon when lowering its energy state?