**Ask a monkey a physics question thread**

[OngBonga]

I'm less skeptical about secret propulsion technology than I am other things. Tesla was doing some really interesting work, and others (with far less credibility) have claimed to have continued this work. I can certainly see why it would be kept secret, if indeed it is for real.

I was talking about this with my friend. he suggested that it's possible to propel something upwards by firing lasers at the underside to cause the air to expand. I kind of like the idea of that, I mean essentially it's turning the air into the fuel, which means it isn't necessary to take any fuel. That isn't what Hutchison was doing, that's a second theory I've heard which might explain how heavy things can get into space cheaply.

And yes, velocity would be much lower at ground level. At what altitude would plasma production cease? Could it look from the ground like a shooting star, or lightning, or something else perceived as innocent?

[MadMojoMonkey]

I'm less skeptical about secret propulsion technology than I am other things. Tesla was doing some really interesting work, and others (with far less credibility) have claimed to have continued this work. I can certainly see why it would be kept secret, if indeed it is for real.

I'm not going to get into the whole "Tesla was an under-appreciated god of science who hid/destroyed all his best work" conspiracy theories.

Whatever he hid and or destroyed was done in an era before modern computers. He was intelligent, but he wasn't the most intelligent person ever to study this stuff.

Your supposed reasons to keep efficient energy sources a secret are lost on me. All I hear is conspiracy theories. Trust me, if my department got word of a practical power source, we're not keeping it a secret. We're testing it, quantifying it and monetizing it. The blind accusation that "big oil" or something similar is somehow incentivized to suppress innovation is lost on me.

If there is a real conspiracy, then show me the evidence. Make it good. Don't make it a series of open-ended questions to which you have no verifiable answers. Don't then attempting to wrap up your ignorance with accusations.

I was talking about this with my friend. he suggested that it's possible to propel something upwards by firing lasers at the underside to cause the air to expand. I kind of like the idea of that, I mean essentially it's turning the air into the fuel, which means it isn't necessary to take any fuel. That isn't what Hutchison was doing, that's a second theory I've heard which might explain how heavy things can get into space cheaply.

It's possible to do so in theory. Control and stability would be ever-present issues, but they usually are with rockets.

I fear that it would cost obscene amounts of energy to attempt to do this. Plus the whole "Don't kill everything behind you when send a rocket into space" thing might come into play... again. (Project Orion is so cool.)

And yes, velocity would be much lower at ground level. At what altitude would plasma production cease? Could it look from the ground like a shooting star, or lightning, or something else perceived as innocent?

IDK about the altitude. It would probably be a function of the initial speed of the falling object. If it starts faster, it'll take longer to slow down.

It would look exactly like a shooting star, 'cause that's what a shooting star is - i.e. a hunk of metal falling from space.