http://www.photonics.com/content/news/2007/September/7/88894.aspx This site is currently undergoing a digg effect, so if it's down give it a day or so. Still is this exciting news, or just fantasy?
Always lock up your checkbook when the investment brokers come calling. I've seen too many Moller "flying car"-type scams. But if they'd produce and test a working model, I'd happily applaud them....
A 'Photonic' Laser Thruster ? I wonder what the Doctor would think about that Kidding asside, it does sound neat, it sounds like it is a long ways off from application though.
My question is would humans be able to withstand the acceleration forces at work by going to Mars in a week?
Why not ? Simulations would have to be done to see what kind of a strain would it put the human body through exactly, and possibly modify the crafts hull design to lessen the impact of the forces in question. This would be in any case a viable option for sending automated probes faster to Mars ... We wouldn't have to wait as long as we did up until now.
There would be a considerable amount of time at the beginning of the journey taken up with accelerating and at the end of the journey taken up with braking, so I shouldn't think 1 week is anything other than fantasy.
Assuming a distance of 100 million km, constant acceleration for half the time and contant deceleration for the other half, and a duration of 6x10^5 seconds gives a max speed of 335 km/s (1.2 million km/hour) and an acceleration of 1.1 m/s/s (compared to 9.81 m/s/s due to gravity at the surface of the Earth, so about 0.1G). Is that about right? Sounds promising -- I don't know anything about the validity of the propulsion mechanism though...
Yeah, at that acceleration you wouldn't even need to spin the ship, just weight down the astronauts with some lead weights and for an added bonus the ship has "gravity" as long as the engine is on. If you can keep accelerating for a large amount of time you start gettign into signifigant fractions of "C", interstellar flight becomes possible. (crosses fingers) please be true, please be true, for the sake of spock, please be true!
Then if you think back to Einstein's theories (it was him wasn't it?), that then presents another problem - time dilation Plus getting anywhere near fractional C would either involve a humongous amount of time spent accelerating or inertial dampeners so you astronauts aren't a smear on the back of the crew compartment when you really get moving. And hopefully one is working on structural integrity fields and navigational deflectors...
This just blew me away...obviously, for interstellar it won't be workable any time soon. But the idea of getting to Mars so quickly (if the acceleration can be sustained at a reasonable level) is amazing. This could really change the size of our solar system.
No dampners needed as you can accelerate close to lightspeed at 1G, that is earth's gravity and it only takes 1 year, you could tweak it up to 1.5G without too much adverse health effects and get close to C even quicker. No dampners needed, sheilding from interstellar dust though.....
Something else I thought of afterwards - what happens if you're travelling at .25c (aka full impulse) what would happen if you needed to change course for some reason?
Minor course corrections should be possible without undue health effects, even at that speed. But any significant change would take quite a while. David Weber's Honor Harrington series goes into the logistics of this a bit.
Though I remain skeptical, I do hope this is true. Mars? Something like this can open up the entire solar system to Human exploration.
I was under the impression that so long as the acceleration was steady and not too strenuous on the human body that we could travel at any speed, so I dont see why we cant get to Mars in pretty good time so long as the ship doesnt accelerate to max speed too quickly.
But wouldn't the mass of everything on the ship increase as the speed increased? It seems to me that you'd want your acceleration to gradually slow a bit as your mass increased. ---------------
relative mass increases, mass according to your reference frame inside of the vehicle would remain the same. So if someone from a planet you were passing by would measure your mass they would find it larger than if you inside your own ship would measure your mass. At near the speed of light your ship would be flatter than a dime (as viewed from a passing planet), from inside the craft all would seem normal, mass, measurement and time are all relative and change depending on relative speed. http://en.wikipedia.org/wiki/Mass_in_special_relativity