Astrodude

15th December 2010, 11:14 AM

The Alcubierre Drive is a theoretical means of propulsion that is faster-than-light from an observer's frame of reference. If someone were to build a spaceship with Alcubierre Drive to leave Earth, if they could get to Neptune before the light from the Sun. Alcubierre's method is consistent with General Relativity because the propulsion essentially manipulates space-time.

Aside from numerous practical obstacles, the major problem with the theory of Alcubierre Drive is that it supposedly requires exotic matter, which is anything with a hypothetically negative mass. My question is how so?

I've carefully looked at the math. There is no reason mathematically that a traveler would need to obtain negative energy for this propulsion. The only mathematical need for negative energy is for the observer to witness the faster than light travel, or to be precise, the travel at the essentially superluminal speed. As far as I can tell, Alcubierre drive could be done without exotic matter with many bizarre consequences.

If a ship were to really travel at a speed of 1000c from the stationary observer's frame of reference with strict Alcubierre propulsion, the observer would simply see the ship to be one thousand times closer to him than it actually is. The ship reached its long destination traveling at 1000c and then returned to the observer using the Alcubierre drive, the observer would see the ship near him and far away at the same time. In fact, the observer could witness the spaceship's journey and the spaceship at the same time after the spaceship has been out of the bubble and near Earth for some time. Theoretically by altering speeds of the distortion in spacetime, the ship could appear to be in an infinite number of places at once for the observer.

The calculations used to claim that negative energy is required for the Alcubierre drive rely on the metric of the observer, but it's not the metric of the observer at the time of observation that's relevant because the ship is in the spacetime distortion. It's the metric of the of the observer at the time of flight, when he is ironically not observing, that matters concerning the flightpath.

Please point out any mistakes.

Aside from numerous practical obstacles, the major problem with the theory of Alcubierre Drive is that it supposedly requires exotic matter, which is anything with a hypothetically negative mass. My question is how so?

I've carefully looked at the math. There is no reason mathematically that a traveler would need to obtain negative energy for this propulsion. The only mathematical need for negative energy is for the observer to witness the faster than light travel, or to be precise, the travel at the essentially superluminal speed. As far as I can tell, Alcubierre drive could be done without exotic matter with many bizarre consequences.

If a ship were to really travel at a speed of 1000c from the stationary observer's frame of reference with strict Alcubierre propulsion, the observer would simply see the ship to be one thousand times closer to him than it actually is. The ship reached its long destination traveling at 1000c and then returned to the observer using the Alcubierre drive, the observer would see the ship near him and far away at the same time. In fact, the observer could witness the spaceship's journey and the spaceship at the same time after the spaceship has been out of the bubble and near Earth for some time. Theoretically by altering speeds of the distortion in spacetime, the ship could appear to be in an infinite number of places at once for the observer.

The calculations used to claim that negative energy is required for the Alcubierre drive rely on the metric of the observer, but it's not the metric of the observer at the time of observation that's relevant because the ship is in the spacetime distortion. It's the metric of the of the observer at the time of flight, when he is ironically not observing, that matters concerning the flightpath.

Please point out any mistakes.