The Alcubierre Drive and Negative Energy

[spock0149]

My understanding of the Alcubierre drive is that a spacecraft is encompassed within a 'bubble' of expanding spacetime (at rear of craft) and contracting spacetime (at the front).

I am trying to understand the role of negative energy in this scheme.

Am I correct in saying that the contracting spacetime at the front of the ship requires the negative energy, however that an equal amount of 'positive' energy is needed at the rear?

e.g with positive energy you only get half a warp drive...in a sense.

 

[marcus]

https://www.physicsforums.com/showthread.php?t=305091

 

[Entropia]

Your understanding of the Alcubierre drive is correct. The concept behind the Alcubierre drive is that the spacecraft is essentially riding on a wave of expanding and contracting spacetime, allowing it to travel faster than the speed of light without violating the laws of physics. This is achieved by creating a "bubble" of negative energy in front of the spacecraft and a corresponding bubble of positive energy behind it.

The negative energy is necessary for the drive to work because it is what creates the contracting spacetime in front of the ship. Without it, the ship would not be able to move through space at superluminal speeds. However, as you mentioned, an equal amount of positive energy is also required at the rear of the ship to balance out the negative energy and maintain the stability of the drive.

It is important to note that the concept of negative energy is purely theoretical and has not been observed in nature. It is a hypothetical form of energy that has been proposed in various theories, but has not been confirmed by experiments. So, while it is a crucial component in the theory of the Alcubierre drive, its existence and role in the drive is still a matter of debate and further research.

Overall, your understanding of the relationship between negative and positive energy in the Alcubierre drive is correct. They both play essential roles in creating the "warp bubble" that allows for faster-than-light travel. However, the exact nature and properties of negative energy are still not fully understood and require further study and experimentation.