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Q&A Restricted Directions for an Alcubierre Drive?

Yes. By restricting the directions it can travel in, you can create an Alcubierre drive that can't be used as a time machine to create paradoxes. The simplest way to do this is to pick a single fra...

posted 4y ago by lsusr‭  ·  edited 4y ago by lsusr‭

Answer
#4: Post edited by user avatar lsusr‭ · 2020-07-20T03:40:51Z (over 4 years ago)
#3: Post edited by user avatar lsusr‭ · 2020-07-20T03:40:06Z (over 4 years ago)
  • Yes. By restricting the directions it can travel in, you can create an Alcubierre drive that can't be used as a time machine to create paradoxes.
  • The simplest way to do this is to pick a single frame of reference for the warp drive. The Alcubierre drive must never go back in time /according to this reference frame/. There are no other restrictions. It's hard to explain further without turning this answer into a primer on special relativity and Minkowski spacetime.
  • ## Relativity, Causality, FTL: Pick 2
  • "Relativity" is the idea that the laws of physics are the same for every reference frame. An Alcubierre drive with a preferred reference frame would therefore violate the abstract idea of "relativity". But Newtonian relativity, special relativity and general relativity would all be preserved.
  • In other words, you get to have 2 of the following 3 things.
  • - Relativity (background independence)
  • - FTL (faster-than-light travel)
  • - Causality (world without time travel)
  • Our universe has relativity and causality. If you want a causal world with FTL then you have to throw out relativity, but just for the Alcubierre drive itself. The rest of the universe would still work the way we're used to.
  • Yes. By restricting the directions it can travel in, you can create an Alcubierre drive that can't be used as a time machine to create paradoxes.
  • The simplest way to do this is to pick a single frame of reference for the warp drive. The Alcubierre drive must never go back in time /according to this reference frame/. There are no other restrictions. It's hard to explain further without turning this answer into a primer on special relativity and Minkowski spacetime.
  • Relativity, Causality, FTL Pick 2
  • "Relativity" is the idea that the laws of physics are the same for every reference frame. An Alcubierre drive with a preferred reference frame would therefore violate the abstract idea of "relativity". But Newtonian relativity, special relativity and general relativity would all be preserved.
  • In other words, you get to have 2 of the following 3 things.
  • - Relativity (background independence)
  • - FTL (faster-than-light travel)
  • - Causality (world without time travel)
  • Our universe has relativity and causality. If you want a causal world with FTL then you have to throw out relativity, but just for the Alcubierre drive itself. The rest of the universe would still work the way we're used to.
#2: Post edited by user avatar lsusr‭ · 2020-07-20T03:39:30Z (over 4 years ago)
  • Yes. By restricting the directions it can travel in, you can create an Alcubierre drive that can't be used as a time machine to create paradoxes.
  • The simplest way to do this is to pick a single frame of reference for the warp drive. The Alcubierre drive must never go back in time /according to this reference frame/. There are no other restrictions. It's hard to explain further without turning this answer into a primer on special relativity and Minkowski spacetime.
  • # Pick 2: Relativity, Causality and FTL
  • "Relativity" is the idea that the laws of physics are the same for every reference frame. An Alcubierre drive with a preferred reference frame would therefore violate the abstract idea of "relativity". But Newtonian relativity, special relativity and general relativity would all be preserved.
  • In other words, you get to have 2 of the following 3 things.
  • - Relativity (background independence)
  • - FTL (faster-than-light travel)
  • - Causality (world without time travel)
  • Our universe has relativity and causality. If you want a causal world with FTL then you have to throw out relativity, but just for the Alcubierre drive itself. The rest of the universe would still work the way we're used to.
  • Yes. By restricting the directions it can travel in, you can create an Alcubierre drive that can't be used as a time machine to create paradoxes.
  • The simplest way to do this is to pick a single frame of reference for the warp drive. The Alcubierre drive must never go back in time /according to this reference frame/. There are no other restrictions. It's hard to explain further without turning this answer into a primer on special relativity and Minkowski spacetime.
  • ## Relativity, Causality, FTL: Pick 2
  • "Relativity" is the idea that the laws of physics are the same for every reference frame. An Alcubierre drive with a preferred reference frame would therefore violate the abstract idea of "relativity". But Newtonian relativity, special relativity and general relativity would all be preserved.
  • In other words, you get to have 2 of the following 3 things.
  • - Relativity (background independence)
  • - FTL (faster-than-light travel)
  • - Causality (world without time travel)
  • Our universe has relativity and causality. If you want a causal world with FTL then you have to throw out relativity, but just for the Alcubierre drive itself. The rest of the universe would still work the way we're used to.
#1: Initial revision by user avatar lsusr‭ · 2020-07-20T03:38:50Z (over 4 years ago)
Yes. By restricting the directions it can travel in, you can create an Alcubierre drive that can't be used as a time machine to create paradoxes.

The simplest way to do this is to pick a single frame of reference for the warp drive. The Alcubierre drive must never go back in time /according to this reference frame/. There are no other restrictions. It's hard to explain further without turning this answer into a primer on special relativity and Minkowski spacetime.

# Pick 2: Relativity, Causality and FTL

"Relativity" is the idea that the laws of physics are the same for every reference frame. An Alcubierre drive with a preferred reference frame would therefore violate the abstract idea of "relativity". But Newtonian relativity, special relativity and general relativity would all be preserved.

In other words, you get to have 2 of the following 3 things.
- Relativity (background independence)
- FTL (faster-than-light travel)
- Causality (world without time travel)
  
Our universe has relativity and causality. If you want a causal world with FTL then you have to throw out relativity, but just for the Alcubierre drive itself. The rest of the universe would still work the way we're used to.