What would you see traveling faster than light?

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Discussion Overview

The discussion revolves around the hypothetical visual experiences of traveling faster than light using an Alcubierre drive, a theoretical concept in physics. Participants explore what one might see while moving within a warp bubble, considering various aspects of light and electromagnetic radiation, as well as the implications of such travel on visibility and perception.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants suggest that directly behind the warp bubble, one would see nothing due to light not being able to reach the observer.
  • Others propose that directly in front, stars would appear blue-shifted, with the intensity of light depending on the speed of travel, potentially reaching visible ranges.
  • There is a concern raised about the effects of high-intensity electromagnetic radiation on the observer, with some arguing that it could be lethal.
  • Some participants mention the potential danger from space dust and other particles at such high speeds, suggesting that any matter could be fatal.
  • A participant notes that the field of view would increase dramatically at near-light speeds, referencing diagrams seen in other contexts.
  • Questions are raised about the perception of light and stars at different angles, with some arguing that there should still be visibility in all directions except directly behind.
  • One participant describes a "fisheye" view of the universe while traveling, suggesting that the visual experience would be distorted and out of focus unless in a specific position.
  • There is a discussion about the nature of the Alcubierre drive, with some clarifying that the ship does not move through space inside the bubble, but rather space is manipulated around it.
  • Links to academic papers are shared for further reading on the topic, indicating ongoing research and exploration in this area.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the visual experience while traveling faster than light, with no consensus reached on the specifics of what would be seen or the implications of such travel.

Contextual Notes

Discussions include assumptions about the nature of light, the effects of speed on visibility, and the theoretical framework of the Alcubierre drive, which may not be fully resolved or agreed upon by participants.

newjerseyrunner
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In my universe, the laws of physics are exactly the same, except we've figured out how to create an Alcubierre drive (we discovered how to create negative energy density, how is done through handwaving.)

So, with that assumption, what would you actually see while traveling in a warp bubble like the one described by Alcubierre.

I came to the conclusion that it would depend on where you were looking.
  • Directly behind you, you would see absolutely nothing. Light would not be able to reach your eyes from any place outside of the bubble behind you.
  • Directly in front of you, you'd see stars whipping by you, but you'd actually be seeing the far infrared, as they'd be blue-shifted. If the ship is traveling at 3000x the speed of light, light in the 100GHz range would be blue-shifted into the 300THz visible range.
  • To the side of you, you'd see a gradient from heavily blue-shifted stars to heavily redshifted, fading to blackness as you get closer to perpendicular to direction of motion.
 
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newjerseyrunner said:
In my universe, the laws of physics are exactly the same, except we've figured out how to create an Alcubierre drive (we discovered how to create negative energy density, how is done through handwaving.)

So, with that assumption, what would you actually see while traveling in a warp bubble like the one described by Alcubierre.

I came to the conclusion that it would depend on where you were looking.
  • Directly behind you, you would see absolutely nothing. Light would not be able to reach your eyes from any place outside of the bubble behind you.
  • Directly in front of you, you'd see stars whipping by you, but you'd actually be seeing the far infrared, as they'd be blue-shifted. If the ship is traveling at 3000x the speed of light, light in the 100GHz range would be blue-shifted into the 300THz visible range.
  • To the side of you, you'd see a gradient from heavily blue-shifted stars to heavily redshifted, fading to blackness as you get closer to perpendicular to direction of motion.
You have posited a continuous spectrum, so it seems reasonable to me to assume that if EM radiation could reach you then some of it would be shifted into frequencies and intensities that would fry you pretty much instantly, so you wouldn't "see" much because you'd be dead.
 
phinds said:
You have posited a continuous spectrum, so it seems reasonable to me to assume that if EM radiation could reach you then some of it would be shifted into frequencies and intensities that would fry you pretty much instantly, so you wouldn't "see" much because you'd be dead.
Interesting. I hadn't considered what EM radiation from the rest of the spectrum would do to you. I suppose I'll need some technology to fix that, the ship's force fields should be able to handle the high intensity radiation, humans would have to find a way to deflect the normal space radiation anyway.
 
You also need to think about this: if EM radiation can reach you, then why not space dust? Any way you cut it, I think if any of that stuff can reach you at those speeds, you're dead.
 
I may be a bit late, but your field of view would increase dramatically- I wish I had a source for this, so I may have to edit this post later. I'd recalled seeing some sort of diagram of going to the sun at near-light speed, and aside from blueshift, that was one of the effects.
 
newjerseyrunner said:
To the side of you, you'd see a gradient from heavily blue-shifted stars to heavily redshifted, fading to blackness as you get closer to perpendicular to direction of motion.
Why is that? The blackness perpendicular.

For a ship at c, what was once perpendicular (at zero ) is now at a 45 deg angle to the front of you, and what was 45 degrees behind you, is now seen perpendicular to you.
Any thing ahead of the ship from perpendicular ( at zero ) should now be blue-shifted ( at c ), and anything behind should now be red-shifted. Since all the stars were originally stationary wrt the ship, there should be starlight in 360 degrees all around, except for directly behind.

By increasing the speed of the ship above c, I would have thought that there would still be a 360 degree view of stars, but that more rotation towards the direction of travel would occur.
 
256bits said:
Why is that? The blackness perpendicular.

For a ship at c, what was once perpendicular (at zero ) is now at a 45 deg angle to the front of you, and what was 45 degrees behind you, is now seen perpendicular to you.
Any thing ahead of the ship from perpendicular ( at zero ) should now be blue-shifted ( at c ), and anything behind should now be red-shifted. Since all the stars were originally stationary wrt the ship, there should be starlight in 360 degrees all around, except for directly behind.

By increasing the speed of the ship above c, I would have thought that there would still be a 360 degree view of stars, but that more rotation towards the direction of travel would occur.
Wouldn't all the stars behind you be moving away from you faster than light? I would think that they would be redshifted to infinity like the galaxies at the edge of the universe?

 
So I approximated some geodesic around a positive and negative energy densities and I came up with the conclusion that in front of you you'd see a fisheye view of the universe, like looking out through a peephole in a door. Behind you, you'd see a reverse fisheye view, sort of like trying to look through a peephole backwards. However, both it wouldn't be clear, the entire thing would be out of focus unless you were in an exact sweet spot.

Does this sound right? In my image, the blue is positive energy density and the red is negative energy density. There are three stars, one green, pink, and brown, the brown on is behind the spacecraft .
 

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I thought the idea behind the Alcubierre drive was that the ship is not moving through the space inside of the bubble, and that space outside of the bubble (and the light traveling through it) was moved around the outside of the bubble.

How big is your bubble? As long as you're bending space, there's no reason to make the outside bigger than the inside, and this could help with that annoying energy flux.
 
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newjerseyrunner said:
...
So, with that assumption, what would you actually see while traveling in a warp bubble like the one described by Alcubierre.

Here's a paper discussing exactly that--
http://arxiv.org/abs/gr-qc/9907019
The first few pages are a lot of equations; starting about page 10 is an interesting discussion.
 
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