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Author Topic: How would an entity on a neutron star observe the outside universe/reverse  (Read 1516 times)

Offline Alan McDougall

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 Greeting forum


If we use a thought experiment and supposed an entity on a neutron star, could look out at the outside universe, would the enormous gravity field of such a massive neutron star skew time so that the outside universe would appear to move faster relative to it?

We could take this further and suppose two entities on different neutron stars could look at each other, what effect would time dilation then have on each of the entities?

Or an entity on a neutron star looking at an earth person , or he reverse?


 

Offline evan_au

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I read a Science Fiction story once that assumed that life could exist on a neutron star....

Assuming this premise:
  • They would see events happening much faster "on the outside" than were happening locally
  • Events on a similar-mass neutron star would happen at the familiar rate.
  • Although if your ambient temperature is 1 million degrees or more, presumably vision would use X-Rays; if the surrounding medium has a density millions of times higher than water, hearing would use sonar that travels at near light-speed. I wonder how much of the non X-Ray universe you would be able to see?
  • The story suggested that the incredibly strong magnetic fields that exist on some neutron stars would make it easier to move in certain directions than others
  • If your whole world is 10km across, the story speculated that the life in such an environment would be very small, and move very fast - perhaps millions of times faster than the human timescale.

(The story might have been "Dragon's Egg", by Robert L. Forward?)
 

Offline yor_on

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They would see a a 'speeded up' SpaceTime, relative anyone defining it from Earth. They should also see some weird relativistic effects by incoming light 'bending', and blue shifting, as a guess. But they would not find themselves moving any faster locally, relative a own (local) wrist watch. You can refer those effects to the fact that lights speed in a vacuum is a 'constant', wherever you measure. And there are no set values for a arrow, except lights constant in a vacuum. The arrow and that constant 'c' will both be invariants locally measured.

And that's the only way you can measure it.
 

Offline Alan McDougall

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I read a Science Fiction story once that assumed that life could exist on a neutron star....

Assuming this premise:
  • They would see events happening much faster "on the outside" than were happening locally
  • Events on a similar-mass neutron star would happen at the familiar rate.
  • Although if your ambient temperature is 1 million degrees or more, presumably vision would use X-Rays; if the surrounding medium has a density millions of times higher than water, hearing would use sonar that travels at near light-speed. I wonder how much of the non X-Ray universe you would be able to see?
  • The story suggested that the incredibly strong magnetic fields that exist on some neutron stars would make it easier to move in certain directions than others
  • If your whole world is 10km across, the story speculated that the life in such an environment would be very small, and move very fast - perhaps millions of times faster than the human timescale.

(The story might have been "Dragon's Egg", by Robert L. Forward?)

A great reply,thanks!

I also wonder if the neutron star entity could somehow, observe what is happening on our earth , would they see, for instance, great cities like London or New York, being built up at a rapid rate, relative from their vantage point, in a matter of minutes or hours or even less?
 

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