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John Byrne
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Joined: 11 May 2005
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Posted: 29 November 2021 at 4:09pm | IP Logged | 1 post reply

Suddenly I’m reminded of an old FIREBALL XL5 episode in which the ship accidentally exceeded the speed of light. We were shown the “speedometer” as she went faster and faster. One of the increments was “heat”.

Yes, faster than heat!

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Conrad Teves
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Posted: 30 November 2021 at 2:52am | IP Logged | 2 post reply

Bob>>I'm far from an expert on this, but my interpretation of what I've read is that our "common sense notion" of two events (a significant distance apart) happening "at the same time" is fundamentally flawed<<

My favorite relativity Thought Experiment is the pole/barn paradox. (The pole is often changed to a rocket for flavor, but same result).


An important takeaway is that a different point in space is ALSO a different point in time (very much flying in the face of intuition)--and events can only be truly simultaneous (instead of relatively so) if they happened at the exact same point in space.

Our "common sense" notion is only because everything in our experience that moves is moving much less than the speed of light relative to us.

Fun visualization on this episode of Minute Physics : Link


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James Woodcock
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Posted: 30 November 2021 at 7:58am | IP Logged | 3 post reply

From a storytelling perspective, it can be fascinating to think about this,
& also fascinating to NOT think about this.

For example, there were a couple of Star Wars stories where Leia,
having travelled through hyperspace to different parts of the galaxy,
would look to & see Alderaan.
It was still there in the night sky, but she knew everyone who was on
that planet she could see, was now dead.
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John Byrne
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Posted: 30 November 2021 at 8:23am | IP Logged | 4 post reply

I find it fascinating that when I look at the Andromeda Galaxy the photons striking my eyes have been traveling unimpeded thru space for two million years. Then my retina stops them.

(I have a similar feeling about not having had children. My genetic heritage is an unbroken chain stretching back almost four and a half billion years. And I broke it.)*

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* First person to suggest there is "still time" for me to breed will be invited to step off the nearest cliff.

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Andrew Bitner
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Posted: 30 November 2021 at 1:50pm | IP Logged | 5 post reply

Fascinating question about gravity vs light/heat. The Earth and everything else circling the Sun would have massive inertia but without the solar gravity well bending their trajectory, what would their revised "orbit" become?

Edited by Andrew Bitner on 30 November 2021 at 1:54pm
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Bob Brown
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Posted: 30 November 2021 at 2:05pm | IP Logged | 6 post reply

Conrad - thank you for the links - I think I'll be watching some more Minute Physics!!
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Eric Sofer
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Posted: 30 November 2021 at 2:28pm | IP Logged | 7 post reply

Andrew, planets would continue relatively straight from themoment the sun's gravity went away, However, their gravity would affect each other, so that the trajectories would actually be curves affected by gravity,

I wonder about inner planets with moons, Does Luna, free of the sun's affect, start to crash down onto Earth? Does it take a "higher" orbit? Do one of Phobos or Deimos crash into Mars? 

I'm pretty sure that the planets just go flying off into space on courses tangent to their old orbits,
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Andrew Bitner
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Posted: 30 November 2021 at 2:49pm | IP Logged | 8 post reply

Probably so, Eric. I'm looking up contacts to see if I know any astrophysicists (and I do know one but we're not connected via social media so I might not get a reply)... but my bet is that you're right, there would be some wobbling due to the gravity of other celestial bodies, but more-or-less they'd go off on slightly-curved tangents to their orbits.
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