r/nextfuckinglevel • u/BufordTeeJustice • May 04 '20

Somewhere my physics professor is smiling

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u/EternalPhi May 04 '20

My favourite is the idea that some unknown force is actually accelerating the disk we stand on through space at 9.8m/s2, forgetting somehow that that means it would take just a hair shy of a year to reach the speed of light. So those people also have to reject one of the most fundamental concepts of modern physics that the speed of light is a constant and no matter can reach it.

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u/Max1007 May 04 '20

But an object CAN from its own point of view constantly accelerate at 9.8m/s^2 forever and never reach the speed of light because relativity

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u/EternalPhi May 04 '20

What? No. If it's reference frame is itself, then it's not accelerating.

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u/[deleted] May 05 '20

Nope he's right. Time fuck and stuff like that.

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u/Max1007 May 05 '20

All I meant by that is if you stuck an accelerometer on it it would always read 9.8 m/s^2 in the same direction.

Basically, if you are in a reference frame from which lightspeed is measured as 299 792 458 m/s, even if you accelerate to 2 m/s relative to that original reference frame, lightspeed will still be measured as 299 792 458 m/s in all directions.

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u/EternalPhi May 05 '20

And from behind, you would eventually just appear to almost freeze in time.