Quantcast
  • Register
PhysicsOverflow is a next-generation academic platform for physicists and astronomers, including a community peer review system and a postgraduate-level discussion forum analogous to MathOverflow.

Welcome to PhysicsOverflow! PhysicsOverflow is an open platform for community peer review and graduate-level Physics discussion.

Please help promote PhysicsOverflow ads elsewhere if you like it.

News

PO is now at the Physics Department of Bielefeld University!

New printer friendly PO pages!

Migration to Bielefeld University was successful!

Please vote for this year's PhysicsOverflow ads!

Please do help out in categorising submissions. Submit a paper to PhysicsOverflow!

... see more

Tools for paper authors

Submit paper
Claim Paper Authorship

Tools for SE users

Search User
Reclaim SE Account
Request Account Merger
Nativise imported posts
Claim post (deleted users)
Import SE post

Users whose questions have been imported from Physics Stack Exchange, Theoretical Physics Stack Exchange, or any other Stack Exchange site are kindly requested to reclaim their account and not to register as a new user.

Public \(\beta\) tools

Report a bug with a feature
Request a new functionality
404 page design
Send feedback

Attributions

(propose a free ad)

Site Statistics

205 submissions , 163 unreviewed
5,082 questions , 2,232 unanswered
5,355 answers , 22,793 comments
1,470 users with positive rep
820 active unimported users
More ...

  What happens if an object falling in vacuum(disobeys the general theory of relativity), falls faster than the speed of light?

+ 0 like - 0 dislike
9491 views

I know the question sounds crazy enough to laugh at. But what if it happens? Feel free to criticize and give some astounding answers!

asked Oct 6, 2021 in General Physics by Parzival (0 points) [ no revision ]
recategorized Oct 30, 2021 by Dilaton

2 Answers

+ 0 like - 0 dislike

There's a problem of getting 'over the fence' - to reach the speed of light you need infinite energy - in special relativity you have a 'gamma' factor which goes infinite when v=c  .
And it gets weird from there, the energy amongst other quantities goes imaginary if v>c.   Possibly such things could exists from the get-go and thus wouldnt have to cross the v=c barrier, the idea is called 'tachyons' but I blv. no evidence exists for them and its not clear if these should be detectable.

answered Oct 20, 2021 by jeremyrutman (0 points) [ no revision ]
+ 0 like - 0 dislike
There will be a kind of Cherenkov effect as in all physical media where the speed of
 the particle exceeds the speed of light. 
answered Oct 23, 2021 by anonymous [ no revision ]

Your answer

Please use answers only to (at least partly) answer questions. To comment, discuss, or ask for clarification, leave a comment instead.
To mask links under text, please type your text, highlight it, and click the "link" button. You can then enter your link URL.
Please consult the FAQ for as to how to format your post.
This is the answer box; if you want to write a comment instead, please use the 'add comment' button.
Live preview (may slow down editor)   Preview
Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
If you are a human please identify the position of the character covered by the symbol $\varnothing$ in the following word:
p$\hbar$ysicsOve$\varnothing$flow
Then drag the red bullet below over the corresponding character of our banner. When you drop it there, the bullet changes to green (on slow internet connections after a few seconds).
Please complete the anti-spam verification




user contributions licensed under cc by-sa 3.0 with attribution required

Your rights
...