Hi, Shrewd!        Login  
Shrewd'm.com 
A merry & shrewd investing community
Best Of STEMBest OfAll BoardsThe Shrewd’m WeeklyLearn to InvestHow to Become Shrewd
Search
Shrewd'm.com Merry shrewd investors
Search
Best Of STEMBest OfAll BoardsThe Shrewd’m WeeklyLearn to InvestHow to Become Shrewd


The week's question
In December 2024, in the thread "Re: BRK: Why Not XOM?", BreckHutHigh asked the members: "What about the long road trips with kids?" This week it is put to everyone again. The button below opens the small thread re-asking it - read what others have said so far, then give your own answer as an ordinary reply.
Answer this questionContinue to Shrewd'mThis note won't appear again
Outskirts of Shrewd'm / Science, Technology, Engineering and Mathematics
Unthreaded | Threaded | Whole Thread (11) |
Author: bighairymike   😊 😞
Number: of 311 
Subject: Re: Wacky World of Lightspeed
Date: 03/18/23 10:41 PM
Post New | Post Reply | Report Post | Recommend It!
No. of Recommendations: 0
Yes, but I suspect that is a function of geometry. For example, it is possible to have a lighthouse whose beacon is spinning so quickly that the spot of light in the distance (at some distance "r") is moving faster than c, even though the rotation of the lamp is not faster than c, nor is the actual light beam. - 1pg

------------------

That makes for an interesting thought experiment. As the lighthouse beams radius approaches the point where the "tip" of the light beam approaches the speed of light, what would it look like if you could observe it? Perhaps better to visualize some distant wall against which the light beam sweeps. Rather than extending r to some humongous distance, you just keep accelerating the rotation of the beacon.

At slower speeds, the beam traces a continuous path across the wall. This is what we experience in everyday life. But as the sweep speed reaches and exceeds c, it seems to me the sweep would not be continuous but rather become a series of spots separated first by the planck length, then as speeds continue to increase past c, the separation of the spots would increase I suppose all the way to infinity.

The size the "spot" seems like it would have to shrink ultimately to the diameter of a single photon, if a photon can even be said to possess such an attribute. Perhaps it is better described as the beam disappearing altogether but then do you still have a beam at all after c is reached?
Post New | Post Reply | Report Post | Recommend It!
Print the post
Members reply directly to bighairymike here — and replies get answered. Reading is free; so is joining the conversation. Join Shrewd'm »
Unthreaded | Threaded | Whole Thread (11) |


Announcements
Science, Technology, Engineering and Mathematics FAQ
Contact Shrewd'm
Contact the developer of these message boards.

Best Of STEM | Best Of | Favourites & Replies | All Boards | Followed Shrewds | Open Questions | Moving a community