Observing a Collapsing Shell: Time Dilation Explained

In summary: After that, the curvature is everywhere inside the shell. There is no shell observer inside the black hole. There is no inside the black hole. It's a single point in spacetime. That's why it's called a "singularity".In summary, an observer inside a collapsing shell would see the rest of the universe appear to be distorted and time dilated as the shell approaches the Schwarzschild radius. Once the shell passes the Schwarzschild radius, the observer would not be able to detect any local curvature until the shell passes in the other direction. As the shell contracts, the observer's clock would appear to slow down compared to clocks attached to the shell and at a great distance.
  • #1
blademan9999
1
0
TL;DR Summary
Observer inside collapsing shell problem.
What does and observer inside of a collapsing shell observe? Lets say we have a shell of matter collapsing to a black hole. What would observers near the center see? How would the rest of the universe appear when,

The shell is approaching the Schwarzschild radius?

After the shell passes the Schwarzschild radius?

Time Dilation inside a hollow shell According to here you get time dialation, so what happens as the shell contracts?

Say the observer has a clock, and the inside of the shell is like a mirror, theres a clock attached to the shell and finally there's a clock at a great distance. How fast would these clocks go relative to eachother?

Until the shell reaches the observer, the observer is free to move aorund, so the issue to me seems to be that whe have a shell observer inside of a black hole, which normally you're not supposed to be able to have.
 
Physics news on Phys.org
  • #2
Welcome to PF. :smile:

One tip -- you can scroll to the bottom of your thread to see the similar threads that the forum software automatically suggests based on your thread title. You may find some of your answers in those recent threads. :smile:
 
  • #3
See https://www.physicsforums.com/threa...of-a-singularity-before-it-is-formed.1017274/. A lot of your question is answered by that. Basically, the event horizon forms inside the shell and expands outward at the speed of light. Once it passes you (you can't detect anything locally as it does) you're doomed. You just don't see any local curvature until the shell passes you in the other direction.
 
Last edited:
  • Like
Likes PeterDonis and PeroK

FAQ: Observing a Collapsing Shell: Time Dilation Explained

What is time dilation?

Time dilation is a phenomenon in which time passes at different rates for objects that are moving at different speeds or in different gravitational fields. This means that time can appear to pass slower or faster depending on the observer's perspective.

How does time dilation occur in a collapsing shell?

In a collapsing shell, time dilation occurs due to the effects of gravity. As the shell collapses, the gravitational field becomes stronger, causing time to pass slower for objects inside the shell compared to those outside the shell. This means that an observer inside the shell would experience time passing slower than an observer outside the shell.

Why is it important to study time dilation in a collapsing shell?

Studying time dilation in a collapsing shell can help us better understand the effects of gravity on time. It also has implications for our understanding of black holes and the nature of space and time.

How is time dilation in a collapsing shell measured?

Time dilation in a collapsing shell can be measured using clocks placed at different distances from the center of the shell. The clock closer to the center will experience a slower passage of time compared to the clock further away. This difference in time can be measured and used to calculate the amount of time dilation.

Can time dilation in a collapsing shell be observed in real life?

Yes, time dilation in a collapsing shell has been observed in experiments using atomic clocks. These experiments have shown that time does indeed pass slower for objects in a stronger gravitational field, confirming the predictions of Einstein's theory of general relativity.

Similar threads

I Observer Inside Collapsing Shell
Replies
6
Views
904
I On the gravitational collapse of a massive shell
2
Replies
45
Views
3K
I Time Dilation in Gravitational Field: Potential vs Field Strength
Replies
12
Views
2K
I Black hole event horizon confusion
2
Replies
57
Views
5K
I Falling through the event horizon of an evaporating black hole
2
Replies
51
Views
2K
I Do any real macroscopic black holes have a singularity?
Replies
11
Views
1K
B Can we see 2 black holes orbiting each other?
2
Replies
57
Views
2K
B Exploring Time and Space Dilatation Near Black Hole Event Horizon
Replies
3
Views
2K
B Falling into a black hole
2
Replies
43
Views
2K
B Entering a black hole -- I know I must be wrong (Help me understand why)
Replies
29
Views
1K

Hot Threads

Recent Insights

Back
Top