Noob time-space thought problem

  • Context: Undergrad 
  • Thread starter Thread starter MarvinMartian
  • Start date Start date
  • Tags Tags
    Noob
Click For Summary
SUMMARY

The discussion centers on the nature of time-space as a 'fabric' and the implications of manipulating this fabric. When an object with mass deforms this 2D 'sheet', the question arises whether pulling one edge of the sheet results in an instantaneous movement across the entire sheet or if the response is delayed, similar to pulling a rubber sheet. The consensus is that changes in the curvature of space-time, such as those caused by gravitational waves, propagate at the speed of light (c).

PREREQUISITES
  • Understanding of general relativity and its implications on space-time
  • Familiarity with the concept of gravitational waves
  • Basic knowledge of the analogy of space-time as a fabric
  • Awareness of the speed of light as a universal constant
NEXT STEPS
  • Research the principles of general relativity and how mass affects space-time curvature
  • Explore the properties and implications of gravitational waves in astrophysics
  • Study the mathematical models that describe the deformation of space-time
  • Investigate the speed of light and its role in the transmission of information and forces in physics
USEFUL FOR

This discussion is beneficial for physicists, students of astrophysics, and anyone interested in the fundamental concepts of gravity and space-time dynamics.

MarvinMartian
Messages
2
Reaction score
0
this one bothers me - pls point out the flaw in my reasoning:

Time-space may be called a 'fabric', and may be depicted as a 2D 'sheet'. An object with mass deforms the sheet.

If i were to grab one edge of this 'inelastic sheet' and pull it 1 cm, would the movement would be instantaneous across the sheet .. i.e... anyone point of the sheet moves just 1 cm, but the distant edge, many light-years away, also *immediately* moves towards me 1 cm. too?

Or, would the tension I create warp the 'elastic sheet', and so cause my immediately surrounding fabric to move ~1 cm, but stretching the fabric so that the distant part only responded to the tug over some much longer time period, analogous to pulling a rubber sheet of the same size.

Would the transfer of this pull across the sheet be faster/slower/the same speed of light?
 
Physics news on Phys.org
Don't take the rubber sheet analogy too literally.

The very quick answer to your question is that curvature of space-time is what gravity is, so gravitational waves, and thus changes in the curvature, are presumed to travel at c.
 
ok thanks!
 

Similar threads

Undergrad Curved spacetime bulging in time direction
  • · Replies 30 ·
2
Replies
30
Views
2K
Undergrad Gravitational Waves: Questions from Josh on Mass & Space-Time
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Why Do Objects Fall Along Spacetime Ripples?
  • · Replies 16 ·
Replies
16
Views
3K
Graduate The shape of space-time around a star
  • · Replies 27 ·
Replies
27
Views
5K
Undergrad Some thoughts about Bell's string paradox alternatives
  • · Replies 75 ·
3
Replies
75
Views
7K
Undergrad How can General Relativity explain the Moon drifting apart from Earth
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad "Exploring Time Perception Across Different Regions of Space"
  • · Replies 20 ·
Replies
20
Views
2K
Undergrad Time Dilation & Length Contraction: Graphically Explained
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad What is it that forces an object down curved space time?
  • · Replies 11 ·
Replies
11
Views
2K
Undergrad Teaching Minkowski diagrams effectively
  • · Replies 15 ·
Replies
15
Views
3K