Questioning the Physics of a Hypothetical Cord

  • Context: Undergrad 
  • Thread starter Thread starter 01001101
  • Start date Start date
  • Tags Tags
    Hypothetical Physics
Click For Summary
SUMMARY

The discussion centers on a hypothetical cord made from a material that cannot bend, stretch, or condense, spanning one light year. Participants concluded that if person A pulls the cord, person B would perceive the pull instantaneously, contradicting the principles of relativity. The consensus is that such a perfectly inelastic cord cannot exist, as mechanical force propagation is limited by the speed of sound in any material. Therefore, the premise is fundamentally inconsistent with established physical laws.

PREREQUISITES
  • Understanding of basic physics concepts, particularly relativity.
  • Familiarity with mechanical force propagation and the speed of sound in materials.
  • Knowledge of hypothetical materials and their theoretical implications in physics.
  • Basic grasp of inelastic materials and their properties.
NEXT STEPS
  • Research the principles of Einstein's theory of relativity and its implications on information transfer.
  • Study the speed of sound in various materials and its limitations.
  • Explore the concept of inelastic materials and their theoretical existence in physics.
  • Investigate hypothetical materials in physics and their role in theoretical discussions.
USEFUL FOR

Physics students, theoretical physicists, and anyone interested in the implications of relativity and material properties in physics discussions.

01001101
Messages
1
Reaction score
0
I had a thought that's been bugging me and I wanted to ask some people who have more than a two semesters of physics about it.


Let's say I have a cord made out of a hypothetical material that can't bend, stretch, or condense. Now, I take that cord and span it across one light year. If person A on one end of the cord pulls it, would person B on the other end instantly see the cord getting pulled, or would it take a year for person B to notice it?
 
Physics news on Phys.org
01001101 said:
Let's say I have a cord made out of a hypothetical material that can't bend, stretch, or condense. Now, I take that cord and span it across one light year. If person A on one end of the cord pulls it, would person B on the other end instantly see the cord getting pulled, or would it take a year for person B to notice it?
Given your premise, B would see the effect instantaneously. This contradicts relativity, so we conclude that your premise is not consistent with relativity. According to relativity, it is not possible to have a perfectly inelastic cord.
 
Hi 77. Mechanical force propagates at speed of sound through object. In the case of material that 'can't band, stretch, or condense', speed of sound would be infinite, so person B would instantly feel pulling. Of course, such material does not exist, nor it is theoretically possible to exist.
 

Similar threads

Force transmitted to a block in viscous fluid through a spring, cord, and pulley
  • · Replies 6 ·
Replies
6
Views
1K
Undergrad Question about geometrical engineering (placeholder name)
  • · Replies 32 ·
2
Replies
32
Views
2K
Undergrad Can Crafts Reach 2c Relative to Me?
  • · Replies 3 ·
Replies
3
Views
2K
High School Does Force Travel Faster Than Light?
  • · Replies 8 ·
Replies
8
Views
3K
Stargazing Inquiry Regarding Hypothetical Faster-Than-Light Travel Scenario
  • · Replies 2 ·
Replies
2
Views
2K
Final amplitude with damping of bungee cord
  • · Replies 8 ·
Replies
8
Views
3K
High School Can Info Travel FTL? Understanding Speed of Information
  • · Replies 6 ·
Replies
6
Views
2K
Impulse and Momentum: Ball and cart connected by a cord
  • · Replies 24 ·
Replies
24
Views
4K
Undergrad Synchronizing clocks at different locations to measure speed of light
  • · Replies 58 ·
2
Replies
58
Views
6K
Newtonian Mechanics/Forces Question
  • · Replies 4 ·
Replies
4
Views
2K