How do waves travel in a vacuum?

  • Context: High School 
  • Thread starter Thread starter MrPickle
  • Start date Start date
  • Tags Tags
    Travel Vacuum Waves
Click For Summary

Discussion Overview

The discussion revolves around the nature of wave propagation in a vacuum, particularly focusing on electromagnetic waves and the conceptual challenges associated with their transmission without a medium. Participants explore theoretical implications and analogies related to wave behavior and energy transfer.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses confusion about how electromagnetic waves can travel through a vacuum, questioning the mechanism of energy transfer without particles.
  • Another participant suggests that thinking of light as a wave may not be useful and proposes an analogy of photons as bullets, emphasizing the relationship between frequency and speed.
  • A historical perspective is provided, noting that the concept of "aether" was once thought necessary for wave propagation, which was challenged by the Michelson-Morley experiment that established the constancy of the speed of light in a vacuum.
  • One participant critiques the aether theory, arguing that if it existed, it would have significant effects on Earth's motion around the sun.
  • A later reply draws a parallel between the question of wave propagation in a vacuum and gravitational or electrostatic attraction between masses or charges separated by a vacuum.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the nature of wave propagation in a vacuum, with multiple competing views and analogies presented. The discussion remains unresolved regarding the underlying mechanisms of energy transfer in the absence of a medium.

Contextual Notes

Limitations include the reliance on historical theories like aether and the lack of clarity on the fundamental nature of electromagnetic waves in a vacuum. The discussion also touches on analogies that may not fully capture the complexities of wave behavior.

MrPickle
Messages
56
Reaction score
0
Today in class we started talking about waves.

I understand waves to be energy. This makes sense to me when thinking about sound waves, because the energy can travel from one particle to the next to travel; but I don't understand how things like electromagnetic waves can travel through a vacuum. The wave's energy can't be passed from one particle to the next because there are no particles in a vacuum and I don't understand how the energy could move because well, it's energy. I accept that it travels because otherwise we wouldn't be able to see the planets and Martians and what-not.

Is this something to do with E=mc2? Do we even know the answer?

This isn't a homework question, just me questioning things, but it's still related to school so I'm sorry if this is the wrong place.
 
Physics news on Phys.org
Thats where thinking of light as a wave isn't useful.
Think of a photon as a little bullet that is vibrating with a certain frequency, the wavelength is then just this frequency * the speed of the bullet.

One good analogy is to think of a police car with a flashing light driving along a street. The light flashes with a certain frequency and the car goes at a fixed speed.
If you mark on the road the position of the car everytime the light flashes - this gives a wavelength, but it doesn't mean the car is this long.
 
At one time, physicists thought that empty space was filled with "aether", and there was a preferential reference frame where the speed of light was constant. The Michelson Morley experiment disproved this, and verified that the speed of light was indeed constant = c in every inertial frame. See
http://en.wikipedia.org/wiki/Michelson–Morley_experiment

So light propagates in empty space without any medium (aether or particles) to propagate it..

Bob S
 
I think it is weird that they thought they wan an aether because if there was it would have slowed the Earth down to a stop , the Earth wouldn't have been able to go around the sun . , the electromagnetic field is doing the waving
 
This is a little like asking, how can two masses that are separated by a vacuum attract each other gravitationally? Or more on topic, how can two charges that are separated by a vacuum attract or repel each other?
 

Similar threads

Undergrad What can we scientifically measure directly?
  • · Replies 27 ·
Replies
27
Views
4K
Undergrad How Can I Build a DIY High Vacuum System Using Copper Instead of Glass?
  • · Replies 5 ·
Replies
5
Views
4K
High School What is the analogy for EM waves traveling in vacuum?
  • · Replies 42 ·
2
Replies
42
Views
4K
Undergrad Is "scalar wave" a legitimate term?
  • · Replies 46 ·
2
Replies
46
Views
12K
Graduate "Heuristics" for Casimir: how close to reality do they have to be?
  • · Replies 4 ·
Replies
4
Views
2K
High School Can Waves Reveal the Properties of Their Medium?
  • · Replies 4 ·
Replies
4
Views
9K
High School Confusion about Wave Motion
  • · Replies 14 ·
Replies
14
Views
2K
Undergrad Do electromagnetic waves fade with distance in vacuum?
  • · Replies 2 ·
Replies
2
Views
1K
Graduate Physical properties of the vacuum in GR vs. QFT
  • · Replies 15 ·
Replies
15
Views
2K
High School Energy loss of a photon
  • · Replies 1 ·
Replies
1
Views
1K