Question about energy and speed

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Discussion Overview

The discussion revolves around the concept of energy and speed in the context of the universe's motion, particularly questioning the implications of moving at high speeds and whether such motion would lead to energy consumption or heating effects. Participants explore various aspects of motion, energy, and forces in space, including gravitational and electromagnetic influences.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants question the notion of the universe rotating, suggesting that it may be a misunderstanding and that the galaxy is what is being referred to.
  • One participant argues that the spinning of celestial bodies does not consume energy in the same way as friction does on Earth, as there is no friction in the vacuum of space.
  • Another participant challenges this by suggesting that galaxies are not perfectly isolated systems and may experience some form of friction.
  • It is noted that while gravitational forces act over distances, they do not cause friction in the traditional sense, as friction requires contact between objects.
  • A participant introduces the concept of gravitomagnetic radiation, stating that rotating massive objects lose energy, although the effect is minimal.
  • Another participant disputes the claim that electromagnetic fields do not cause friction, arguing that eddy currents induced in conductors moving through magnetic fields can create a retarding force and generate heat.
  • Further discussion includes the effects of light as electromagnetic radiation, suggesting that photons can exert a force on matter, which could be interpreted as a form of friction at high velocities.

Areas of Agreement / Disagreement

Participants express differing views on the nature of motion in space, the role of friction, and the implications of electromagnetic fields. There is no consensus on whether electromagnetic fields can be considered a form of friction or the extent to which galaxies experience frictional forces.

Contextual Notes

Participants highlight the complexity of defining friction in the context of space, the relative nature of energy, and the assumptions regarding isolation of systems in the universe. The discussion remains open-ended with various interpretations of physical principles.

fizzzzzzzzzzzy
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if we are moving at tousands of millions of miles per hour (rotation of universe) then souldn't we have burned up by now because of all the energy used to go that fast?
 
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rotation of the universe?
you mean the galaxy?
hows the universe rotate if its got nothing to compare against?

dont quite understand the question
 
Welcome fizzzzzzzzzzzzy!

Nowhere have I ever seen that the Universe rotates. I rather expands. I suspect you mean the galaxy.

But neither the spinning of the Earth, nor its displacement (around the Sun or galaxy) consumes any energy. If you're going 20 mph on a bicycle and you stop pedalling, the bike would go on forever (just like the Earth) if it weren't for friction between tire and road and friction in the wheel axles. There's no such friction in space to slow down the Earth.
 
^ Somehow I find your answer isn't actually it... I'm not sure but I don't think our galaxies are perfectly isolated systems, so there would still be some sort of friction, right?
 
There is no friction in outer space, only gravitational forces that can act on each other over distances. Friction occurs between two objects in contact. Since space is a vaccume, there is no "contact" other than the forces that act over distances.
 
"Moving fast" does not "require" energy. If we were suddenly to slow down, all the "kinetic energy" we have (which is what i think you are talking about) and if it were friction that was causing the slowing, it would go into heat. That is what cyrusabdollahi was talking about. Furthermore, all energy is relative to something else.
I you move a box of mass m up a height h, its potential energy is now mgh relative to its initial position. Our kinetic energy due to the "rotation of the universe" would be relative to the center of the universe (wherever that is) and is not particularly significant.
 
According to general relativity, rotating, massive objects lose energy due to gravitomagnetic radiation. It's kind of the gravitational equivalent of the electromagnetic radiation emitted by accelerated charges. However, the rate of energy loss due to this gravitomagnetic radiation is incredibly small, so it's not a large immediate effect.
 
Grev said:
^ Somehow I find your answer isn't actually it... I'm not sure but I don't think our galaxies are perfectly isolated systems, so there would still be some sort of friction, right?

The only possible friction is cosmic rays, and collisions with dust, meteorites etc, which are negligeable as far as I know and can come from any direction quite symetrically.

Gravity and electromagnetic fields that could influence the course of something moving in space don't cause friction. They can accelerate it in any direction, but not stop it. There are conservative fields and non-conservative fields. Gravity and EM fields are conservative, friction is non-conservative.
 
I disagree with the statement about EM fields not causing friction, or at least some force very much like it. Magnetic fields in space will induce eddy currents in conductors (plasmas, iron-nickel meteors, cores of planets) moving across the field lines. Creating eddy currents will slow down the conductor relative to the field lines. Unless these conductors have zero resistance (superconductor), then the eddy currents are dissipated as heat in the conductor. The overall effect is a retarding force on the conductor and the generation of heat. Seems a lot like friction.

There are also friction arguments that could be made for time or position changing EM fields that act on matter, even nonconductors, via dielectric or diamagnetic effects.

Finally, since light is EM, and also carries momentum, and can be absorbed, matter colliding with photons experiences a force somewhat like friction. For very high velocities, an object will have hard hitting blue-shifted photons hitting it from the front while only wimpy red-shifted photons will hit it from the rear. This situation would imply some sort of velocity dependent retarding force on the object.
 
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