a couple ofvital questions for some physicists

[Twilight_guy]

You can't have an object without energy. E=MC squared bro. Mass is energy. No energy = no mass = not an object. Your question does not make sense.

That's not how that works. And to be pedantic, c should be lower case.

If you're going to call me wrong then explain why. I legitimately would like to know as I'm not a physics major.

 

[Jorpho]

You can't have an object without energy. E=MC squared bro. Mass is energy. No energy = no mass = not an object. Your question does not make sense.

That's not how that works. And to be pedantic, c should be lower case.

If you're going to call me wrong then explain why. I legitimately would like to know as I'm not a physics major.

It's more like this: an object that has lots of energy will have less mass than it does when it is at rest, such that an object moving at the speed of light (i.e. a photon) has no mass. See for instance http://www.desy.de/user/projects/Physics/ParticleAndNuclear/photon_mass.html .

It's pretty hard to tell what exactly "an object has no energy going through it" is supposed to mean, but it seems to me it is much more sensible to interpret it as meaning "an object that is at rest" rather than "an object that does not exist".

 

[Zantos]

You can't have an object without energy. E=MC squared bro. Mass is energy. No energy = no mass = not an object. Your question does not make sense.

That's not how that works. And to be pedantic, c should be lower case.

If you're going to call me wrong then explain why. I legitimately would like to know as I'm not a physics major.

It's more like this: an object that has lots of energy will have less mass than it does when it is at rest, such that an object moving at the speed of light (i.e. a photon) has no mass. See for instance http://www.desy.de/user/projects/Physics/ParticleAndNuclear/photon_mass.html .

It's pretty hard to tell what exactly "an object has no energy going through it" is supposed to mean, but it seems to me it is much more sensible to interpret it as meaning "an object that is at rest" rather than "an object that does not exist".

An object will have the same rest mass when it's still as it does when it's moving (and that is not a contradiction, it's relative frames of motion), then if you get funky with frames it'll undergo mass dilation and have extra energy and stuff, but it can't go under it's rest mass by simply moving.

Photons are different. They're intrinsically quantum objects. They have no rest frame, and as such have to be defined separately in special relativity.

 

[Twilight_guy]

You can't have an object without energy. E=MC squared bro. Mass is energy. No energy = no mass = not an object. Your question does not make sense.

That's not how that works. And to be pedantic, c should be lower case.

If you're going to call me wrong then explain why. I legitimately would like to know as I'm not a physics major.

It's more like this: an object that has lots of energy will have less mass than it does when it is at rest, such that an object moving at the speed of light (i.e. a photon) has no mass. See for instance http://www.desy.de/user/projects/Physics/ParticleAndNuclear/photon_mass.html .

It's pretty hard to tell what exactly "an object has no energy going through it" is supposed to mean, but it seems to me it is much more sensible to interpret it as meaning "an object that is at rest" rather than "an object that does not exist".

I took it to imply an object that has no energy in it in any way which would imply that it has no mass either since mass can be converted to energy and thus it has mass it has some notion of energy to it.

 

[Deef]

okay my first question is: if an object has no energy going through it can it move through space?

second question is: if two objects both had no energy going through them what would happen if they hit each other?

thanks alot

Objects that move contain Kinetic energy.
Ergo, objects with no energy cannot move.

It space moving objects don't consume kinetic energy due to the lack of friction.
But in order to have been set in motion they have to had some.

For your second question.
They can't hit, because they can't move.

Photons can move, but they don't have a mass, and therefore can't have kinetic energy.
Quantum physics ruins pretty much everything you thought was real.

 

[isometry]

You can't have an object without energy. E=MC squared bro. Mass is energy. No energy = no mass = not an object. Your question does not make sense.

That's not how that works. And to be pedantic, c should be lower case.

If you're going to call me wrong then explain why. I legitimately would like to know as I'm not a physics major.

It's more like this: an object that has lots of energy will have less mass than it does when it is at rest, such that an object moving at the speed of light (i.e. a photon) has no mass. See for instance http://www.desy.de/user/projects/Physics/ParticleAndNuclear/photon_mass.html .

It's pretty hard to tell what exactly "an object has no energy going through it" is supposed to mean, but it seems to me it is much more sensible to interpret it as meaning "an object that is at rest" rather than "an object that does not exist".

I took it to imply an object that has no energy in it in any way which would imply that it has no mass either since mass can be converted to energy and thus it has mass it has some notion of energy to it.

You are right Twilight guy. An object with zero energy must have zero mass because of E = m c^2. If it had any mass then it would have some energy by that equation, which is exactly what you're saying.

Oh and Jorpho, you say "It's more like this: an object that has lots of energy will have less mass than it does when it is at rest", that's actually backwards: massive objects with a lot of kinetic energy act more and more massive as their speed increases. By "act more massive" I mean that it takes more and more energy to increase the objects speed, such that it would take infinite energy to actually reach the speed of light.

 

[isometry]

Photons can move, but they don't have a mass, and therefore can't have kinetic energy.
Quantum physics ruins pretty much everything you thought was real.

Well, photons carry momentum and have kinetic energy by the equation E = p c (p is the momentum), this is how they cause sunburn, etc.

The equation (1/2)m v^2 for kinetic energy is a non-relativistic equation for massive particles, only valid at speeds much less than c. It doesn't apply to massless particles traveling at the speed of light.

 

[Deef]

Photons can move, but they don't have a mass, and therefore can't have kinetic energy.
Quantum physics ruins pretty much everything you thought was real.

Well, photons carry momentum and have kinetic energy by the equation E = p c (p is the momentum), this is how they cause sunburn, etc.

The equation (1/2)m v^2 for kinetic energy is a non-relativistic equation for massive particles, only valid at speeds much less than c. It doesn't apply to massless particles traveling at the speed of light.

And now I know!

I never understood how an object with no mass could still have a momentum.
I understand that that's how it works, I just don't understand why.

 

[ShindoL Shill]

okay my first question is: if an object has no energy going through it can it move through space?

second question is: if two objects both had no energy going through them what would happen if they hit each other?

1. if an object has no mass, it cannot move. v=root(Ek/0.5*m) where v=velocity, Ek=kinetic energy and m=mass.
2. assuming you can move them, then they would each try to move the other out of the way. the bigger one will keep a straighter path, by shoving the smaller out of the way.

I never understood how an object with no mass could still have a momentum.
I understand that that's how it works, I just don't understand why.

E=mc[sup]2[/sup] basically says energy is mass somehow. waves carry energy. photons are particles that act like theyre waves, because quantum physics is trolling us.

 

[isometry]

Photons can move, but they don't have a mass, and therefore can't have kinetic energy.
Quantum physics ruins pretty much everything you thought was real.

Well, photons carry momentum and have kinetic energy by the equation E = p c (p is the momentum), this is how they cause sunburn, etc.

The equation (1/2)m v^2 for kinetic energy is a non-relativistic equation for massive particles, only valid at speeds much less than c. It doesn't apply to massless particles traveling at the speed of light.

And now I know!

I never understood how an object with no mass could still have a momentum.
I understand that that's how it works, I just don't understand why.

It helps to think of photons as not just particles of light, but also as the particles that carry the electromagnetic force. Think about this scenario: two electrons pushing against each other with an electric force, what's really happening is electron #1 is sending out photons that travel at the speed of light across the distance to push electron #2. That means electron #1 exchanges some momentum with #2, and they both change their motion. It must be the photons that carry the momentum, since we know momentum is conserved and it doesn't just jump instantly from electron #1 to #2.

 

[isometry]

1. if an object has no mass, it cannot move. v=root(Ek/0.5*m) where v=velocity, Ek=kinetic energy and m=mass.

What happens if you plug in m = 0 to your equation? You get a divide by zero, in other words that equation says v = infinity for a massless particle.

The real truth is, your equation v=root(Ek/0.5*m) is only true for a massive particle at non-relativistic speeds (that means speeds much less than the speed of light).

Like we've been saying in this thread, photons (particles of light) do not have any mass, but they still move. This comes from different equations in relativity and quantum physics, but it's a very important fact of nature.

 

[Ranorak]

okay my first question is: if an object has no energy going through it can it move through space?

second question is: if two objects both had no energy going through them what would happen if they hit each other?

thanks alot

Objects that move contain Kinetic energy.
Ergo, objects with no energy cannot move.

It space moving objects don't consume kinetic energy due to the lack of friction.
But in order to have been set in motion they have to had some.

For your second question.
They can't hit, because they can't move.

Photons can move, but they don't have a mass, and therefore can't have kinetic energy.
Quantum physics ruins pretty much everything you thought was real.

I know that,
You know that.
But the OP ask what happens when two objects with no energy 'going through them' hit.
Blowing brains wasn't needed at this point

 

[ShindoL Shill]

1. if an object has no mass, it cannot move. v=root(Ek/0.5*m) where v=velocity, Ek=kinetic energy and m=mass.

What happens if you plug in m = 0 to your equation? You get a divide by zero, in other words that equation says v = infinity for a massless particle.

The real truth is, your equation v=root(Ek/0.5*m) is only true for a massive particle at non-relativistic speeds (that means speeds much less than the speed of light).

Like we've been saying in this thread, photons (particles of light) do not have any mass, but they still move. This comes from different equations in relativity and quantum physics, but it's a very important fact of nature.

yeah, but i assumed that the OP was talking about object with mass. i know pretty much nothing about quantum physics (i'm only doing higher physics right now and i'm doing the electronics module anyway...)

 

[Lukeje]

okay my first question is: if an object has no energy going through it can it move through space?

second question is: if two objects both had no energy going through them what would happen if they hit each other?

thanks alot

Is this a homework question? And if so, what level of schooling is it for?

 

[x EvilErmine x]

1) An object can travel through space with no apparent energy because there is nothing resisting it or slowing it down(Hmm well in order for t to be moving at all then it will have needed some energy to get it going at the start. All objects base state is at rest unless acted upon by a force. I think what you are referring to here is the conservation of momentum, and if that's it then you are right. Objects moving through space will carry on forever unless they hit something or are acted upon by a force e.g. gravity or an electromagnetic force.)
Here on Earth there is friction and gravity that will eventually stop an object from moving. In space, once something is pushed in a direction it will continue in that direction until it hits something or something hits it. There is no friction in space, there is nothing to slow the object down or stop it. ( Actually there's a fair amount of things, but the gavatational attraction from the rest of the universe is probably going to be the biggest influence. This however is quite small so it'll take a while for it to come into play. No to mention that the universe looks the roughly the same in any direction that you care to look in so eventually the object will stray close enough to a concentration of mass sufficient to influence it's trajectory via gravitation.)
2) If an object has no energy, it is not moving. If it is drifting through space, it has momentum therefore it has energy. When to things hit each other energy is converted. From kinetic into one of the many forms of energy.

Hopefully that answers your questions

P.S. IIRC There can be no natural object in the universe the has zero energy as this would mean that the object would measure 0[sup]o[/sup]K (Kelvin), or be at absolute zero if you prefer. For this to happen the the object would need to be artificially cooled as the ambient temperature of the universe is about 2.735[sup]o[/sup]K. This 'heat' would radiate into the object and raise it's temperature.

 

[Jorpho]

Oh and Jorpho, you say "It's more like this: an object that has lots of energy will have less mass than it does when it is at rest", that's actually backwards: massive objects with a lot of kinetic energy act more and more massive as their speed increases. By "act more massive" I mean that it takes more and more energy to increase the objects speed, such that it would take infinite energy to actually reach the speed of light.

Oops.

I took it to imply an object that has no energy in it in any way which would imply that it has no mass either since mass can be converted to energy and thus it has mass it has some notion of energy to it.

...Then what exactly would you call an object at rest?

I suppose it's a bit irrelevant to argue semantics at this point since the OP probably isn't coming back to say exactly what he was talking about with his "vital questions".

 

[Deef]

okay my first question is: if an object has no energy going through it can it move through space?

second question is: if two objects both had no energy going through them what would happen if they hit each other?

thanks alot

Objects that move contain Kinetic energy.
Ergo, objects with no energy cannot move.

It space moving objects don't consume kinetic energy due to the lack of friction.
But in order to have been set in motion they have to had some.

For your second question.
They can't hit, because they can't move.

Photons can move, but they don't have a mass, and therefore can't have kinetic energy.
Quantum physics ruins pretty much everything you thought was real.

I know that,
You know that.
But the OP ask what happens when two objects with no energy 'going through them' hit.
Blowing brains wasn't needed at this point

To be fair, 'no energy going through them' is vague as all hell.

 

[ResonanceGames]

http://en.wikipedia.org/wiki/Absolute_zero

An object can't be devoid of energy, so an object with no energy cannot move through space.

 

[Ranorak]

okay my first question is: if an object has no energy going through it can it move through space?

second question is: if two objects both had no energy going through them what would happen if they hit each other?

thanks alot

Objects that move contain Kinetic energy.
Ergo, objects with no energy cannot move.

It space moving objects don't consume kinetic energy due to the lack of friction.
But in order to have been set in motion they have to had some.

For your second question.
They can't hit, because they can't move.

Photons can move, but they don't have a mass, and therefore can't have kinetic energy.
Quantum physics ruins pretty much everything you thought was real.

I know that,
You know that.
But the OP ask what happens when two objects with no energy 'going through them' hit.
Blowing brains wasn't needed at this point

To be fair, 'no energy going through them' is vague as all hell.

That's my point.
It's already a vague question.
Judging that the OP has little physics knowledge, it would be a bit harsh to bother him with Quantum physics.

 

[Silent_Protagonist]

1) An object can travel through space with no apparent energy because there is nothing resisting it or slowing it down(Hmm well in order for t to be moving at all then it will have needed some energy to get it going at the start. All objects base state is at rest unless acted upon by a force. I think what you are referring to here is the conservation of momentum, and if that's it then you are right. Objects moving through space will carry on forever unless they hit something or are acted upon by a force e.g. gravity or an electromagnetic force.)
Here on Earth there is friction and gravity that will eventually stop an object from moving. In space, once something is pushed in a direction it will continue in that direction until it hits something or something hits it. There is no friction in space, there is nothing to slow the object down or stop it. ( Actually there's a fair amount of things, but the gavatational attraction from the rest of the universe is probably going to be the biggest influence. This however is quite small so it'll take a while for it to come into play. No to mention that the universe looks the roughly the same in any direction that you care to look in so eventually the object will stray close enough to a concentration of mass sufficient to influence it's trajectory via gravitation.)
2) If an object has no energy, it is not moving. If it is drifting through space, it has momentum therefore it has energy. When to things hit each other energy is converted. From kinetic into one of the many forms of energy.

Hopefully that answers your questions

P.S. IIRC There can be no natural object in the universe the has zero energy as this would mean that the object would measure 0[sup]o[/sup]K (Kelvin), or be at absolute zero if you prefer. For this to happen the the object would need to be artificially cooled as the ambient temperature of the universe is about 2.735[sup]o[/sup]K. This 'heat' would radiate into the object and raise it's temperature.

Yes, I was talking about conservation of momentum, guess I left it out, thanks
And as for the other forces acting on the object in space, I left them out cause they are almost pointless. The gravitational pull from stars and large bodies of mass that could pull the object is somewhat unlikely to happen given the vastness that is space. I was just giving the elementary response to the question without going too over-the-top-sciencey on the OP