Frame of reference

[questionposter]

Is there a frame of reference that is an object itself? Because to something like a bullet, it would only contain a specific amount of energy no matter who was observing it form where, yet speed and energy seem to always be relative. To a bullet, doesn't it have to have a specific amount of energy to travel at a specific speed that its traveling to from another frame of reference.

Edited August 12, 2011 by questionposter

[J.C.MacSwell]

Is there a frame of reference that is an object itself? Because to something like a bullet, it would only contain a specific amount of energy no matter who was observing it form where, yet speed and energy seem to always be relative. To a bullet, doesn't it have to have a specific amount of energy to travel at a specific speed that its traveling to from another frame of reference.

 

In terms of local inertial frames the object is in one inertial rest frame and an infinite number (quantum physics notwithstanding) of others between that and the approaching of lightspeed in every direction. (light speed itself cannot define an inertial frame). In it's own inertial rest frame it's kinetic energy is zero and in that of a frame that it is approaching light speed in it's kinetic energy is approaching infinite, though for practical purposes one would have to ask "infinite relative to what?"

[questionposter]

In terms of local inertial frames the object is in one inertial rest frame and an infinite number (quantum physics notwithstanding) of others between that and the approaching of lightspeed in every direction. (light speed itself cannot define an inertial frame). In it's own inertial rest frame it's kinetic energy is zero and in that of a frame that it is approaching light speed in it's kinetic energy is approaching infinite, though for practical purposes one would have to ask "infinite relative to what?"

 

But I mean, say I'm biking down the street. I don't give a **** what anyone else thinks they see me doing, I'm burning .1 calories every leg stroke, even though to some frame of reference I could be going faster therefore making it look like I am having a higher amount of energy therefore making it seem like I put more energy into a leg stroke in order to go that speed than I myself actually measure.

 

Or maybe, is it that every object has a frame of reference that is equal to 0 distance of itself?

 

Also I notice it says I'm a quark, but aren't there smaller things than quarks? Like neutrinos or gluons or something?

Edited August 12, 2011 by questionposter

[ajb]

A frame of reference is just a coordinate system you set up to measure things. Every (massive) object is moving at speed v=0 in its rest frame.

 

I assume we are talking about special relativity, in which case energy is not invariant under changes of inertial frames of reference.

[Janus]

But I mean, say I'm biking down the street. I don't give a **** what anyone else thinks they see me doing, I'm burning .1 calories every leg stroke, even though to some frame of reference I could be going faster therefore making it look like I am having a higher amount of energy therefore making it seem like I put more energy into a leg stroke in order to go that speed than I myself actually measure.

 

 

 

That 0.1 calorie per leg stroke is just the energy you are expending to overcome friction, etc, and isn't any true measure of how fast you are moving. Increase or decrease the friction and you will use up more or less calories per leg stroke. In fact, put the bike on a treadmill and you can expend exactly the 0.1 calorie without moving with respect to the road at all.

[questionposter]

That 0.1 calorie per leg stroke is just the energy you are expending to overcome friction, etc, and isn't any true measure of how fast you are moving. Increase or decrease the friction and you will use up more or less calories per leg stroke. In fact, put the bike on a treadmill and you can expend exactly the 0.1 calorie without moving with respect to the road at all.

 

That's true, but to some frame of reference, I could be going fast than I myself actually measure, so to that frame of reference, I HAVE to be putting more energy into a leg stroke in order to go at that greater speed, which means to that frame of reference I would be putting more than .1 calorie into every leg stroke.

A frame of reference is just a coordinate system you set up to measure things. Every (massive) object is moving at speed v=0 in its rest frame.

 

I assume we are talking about special relativity, in which case energy is not invariant under changes of inertial frames of reference.

I'm trying to say that another frame of reference is wrong because to myself I know what is actually going on, but doesn't that mean that every frame of reference is actually wrong because to an object it has definite values that will never change no matter who is observing it from where? I guess with something like speed, an object HAS to compare that to something else, but what about something like energy, but then, doesn't a specific amount of energy have to make something go a specific kilometers per hour no matter who is observing it too?

 

What about electrons in matter? Don't they have to have a specific amount of energy to be in the energy level they are in? Let's say I have a hydrogen atom with an electron in the ground state, but from a frame of reference, the object that it is a part of "looks" hotter than that in a way that there's no way a photon as delocalized as infrared light at that hot of a temperature couldn't possibly have missed that electron. How do you get over this problem? Because the electron is actually in a lower energy level, but that frame of reference is still saying that its not, so isn't that frame of reference just plain wrong? And if that frame is wrong, how can we be sure that any frame of reference is actually right?

Edited August 13, 2011 by questionposter

[swansont]

I'm trying to say that another frame of reference is wrong because to myself I know what is actually going on, but doesn't that mean that every frame of reference is actually wrong because to an object it has definite values that will never change no matter who is observing it from where? I guess with something like speed, an object HAS to compare that to something else, but what about something like energy, but then, doesn't a specific amount of energy have to make something go a specific kilometers per hour no matter who is observing it too?

 

No, it's dependent on the frame in which it is measured.

 

What about electrons in matter? Don't they have to have a specific amount of energy to be in the energy level they are in? Let's say I have a hydrogen atom with an electron in the ground state, but from a frame of reference, the object that it is a part of "looks" hotter than that in a way that there's no way a photon as delocalized as infrared light at that hot of a temperature couldn't possibly have missed that electron. How do you get over this problem? Because the electron is actually in a lower energy level, but that frame of reference is still saying that its not, so isn't that frame of reference just plain wrong? And if that frame is wrong, how can we be sure that any frame of reference is actually right?

 

Frames are not right or wrong.

 

A hydrogen atom at rest will absorb a 10.2 eV photon to excite it one level. If the atom is moving with respect to the frame where the photon has that energy (such that kv >> the linewidth; transitions are not infinitely narrow) the atom will not absorb the photon.

[J.C.MacSwell]

 

That's true, but to some frame of reference, I could be going fast than I myself actually measure, so to that frame of reference, I HAVE to be putting more energy into a leg stroke in order to go at that greater speed, which means to that frame of reference I would be putting more than .1 calorie into every leg stroke.

 

I'm trying to say that another frame of reference is wrong because to myself I know what is actually going on, but doesn't that mean that every frame of reference is actually wrong because to an object it has definite values that will never change no matter who is observing it from where? I guess with something like speed, an object HAS to compare that to something else, but what about something like energy, but then, doesn't a specific amount of energy have to make something go a specific kilometers per hour no matter who is observing it too?

 

What about electrons in matter? Don't they have to have a specific amount of energy to be in the energy level they are in? Let's say I have a hydrogen atom with an electron in the ground state, but from a frame of reference, the object that it is a part of "looks" hotter than that in a way that there's no way a photon as delocalized as infrared light at that hot of a temperature couldn't possibly have missed that electron. How do you get over this problem? Because the electron is actually in a lower energy level, but that frame of reference is still saying that its not, so isn't that frame of reference just plain wrong? And if that frame is wrong, how can we be sure that any frame of reference is actually right?

 

If you are looking at a can of soup on a shelf at eye level you "know" that it is square. The guy looking from above "thinks" it is round, but of course you know he is wrong? Or does your experience tell you that both can be correct?

 

Not having travelled much at light speed relative to cans of soup, how do you know know their shape when measured in that frame? How is it that you know what is going on?