Whats the point particle energy due to its referance frame ?

[RyanH42]

Lets suppose we have infinitly small particle.And we want to measure the kinetic and potantial energy of particle.Can we use the particle itself a referance frame to calculate this energy ? To clarify my question let's suppose the point position shown by P point and its P(x,y,z) then we want to measure kinetic energy due to the referance frame which the referance frame point F is;F(x,y,z)

Is this possible ?
If its possible do we get zero ?
Or we get $mc^2$

 

[Joe Ciancimino]

With regards to kinetic energy, it is not dependent upon size only mass:

Momentum
https://en.wikipedia.org/wiki/Momentum

The potential energy however would be dependent upon what model you place it in. Potential for what? Now if we are talking gravity, then it would depend on if the pariticle had mass. If it does have mass and it is infinitely small, then we get into the same problems everyone has with black holes. Depending on your theoretical view of the Plank Constant, you either have an infinite potential energy, or we state that the particle is of finite size due to the lower limits of size within the space time manifold of our universe.

 

[Noctisdark]

What do you mean ?, in it's own reference frame the particle is at rest !, When you are in a car, you never see it moving, because you are moving with it and it velocity will become 0 (in your frame) so you should expect no kinetic energy but you'll be able to measure it's potential energy (because fields transform when you move from a frame to the other), but even though an infinitesimally small particle would rather obey a quantum mechanical law (quantum in action), and the particle's "frame" isn't well defined, you don't even sure about were it it, but even if you weren't at that frame, the particle's energy E will appear in discrete quantities every time and you can't really decide what's the particle energy and there is also uncertainty that depend on the time you measure it's energy, so talking the particle's frame will make things impossibly complicated !

 

[Joe Ciancimino]

In your statement you said there was a particle infinitely small and no reference to any other object. With your example of a car, you are giving reference to the it moving presumably against the ground. So you have the mass of the car verse the mass of the planet to which you have potential energy of the gravity between the two. So a particle at rest with no other object in reference to react with has zero potential energy. It can only have energy in relation to another object, not space itself.

 

[RyanH42]

In your statement you said there was a particle infinitely small and no reference to any other object. With your example of a car, you are giving reference to the it moving presumably against the ground. So you have the mass of the car verse the mass of the planet to which you have potential energy of the gravity between the two. So a particle at rest with no other object in reference to react with has zero potential energy. It can only have energy in relation to another object, not space itself.

This is my idea there's no other object to effect this particle.

Now you claimed that potantial energy is zero.

For about mass think electron.Its Infinitly small but it has mass.

What will happen kinetic energy ?

 

[Joe Ciancimino]

How big is an electron?
https://gravityandlevity.wordpress.com/2015/04/11/how-big-is-an-electron/

This gets more detailed into your questions as well as covers some of the basics of understanding the Plank length. The main thing you have to understand is there is no one single answer. This is a subject still being debated.

 

[RyanH42]

and the particle's "frame" isn't well defined,

What that suppose to mean I well defined it with position.Is there anything to add ?
And I don't think this question needs QM.Well you can't detect particles position exactly in realty but for simplicity let's assume this not true.Or let's assume you are in room (you are in or outside the room its not matter)Now think this room is in exist infinite universe.So at some point we can think this room is infinitly small.Think this way.

 

[RyanH42]

The main thing you have to understand is there is no one single answer.

Are you trying to say when we change the size of electron we are changing our answer?

 

[HallsofIvy]

This is my idea there's no other object to effect this particle.

Now you claimed that potantial energy is zero.

No, no one has claimed that the potential energy is zero. What you have been told several times here is that the potential energy of an object depends upon the frame of reference. Given any particle in the universe, there exist a frame of reference in which its potential energy is 0 and another in which it is what ever value you wish.

For about mass think electron.Its Infinitly small but it has mass.

But the size of an object, as opposed to its mass, has nothing to do with either potential or kinetic energy.

What will happen kinetic energy ?

"What will happen to kinetic energy" when what happens?

 

[RyanH42]

Here my idea kinetic energy is zero Why cause kinetic energy is $W=∫Fdx$ here there's no change in position so its zero.For potantial energy same thing $W=-∫Fdx$ so there's no change in potantial energy so again zero.
Whats wrong with this ?

Here the main problem is referance frame and particle is same place.Is something like this possible in physics ? Thats my question from the begining.You answered yes I guess but I am not sure.If you answered yes then I need to move my next question.

 

[Noctisdark]

One thing for sure is that kinetic energy is zero, and there maybe be a potential of any kind, a good example would be an electron in a conducting wire, or an electron in the Earth's gravitational field, if you try to do the expirement, you'll not be able to do it, because you simply can't find an electron and be in it's reference frame, this is purely theoretical and thus many answers should arise, but you'll never know for sure !

 

[RyanH42]

No, no one has claimed that the potential energy is zero. What you have been told several times here is that the potential energy of an object depends upon the frame of reference. Given any particle in the universe, there exist a frame of reference in which its potential energy is 0 and another in which it is what ever value you wish. But the size of an object, as opposed to its mass, has nothing to do with either potential or kinetic energy.

"What will happen to kinetic energy" when what happens?

For your first question answe look #4 post.And I have already give the referance frame.

You second statement.I know size does not affect anything but here you guys didnt undstand the conceot of inifintly small I guess.So I am trying to explain here my ideas.

Third statement ask when.Here there's no importance of time.Its not relevant with my question.

Please post If you know something about this issue.

 

[RyanH42]

One thing for sure is that kinetic energy is zero, and there maybe be a potential of any kind, a good example would be an electron in a conducting wire, or an electron in the Earth's gravitational field, if you try to do the expirement, you'll not be able to do it, because you simply can't find an electron and be in it's reference frame, this is purely theoretical and thus many answers should arise, but you'll never know for sure !

I understand.Hmm You said you will never know.Is that a problem for physics rules ? Is that violates anything ? Or Is this is a not preferred referance frame ? Isnt it

 

[Noctisdark]

The problem is the object is real small, quantum mechanics is in action and you won't know anything for sure, that is the REAL world and what's REALLY happening, and doing that expirement is almost impossible, and before doing and expirement you can't know, the most difficult part is taking the particle's frame of reference, and that's impossible to do without messing the particle state (also changing her energy),

 

[RyanH42]

Here the thing.I give electron example to visualise the idea.Let suppose you are looking 13 billion away galaxy.You will see it so so small even like a electron.Size is relative thing.Electron is so small for US.But not for an another electron.Here the important thing.If you look further and observe a so small object and size is like electron size.
This time can you say this galaxy obeys QM.
If your answer is yes no problem.But your answer is no.Then you should consider your answer again cause I am not talking about electron.I am talking about huge objects.What will happen when I see a galaxy (its so far which its radius or size is like an electron due to us)What will happen the referance frame and kinetic energy ? Theres again a problem ?

And I need a really answer to this question : Is this is a not preferred referance frame ?

 

[Noctisdark]

What you are saying are thought expirements, can you do the expirement? ,well a straight forward answer will be No kinetic energy but potential energy may arise, but you can't do the expirement(extremely hard), and if you look at a galaxy and see something happen, it has happened millions of years ago, It's already been decided so you can't really know if they do obey quantum mechanics from your reference (of course, this is purely theoretical), come up with an expirement and blow my mind !,

 

[RyanH42]

I am University first grade.Maybe later of my academic career

 

[Drakkith]

Lets suppose we have infinitly small particle.And we want to measure the kinetic and potantial energy of particle.Can we use the particle itself a referance frame to calculate this energy ?

No. Using the particle's reference frame means we define our coordinate system so that the electron is not moving within that coordinate system. Since the particle isn't moving, it's velocity is zero and so is its kinetic energy.

To define potential energy, you need two points. One for the particle's position, and one for the position you are defining the potential energy against. Since the change in potential energy ΔU is given by the equation ΔU = -W, where W is the work performed on the particle to move it between the two points, setting both of your points the same means no work is done to the particle and the potential energy is zero. In other words, the particle has no potential energy relative to its own frame of reference because no work can be done on the particle without moving it away from that point.

 

[Noctisdark]

I am human and when I jump, I feel that I have potential energy, That potential came from the work I've done to go few centimeters high and the only frame I have is myself, tell me if I'm wrong !,

 

[RyanH42]

No. Using the particle's referance...

Your first "No" answer of this question isn't it "Can we use the particle itself a referance frame to calculate this energy ?"

Then my #10 post is correct I made right assumption.

 

[Drakkith]

Then my #10 post is correct I made right assumption.

Pretty much, yes.

 

[Drakkith]

I am human and when I jump, I feel that I have potential energy, That potential came from the work I've done to go few centimeters high and the only frame I have is myself, tell me if I'm wrong !,

From your own frame of reference you have zero kinetic and potential energy and it is the Earth that has the kinetic and potential energy.

 

[Noctisdark]

Okay, Thanks for the feed back, if I do 10J to move at 10m/s, from my frame the Earth moves at 10m/s and Obviously it's kinetic energy is largee than 10J, what's the problem here ?

 

[Drakkith]

Okay, Thanks for the feed back, if I do 10J to move at 10m/s, from my frame the Earth moves at 10m/s and Obviously it's kinetic energy is largee than 10J, what's the problem here ?

There's no problem. Potential energy isn't related to kinetic energy, and kinetic energy is frame dependent. A 1 kg object traveling at 1 m/s relative to the Earth has 0.5 J of kinetic energy. However, from the object's frame, it is the Earth which is moving at 1 m/s, and it has a LOT of kinetic energy.

 

[RyanH42]

You said No.But we get zero so actually we used referance frame to find an answer.If I am saying something wrong its normal cause I am awake over 23 hour.

 

[Noctisdark]

Well, good luck of you can do it, because of you have a relativity course, a "reference frame" isn't set like that, clock must be sychronized, etc, these can be done on an infinetesimaly small things, the problem isn't theoretical, it's you can do the expirement or not, and obviously you cannot :), sorry if I confused you :/

 

[RyanH42]

If you say No to my question you mean "we can't measure any type of energy".Its theortically impossible.If you say yes but zero it mean "we can use referance frame and particle location as same" but we get zero.Thats why I asked again to confirm your answer.But you didnt reply me.But I guess you means yes and no option.

 

[RyanH42]

Well, good luck of you can do it, because of you have a relativity course, a "reference frame" isn't set like that, clock must be sychronized, etc, these can be done on an infinetesimaly small things, the problem isn't theoretical, it's you can do the expirement or not, and obviously you cannot :), sorry if I confused you :/

No problem :)

 

[RyanH42]

Or you try to mean we get always zero when we think this way, so its not a "true" or "real" answer or this is not usefull cause energy will be always zero.
I need help please.

 

[Noctisdark]

If you are adressing to me (because i don't know who the "you" is), my problem is with the infinitesimally small size, if you pick it to be big enough, then we're OK and everything can be done and verified !

 

[RyanH42]

I was asked Drakkith cause he answered No.And I don't know why

 

[Drakkith]

You said No.But we get zero so actually we used referance frame to find an answer.If I am saying something wrong its normal cause I am awake over 23 hour.

I guess nothing's wrong with calculating the kinetic and potential energy of the particle in its own frame, but the fact that you will always get zero means that it isn't very useful.

 

[RyanH42]

Ok,Now I feel better.Thanks