I Lorentz boost -- speed or velocity?

[vanhees71]

Yes, as long as you remenber that $v$ is the velocity of $S'$.

...as measured in $S$ (just to be pedantic ;-)).

 

[sysprog]

A boost is a change of reference frame. There is no sense in which one reference frame is moving "away from" or "towards" another reference frame. The relationship is one of relative velocity.

Likewise, the relative velocity of two objects is not defined by whether they are moving towards each other or not. An object may move towards you, past you and away from you, but its relative velocity remains the same throughout.

The sign of the relative velocity (positive or negative) is determined by whether you take the object to be moving in the positive x-direction or negative x-direction; not whether it's moving towards you or away from you.

If I throw you another mag I hope and trust that you don't suppose that the difference between uprange and downrange doesn't matter.

 

[bill hart]

Summary:: The v and x in the factor (t-vx/c^2) in the Lorentz boost: if v is the speed and x is the distance, then it doesn't matter if the movement is away or towards or anything else, the boost will be the same, but if vx is the dot product of velocity and a spatial position vector, then the direction makes a difference So which is it?

The Wikipedia article on Lorentz transformations is a bit confusing by its using speed and velocity almost interchangeably: of course γ (Gamma) stays the same, but (letting c=1) t'=γ(t-vx) , then if this is v⋅x, and x stays the same, then there would be a difference if something were going away from the other at v or going towards each other at -v. I seem to recall that there is no difference, indicating that the scalars are what is meant, but in the Wiki article, there is a section in which they are, so I am obviously overlooking something.

If velocity is important does this speed apply to the nucleus of the atom?

 

[Ibix]

If velocity is important does this speed apply to the nucleus of the atom?

Why are you asking? What's this atom you are thinking of doing?

A couple of general points: the Lorentz transforms relate coordinates in two different frames of reference. Thus they apply to measurements of anything made using those two frames. However you need to be careful with atoms because you need a relativistic quantum theory to describe them, and naive application of special relativity to tiny billiard balls may well give you misleading results.

 

[bill hart]

Somewhere in the opposing direction of velocity in the atom there must be a deference between polarities. If so what causes the difference between pos and neg. it appears to be difference in clockwise and anti-clockwise. One produces a specific charge. And this seems to depend on the outside charge applied. What is this? Therefore it seems that it must be an outside force. This force must have a starting point. Either outer space or influence from the sun. As applied it must drive the nucleus in one or the other direction. And that influence or velocity (spin) seems to determine or result in almost all of our envirenment. SPIN amounts to everything. A black hole in the begging is a direction movement, but when spin is encoded it changes polarity, and alters the total (NET)strength of the BH.
Here directional rotation towards or away from is reduced to a strong force or a weak force. and is altered to or involves the work that BH does.
SPIN is applied to everything! Here right hand or left hand rules must be the deciding factor. So if the (rule of charges) is applied and we use have the intelligence to use it we can override the assumption that there remains can we or can't we!

we have no control. Not so all of this implies that as energy it can be altered to do what mankind needs or desires.

 

[Ibix]

I'm afraid that seems to me to be nonsense. If you are attempting to describe a published theory, please provide a reference (preferably a link) to wherever you read it. If you are proposing personal speculation, I recommend that you review the PF posting rules (in short: posting personal speculation is not allowed).

 

[fresh_42]

I'm afraid that seems to me to be nonsense. If you are attempting to describe a published theory, please provide a reference (preferably a link) to wherever you read it. If you are proposing personal speculation, I recommend that you review the PF posting rules (in short: posting personal speculation is not allowed).

Unfortunately.

This thread is closed.