Relative motion - Split from Various ways of determining particles rest mass

[fiveworlds]

If that were the case, then I would soon find myself on the floor as my chair moved from under me.

 

No.

You sit on your chair. You are above your chair. The wheel rotates at 1 rpm. The inner circle is 1 meter. The outer circle is 1.01 meters. Therefore you move at 1.01 meters a minute and the chair moves at 1 meter a minute. Now if the chair was in the same circle as me 1 meter circle and didn't occupy the same space as me it would have a different instantaneous velocity.

Edited October 15, 2014 by fiveworlds

[ajb]

In case above 'you' and the chair are not inertial observers; they are both experiencing an acceleration.

 

And anyway, we are talking about linear velocity and so you and the chair are still linearly co-moving.

[swansont]

Correct but it is in motion relative to me.

 

 

No.

 

You sit on your chair. You are above your chair. The wheel rotates at 1 rpm. The inner circle is 1 meter. The outer circle is 1.01 meters. Therefore you move at 1.01 meters a minute and the chair moves at 1 meter a minute. Now if the chair was in the same circle as me 1 meter circle and didn't occupy the same space as me it would have a different instantaneous velocity.

So really the objection is a matter of how well we can make a measurement. i.e. whether that speed difference really matters in our rotating coordinate system.

 

OTOH, what if you were sitting next to the chair? Where's the relative motion?

[fiveworlds]

OTOH, what if you were sitting next to the chair? Where's the relative motion?

 

You aren't in the same position as the chair therefore it has a different velocity. The only time it would be was if you swapped you for the chair however this isn't easy because we aren't in the same place. Not only that but everything else has to be in the same position and moving at the same rate.

 

Edited October 15, 2014 by fiveworlds

[ajb]

You aren't in the same position as the chair therefore it has a different velocity.

So, linear velocity relative to what?

[fiveworlds]

So, linear velocity relative to what?

 

It doesn't matter we also know that the universe is speeding up so technically speaking your mass is larger than 1 second ago.

[swansont]

So it's a matter of precision. Now you have to show that this matters, i.e. that the error introduced is significant when compared to experimental precision.

 

Another way of looking at this is that we should get a different value depending on time of day or year. Of course, if we do several experiments over the course of a day or year and average them, or do a continuous experiment that lasts that long, then any effect will appear in the experimental error of the results.

 

That we can't do an exact measurement of anything isn't exactly an epiphany.

[ajb]

It doesn't matter we also know that the universe is speeding up so technically speaking your mass is larger than 1 second ago.

Go grab an apple from your fruit bowl and place it on your desk. Then take a step back and just stand there. What is the velocity of the apple relative to you?

 

Now jump in your car or get on a train with your apply. While in motion place the apple on the chair next to you. Now what is the velocity of the apple relative to you?

 

Then you can think about the velocity of the apple in your car or on the train relative to someone say standing at the bus stop or train station as you wizz past.

[fiveworlds]

So it's a matter of precision. Now you have to show that this matters, i.e. that the error introduced is significant when compared to experimental precision.

 

 

Close but no. You see velocity is a vector and not a scalar quantity. So in three-dimensional euclidean mathematics velocity is always in a particular direction from a point. Supposing it was a linear vector. So I take two trucks side by side. One is at point(x,y,z) A(0,0,0) and the other at point B(0,1,0). Both trucks move from z=0 to z=1 at 40 miles an hour. Both trucks move with the same speed but different velocity because A moves to (1,0,0) and B moves to (1,1,0) which are different vectors.

[studiot]

 

Supposing it was a linear vector.

 

With the greatest of respect, old bean, this displays your ignorance.

 

And all ajb was trying to do was explain that relativity is about relative velocity, not 'velocity', funny how that word relative creeps in.

 

FYI, 'linear' and 'vector' are synonymous as they refer to the same thing.

Edited October 16, 2014 by studiot

[fiveworlds]

FYI, 'linear' and 'vector' are synonymous as they refer to the same thing.

 

 

No they don't a vector is a description of the movement of a particle. Of how it moves. If I follow a road that road is the vector. Which is completely separate from speed. ie how fast I am moving.

 

According to relativity, the difference between relativistic (or kinetic) mass and rest (or invariant) mass is

velocity. If you travel at near-c, your mass increases as a result of an increase in velocity.

 

 

No my mass does not increase if I travel farther. I am not traveling faster I still move at near -c.

Edited October 16, 2014 by fiveworlds

[xyzt]

In a recent thread (now rightfully deposited in "Trash"), a member was disputing the idea that mainstream science can measure particles rest mass. Contrary to those crank claims, the measurement can and IS done, there are multiple methods (you can google "rest mass measurement"). I will present a method that, though quite routine, doesn't show up in the search (not clear why).

In a cyclotron, a particle of charge [math]q[/math] and rest mass [math]m_0[/math] will describe a circular trajectory of radius [math]R=\frac{\gamma m_0 v}{qB}[/math] when subjected to a transverse Lorentz force due to a magnetic induction [math]B[/math]. [math]v[/math] is the measured speed of the particle and [math]\gamma=\frac{1}{\sqrt{1-v^2/c^2}}[/math]

From the above, the rest mass is calculated easily as [math]m_0=\frac{RqB}{\gamma v}[/math].

Since [math]v[/math] is difficult to measure accurately, we tend to use the fact that [math]v=\frac{2\pi R}{T}[/math] where [math]T[/math] is the period of rotation (that can be measured very precisely).

Once again, a mainstream physics thread has been turned into pure rubbish.

[studiot]

 

Once again, a mainstream physics thread has been turned into pure rubbish.

 

 

Unfortunately I have to agree (and sympathise) with you. +1

[elfmotat]

 

No they don't a vector is a description of the movement of a particle. Of how it moves. If I follow a road that road is the vector. Which is completely separate from speed. ie how fast I am moving.

 

 

No my mass does not increase if I travel farther. I am not traveling faster I still move at near -c.

 

You really need to pick up an intro physics textbook, because this is unbearable. It's like the Hydra of misconceptions: you correct one and two more pop up. But worst part of it is the sheer arrogance you display in your posts. You refuse to listen to what others are saying, which makes discussion with you pointless.

[Strange]

Close but no.

 

You have completely ignored the point as to whether this difference (if it exists) is significant or not.

 

But apart from that if the difference in velocity is known, then it is possible to take it into account in measuring the rest mass.

No they don't a vector is a description of the movement of a particle. Of how it moves. If I follow a road that road is the vector.

 

[swansont]

 

 

Close but no. You see velocity is a vector and not a scalar quantity. So in three-dimensional euclidean mathematics velocity is always in a particular direction from a point. Supposing it was a linear vector. So I take two trucks side by side. One is at point(x,y,z) A(0,0,0) and the other at point B(0,1,0). Both trucks move from z=0 to z=1 at 40 miles an hour. Both trucks move with the same speed but different velocity because A moves to (1,0,0) and B moves to (1,1,0) which are different vectors.

Solve the actual problem and show that the vectors are different.

[xyzt]

 

Solve the actual problem and show that the vectors are different.

Would it be possible to split all the nonsense about "fireworlds" misunderstandings in terms of basic science OUT of this thread? Please.

[fiveworlds]

Solve the actual problem and show that the vectors are different.

 

Imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. While this might result in a frenzy of activity, it would result in a zero velocity.

http://www.physicsclassroom.com/class/1DKin/Lesson-1/Speed-and-Velocity

 

Einstein Velocity Addition

The relative velocity of any two objects never exceeds the velocity of light.

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/einvel.html#c1

 

If I put light in a box so that it has zero velocity. Can something have a greater velocity than light? Note that I am not actually coming up with these myself I am referencing from various sites and asking questions about various possible interpretations.

Edited October 16, 2014 by fiveworlds

[Strange]

and asking questions about various possible interpretations.

 

You are not asking questions. You are making a series of not just incorrect but nonsensical statements.

 

 

If I put light in a box so that it has zero velocity.

 

That is not a sentence. And light cannot have zero velocity.

 

Can something have a greater velocity than light?

 

The one question you ask is answered by the source you quote: no.

[fiveworlds]

Imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. While this might result in a frenzy of activity, it would result in a zero velocity.

 

 

The one question you ask is answered by the source you quote: no.

 

So the quote up top is incorrect?

And light cannot have zero velocity.

 

Even if all it does is return to the original starting position by reflecting around the box?

Edited October 16, 2014 by fiveworlds

[Strange]

So the quote up top is incorrect?

 

This one:

Einstein Velocity Addition

The relative velocity of any two objects never exceeds the velocity of light.

http://hyperphysics..../einvel.html#c1

 

 

Even if all it does is return to the original starting position by reflecting around the box?

 

Light always travels at c.

[fiveworlds]

Light always travels at c.

 

Which is the speed of light. That does not necessarily mean it is the velocity. Unless you believe Einstein intended for it to mean speed.

[Strange]

So the quote up top is incorrect?

 

I would say incomprehensible, rather than just incorrect.

Which is the speed of light. That does not necessarily mean it is the velocity.

 

Light always travels in straight lines.

[fiveworlds]

Light always travels in straight lines.

 

Light has a wave nature. Also note in http://www.einstein-online.info/elementary/specialRT/speed_of_light

c is referred to as the speed of light and not velocity.

[Strange]

Light has a wave nature.

 

Why do you think that is relevant?