[Centra (OP)]

It was designed to detect motion relative to the medium (aether) in any direction.

Excellent post, too bad Centra won't read it with an open mind, I have no doubt many of the members and guests will however.  I admire your patience with posters like Centra, keep up the good work.

Patience, are you kidding? He insults me regularly. You know, like you.

[Origin]

Patience, are you kidding? He insults me regularly. You know, like you.

This is a science site and your pseudoscience attitude is insulting.  It's also insulting to take time to help you understand a concept and have you ignore it.  Purposely or not you are trolling so don't be surprised to be treated like a troll.

[Centra (OP)]

Patience, are you kidding? He insults me regularly. You know, like you.

This is a science site and your pseudoscience attitude is insulting.  It's also insulting to take time to help you understand a concept and have you ignore it.  Purposely or not you are trolling so don't be surprised to be treated like a troll.

You too huh?

[Centra (OP)]

Here is a comment about the illusion of relative motion, which is in the same vein as the illusion of velocity, it shows how wrong assumptions can be made in the subject of relativity. I mentioned something about this earlier but I was thinking about again just now so thought I would write a new comment about it.

Seems to me that two objects of very different masses shouldn't really be considered interchangeable as to mutual motion. It's obvious that it would take 10 times as much energy or force to move a 10 kg object the same distance as a 1 kg object, so why should they be given equal relative motion? If they move apart 100 m then isn't it logical that the 10 kg object should be regarded as having moved 9.090909 m and the 1 kg object 90.90909 m? Granted the velocity between the two objects would be the same, but the relative share of the distance between the two objects would not. Two objects moving apart, regardless of how it came about, can be viewed as the two spaces between the barycenter and each object both increasing while maintaining the same ratio. I think Einstein overlooked that important concept.

 Now you might ask what if a planet and a rocket are involved? The planet's share off the distance would be practically nil in that case and couldn't even be calculated with accuracy. Such are the problems that can arise in working with relative motion, sometimes it's essentially a stationary frame and a moving one, the mismatch in mass is so extreme. The speed of light would be constant in relation to the center of mass, like the earth, not necessarily the surface thereof, if it's in rotation. Why? because it would have to be constant in relation to different levels of the surface, and even underground levels, all of which would be moving at different angular velocities, thus, light would have no one constant reference at all. Looking at light at sea level from the top of a mountain would present some simultaneity problems, even though there was seemingly only a single frame, the ground at sea level would not actually be in relative motion to the mountaintop and yet light would seem to move at different rates.

[Bored chemist]

so why should they be given equal relative motion?

Because it's exactly as far from A to B as it is from B to A.
So, when you write stuff like  this, and then say

Granted the velocity would be the same, but the relative motion would not.

It looks like you are trolling.
Because the time taken is the same, and the velocity is the same, but somehow, you think the distance (which you can calculate by multiplying the same velocity by the same time) is different.

Why don't you stop this nonsense?

[Centra (OP)]

so why should they be given equal relative motion?

Because it's exactly as far from A to B as it is from B to A.
So, when you write stuff like  this, and then say

Granted the velocity would be the same, but the relative motion would not.

It looks like you are trolling.
Because the time taken is the same, and the velocity is the same, but somehow, you think the distance (which you can calculate by multiplying the same velocity by the same time) is different.

Why don't you stop this nonsense?

Because the velocity is the time and distance between the two points but the relative motion is split at the barycenter into two sections, that's why. Now Why don't you stop this nonsense of critiquing things which are apparently beyond your level of comprehension?

[Bored chemist]

but the relative motion is split at the barycenter into two sections, that's why

Why?
Why not split it in the middle or, even better, why not decide that splitting it at all is pointless?

The reason why the distance between the two is not split is because there's no reason to.
Once you stop doing the pointless thing, it stops mattering how you might choose to do it.

Now Why don't you stop this nonsense of critiquing things which are apparently beyond your level of comprehension?

Everyone here apart from you agrees.
The whole of the world of physics agrees.
You are the only one who thinks you are right.
And it's clear  that you do not know what you are talking about.

So why are you trolling?

[Kryptid]

Because the velocity is the time and distance between the two points but the relative motion is split at the barycenter into two sections, that's why.

I'd like to see a source that supports this claim.

[Origin]

It's obvious that it would take 10 times as much energy or force to move a 10 kg object the same distance as a 1 kg object, so why should they be given equal relative motion? If they move apart 100 m then isn't it logical that the 10 kg object should be regarded as having moved 9.090909 m and the 1 kg object 90.90909 m?

No that would be absurd.  We are talking about relative velocity between objects.  It takes exactly the same amount of force to maintain the velocity of a 10 ton object as it does a 1 gram object.  They both require 0.0N to maintain their velocities.

[Centra (OP)]

Because the velocity is the time and distance between the two points but the relative motion is split at the barycenter into two sections, that's why.

I'd like to see a source that supports this claim.

Uh, you need a source for something which is obvious? You know a barycenter is a real thing, right? Well, if there were two unequal masses in outer space and a spring between them was released what do you think would happen? Would they both move an equal distance from the barycenter? Unless your answer is yes, no source is required, much like no source is required for me stating that the sky is blue, though for you, I guess i should specify when there are no clouds and it's noon. If you claim that the statement I just made is false then YOU are the one who would require a source, because then you're statement would be in contradiction to the established laws of physics, not mine. My source is the established laws of physics? Just Google "laws of physics". Do you want me to provide the URL for Google?

[Centra (OP)]

It's obvious that it would take 10 times as much energy or force to move a 10 kg object the same distance as a 1 kg object, so why should they be given equal relative motion? If they move apart 100 m then isn't it logical that the 10 kg object should be regarded as having moved 9.090909 m and the 1 kg object 90.90909 m?

No that would be absurd.  We are talking about relative velocity between objects.  It takes exactly the same amount of force to maintain the velocity of a 10 ton object as it does a 1 gram object.  They both require 0.0N to maintain their velocities.

No, YOU'RE talking about relative velocity between two objects, I'm talking about relative motion based on mass. Did the two objects start moving in opposite directions instantly and with equal velocity relative to the barycenter between them? What I stated is exactly what would happen if equal force was applied to both objects in opposite directions with no source of friction or resistance. By the time the distance between them was 100 m, the 10 kg one would be 9.090909 cm from their barycenter and the 1 kg object would be 90.90909 cm from it. Let's see you refute that.

[Centra (OP)]

People will say "but uniform motion does not involve accelerating so it would be equally interchangeable between objects of different mass". Maybe, but maybe not. To get to that uniform motion, one had more kinetic energy added to it than the other. A 10 kg mass moving away at 100 m/s from the same reference object that a 1 kg mass is also moving away from at the same velocity in the opposite direction has more stored kinetic energy than the 1 kg mass. Can objects of equal mass, one with no kinetic energy stored and the other with a certain amount stored be considered equally in motion relative to each other? I contend that they cannot, there is an asymmetry so how can they be considered equal?

 If there are two equal mass objects with rocket engines on them and rocket fuel is added to one and it fires the rocket until all fuel is consumed, both objects would then have equal mass but one would have the kinetic energy added by that fuel burn. Could you then say that both objects are identical because they are moving apart at the same relative velocity? There is clearly an asymmetry, one has momentum and kinetic energy and the other doesn't so they cannot be considered equal. The rocket that did not burn fuel could be considered to be moving away from the one that did at the same velocity but would it have momentum and kinetic energy? Logically it would not, it didn't do anything, it just sat there. Stored energy is a real thing, it can't just be disregarded, so the two objects cannot be considered equal, the one with stored kinetic energy is in motion, the other is not, even though they may appear equally in motion relative to each other.

[Bored chemist]

Uh, you need a source for something which is obvious?

It's only "obvious" to you.
The rest of us realise it's wrong or meaningless.

[Bored chemist]

Well, if there were two unequal masses in outer space and a spring between them was released what do you think would happen?

From the point of view of an ant standing on one of the masses, the other mass moves.
That's what relative means.

[Origin]

No, YOU'RE talking about relative velocity between two objects,

This thread is about velocity, but I guess you forgot.  Now you want to talk about acceleration.

I'm talking about relative motion based on mass.

Now you want to talk about velocity again.  Relative motion is not based on mass.

Did the two objects start moving in opposite directions instantly and with equal velocity relative to the barycenter between them?

It does not matter, one or both objects could have accelerated at any rate in the past it is immaterial.

What I stated is exactly what would happen if equal force was applied to both objects in opposite directions with no source of friction or resistance.

Now you want to talk about forces.  Yes a given force will accelerate different mass at different rates.  F=ma.

[Centra (OP)]

No, YOU'RE talking about relative velocity between two objects,

This thread is about velocity, but I guess you forgot.  Now you want to talk about acceleration.

I'm talking about relative motion based on mass.

Now you want to talk about velocity again.  Relative motion is not based on mass.

Did the two objects start moving in opposite directions instantly and with equal velocity relative to the barycenter between them?

It does not matter, one or both objects could have accelerated at any rate in the past it is immaterial.

What I stated is exactly what would happen if equal force was applied to both objects in opposite directions with no source of friction or resistance.

Now you want to talk about forces.  Yes a given force will accelerate different mass at different rates.  F=ma.

Oh I didn't realize I had to start a new thread for every word. Maybe I should have called it the Mass Velocity Force Rotation Motion Kinetic Energy Momentum Relativity Acceleration Gravity Light Theory. Would that make you happy?

[Origin]

People will say "but uniform motion does not involve accelerating so it would be equally interchangeable between objects of different mass". Maybe, but maybe not.

No maybes about it the answer is yes.

To get to that uniform motion, one had more kinetic energy added to it than the other.

False.

A 10 kg mass moving away at 100 m/s from the same reference object that a 1 kg mass is also moving away from at the same velocity in the opposite direction has more stored kinetic energy than the 1 kg mass.

From the frame of the reference object the 10 kg object would have the highest KE.  From the frame of the 10 kg object the 1 kg object would have the highest KE unless the reference object was much more massive in which case the reference object would have the highest KE, but you didn't specify the mass of the reference object so I can't say for sure.

Can objects of equal mass, one with no kinetic energy stored and the other with a certain amount stored be considered equally in motion relative to each other?

Yes they absolutely can.  Energy is frame dependent.  Let's name the objects of equal mass A and B.  From As frame it has no KE and object B has KE.  From Bs frame it has no KE and object A has KE.
By the way KE isn't "stored".

If there are two equal mass objects with rocket engines on them and rocket fuel is added to one and it fires the rocket until all fuel is consumed, both objects would then have equal mass but one would have the kinetic energy added by that fuel burn. Could you then say that both objects are identical because they are moving apart at the same relative velocity?

The rocket that had the fuel let's call A and the other we will call B.  Once As burn is over then you can say that from As frame it has no KE and that rocket B is moving away from it at some velocity and that it has KE.  From Bs frame it has no KE and A is moving away at some velocity and has KE.

The rocket that did not burn fuel could be considered to be moving away from the one that did at the same velocity but would it have momentum and kinetic energy?

Yes, absolutely from the frame of the rocket that did the burn.

Stored energy is a real thing, it can't just be disregarded, so the two objects cannot be considered equal, the one with stored kinetic energy is in motion, the other is not, even though they may appear equally in motion relative to each other.

There is no such thing as 'stored KE', KE is frame dependent.

You know Centra you could always learn some physics before you try to teach it!

[Halc]

Careful about using the word 'obvious', especially in a discussion of relativity, especially when you don't know relativity at all.

Two objects moving apart, regardless of how it came about, can be viewed as the two spaces between the barycenter and each object both increasing while maintaining the same ratio.

Your frame reference seems to be this 'barycenter'. One could indeed choose to express the locations of the objects in the frame of the system center of mass (or barycenter as you inappropriately call it), which is exactly the choice most often made for analysis of a closed system like this. The ratio part works only in Newtonian mechanics, so your statement is still wrong.

Because the velocity is the time and distance between the two points but the relative motion is split at the barycenter into two sections, that's why.

Uh, you need a source for something which is obvious?

We need a source supporting something that is obvious only to you, especially when it's blatantly wrong. See numeric example below.

You know a barycenter is a real thing, right?

It's an abstract thing, and one that only applies to orbiting systems, which this isn't. For non-orbiting systems or for systems of more than two masses, it's called the center of mass (CoM), which is real only if you consider abstractions to be real. You can put a small particle near the abstract CoM and the particle will not be necessarily attracted to it, so it isn't real in that sense.

Well, if there were two unequal masses in outer space and a spring between them was released what do you think would happen? Would they both move an equal distance from the barycenter?

The smaller mass would move at a higher speed, but not at speeds proportional to the inverse of their masses.

In the frame of the system CoM, suppose the two proper masses of 1 and 10 kg push off on each other and the 10 kg mass moves left at 30000 km/sec. The 1 kg mass will move right at about 228900 km/sec, which is not a 1-10 ratio like their masses. The rate at which either mass increases its distance from the other (the 'relative motion between masses') is about 240600 km/sec which is not the sum of 228900 and 30000. So the statement further up that you find 'obvious' is actually wrong. Don't assert intuitions. Run the numbers. Numbers don't lie.

From the point of view of an ant standing on one of the masses, the other mass moves.
That's what relative means.

It's not that simple. The ant also notices the proper acceleration and is not fooled into thinking that his own rock is not exhibiting motion.

[Bored chemist]

It's not that simple. The ant also notices the proper acceleration and is not fooled into thinking that his own rock is not exhibiting motion.

You are assuming the ant is clever.
He may still think the Sun goes round the Earth.
:-)

[Centra (OP)]

Quote
"You know a barycenter is a real thing, right?"

It's an abstract thing, and one that only applies to orbiting systems, which this isn't. For non-orbiting systems or for systems of more than two masses, it's called the center of mass (CoM), which is real only if you consider abstractions to be real. You can put a small particle near the abstract CoM and the particle will not be necessarily attracted to it, so it isn't real in that sense.

[ băr′ĭ-sĕn′tər ] The center of mass of two or more bodies, USUALLY bodies orbiting around each other, such as the Earth and the Moon

https://www.dictionary.com/browse/barycenter#:~:text=%5B%20băr′ĭ-sĕn′,the%20Earth%20and%20the%20Moon.

So much for your expertise in scientific word definitions, Halc.