a Thinking Man's discussion

[someguy]

no the amount of energy is not relative. an object is energy. at the end of the day everything in the universe is energy. there's stuff that doesn't exist.. nothing.. (but there is no nothing because if there were then it would be something) and then there's energy. most energy is in fact motion. E=mc^2 means that a small quantity of matter is a huge amount of energy, if you look at what matter is made up of most of it is motion. when you move an object you are adding energy to it, thus making it more massive. there is a set quantity of energy in the universe and any type of energy is a fraction of that energy. it is a set quantifiable thing not relative to anything else. it doesn't matter whether or not the pool balls are moving slowly or not, the point is if one is moving and the other is not then it is different and identifiable regardless of your frame of reference. just because we don't have tools precise enough to notice the difference in mass for objects moving so slowly compared to each other doesn't matter. things don't really change when you move faster they just become more noticeable.

 

 

I'm pretty sure this is the answer you are looking for, it took me a while of thinking about it, your question really had me confused. but i think this is it. the more you learn about relativity the more it will be intuitive. I'm pretty certain you don't have that intuitive understanding of relativity yet since you seem to believe it may be flawed in some way and that you can find the flaw. but that's ok it will help you learn. it can be refined for sure added to something else. but it's your skepticism will help you get that intuitive understanding of it, questions like the one you asked. nothing starts off intuitive. even things you seem to have known intuitively your whole life were lifetime achievements of discovery for someone else. weird huh? intuition is learned, even though it pretty much means knowledge without learning. intuition really means in my opinion to have well learned. if you are still stumped think about why and ask the question to what is stumping you.

 

my point was exactly that before 1904 they couldn't solve this problem, we are after 1904 now and the problem is solved.

 

 

traveling at the speed of light is impossible because the faster you move the more massive you become therefore the more energy you need to increase your speed the faster you are going. remember matter is energy motion is energy everything is energy. when you increase the speed of something you're not making more matter but you're adding more of the ingredients matter is made of. if you grid this out in a graph or just imagine what one would be like then you would notice that there would be an imaginary line your curve could never touch. that speed where the imaginary line is also the speed at which light travels.

[galaxyblur]

I understand the exponential curve associated with reaching light-speed. That's not what I meant.

 

I think I'll start a new thread for that one

[someguy]

then you must understand why you can't go the speed of light. if you don't understand why you can't go the speed of light then you don't understand the exponential curve. knowing it exists and understanding it are different. maybe your question should be why does light travel at that speed?

[galaxyblur]

then you must understand why you can't go the speed of light. if you don't understand why you can't go the speed of light then you don't understand the exponential curve. knowing it exists and understanding it are different. maybe your question should be why does light travel at that speed?

 

I understand the curve very much, if you believe that in your reference frame inside a rocket, let's say, you have acquired "energy" and therefore mass. My question was, relative to you inside the rocket, have you acquired energy?

[someguy]

me in my rocket the whole thing has acquired energy the whole thing is moving. i gained the same exact amount proportionally to the rocket. we are together one mass that has been accelerated. if i move forward in the forward moving rocket i have a slightly more increased energy level (well not really if i moved myself since i didn't get energy from anywhere different but if i was moved from an external source) and therefore a slight increase proportionately to the rocket. but I'm not sure if i understood your question correctly.

 

I took you to be saying that: if the rocket moves faster do the people inside have increased energy and therefore mass?

[galaxyblur]

I took you to be saying that: if the rocket moves faster do the people inside have increased energy and therefore mass?

 

Kind of... Let's look at it like this: does the Sun have kinetic energy relative to us?

[someguy]

the sun orbits the earth just the same as the earth orbits the sun. we orbit around each other all things in orbit do this. the middle point between the two orbiting objects is the center of mass between them. the sun is so huge compared to the earth that this middle point is actually inside the sun so it seems as though we are orbiting around it. and so the sun is actually kind of wobbling. in fact this is how they can know that some stars have planets orbiting around them. so then i would have to say that yes it does. but again, i'm not sure if i totally understand your question and i have a feeling that this didn't help you know what you're trying to figure out. but..

 

If we assume the sun is stationary in our orbit relationship, and forget that it is moving around in the milky way. then the earth has a portion of it's mass that is due to the whole thing moving, whereas the sun's mass wouldn't have that.

 

actually i think maybe you needed for the sun to be moving around in the milky way for your question, but not moving around the earth.

 

the whole of the solar system is moving at the same rate in the milky way and so the percentage of added mass would be equal for the earth and for the sun but the sun is much more massive and so the added mass would be greater. but the percentage would be the same for "increased mass/initial mass" determined by the speed of the whole system. is that what you meant?

[swansont]

Hey, it may be useful, and we may build theory upon theory. But I don't see what's so sacreligious about trying to think of things from a different angle. I stated, first thing, that this was somewhat in the realm of philosophy as well. Yes, I know what a law is, but my point was that our laws are not the true nature of things. Maybe that's an obvious point to make, but physics has built a house of cards that will not stand long.

 

Sacrilege doesn't enter into it. You are taking well-defined terms and concepts, and misapplying them. And then claiming the system doesn't work.

 

You claim I misunderstand relativity, but I believe its been misunderstood and misused in modern theory. Just my two cents.

 

See above

 

Yet still, no one has explained to me why an accelerating frame is considered "invalid" other than that "it breaks stuff". By that logic, our view from the Earth is an invalid one, and perhaps from the sun, the galaxy, who knows.

 

The rules (Newton's laws) were observed for non-accelerating frames. That's when they apply, and that's when all of the derived concepts apply as well.

 

There are times that using the earth as a reference frame is invalid, if one does not account for the accelerations.

[galaxyblur]

Any frame needn't be invalid, if we can find the true nature of things, right?

[someguy]

didn't we solve this problem? aren't all the frames of reference of your scenario complying with all of the rules of physics as currently described?

[Sayonara]

Not if you discard some of the rules.

[swansont]

Any frame needn't be invalid, if we can find the true nature of things, right?

 

I fail to see how an incorrect measurement will lead to finding the true nature of anything.

[lucaspa]

Oh, right. Now I remember. This has nothing to do with my example. The author clearly states that conservation laws seemingly fail with curved spacetimes in General Relativity. And then he goes on to dig his way out of the paradox. My example doesn't even involve curvature/gravity/mass. Its much simpler than that.

 

From the page: "In certain special cases, energy conservation works out with fewer caveats. The two main examples are static spacetimes and asymptotically flat spacetimes."

 

You seem to have missed that. The more complex solutions reduce when you have your example.

[someguy]

Not if you discard some of the rules.

 

I don't think we did.

[Sayonara]

I don't think we did.

Obviously I am not referring to you.

 

The MO at work here seems to be "if it's not broken, break it." And if it isn't now, that's where it is heading.

[lucaspa]

Yes I did. It's a different frame of reference, since it undergoes an acceleration during the collision.

 

I was hoping for a more detailed explanation than that one-liner. Galaxyblur's issue is the reference frames and that different reference frames seem to give differnt answers. Just saying "it's a different reference frame" doesn't address the issue. It would be better if you could show how changing the reference frame makes it appear different but that there really isn't any new momentum.

 

Again, I'm sure there IS an answer, it's just whether WE know what it is.

 

Galaxyblur, I say that because I respect the intelligence of Einstein, Eddings, and other physicists. If this dilemma could occur to you, it should have occurred to them. So, the issue is first to see if we can find where it is dealt with textbooks and other literature on Relativity. Only when we (and particularly you) have completely exhausted that option should you consider that the theory is challenged.

 

If velocity is relative, is not also acceleration?

 

In relativity, speed of light in a vacuum is constant. Therefore, not all velocity is "relative". It is always absolute in regards to c.

 

If you were measuring the gravitational attraction of two identical balls, you could equally say one was static and the other accelerating, vice versa, or that they both moved and met at some arbitrary point.

 

No, because now YOU are the reference frame. You look at what they are doing relative to you. Now, you could change reference frames and then the interaction would appear different to you, but it is still the same interaction.

 

You cannot have two reference frames for one object. Your coordinate origin should never change.

 

Remember that we are dealing with spacetime. Over time, your reference frame is indeed going to change. So yes, you can have 2 reference frames for one object; you just have them at different times.

 

I understand that you can falsify a theory... perhaps my wording was incorrect. My point was that, accepted data may prove theories wrong, but never prove them right.

 

The idea of "proof" is only strictly speaking. Yes, strictly speaking, we cannot absolutely prove. One reason is that, no matter how many tests we perform, there are still an infinite number of tests yet to perform, and the theory may fail. However, at some point in the testing, the theory has been tested enough that we accept it as (provisionally) true unless and until new contradictory data comes to light.

 

What you are doing is not finding contradictory new data. Instead, you are finding examples where you are personally puzzled as to how relativity handles the situation. This is an issue with yours (and my) personal knowledge of Relativity, not a weakness of the theory.

 

I will be the first one to admit that I'm wrong if it is shown to be the case.

 

So far you have demonstrated the opposite. You casually dismissed the website I provided without a detailed read. You simply decided that, because it dealt with more complicated examples than the one you gave, that those solutions would not work on your simpler case. I am hoping that you will get better.

 

The "artifacts" of a particular coordinate system? WTF does that mean? You mean the things that are there that we can't explain?

 

No, I mean the apparent gain of momentum. In science an "artifact" is something that is not "real" or part of the system, but instead is introduced from outside. In this case, by not taking into account that, when the 1 ball is accelerated, it is now in a different reference frame because it is moving, you have introduced an artifact into your thinking. You are vieiwng the 1 ball as being in the same reference frame both before and after the collision. But it is not. Once the cue ball hits it and the 1 ball experiences acceleration, it's reference frame is no longer the same one when it was "at rest" relative to the 5 ball.

[someguy]

oh, my bad.

 

well hopefully, though i can't believe it will be busted, it will be refined or combined with things so that it can explain more, but i find that trying to bust the theory is the best way to understanding it. you will almost certainly fail at trying to bust it, but once you've ran out of ideas of how to bust it and all your attempts have been proven wrong then i guess you'd have a pretty good understanding of it and then you can maybe try to explain things the current theories cannot.

 

I also kind of like it when people try to break what isn't broken because It helps me too. because if i can't see their flaw right away then there's something i don't fully completely grasp either and when someone points out the flaw in their attempt to bust it, then i have reached a deeper understanding of the theory also. if nobody ever tried to bust anything, science wouldn't really be reliable. so, trying to break what isn't broken is a healthy and necessary component of science i think.

 

 

What you are doing is not finding contradictory new data. Instead, you are finding examples where you are personally puzzled as to how relativity handles the situation. This is an issue with yours (and my) personal knowledge of Relativity, not a weakness of the theory.

 

 

did you read the post i made earlier? i think i may have found the answer.

[swansont]

I was hoping for a more detailed explanation than that one-liner. Galaxyblur's issue is the reference frames and that different reference frames seem to give differnt answers. Just saying "it's a different reference frame" doesn't address the issue. It would be better if you could show how changing the reference frame makes it appear different but that there really isn't any new momentum.

 

Again, I'm sure there IS an answer, it's just whether WE know what it is.

 

 

Well, one has to assume a certain threshold of knowledge. When the original post discusses frames of reference, principle of relativity and conservation of momentum, one might assume that these were understood. I did, and it is apparent from the followups that I was mistaken to do so.

 

As I (and others) later explained, these concepts are based in Newtonian physics, which uses inertial frames. If you are in an accelerating frame, you have to add in a pseudoforce to make things "look" Newtonian.

 

So a reference frame that undergoes an intermittent acceleration is non-Newtonian, and momentum won't be conserved. It follows directly from Newton's second law: ^{[math]\vec{F }= \frac{d \vec{p}}{dt}[/math]}

 

If you define a system that has an external force, momentum won't be conserved. Same thing if your coordinate system accelerates. (The irony here is the gnashing of teeth that the laws aren't universal, and yet one of Newton's laws tells you precisely when conservation of momentum does and doesn't apply. One of the others tells you when Newton's laws are holding true. So it's far from the case of not applying in all instances means they are useless.)

[someguy]

i think though, that the point he was making that there is nothing to compare the coordinate system to in order to say whether or not it is accelerating. since there is no ether you could say from a newtonian point of view that the coordinate system is stable and that the two other balls are the ones that are moving. From a newtonian standpoint you can't really argue this. but from a relativistic standpoint there is a way to identify that which is moving since the object with kinetic energy is actually different than it is without it. and by that token you could identify that the ball to which you associated your coordinate system is moving and therefore your coordinate system. but without that you cannot say your coordinate system is moving since the only thing you can compare it to is the other two balls and you could just as easily that they are the ones moving.

[swansont]

i think though, that the point he was making that there is nothing to compare the coordinate system to in order to say whether or not it is accelerating. since there is no ether you could say from a newtonian point of view that the coordinate system is stable and that the two other balls are the ones that are moving. From a newtonian standpoint you can't really argue this. but from a relativistic standpoint there is a way to identify that which is moving since the object with kinetic energy is actually different than it is without it. and by that token you could identify that the ball to which you associated your coordinate system is moving and therefore your coordinate system. but without that you cannot say your coordinate system is moving since the only thing you can compare it to is the other two balls and you could just as easily that they are the ones moving.

 

No, there's always some measurement you can do to see if an object at rest remains at rest, or if an object moving in a straight line at constant speed continues moving that way. In the given example, the fact that the 5-ball spontaneously starts moving is the clue that you have not chosen an inertial frame.

 

You cannot make the argument about kinetic energy, since that measurement depends on what frame you are in.

 

You also generally define a coordinate system separate from the objects in it, i.e. the frame isn't the ball, the frame is a coordinate system in which e.g. a ball is initially at rest, or the origin is the center of mass, or some other convenient set of coordinates.

[someguy]

but you could make the frame the ball if you wanted.

 

I think you can make the argument of kinetic energy because adding kinetic energy does not only cause the object to move but also changes it absolutely. this is new from a standpoint of relativity as compared to newtonian physics. you can identify which ball is moving because it not only is comprised of the energy accounted for by matter but also by kinetic energy therefore by calculating the mass you can identify which object is moving. the ball that is your reference would suddenly become more massive therefore you could know that it is moving even though your reference frame could be pegged to it. so then i think the clue the 5 ball gives us is that the 5 ball spontaneously started moving without any increase in mass.

 

if it depended only of the frame you are in and there was nothing absolute about it then the twin paradox would not be possible like i was saying in a previous post. I think that's why they used to think there must be some kind of ether.

[swansont]

but you could make the frame the ball if you wanted.

 

I think you can make the argument of kinetic energy because adding kinetic energy does not only cause the object to move but also changes it absolutely. this is new from a standpoint of relativity as compared to newtonian physics. you can identify which ball is moving because it not only is comprised of the energy accounted for by matter but also by kinetic energy therefore by calculating the mass you can identify which object is moving. the ball that is your reference would suddenly become more massive therefore you could know that it is moving even though your reference frame could be pegged to it. so then i think the clue the 5 ball gives us is that the 5 ball spontaneously started moving without any increase in mass.

 

if it depended only of the frame you are in and there was nothing absolute about it then the twin paradox would not be possible like i was saying in a previous post. I think that's why they used to think there must be some kind of ether.

 

 

Your own mass never changes. You cannot tell if you are moving or somebody else is moving, as long as it's inertial. All you can say is that there is relative motion. That's one of the conclusions of relativity — no absolute frames.

 

The twin paradox solution lies in the fact that you can tell who accelerated and therefore changed reference frames. Other than that, you can't do a measurement that would tell who was moving and who was stationary.

[someguy]

but i think your mass does change, relative to other objects that did not partake in the same acceleration you did. no? matter is energy. motion is energy most of matter is motion. therefore by moving an object you are adding energy to it and thus increasing its mass. no? by that token it would need to also follow that heating an object also increases its mass but i don't think you can really heat an object so much that the molecules would be moving around at speeds near the speed of light so it would be really hard to observe. I don't think this would make an absolute frame. it is still all relative. it only allows you to figure out which object has been accelerated. still all you can say is that there is relative motion.

 

but you say that "The twin paradox solution lies in the fact that you can tell who accelerated and therefore changed reference frames. Other than that, you can't do a measurement that would tell who was moving and who was stationary." and this i think is exactly compatible with what i am saying its just i'm saying the manner in which you can know who accelerated. How else could you know?

 

maybe i should have said accelerated. granted if you look at two moving objects you could not know that one is stationary and the other isn't, they are both moving compared to each other. but if they were the same mass when moving at the same speed and you accelerated one of them this would be an identifiable thing no? because otherwise if a spaceship accelerating away from earth increases in mass then so would the earth and that doesn't make a lick of sense to me since no energy was added to the earth. and in this thought experiment one of the balls never accelerated and therefore would never have altered its mass/energy and the other ones would have traded speed and mass assuming they were all the exact same mass when at relative rest.

[foodchain]

Your own mass never changes. You cannot tell if you are moving or somebody else is moving, as long as it's inertial. All you can say is that there is relative motion. That's one of the conclusions of relativity — no absolute frames.

 

The twin paradox solution lies in the fact that you can tell who accelerated and therefore changed reference frames. Other than that, you can't do a measurement that would tell who was moving and who was stationary.

 

So basically if I am just traveling in space for example and I come upon a asteroid traveling in space the only thing I can understanding at that point is purely relational to my position and other variables such as maybe whatever speed I am traveling at?

 

To me it sounds like such goes along on some degree basically with the uncertainty principal, am I generalizing to much?

[someguy]

I'm not sure exactly what you mean about the asteroid part. but I was thinking of the uncertainty principle one time and it occurred to me... the faster an object moves, if you take frame by frame pictures of it the closer it will be to itself in every frame. in essence the faster an object moves the closer it gets to being in the same place at the same time. therefore if a dot was moving at speed infinity it would no longer be a moving dot anymore but it would be a solid line, of course you can't achieve this because you can't achieve speed infinity. but, i think it may be possible that this actually happens at the speed of light which kind of is speed infinity in a way, at least for things with mass it is, and this may be perhaps why light is sometimes considered to be a particle and sometimes a wave because since it is moving at the speed of light it is kind of both a particle and a wave in this way. if you had a cloud of particles moving at ultra high speeds then they would be almost making a solid cloud. therefore you could never really know the exact location of the objects forming this cloud at a given moment in time. if you, a dot, achieve a fast enough speed (not speed infinity), moving in a straight line, rather than being a perfect line forever, you would be a short line moving forward rather than just a dot. so in a way an electron if it is moving fast enough, and if they are this would partially account for why E=mc^2 says matter is such a high concentration of energy, then they would essentially sort of be in more than one place at once in our reference frame. and if you managed to know exactly where they were you would have needed to erase some of the information indicating what speed they are moving at since to include all the information regarding their speed would make them not a dot anymore but some other shape. and this is why the uncertainty principle must be and is not a limitation of observation but instead just a fact of life. Maybe what i just said is crazy talk and maybe it should have its own thread but at any rate it's food for thought.

 

but if i wasn't just full of doo doo then i don't see how in this case how the uncertainty principle comes into play.