No real purpose in space-time?

[mixinman7]

Hello. This is my first thread.

I consider relativistic frames of reference in terms of E=MC². I'll discuss the mass of my body for an example. If I increase the energy in my mass I lose mass and gain energy. So if I travel at the speed of light, I will have 0% mass, and 100% energy. I would therefore have to travel at the speed of light, and time to me would pass infinitely. If I decrease my energy to 0% I would have 100% mass and time would stop. These two extremes are impossible, but extremes helps me understand degrees in between.

With this line of reasoning, I see no purpose in thinking that physical space and time are a connected fabric. Time instead is only relative to the observer, based on their proportion of energy and mass.

Considering that the concept of space-time is practically the law-of-the-land, I must be mistaken. Can someone help me understand what the point of a space-time fabric is, or where the err in my reasoning is?

Thanks in advance.

 

[Pengwuino]

I consider relativistic frames of reference in terms of E=MC². I'll discuss the mass of my body for an example. If I increase the energy in my mass I lose mass and gain energy. So if I travel at the speed of light, I will have 0% mass, and 100% energy. I would therefore have to travel at the speed of light, and time to me would pass infinitely. If I decrease my energy to 0% I would have 100% mass and time would stop. These two extremes are impossible, but extremes helps me understand degrees in between.

Uhm... none of these words make sense in the order you have put them in.

 

[atyy]

There are many technical errors in your post, but it is true in some sense that coordinates have no meaning. However, there are quantities that are the same in all reference frames. These are things like proper time and rest mass.

 

[mixinman7]

According to http://en.wikipedia.org/wiki/X-ray , x-rays can have an energy of 120 eV. If I consider the energy mass equivalence, x-rays can have a rest mass of 120/c². Photons do not have mass. This example is the same idea I was describing - 100% energy when it is an x-ray, 0% energy when it is only mass. It is the same concept as "rest mass," and its opposite. From the perspective of the photon, time has no measurement, and would therefore not have a measure of mass. From the perspective of a mass at rest with 0 energy, it would have no measure of time. Time cannot be measured in these extreme examples except to say that from the perspective of light, its time is infinitely faster than anything with a lower proportion of mass to energy. A photon does not experience time in other words. From the perspective of a theoretical mass at absolute 0 (maybe the center of a black hole fits this?) its time is infinitely slower than than anything with a higher proportion of energy to mass. This reasoning leads to light always traveling at the same speed from any perspective.

Hopefully this is explained better for you Pengwuino. It is hard to explain these concepts.

I'll restate the purpose of this post since I believe my first post may be confusing. What is the purpose of the space-time concept? Is it just to help people understand relativity? It seems implicit in energy-mass equivalence that time is only relative to the proportion of energy and mass, and dimensions are not relevant to that relationship to time.

There is a physics concept that I cannot recall a name for. With hydrogen you need fusion, with iron you cannot get energy from the nucleus, and from higher elements you need fission. This is how the nuclear bomb and sun emit energy. The core concept is that the mass of a nucleus decreases as the strong nuclear force binds nucleons. At a point the range limits the force and the mass begins to increase with the number of nucleons. If you know the name of this concept feel free to tell. It is a direct proof of the energy mass equivalence.

From this I reason that the mass of substance is variable depending on the forces acting on it, and therefore its energy. Consider that the energy emitted in these conversions is EM radiation that travels at c, and the atoms still contain energy since they still have mass. Its like dividing the time an atom experiences in two. This is what I mean by "understand degrees in between."

Thanks.

 

[cosmik debris]

Spacetime is a manifold. A manifold is a topological structure on which you can put a geometry with a co-ordinate system so that you can make measurements and do science.

 

[mixinman7]

Thanks for the reply cosmik.

Space-time is a manifold that measures relative times based on coordinates.

From what I understand, time never actually changes in the way we think of time - a chronological sequence of events. What changes are the forces exerted on matter and energy, and the subsequent conversion of mass to energy or vice versa. If you cool to 0 kelvin, fall into the center of a black hole, or otherwise lose energy, the energy does not disappear. Rather it is conserved in its conversion to "rest mass." If you heat up to theoretical temperatures, escape all gravitational forces or otherwise gain energy, the mass is converted to energy.

In this conceptual frame, the space-time manifold is measuring the proportion of mass and energy a unit has, their subsequent effects on each other and not the time warp that exist within those coordinates. This concept ties back to the mass-energy conversions that are proven to occur on a subatomic scale.

With hydrogen you need fusion, with iron you cannot get energy from the nucleus, and from higher elements you need fission. This is how the nuclear bomb and sun emit energy. The core concept is that the mass of a nucleus decreases as the strong nuclear force binds nucleons. At a point the range limits the force and the mass begins to increase with the number of nucleons. If you know the name of this concept feel free to tell.

Hopefully this concept is understandable. It makes sense to me. If it will help, I might mention related concepts that are based on this reasoning. If space-time is not measuring time warp, rather it is measuring the effects on substances due to forces, it would suggest that the concept of time-travel is not valid except to say that once's experience with time can be accelerated, but not reversed. A reversal in time would be a limit that should be applied to math.

Thanks

 

[Daverz]

Space-time is a manifold that measures relative times based on coordinates.

I'm not sure what you are trying to accomplish here, but it appears that you are stringing words together without an understanding of how they are used in physics.

 

[mixinman7]

Hello Daverz.

I'm not sure what you are trying to accomplish here, but it appears that you are stringing words together without an understanding of how they are used in physics.

Your observation is at least partially valid. I am explaining concepts, and when I am given a response I use the language in the response to formulate an answer. Langauge is critical in communication, and I do not know how to explain my concepts using the language physicist are familiar with. This is a very educating and beneficial process for me, or anyone.

Your comment is somewhat odd considering that I effectively paraphrased what cosmik debris stated, and added that the measure is of time.

Spacetime is a manifold. A manifold is a topological structure on which you can put a geometry with a co-ordinate system so that you can make measurements and do science.

I then went on to explain that my objection is that the measure should not be considered as measuring time, but rather an effect that can be interpreted as time. I followed by giving the evidence I consider to be proof of this concept.

__________

As for what I intend to do, my intent is to attempt-to-explain my concept to the many well educated individuals here on physics forums, and hopefully receive a response that helps me understand why I am wrong. As it is now, I do not agree that time is linked to space. I consider time to be an effect, not a cause. The cause is as I have described, a conversion of mass into energy or vice versa.

Thanks.

 

[Daverz]

I'll try to parse your original argument, mixinman7.

I consider relativistic frames of reference in terms of E=MC2.

What does it mean to "consider relativistic frames of reference" in terms of a formula for energy in the rest frame? What's the connection?

I'll discuss the mass of my body for an example.

Example of what?

If I increase the energy in my mass I lose mass and gain energy.

Why do you think an increase in energy implies a loss of mass? An electron accelerated in a cyclotron always has the same mass, for example.

So if I travel at the speed of light

A massive body can't travel at the speed of light.

, I will have 0% mass,

Where did the mass go?

and 100% energy.

A percentage implies a ratio; 100% of what energy? The energy of a body is not bounded.

I would therefore have to travel at the speed of light, and time to me would pass infinitely.

This seems to be the conclusion of a syllogism. What are the premises?

If I decrease my energy to 0%

Did you forget $E=mc^2$ already?

I would have 100% mass

A percentage implies a ratio. 100% of what mass? The original mass? It's all come back somehow to the same value?

and time would stop.

Why? What does it mean for time to stop? Clocks stop running?

With this line of reasoning, I see no purpose in thinking that physical space and time are a connected fabric.

You haven't made any connection between the reasoning above and spacetime.

Time instead is only relative to the observer, based on their proportion of energy and mass.

"Observer" in relativity just means "inertial reference frame". A reference frame has neither energy nor mass.

 

[Dale]

From what I understand, time never actually changes in the way we think of time - a chronological sequence of events.

If the events are spacelike separated then the chronological sequence of events does change when you change reference frames. This is the meaning of the relativity of simultaneity.

If you compare the Lorentz transform to the Galilean transform you see that in the Galilean transform t'=t while in the Lorentz transform t'=γ(t-xv). So in the Galilean transform time is completely separate from space, but in the Lorentz transform space and time are inextricably mixed together.

 

[harrylin]

Hello mixinman, welcome to the group.

[...]
From what I understand, time never actually changes in the way we think of time - a chronological sequence of events.

[...snip sentences that don't make sense to me]
If space-time is not measuring time warp, rather it is measuring the effects on substances due to forces, it would suggest that the concept of time-travel is not valid except to say that once's experience with time can be accelerated, but not reversed. A reversal in time would be a limit that should be applied to math.

Thanks

Perhaps you meant that time as experienced by you ("proper time") is a chronological sequence of events. You are right that that cannot be reversed. But the true sequence of distant events is not necessarily fixed.
And space-time is not measuring, it is (and always was) a representation of the results of measurements.

Some of what you said reminded me of one of the first discussions of this topic, "The Evolution of Space and Time". It is very long-winded but it includes such thoughts as "consider a portion of matter [..] and the sequence of events that constitute the life of this portion of matter". You can read it here:

http://en.wikisource.org/wiki/The_Evolution_of_Space_and_TimeHarald

 

[nitsuj]

Hello Daverz.
As it is now, I do not agree that time is linked to space. I consider time to be an effect, not a cause. The cause is as I have described, a conversion of mass into energy or vice versa.

Thanks.

Heya Mixinman,

I don't know physics very well, but am also interested in it.

I agree with you on the idea time is an "effect". Look far back in history (philosophy) and you'll see that this is not at all a new perpspective on time.

I find it odd that there is a "Time" dimension. From my ignorant perspective it implies it could be all on it's own. Often 2D planes are discussed, so I assume the same could be true for time, I just don't agree time is it's own thing. merely an observable consiquence of comparison. That being said I don't know physics graphs and stuff at all.
Harrylin's comment was great. And I think it is what you are experienceing :)

finding congruency between time as we experience and time in physics is tough, but worth the while, for a while.

 

[PAllen]

If you are interested in the range of thought about time considered in depth, you can do no better than sample the following:

http://www.fqxi.org/community/essay/winners/2008.1

 

[Passionflower]

I find it odd that there is a "Time" dimension.

Not everyone will agree that time is a dimension.

Spacetime has four dimensions, time, as measured by a clock, is the length of the path between two events in this spacetime.

Of course could attempt to make a coordinate system where such a path is plotted as a straight axis orthogonal to three spatial dimensions and call that coordinate system spacetime. But even that is not always possible, for instance it is not possible (except locally) in non-stationary spacetimes.

One could however argue that in a Galilean spacetime time is indeed a separate dimension.

Minkowski understood that early on as is clear in his famous statement:

"The views of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality." – Hermann Minkowski, 1908

 

[pervect]

I'd suggest that the OP read some books on the topic, for instance "Spacetime Physics", the 1st edition of which is available online at http://www.eftaylor.com/special.html, to gain a better understanding of why relativity considers space-time to be a unifed quantity, rather than two separate things.

Particularly relevant to the discussion is the "parable of the surveyor" which forms the basis of chapter 1 in the book.

The bottom line is that just as north-south intervals "mix with" east-west intervals to form a concept of distance in classical physics, space intervals (distances) "mix with" time intervals (proper times) to form a fundamental and very important concept, the invariant Lorentz interval, that is constant for all observers.

 

[mixinman7]

Thanks to all the responders.

I intend to read everything suggested in detail, but that shouldn't stop me from responding to some comments.

My premise is that mass is not a constant in a given unit. The "unit" is ambiguous, so I have described it as myself etc... On an atomic scale the "mass per nucleon" is variable. The mass of a hydrogen nucleon is higher than an iron nucleon, where the "mass per nucleon" is lowest, and the mass per nucleon increases with higher elements. The conversion of this mass into energy is the basis for observable phenomena.

I question why this mass conversion is limited to the nucleon of atoms, and is only applied to the strong nuclear force.

My premise continues with the assumption that any force on mass will influence its proportion of mass and energy. From this premise I question what the effect of such a conversion will be on observable phenomena. If the force the sun exerts on the Earth influences the mass of the earth, how should we measure the effect? I suggest the variation in time we experience on Earth would be that measure. Further, if the mass changes, why do we measure it as constant? Mass is only measurable in its comparison to another mass. This would imply that the necessity of time changing to accommodate a constant mass is no longer necessary.

Lastly, I note that light is pure energy and that it travels with a velocity of c, and that light travels at the same speed from all frames of reference. From this I reason that in the conversion of mass to energy, the unit's experience with velocity shifts from a variable speed, to a fixed speed. At one extreme, the velocity experienced by a black hole at its center is always slower than anything else with different properties. At the other extreme, the velocity a unit experiences when traveling with a velocity of c will always be faster than anything else with different properties.

Hopefully this clarifies my "sentences that don't make sense..."

Thanks

Note: I am thinking of mass as potential energy, and energy as kinetic energy.

 

[Dale]

I question why this mass conversion is limited to the nucleon of atoms, and is only applied to the strong nuclear force.

It is not limited to the strong force. You should look up the Wikipedia articles on mass deficit and binding energy.

I suggest the variation in time we experience on Earth would be that measure.

Have you any rigorous derivation or proof of this or is it purely idle speculation? If the latter then I would remind you about the prohibition on overly speculative posts.

 

[nitsuj]

At one extreme, the velocity experienced by a black hole at its center is always slower than anything else with different properties. At the other extreme, the velocity a unit experiences when traveling with a velocity of c will always be faster than anything else with different properties.

Interesting, what role does spacetime play in your comment above? Does a black hole "displace" spacetime? Does the black hole have it's "grips" in spacetime (ie pulled/stretched into the black hole)? Or do you think it plays no role in your comment above?

Last do you think that light (energy) is simply unimpeded by spacetime (unlike it's mass counterparts)?

 

[mixinman7]

Thanks DaleSpam.

The binding energy page is informative.

It will likely take me days or weeks to read the suggested material. I am a slow reader and am about to finish my last final and move off campus.

Considering that I am an undergraduate in medical imaging technology who has no skill in calculus, remote skills with college algebra (from 10 years ago), and no lab or otherwise profitable incentive for these concepts I am sharing, what "rigorous derivation or proof" might be expected of me? Could I explain it in conceptual terms so that it is framed to explain experiments such as the atomic clock difference on satellites in orbit? If I had to know calculus just to post on this forum, I'd be way out of my league.

Again, my intent was to explain how I conceive space-time, so that a well educated individual could explain why it is wrong, or why it is not or cannot be accepted. Perhaps I should imagine that my concept might be valid, but that is not the frame of mind I have of it now.

As for your question Nitsuj, I imagine events happening at the same time for both extremes. It is just that time passes faster as velocity increases, and slower as velocity decreases. Space-time serves no purpose when the proportion of mass and energy are thought to be the cause of velocity. This is why I think the concept is wrong. Maybe the answer is buried somewhere in the mountain of material I have been referred to.

Thanks

 

[WannabeNewton]

Actually an observer will measure time as running slower when someone is moving faster relative to him/her not faster.

 

[mixinman7]

Actually an observer will measure time as running slower when someone is moving faster relative to him/her not faster.

Time passes slower from the perspective of the observer for who time is passing faster

 

[nitsuj]

Time passes slower from the perspective of the observer for who time is passing faster

Can you please clarify that for me?

 

[danR]

You are addressing people who spend much of their time trying to clarify their terms and language to each other. So when you or I try to describe something to them, it's so much the harder for them to follow if we don't sit back and ask if this or that could be made clearer. Often, too often, it's just not possible, but as laypersons we have to do our best.

 

[Dale]

Considering that I am an undergraduate in medical imaging technology who has no skill in calculus, remote skills with college algebra (from 10 years ago), and no lab or otherwise profitable incentive for these concepts I am sharing, what "rigorous derivation or proof" might be expected of me? Could I explain it in conceptual terms so that it is framed to explain experiments such as the atomic clock difference on satellites in orbit? If I had to know calculus just to post on this forum, I'd be way out of my league.

You do not need to know calculus to post on this forum, it is primarily educational in nature. If you stick to asking questions about mainstream science then you will be able to learn a lot here and get a lot of good information.

What you should not do is continue to post speculative ideas like the one above. It is against the forum rules and, frankly, even if it were not against the rules you are by your own admission not qualified to make a useful contribution to theoretical physics at this time.

 

[Dale]

Time passes slower from the perspective of the observer for who time is passing faster

Whose time passes slower? The principle of relativity ensures that for each observer their own time passes normally from their own perspective, regardless of how their time may be passing from someone else's perspective.

When you combine that with the invariance of c then you find that for each inertial observer all other inertially moving clocks run slow. If A and B are two inertial observers moving relative to each other then A's clock will run slow from B's perspective and B's clock will also run slow from A's perspective.

 

[mixinman7]

...stick to asking questions about mainstream science... What you should not do is continue to post speculative ideas like the one above...

If I ask a series of questions about mainstream science that when looking at 'the forest rather than the trees,' appears to be the same whole concept I have already explained, would that be inappropriate? I have learned much from the responses so far, and feel like crap when I am told to buzz off because you do not like my post for whatever reason. I am asking a simple question. Why cannot the time an observer experiences be thought of in terms of the proportion of mass and energy...

It is kinda hard to talk about a wrong idea so that the correct idea can be explained when the wrong idea is banned.

You are addressing people who spend much of their time trying to clarify their terms and language to each other. So when you or I try to describe something to them, it's so much the harder for them to follow if we don't sit back and ask if this or that could be made clearer. Often, too often, it's just not possible, but as laypersons we have to do our best.

Thanks. I'll keep in mind that I should try harder to be clear.

Whose time passes slower?...

I was not originally mentioning the role of an observer. WannabeNewton responded with a comment about time from the perspective of the observer. I responded that if the observers time is passing faster than any other reference, that observer will see its time passing slower than the other reference sees, and the other reference will see the observer's time passing faster. If you ignore the role of the observer, time will go faster for anything that travels faster.

 

[WannabeNewton]

The observer does not experience time dilation in his/her own frame. An observer can't see his/her own time passing slower or faster; he/she will measure time for observers moving relative to him/her as passing slower. Time doesn't go faster for anything that travels faster.

 

[Dale]

if the observers time is passing faster than any other reference, that observer will see its time passing slower than the other reference sees, and the other reference will see the observer's time passing faster.

No, this is not correct. Any observer will always see its own time passing normally and anybody else's time passing slower. (As WannabeNewton said)

 

[Mentz114]

If you ignore the role of the observer, time will go faster for anything that travels faster.

There is no 'faster'. That implies absolute velocity, which is flouting a basic tenet of relativity - i.e. that only relative velocity is meaningful.

If you by 'faster', you mean something that accelerates, you are wrong to say time goes faster, because elapsed times on kinked or curved worldlines are shorter than on straighter ones.

You should do some basic physics before advancing an incoherent jumble of ideas as a theory.

 

[Dale]

Why cannot the time an observer experiences be thought of in terms of the proportion of mass and energy.

For one because the units don't work out right. The ratio of energy to mass would have units of speed squared, not time.

 

[mixinman7]

...if the observers time is passing faster than any other reference, that observer will see its time passing slower than the other reference sees, and the other reference will see the observer's time passing faster. If you ignore the role of the observer, time will go faster for anything that travels faster.

Three people in a row missed this word (than)?

No, this is not correct. Any observer will always see its own time passing normally and anybody else's time passing slower. (As WannabeNewton said)

That's what I meant, thanks. Except that the observer will see its clock traveling faster than anyone else's time if that anyone is traveling slower.

 

[mixinman7]

...while in the Lorentz transform t'=γ(t-xv)...

For one because the units don't work out right. The ratio of energy to mass would have units of speed squared, not time.

I might be wrong, but I'm thinking this ties back to what you said earlier DaleSpam. "Lorentz transform t'=γ(t-xv)." The x means distance, v means velocity, t means time, and y means 1/sqrt(1-v2/c2) right? Also, what is the ' mark next to t? Last, why isn't mass in this equation?

Thanks

 

[mixinman7]

There is no 'faster'. That implies absolute velocity, which is flouting a basic tenet of relativity - i.e. that only relative velocity is meaningful.

If you by 'faster', you mean something that accelerates, you are wrong to say time goes faster, because elapsed times on kinked or curved worldlines are shorter than on straighter ones...

I think I might be misunderstanding this comment. The way I think of it, if the role of the observer is ignored, the statement "time will go faster for anything that travels faster" is true because the sequence of events measured from a given perspective of anything traveling faster will elapse faster. If I look at the clock an a spaceship traveling near the speed of light, I will see its clock moving faster than mine. Am I wrong?

 

[PAllen]

Except that the observer will see its clock traveling faster than anyone else's time if that anyone is traveling slower.

This statement is complete nonsense. A given observer sees themselves as stationary. All other clocks are traveling faster and going slower for any observer (or stationary and the same). There is no meaning, for a given observer, for other clocks to traveling slower - slower than stationary ??!

 

[PAllen]

I think I might be misunderstanding this comment. The way I think of it, if the role of the observer is ignored, the statement "time will go faster for anything that travels faster" is true because the sequence of events measured from a given perspective of anything traveling faster will elapse faster. If I look at the clock an a spaceship traveling near the speed of light, I will see its clock moving faster than mine. Am I wrong?

Yes, you are wrong. If you look at the clock on a spaceship moving near the speed of light relative to you, you will see the clock moving much slower. People on the rocket will see your clocks moving much slower. That is the essence of relativity.