Looking For Criticisms

  • Thread starter Hertz
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Main Question or Discussion Point

So I've been thinking, and from what I can tell some of the laws of physics have been silently battling it out ever since they've been discovered. A few of the things I'm about to say are my theories based on my lacking knowledge, I'm sure you'll find that I'm just misunderstanding things instead of actually finding contradictions within the laws of physics.

I'll start out with my own ideas so that you possibly wont have to read very much to find my problem.

So, they say that time goes slower if you travel right? Well, wouldn't that mean that time is actually traveling and those that are moving are simply keeping up with it better then those that are stationary? If this is true then we come to our first actual theory, Einsteins theory that nothing can travel faster than light. Wouldn't this mean that time cannot travel faster then the speed of light, or in other words, if we traveled the speed of light time would be completely stopped, or in even more other words, if we traveled faster than the speed of light we would go back in time?

Let's imagine for a second that we can travel faster than the speed of light and that we are able to go back in time. This would mean there would be two of us in space because we are not only back in time, but we are also living the time we lived before we reached the speed of light. Wouldn't this be breaking Newton's Law of the Conservation of Mass? Yes, it would, but only assuming it was possible to travel faster than the speed of light.

Well let's imagine the same situation, but this time we are traveling exactly the speed of light. Time is perfectly stopped, but we are still moving. That would mean that we are in every single place we have been in since time stopped, all at once. This is still challenging Newton's Law. But still, I recall hearing something about the exact speed of light still being impossible to reach.

So let's step it down another notch...

You are traveling a little less than the speed of light, but judging by my previous novel, (two paragraphs up) your past actually needs time to catch up to your present (this is shown by the infinite amount of superposition you have when time is stopped but you are not.) This would mean you are leaving a tracer as you are moving, or in other words, your mass is actually superpositioned behind you for a ways until it is able to catch up to where it is now superpositioned. So your mass is you, but it's also where you used to be, again, challenging Newtons Law.

So who's right here? Einstein or Newton; or Einstein and Newton but not Hertz@physicsforums? I would love to hear what you see that I failed to see, please let me know :)

(I failed proofread this due to the fact that my brain is already sore from trying to come up with this as I write. If I missed a very evident answer, don't h8.)
 

Answers and Replies

  • #2
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"So, they say that time goes slower if you travel right?"
According to Einstein's theory of SR, this is approximately true. That is, if you are traveling at a high velocity, you will measure time intervals to be longer than other people not traveling at high velocities, so that for all intents and purposes it appears that time has been moving more slowly for you.

"Well, wouldn't that mean that time is actually traveling and those that are moving are simply keeping up with it better then those that are stationary?"
The problem with this, as I see it, is that for time to be traveling (in the usual sense, anyway) it must be traveling in some direction... as in, some spacial direction. I'm not sure that this makes a ton of sense to me.

"If this is true then we come to our first actual theory, Einsteins theory that nothing can travel faster than light. Wouldn't this mean that time cannot travel faster then the speed of light, or in other words, if we traveled the speed of light time would be completely stopped, or in even more other words, if we traveled faster than the speed of light we would go back in time?"
Again, I'm not sure I see how time's velocity can be talked about in a meaningful way. It doesn't seem to move in any spacial dimension, and in fact is probably more akin to the idea of dimension itself than a physical property of anything.

"Let's imagine for a second that we can travel faster than the speed of light and that we are able to go back in time. This would mean there would be two of us in space because we are not only back in time, but we are also living the time we lived before we reached the speed of light. Wouldn't this be breaking Newton's Law of the Conservation of Mass? Yes, it would, but only assuming it was possible to travel faster than the speed of light."
First off, I believe the theory of conservation of mass is more accurately attributed to Lavoisier, the father of Chemistry. And yes, I do believe that this would violate Lavoisier's theory of conservation of mass; but I don't find this so troubling, in that nuclear processes can exchange matter for energy, which could hypothetically account for matter seemingly "appearing out of thin air" in some sort of (possible contrived) scenario.

"Well let's imagine the same situation, but this time we are traveling exactly the speed of light. Time is perfectly stopped, but we are still moving. That would mean that we are in every single place we have been in since time stopped, all at once. This is still challenging Newton's Law. But still, I recall hearing something about the exact speed of light still being impossible to reach."
Here's a question for you: if time were stopped for you, how far would you move during the time you were traveling at the speed of light? But yes, the speed of light cannot even be reached, if SR is correct. The reason? It would imply that the "mass" of the thing was infinite, and infinite energy had been put into the system's motion. It is generally assumed that infinity is not normally something we can achieve in terms of energy.

I think that Newton and Einstein were both right, but they both worked under a fundamentally different set of assumptions. Strictly speaking, Einstein is more "correct", in the sense that his laws work at all levels (and in fact reduce to Newton's in the case of relatively low velocities).

Newton had no reason to believe that light traveled at the same speed in all inertial frames of reference; in fact, he assumed that light was like any other particle, and that Galilean transformations applied normally to it. It was only in trying to resolve later paradoxes involving the propagation of EM waves in a vacuum that Einstein said "what if..." and deduced consequences. These consequences were later verified in the laboratory and reconciled with E&M.
 
  • #3
vanesch
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The rules at PF specify that idle speculation isn't allowed for.
So you reformulate your OP as a specific question or issue with accepted theories, or this thread is done.
 
  • #4
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The rules at PF specify that idle speculation isn't allowed for.
So you reformulate your OP as a specific question or issue with accepted theories, or this thread is done.
So who's right here? Einstein or Newton; or Einstein and Newton but not Hertz@physicsforums? I would love to hear what you see that I failed to see, please let me know :)
My question was, "where did I mess up?" I'm surprised you read this while thread under the impression that I didn't have a question, when in fact the whole entire thread is an explanation to the question and not "idle speculation" as you would call it. No offense Mr. Moderator Sir, but you obviously failed to actually read and understand the thread before jumping to criticisms that do not relate to my thread at all. Spam?

The problem with this, as I see it, is that for time to be traveling (in the usual sense, anyway) it must be traveling in some direction... as in, some spacial direction. I'm not sure that this makes a ton of sense to me.
I know what you mean, I was pretty confused by this too, but I eventually just told myself "well, light travels in all directions right? Maybe time does something similar." But this just made me realize a HUGE problem with my theory. If time stops when you travel the speed of light, wouldn't that mean time travels instantly? Or in other words, wouldn't that mean that light travels instantly? That proves that time doesn't travel, or at least if it does, it travels a whole lot quicker than the speed of light.

Does anyone know of any other explanations to slower time at faster speeds?
 
  • #5
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I think the moderator's response was due to the number of times you used expressions like "Let's imagine <some non-physical situation>". The problem is that you're asking questions that are way out ahead of the more basic ones you should be asking first. In other words, the questions go away once you understand the more basic concepts.

The main problem is see is that your whole line of thought seems to be based of the notion of time "traveling". For something to travel, i.e. to move, it must have a position, which can then change. Time has no position - it is something we measure, e.g. by counting clicks of a clock between two events. It makes no sense to speak of time "traveling".
 
  • #6
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That's not a theory.

A theory is not a supposition that one pulls from one's...um...hat. It's a description of a physical process that provides quantitative predictions that could, at least in theory, be tested.
 
  • #7
russ_watters
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My question was, "where did I mess up?" I'm surprised you read this while thread under the impression that I didn't have a question, when in fact the whole entire thread is an explanation to the question and not "idle speculation" as you would call it.
You're not understanding the problem. The problem is that a "where did I mess up?" question is a question based on your idle speculation (and it is idle speculation - you acknowledged in your second sentence that it is speculation based on ignorance). That approach is, quite simply, the incorrect way to learn and as a result is not accepted here.
We will not help people do things incorrectly because it is counterproductive: it will not help you learn what you really need to learn. Heck, you've already gotten a crackpot response to the question (since deleted) due to the speculative nature of the question.

So please reforumlate your question into an inquiry that is absent of speculation.
 
  • #8
fluidistic
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Hertz, as far as I know if you're going to a speed of about 0.99c (or any other possible speed) with respect to the Earth (suppose Earth is an inertial frame), you will feel time as you always did (no slower at all). It's when you go back on Earth that you realize that your time when traveling was in fact different from the time people on Earth as accustomed to.
I didn't studied relativity yet so I can't say it's true but I think it is.
Hope it helps a bit.
 
  • #9
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No, fluidistic is right. If you're in an inertial frame, time seems to work just the same for you.
 
  • #10
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@ fluidistic and AUMathTutor,

So from what I can tell, you guys are claiming that no matter how fast you're traveling time seems to remain the same, but is in fact different from the time of those who are stationary? Would that mean that you are breathing at a "normal" speed from your perspective, but actually breathing much faster from somebody elses perspective?

@ Everyone else,

Sorry, how is this - Why is time different while you are traveling?
 
  • #11
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"Sorry, how is this - Why is time different while you are traveling?"

Because light must travel at c.
 
  • #12
ZapperZ
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This is a prime example where, before you apply your "knowledge" to formulate a "theory", you have to make sure first and foremost that you have understood the basic principle! If not, you are applying a faulty understanding of something to make an even more outrageous speculation.

Ask first about whether you have understood the basic principles of special relativity and how they work. This requires not only the reading of pop-science books, but also the working out of a few problems yourself, on your own, to know how they are applied. Do not be too quick into thinking that you can formulate a "theory" based on what you think you've understood.

Zz.
 
  • #13
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... no matter how fast you're traveling time seems to remain the same, but is in fact different from the time of those who are stationary? Would that mean that you are breathing at a "normal" speed from your perspective, but actually breathing much faster from somebody elses perspective?
Yes. You will measure a different time interval between any two events that might occur (like two clicks of a clock, two firecrackers going off, whatever) than an observer in a different reference frame would measure, but to you your clock will "feel" correct to you, and his will look like it's running slowly. (He would say the opposite, and neither of you would be "right" or "wrong".)
Sorry, how is this - Why is time different while you are traveling?
Now we're getting somewhere - this is a reasonable question. The answer, of course, comes from Einstein's Theory of Relativity, so the best thing to do is to go and find one of the dozens of introductions to the theory that are available on-line, read it (there are some that you can read through in a couple of hours), and then come back here with a specific question about it.
 
  • #14
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Anyone have any recommendations on books about Einstein's Theory of Relativity? I want to really understand why he thinks what he thinks and not just be told what he thinks, if that makes any sense. Also, I wouldn't mind it being fairly easy to understand, I don't have a very wide physics vocabulary :\ After all, I haven't even completed one year of high school non-AP physics lol.

Also, is there anything else I should learn about before trying to get into this kind of stuff? Like I said before, I don't know a whole lot about physics, I just know it really interests me :)
 
  • #15
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Herz: Go first to the source:
http://www.fourmilab.ch/etexts/einstein/specrel/www/

Found by googling:
electrodynamics moving bodies

You should be able to read at least some of this. It is probably one of the best explanations you can find. If you dont understand the notation, ask here. Or go to a library or bookstore, there are tons of popular explanations. If you can find "The Feynman Lectures" borrow them (they are pricey or hard to find, but they explain *everything* in basic physics in a way that most of us nerdy types find irresistable).

Good luck -
 
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  • #16
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Hertz, I think you need to start with Newtonian mechanics. If you don't know the basic vocabulary - what is momentum, energy, velocity, coordinates, etc. - you need to get that down first before launching into relativity.
 
  • #17
fluidistic
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Hertz, I think you need to start with Newtonian mechanics. If you don't know the basic vocabulary - what is momentum, energy, velocity, coordinates, etc. - you need to get that down first before launching into relativity.
That's what I was going to say. That's also why you don't learn Relativity right at the beginning of a freshman university course. The road is long but if you really wants to understand physics, study it deeply. Many of your doubts will go away.
 
  • #18
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My advise:

Learn Newtonian mechanics at school. Most of it isn't really fun enough to be put into pop-science books. Just choose Maths or Further Maths for your A-Levels.

As for relativity/quantum theory/string theory... etc. As other people say, read some pop-science books. My favourites are:

For Einstein's theories: The Elegant Universe By Brian Greene (this actually has a lot more than Einstein's theories)

For Quantum theories: Quantum Theory Cannot Hurt You by Marcus Chown

For string theory: Just stay away from this for now, all popular science books that I have tried to read on the topic haven't really got me interested.

But even if you have read these and understood them, you have only just touched the surface. The maths behind the theories is what drives them. Stick to the philosophy board for interesting, non-mathematical, ideas that have no testable predictions.
 
  • #19
arildno
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@ fluidistic and AUMathTutor,

So from what I can tell, you guys are claiming that no matter how fast you're traveling time seems to remain the same, but is in fact different from the time of those who are stationary? Would that mean that you are breathing at a "normal" speed from your perspective, but actually breathing much faster from somebody elses perspective?

@ Everyone else,

Sorry, how is this - Why is time different while you are traveling?
Who is the one "traveling"??

Relativity works both ways, from the perspective of the guy on the spaceship, it is the Earthlings who are travelling..
 
  • #20
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I think Einstein's own book on relativity suffices for Hertz's purposes, it is a good read I certainly recommend for anyone. It's just so mathematical that the anyone willing to put some thinking into it will be able to actually grasp relativity. It goes a bit further than the typical popular science presentation which brings up space-time bending just for the sake of astonishing the reader without actually explaining a thing.

The book is just called "Relativity", by Albert Einstein.
 
  • #21
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Q

I think Einstein's own book on relativity suffices for Hertz's purposes, it is a good read I certainly recommend for anyone. It's just so mathematical that the anyone willing to put some thinking into it will be able to actually grasp relativity. It goes a bit further than the typical popular science presentation which brings up space-time bending just for the sake of astonishing the reader without actually explaining a thing.

The book is just called "Relativity", by Albert Einstein.
Actually, I believe it's "Relativity, A Simple Explanation Anyone Can Understand", with the additional phrase being a subtitle.

I was going to suggest this book, as it really is the starting point for many (it was my first introduction to the subject some 27 years ago), but I didn't because I've also seen some people criticize it over the years, saying that there are newer, better introductions out there.

In any case, one of the amazing things about Special Relativity is how it really does not require much math beyond high-school algebra (compared to QM or GR). For that reason, I would say that if the OP doesn't want to go through all of Newtonian Mechanics, then it is still possible to read Einstein's or one of the other introductions and get a pretty good understanding of the concepts.
 
  • #22
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Hertz, I think you need to start with Newtonian mechanics. If you don't know the basic vocabulary - what is momentum, energy, velocity, coordinates, etc. - you need to get that down first before launching into relativity.
I learned most of this stuff in my physics class at school, but I got a little thrown off when we got into energy and waves and stuff. But I still basically understand most of it, I'm sure if I started at relativity and got to something I didn't understand I could easily just look up the definition and get it, so I don't really think I should worry about this too much.

I think Einstein's own book on relativity suffices for Hertz's purposes, it is a good read I certainly recommend for anyone. It's just so mathematical that the anyone willing to put some thinking into it will be able to actually grasp relativity. It goes a bit further than the typical popular science presentation which brings up space-time bending just for the sake of astonishing the reader without actually explaining a thing.

The book is just called "Relativity", by Albert Einstein.
Actually, I believe it's "Relativity, A Simple Explanation Anyone Can Understand", with the additional phrase being a subtitle.

I was going to suggest this book, as it really is the starting point for many (it was my first introduction to the subject some 27 years ago), but I didn't because I've also seen some people criticize it over the years, saying that there are newer, better introductions out there.

In any case, one of the amazing things about Special Relativity is how it really does not require much math beyond high-school algebra (compared to QM or GR). For that reason, I would say that if the OP doesn't want to go through all of Newtonian Mechanics, then it is still possible to read Einstein's or one of the other introductions and get a pretty good understanding of the concepts.
This sounds perfect for me, I've always been interested in math but I've never really exceeded average math for someone my age. It would also probably be really nice to read Einstein's own work instead of someone else just trying to describe it.

Thanks for all the help everyone, I'll see if I can grab a copy of this book and maybe some others and get to learning :)
 

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