Is the Universe in an Eternal Cycle of Expansion and Rebirth?

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In summary: If the density of matter is greater than the critical value, then the universe will eventually collapse. And if the density of matter is exactly the critical value, then the universe will oscillate between these two states.Eventually the speed will be reduced to zero, from which point the bodies will then start moving in the opposite direction, with a negative acceleration.That sounds about right. The force that decelerates the expansion is called the Cosmological Constant. It's a mysterious energy that seems to be getting stronger over time. Some physicists think that it might be the cause of the universe's accelerated expansion.i believe that the "centre of the universe" may act as the point of equilibrium, meaning that
  • #36
cepheid said:
It sounds like you're talking about the so-called "big-bounce" scenario. For what level of schooling are you creating this presentation?

the presentation is over now, but it was for my first year university physics program. i was reffering to the big bounce, indeed, just didn't know the name.
The equations that govern the expansion are not those of a simple harmonic oscillator, although that's not a bad guess. I'm not sure what your math background is, but you might consider looking up the Friedmann equations in order to learn more. Very roughly speaking, these equations describe how the 'scale' of the universe evolves with time. One of the implications of the Friedman equations is that this evolution depends upon the different components that contribute to the energy density of the universe, such as matter, radiation, etc. The component that seems to be dominant at this point in time is something whose nature is not understood at all. It has simply come to be called, The Dark Energy. More on that below.
That depends. The force that wants to slow down the expansion is just gravity. Therefore, the ultimate fate of the universe depends (partly) upon how much matter is present within it. This dependence is a direct result of General Relativity (which is where the Friedmann equations come from in the first place). It is simple to explain what the ultimate fates of universes without dark energy would be. There are three possibilities. If the density of matter in such a universe is less than some critical value, then that universe will continue to expand forever, and the expansion rate, although decreasing, will always be positive. If the density of matter happens to be exactly equal to the critical density, then that universe will also continue to expand forever and will once again be decelerating with its rate never quite reaching zero (but approaching it asymptotically). If the density of matter in the universe is greater than the critical value, then the expansion rate will decrease until it becomes zero, and then negative. In other words, the expansion will slow down, stop, and then reverse. The universe will begin to recollapse. This third possibility is essentially the same as the scenario you outlined, with one key difference. Without dark energy, there is no 'bouncing back.' Everything collapses down to a singularity and that's it. This is the so-called 'big crunch.'

I should emphasize that all of these scenarios have been ruled out by observations, which strongly favour the presence of dark energy. The dark energy makes it a bit more complicated to sort out what the ultimate fate of the universe will be (as compared to the neatness of the three cases presented above). However, in all reasonable models that include dark energy, the universe will continue to expand forever, and the rate of that expansion just gets faster and faster (i.e. the expansion is accelerating).

thanks for that, i learned a lot and this improved my research.

i just want to add that in the link i provided, suggests that dark energy is replaced with "single energy field". quote from the link;

"The new model replaces inflation and dark energy with a single energy field that oscillates in such a way as to sometimes cause expansion and sometimes cause stagnation. At the same time, it continues to explain all the currently observed phenomena of the cosmos in the same detail as the big bang theory."

does it not mean that the dark energy problem is solved? I'm finding it difficult to understand the quoted statement as i don't really know what is being talked about, so if u could please elaborate on this point, it would probably improve my understanding by miles.

thanks again xxx
 
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  • #37
i wanted to talk about dark energy because u mentioned that it was due to the dark energy that the big bounce theory's credibility is reduced.
 
  • #38
procrastin said:
i wanted to talk about dark energy because u mentioned that it was due to the dark energy that the big bounce theory's credibility is reduced.

Consider: Gravity as a means of reducing expansion and eventually reversing it was never a sure thing, but when you add this mysterious expansion of space, it just blows Gravity out of the water as a means to "crunch".
 
  • #39
'Bounces' are improbable for now. It appears gravity has no chance against dark energy. It is, however, conceivable quantum fluctuations may become dominant when matter density sufficiently decreases.
 
  • #40
nismaratwork said:
Consider: Gravity as a means of reducing expansion and eventually reversing it was never a sure thing, but when you add this mysterious expansion of space, it just blows Gravity out of the water as a means to "crunch".

yes but the cyclic theory i posted claims to replace dark energy with an energy field. what difference does that make and why?
 
  • #41
procrastin said:
yes but the cyclic theory i posted claims to replace dark energy with an energy field. what difference does that make and why?

It doesn't match observations, which now seem to indicate that DE (or whatever you choose to call it) is a more dominant effect than gravity. A cyclic theory requires gravity to overcome all else, or DE to magically reverse, and neither matches observation. You could go for something like a new universe being created within the remnants of our own, but that's not cyclical, just new.
 
  • #42
DavidGTaylor said:
First and foremost: I am a moderately religious man, but only to the extent that I believe there is an intelligence beyond ours.

That's interesting. I had pizza for lunch yesterday, and I like watching soccer. What does any of this have to do with cosmology?

I know there is no standard model of the Universe.

Yes there is. People talk about the standard model of cosmology which is the consensus view on how things work. Note that the standard model might be wrong, and there is some effort in researching non-standard cosmologies. What tends to happen is that once you come up with something that seems to work, the non-standard model gets absorbed into the standard model.

The standard model is standard. It might be wrong, and the standard model of cosmology in 1994, is considered to be wrong now. The standard model of particle physics in 1975 is also partly wrong now.

One of the most respected right now is that the Universe started primarily/exclusively as energy.

No it doesn't. It's observed that galaxies are moving way from each other and that the universe is cooling. If you just run the movie in reverse, then you end up with a universe that gets hotter as you go back in time. Eventually you reach a point where our knowledge of how matter and energy behaves stops, and about what happened before that, the standard model says nothing. People are working on trying to figure out what happened before "cosmic inflation" but none of that is really part of the current big bang model.

I personally have trouble with that, because gravity is supposed to slow down all zero-rest-mass particles (photons/gluons/mesons-"PGM").

No it doesn't.

If it does so, then the energy represented by those particles has to go somewhere - my simplistic, ignorant leanings makes me think it would lend kinetic energy to matter particles and they would go faster, increasing their momentum.

Again it doesn't. What happens with relativity is that different observers can measure different amounts of energy or momentum, but there is no real energy transfer.

So one idea of the "Cosmic Egg" would be that it would be almost entirely matter - relativistically distorted mass matter, but simple matter. Whether it would be in nucleons, sub-nucleons, or the great-great-great grandchildren of those nucleons we can't know. The actual density of the body also firmly in the air - none of us have ever been near a cosmic egg.

Again, your understanding of the BB theory is incorrect. You can figure out what the universe is made of by looking at it. You then go back in time, and try to figure out how matter behaves at different temperatures.

I admit the idea is contrary to common holy-teaching (forgive the irony) in a lot of BB, but I really have trouble with the energy idea.

The problem is that whoever taught you what cosmologists believe has taught it to you very incorrectly.

Finally, the equations appropriate for calculating distortion from a distorted point of view are different from the ones that Einstein developed.

In order to have anyone take any alternative theories seriously, you have to show that you understand the standard theory.

If you would like to see them, just say so. Please believe me, they are an expansion of Relativity, not a denial. And I have confirmed the equations to the above value range. I could even send you all 39 test values. The confirmations are comprehensive, but 2000 decimal place numbers never really make very light reading. Sorry.

It's also useless. You aren't going to get any experiment to be correct to more than 8 decimal places.
 
  • #43
DavidGTaylor said:
If you're scared of something making claims about additions to relativity whatsoever, it is probably best you ignore this.

There are about half a dozen proposed additions to general relativity that haven't been ruled out, and if you go into arvix there are *hundreds* of papers that propose extensions to GR. My favorite is loop quantum gravity.

The trouble is that it is quite hard to come up with a theory that isn't ruled out by experimental tests. It's even hard to come up with a theory that isn't self-contradictory.

And also this has very little to do with the BB. Basically you can take any theory of gravity, write down how those equations affect the expansion of the universe, and at that point the details of the theory don't matter.
 
  • #44
budrap said:
Logically you seem to be reasoning forward from the first trillionth of a second after the alleged Big Bang and saying it's all good from that point on. But the Big Bang theory was arrived at by reasoning backwards from the assumption that the observed cosmological redshift was caused by a recessional velocity and since that reasoning process culminates in an illogical absurdity isn't it difficult to credit the theory at all, especially considering the additional ad hoc modifications necessary to make the model subsequently conform to observation?

Hi budrap and all.
As I said before I have difficulty with the BB theory. Before physical or Einstein's fourth dimensional time began, energy ( E = h f, ) existed in its pure quantum state or photon state, or light. Time began when sub atomic particles were formed that moved slower than the speed of light.
I just wonder if the cosmological redshift observed in the universe could be caused not by a recessional velocity, but rather could be the affect of the cosmological gravitational constant in the universe, because Einstein showed that light traveling through a gravitational field is gravitationally affected by the gravity and this has an affect on the redshift of the light. Thus the redshift of the light coming from distant galaxies could be gravitational rather than recessional.
Yours Cosvis.
 
  • #45
cosvis said:
As I said before I have difficulty with the BB theory. Before physical or Einstein's fourth dimensional time began, energy ( E = h f, ) existed in its pure quantum state or photon state, or light. Time began when sub atomic particles were formed that moved slower than the speed of light.

Part of your difficulty is that it has been taught badly to you. None of what you have said is in the big bang at all.

I just wonder if the cosmological redshift observed in the universe could be caused not by a recessional velocity, but rather could be the affect of the cosmological gravitational constant in the universe, because Einstein showed that light traveling through a gravitational field is gravitationally affected by the gravity and this has an affect on the redshift of the light. Thus the redshift of the light coming from distant galaxies could be gravitational rather than recessional.

People looked pretty seriously at that possibility in the 1970's. The problem is that gravity bends light so if you had gravitational redshifts you should see the light of distant galaxies being bent by the gravity fields and so the galaxies would appear blurry.

You don't.
 
  • #46
twofish-quant said:
First and foremost: I am a moderately religious man, but only to the extent that I believe there is an intelligence beyond ours.

. . . that's interesting. I had pizza for lunch yesterday, and I like watching soccer. What does any of this have to do with cosmology?
Overly personal detail, I admit, but . . .

All of the relativistic equations are from a single perspective - one that is assumed immobile and not undergoing relativistic distortion. Lorentz–FitzGerald contraction would certainly make the distortion sufficient in one spot so that you couldn't detect the direction of your motion, but if you go a different velocity (as the Earth would on opposing ends of its orbit), the time dilation would make the velocity of light to be different. So we can assume that relativistic effects also slow down EM.
twofish-quant said:
No it doesn't. It's observed that galaxies are moving way from each other and that the universe is cooling.

What is observed is an increasing red shift for objects; the lower their apparent size and luminosity is. An increasing recession rate could explain that - OR a degeneration of the signal - in a way that requires the apparent intergalactic recession to occur. Strong nuclear force/particles exist (that's been established with particle acceleration experiments) but they only "exist" for a limited time and distance. Where does the energy/mass they represent disappear to, when they are not confined to physical dimensions the scale of atomic nucleii? Or extended by relativistic time dilation inside a hight speed accelerator? Isn't it possible that photons/EM have a parallel degradation?

And the space expansion situation is more complex than is sometimes presented. If it took place in the opening seconds, separating everything, how is it M31 (Andromeda) is moving towards us - at a velocity exceeding gigantically the escape velocity? How is it the whole Local Group is held together, when the gravitational force to do so is far too small?
twofish-quant said:
No it doesn't.

And if gravity does 't slow down ALL zero-rest-mass particles - PGM's - how does it keep them from escaping a Schwarzschild radius? Do they just bang their heads? And if it is not going to stop gluons and mesons (whose lifetime would be increased by General Relativistic distortions), isn't an inevitable leakage going to happen? Well beyond "Hawking" leakage. And if that happens, S.O.'s just would not last that long.
twofish-quant said:
The problem is that whoever taught you what cosmologists believe has taught it to you very incorrectly.

The simple fact is that while there is certainly agreement that THIS universe had a catastrophic beginning, the nature and replication of that beginning is not something that is unanimously agreed to. Some folks out there believe it has happened more than once. The simple fact is that if you believe in infinity forward in time, it is not really reasonable to deny it BACKWARD in time. And if there is that infinity, then mathematical theory demands that the same conditions that happened to spawn our Universe has happened an infinite number of times.
twofish-quant said:
. . . to have anyone take any alternative theories seriously, you have to show that you understand the standard theory.

twofish-quant said:
It's also useless. You aren't going to get any experiment to be correct to more than 8 decimal places.

I can't really get into it, because even you (everyone!) has to admit it is a gigantically complex issue. But please, just consider this. The equations I referred to are an algebraic expansion of the time equation in Special Relativity. The reason I checked them to that absurd degree, is because I had a very good, award winning scientist (Dr. Don Page @ the U. of A.) offered the critique that while my equations might have worth at non-relativistic velocities, they would be invalid the closer they got to light speed. They are valid, otherwise the Special Relativity equations themselves are invalid, because I checked them with Einstein's formulas. From very tiny velocity values (1.0E-500m/s) to very relativistic ones (c-1.0E-500m/s) And what they establish is that Relativistic distortions calculated from a moving viewpoint rely on different formulas. Not different fundamental presumptions, simply different from different perspectives. According to Einstein, if you are going at more than 2.11985280E+08m/s it will appear to you that you are going faster than the speed of light by both the blue shift in front of you and the time it appears for you to travel a given distance (though the relativistic blue shift behind you will confuse things). So is the classic:

(1-v^2/c^2)^.5

- format the right one to to determine your relativistic distortion? That equation would tell you that you are imaginary. Or is it possible that those classic equations have a different form when evaluating data that is relativistically altered?

I hope this either a)intrigues you or b)gets you really P.O.'d. Either way, moved to make a reply.

A final point: there are all kinds of theories insisting that the Universe started as exclusively energy, followed by an "imbalanced" transformation into matter/anti-matter. How is that more reasonable that my idea that relativistic distortions are different from different perspectives?
 
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  • #47
Gentlemen (meaning DavidGTaylor and others participating in the discussion he began),

As of yesterday morning it looks like the OP is back after a long absence, and has more questions about "big bounce" scenarios, which is what this thread is really about. I'm not a moderator, so you don't have to listen to me. However, given that this thread has already been de-railed or hijacked twice, once by a proponent of intelligent design, and again by DavidGTaylor, you might want to consider devoting a separate thread to your ideas. I believe that that is what proper forum etiquette suggests. Be careful, as well. Advocating personal theories or even theories that directly contradict mainstream science goes against the rules that have been established for this forum. We wouldn't want to get the thread locked...
 
  • #48
twofish-quant said:
People looked pretty seriously at that possibility in the 1970's. The problem is that gravity bends light so if you had gravitational redshifts you should see the light of distant galaxies being bent by the gravity fields and so the galaxies would appear blurry.

You don't.
Hi twofish-quant and all.

The light coming from the our sun heading towards Earth is red-shifted but not bend and thus the sun is not blurred. Could it be that the light coming from distant galaxies moving through an even force of gravitation like the cosmic gravitational constant, could be re-shifted but not bend and thus not blurred? I am not saying that the recessional redshift is wrong, but I am just wondering if the gravitational redshift could also be an effect on the redshift coming from distant galaxies.
Yours cosvis.
 
  • #49
Moderator's note:

As cepheid said, please stay on topic when posting in this thread. Other topics should be posted in a new thread, as long as they do not violate forum guidelines.


If you need a reminder, the topic of this thread is the "Big Bounce" scenario, or as stated in the OP:
procrastin said:
i'm going to be doing a presentation for my astronomy module, and i was thinking that i should talk about the idea of the universe being in an eternal cycle of expansion and rebirth.
.
.
.
this link will explain what i mean if i haven't made myself clear;

http://www.princeton.edu/pr/pwb/02/0506/0506-cyclicuniverse.htm
 
  • #50
cosvis said:
The light coming from the our sun heading towards Earth is red-shifted but not bend and thus the sun is not blurred.

The amount of gravitational red-shift from the sun is really tiny and I'm not sure it has ever been measured, but the sun does gravitationally bend light a really tiny amount.

If you increase the redshift to the amounts that you see in quasars, you also increase the bending of light.

Could it be that the light coming from distant galaxies moving through an even force of gravitation like the cosmic gravitational constant, could be re-shifted but not bend and thus not blurred?

Based on what we knew in 1965, yes. Based on what we knew in 1980, no. What people did in the 1970's was to come up with models that assume that gravity acts weird, and no one could ever get something like that to work. Suppose there *was* some process that was able to re-redshift light. You then ask yourself would this have any sort of detectable effect in the laboratory or in the solar system.

The other thing that happened was that in 1965, no one could figure out how quasars could generate so much energy. By 1975, people figured out a good explanation.

I am not saying that the recessional redshift is wrong, but I am just wondering if the gravitational redshift could also be an effect on the redshift coming from distant galaxies.

People could never get this sort of thing to work. Once you look at the amount of redshift and where it is, people never were able to come up with a model for something other than redshift. One question, suppose the redshift wasn't due to Hubble flow. They why is it that galaxies with large redshifts then just look younger and dimmer.

I should point out that one reason I dislike the way the textbooks are written is because they just give you facts to memorize and they don't give you the reasons why people believe what they do. Something that is really interesting is to go back in time to around 1970 and watch people fiercely argue about whether quasar redshifts are really due to recession.
 
  • #51
Yes! But some quick comments.

On the comment from cosvis, I agree with you completely: red-shift is not the same as "blurring".

Secondly: Yes Mr./Ms./Your Worship/Highness "Cepheid". I would agree gigantically with you on the idea of setting up a separate thread and very much appreciate your making that intelligent and perceptive observation. This was just the closest thread I could come to start, and I hoped I could attract some attention. Just one last comment before I leave and TRY to start something devoted to Relativistic Perspective. The equations relate "Real" velocity with a travelers perception of the "Relativistic" velocity appearing to be greater because of time slowdown. The equations work and have been verified for length, mass & time (to, yes, a pointless precision). Aren't ADDITIONAL equations that agree entirely with Special Relativity worth SOME debate?

Just take a peek at the attached "Relativistic vs. Non-Relativistic Perspective Space-Time Perspectives.pdf" If you consider those equations invalid, then all of Relativity is invalid because they are simply derived from Dr. A's time equation. Sometimes there are more sophisticated mathematical tools applied to a problem than it deserves.

E=mc^2 is deduced in the end from nothing more than applying simple algebra and binomial theorem to the Lorentz-Fitzgerald equation.
 

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  • #52
DavidGTaylor said:
Just one last comment before I leave and TRY to start something devoted to Relativistic Perspective. The equations relate "Real" velocity with a travelers perception of the "Relativistic" velocity appearing to be greater because of time slowdown.

1) Thinking about "time slowing down" is a horrible and incorrect way of thinking about special relativity.

This is a better way. Take a coke can. If you look at from one angle, it looks like a circle. If you look at it from another angle, it looks like a rectangle. At no time does the can actually change, but there are just different ways of seeing the can depending on what angle you look at it from.

Special relativity works exactly the same way. Time doesn't slow down. Time doesn't speed up. What happens is that if you have a series of events, you can describe them in different ways, but nothing actually slows down or speeds up.

2) Having two velocities is also very bad. The problem is all observers will agree about how fast two objects are moving relative to each other.

3) The equations work and have been verified for length, mass & time (to, yes, a pointless precision). Aren't ADDITIONAL equations that agree entirely with Special Relativity worth SOME debate?

No. In physics, math is a bad thing. You want to keep things simple, and adding extra equations just confuses things. If you have equations that agree completely with special relativity, then it's useless. You want to minimize the number of equations, and if you want to describe something, it's best if you can get it down to zero equations.

Imagine a coke can spinning. Most people can do that without thinking about math, and it turns out that if you want to write out the equations that describe a spinning coke can, they end up to be rather complex.

When you ask me a question about relativity, I just imagine things rotating. It's a weird sort of rotation, but it's still rotation, and it's only when I need to formalize something do I need to write down the equations.

To be blunt, I think you are getting too involved in the equations, and you aren't seeing the underlying theory at all.

E=mc^2 is deduced in the end from nothing more than applying simple algebra and binomial theorem to the Lorentz-Fitzgerald equation.

Well... Yeah.
 
  • #53
One fundamental characteristic of nature is that it repeats itself. There is no event which only happens once. ON the contrary, events repeat themselves over and over again, be they sunrises, seasons, orbits, etc etc.

Which is why we must conclude, however strange it may seem, that the BB happens on a regular basis.

Entropy seems to affect gravity as well. The ultimate irony is that in a universe where every thing is attracted to each other, as entropy increases and erodes gravity, every thing will be separate and alone.
 
  • #54
Godofgamblers said:
One fundamental characteristic of nature is that it repeats itself. There is no event which only happens once. ON the contrary, events repeat themselves over and over again, be they sunrises, seasons, orbits, etc etc.

Which is why we must conclude, however strange it may seem, that the BB happens on a regular basis.

Entropy seems to affect gravity as well. The ultimate irony is that in a universe where every thing is attracted to each other, as entropy increases and erodes gravity, every thing will be separate and alone.

I don't agree, and frankly, you've made a HUGE claim which you now need to back with sources.
 
  • #55
twofish-quant said:
1) Thinking about "time slowing down" is a horrible and incorrect way of thinking about special relativity . . . This is a better way. Take a coke can. If you look at from one angle, it looks like a circle. If you look at it from another angle, it looks like a rectangle. At no time does the can actually change, but there are just different ways of seeing the can depending on what angle you look at it from.

"Slowing down" may be a politically incorrect word to apply to time time dilation. But doesn't riding an object traveling at approximately 2.11E+08m/s (whatever the velocity you would need for a distortion value of 2) mean that in the time the second hand makes a full rotation around the face of your wristwatch the non-relativistically affected second hand on the watch you left on your dresser at home will move twice. You will perceive this to mean that things around you are moving faster. For the distorted object, the progression of time has slowed down. Can't really think of another way to say it.

But again, I hope I can start a new thought/discussion on this, but for now, I will be a good boy and make a comment directly related to Big Bang Alternatives: if time slows down because of general relativity, couldn't it be reasonable that the time slowdown means that while all of the interactions between objects slowdown, any velocity a particle/object has wouldn't decline in the same fashion? Its energy wouldn't disappear, so it would move at the same velocity. But all photons/gluons would have to slowdown (if viewed from an outside perspective), otherwise all interaction in matter/energy would change. As you added energy to a system undergoing G.R. distortion, it would increase the velocity of its composite particles and they would speed up. That speed up would increase more and more as the temperature rose and the particles (at any level) became more and more independent of each other. You can maintain a time dilation in terms of particle interaction as long as they are dependent on each other and maintain their form/structure. Time dilation must have different effects on independent particles (gas, plasma and to a lesser extent, liquids) than it would on solid objects. Do the particles at the centre of a Big Bang move slowly because of G.R. distortion, or do they simply interact with one another more weakly because of that same distortion and not slow down? Does it get colder at the center of a Cosmic Egg?
 
  • #56
DavidGTaylor said:
"Slowing down" may be a politically incorrect word to apply to time time dilation. But doesn't riding an object traveling at approximately 2.11E+08m/s (whatever the velocity you would need for a distortion value of 2) mean that in the time the second hand makes a full rotation around the face of your wristwatch the non-relativistically affected second hand on the watch you left on your dresser at home will move twice. You will perceive this to mean that things around you are moving faster. For the distorted object, the progression of time has slowed down. Can't really think of another way to say it.

But again, I hope I can start a new thought/discussion on this, but for now, I will be a good boy and make a comment directly related to Big Bang Alternatives: if time slows down because of general relativity, couldn't it be reasonable that the time slowdown means that while all of the interactions between objects slowdown, any velocity a particle/object has wouldn't decline in the same fashion? Its energy wouldn't disappear, so it would move at the same velocity. But all photons/gluons would have to slowdown (if viewed from an outside perspective), otherwise all interaction in matter/energy would change. As you added energy to a system undergoing G.R. distortion, it would increase the velocity of its composite particles and they would speed up. That speed up would increase more and more as the temperature rose and the particles (at any level) became more and more independent of each other. You can maintain a time dilation in terms of particle interaction as long as they are dependent on each other and maintain their form/structure. Time dilation must have different effects on independent particles (gas, plasma and to a lesser extent, liquids) than it would on solid objects. Do the particles at the centre of a Big Bang move slowly because of G.R. distortion, or do they simply interact with one another more weakly because of that same distortion and not slow down? Does it get colder at the center of a Cosmic Egg?

For an observer moving at that speed, they wouldn't notice any difference in their day-to-day lives; it's only by comparison with non co-moving observers that a difference becomes apparent.
 
  • #57
DavidGTaylor said:
"Slowing down" may be a politically incorrect word to apply to time time dilation.

It's wrong.

But doesn't riding an object traveling at approximately 2.11E+08m/s (whatever the velocity you would need for a distortion value of 2) mean that in the time the second hand makes a full rotation around the face of your wristwatch the non-relativistically affected second hand on the watch you left on your dresser at home will move twice.

No it doesn't. The problem is that since there are no preferred reference frames, you can either say that you are moving and your house is still or that your house if moving and you are still. So if moving "slows things down" then you have both watches moving slower than the other.

In fact what the situation is that you can't compare watch movements at a distance.

You will perceive this to mean that things around you are moving faster. For the distorted object, the progression of time has slowed down. Can't really think of another way to say it.

That's not how relativity works. Nothing is being distorted.

if time slows down because of general relativity, couldn't it be reasonable that the time slowdown means that while all of the interactions between objects slowdown, any velocity a particle/object has wouldn't decline in the same fashion?

General relativity doesn't cause time to slow down.
 
  • #58
twofish-quant said:
It's wrong.



No it doesn't. The problem is that since there are no preferred reference frames, you can either say that you are moving and your house is still or that your house if moving and you are still. So if moving "slows things down" then you have both watches moving slower than the other.

In fact what the situation is that you can't compare watch movements at a distance.



That's not how relativity works. Nothing is being distorted.



General relativity doesn't cause time to slow down.

I don't believe he understands what you're saying... he's been raised on the notion that time slows down, or speeds up, this missing the whole concept of RELATIVITY, and appreciating only some of its more exotic consequences. Do you know how to teach someone in that position first principles and work from there, because if so, I'd like to 'watch' and learn your technique.
 
  • #59
nismaratwork said:
I don't believe he understands what you're saying... he's been raised on the notion that time slows down, or speeds up, this missing the whole concept of RELATIVITY, and appreciating only some of its more exotic consequences. Do you know how to teach someone in that position first principles and work from there, because if so, I'd like to 'watch' and learn your technique.
I agree with your sentiment, but teaching basic relativity wasn't the intent of this thread.

Thread closed pending moderation.

EDIT: this thread will remain closed.
 
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