# What time is it in the universe?

##### Aug 29, 2014 by Fraser Cain, Universe Today

Flavor Flav knows what time it is. At least he does for Flavor Flav. Even with all his moving and accelerating, with the planet, the solar system, getting on planes, taking elevators, and perhaps even some light jogging. In the immortal words of Kool Moe Dee. Do you know what time it is?

Didn't Einstein tell us it's all relative? Does anyone actually know what it is? I mean, aside from figuratively, or in a political sense, or perhaps as part of rap performance from whence the power is being fought from, requiring the sick skills of a hype man wearing a clock around his neck on a big chain.

So, after all my fancy dancing and longing for a time in rap and hip hop from days gone by, I must present to you "faithful audience member" an answer in the form of your 3 least favorite words I get to deliver.

It all depends…

You have heard that everything is relative, usually we hear it from people who like to talk about "connections on many different levels", which is just nonsense.

But in physics "everything" is relative in a very particular way. Everything is relative to the speed of light, which is the same in every reference frame. Which is confusing and repeated enough that it can become meaningless.

So I'm going to do my best to explain it. If I shine a flashlight in front of me, I will measure the beam to travel at about 300,000 km/s, which is also known as the speed of light.

And if you are moving at 200,000 km/s faster than me, and shine a flashlight ahead of you, I will see the light from your flashlight moving at the 300,000km/s. It will appear to me, as though the light from your flashlight is moving away from you at 100,000 km/s.

But when you will measure the speed of that light, relative to you, you'd think it'd be moving at 100,000 km/s as well, but instead from your perspective it will ALSO clock in at 300,000 km/s.

The speed of light. How is this even possible? It is possible in part because the rate at which you experience time relative to me changes. For you, time will seem normal, but from my perspective your time will seem slower. We agree on how fast light is moving in kilometers per second, but we disagree how long a second is. We also, by the way, disagree on the length of a meter.

This seems strange because we imagine that space and time are absolute things, and light is something that travels through space. This is our experience. Suggesting things like time and space are malleable values at best is unsettling and at worst will make us nanners from thinking too much about.

Hold on to your tinfoil hats, for it is in fact that is the absolute, and space and time are relative to it. So what time it is depends upon your vantage point, and so there is no single absolute time.

Finally, because of relativity, each point in the Universe experiences time at a slightly different rate. For example, when we observe the , we find that we are moving at a of about 630 km/s relative to the background. That means we experience time a bit more slowly that something at rest relative to the cosmic background.

It's just a tiny bit slower, but added over the entire age of the Universe, our cosmic clock is 30,000 years behind the times. Feel free to set your watch. But don't get too precise about it. Your time could be off by tens of thousands of years.

Explore further: Does light experience time?

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##### Doug_Huffman
1 / 5 (1) Aug 29, 2014
Coincidentally I am about half-way through another re-read of Lee Smolin's [i]Time Reborn[/i] (2013 HMH) in preparation for his late November release of [i]THE SINGULAR UNIVERSE AND THE REALITY OF TIME[/i] (2014 Cambridge).

He mentions the difficulties with absolute and relative time late in his devil's advocate first half of the book. I am particularly fascinated by the intersection with Karl Popper, both his 'Logic' and 'Open Society'.

##### Jixo
3.3 / 5 (15) Aug 29, 2014
The relativity handles the time arrow very vaguely. For example, if the curvature of space-time inside of gravitational lens is represented with time dimension of space-time metric, then such a lens shouldn't move and change anymore. Otherwise you would have at least two time dimensions here: the one, which is forming a space-time curvature and the another one, which allows the dynamics of it. A time dimension forbids motion or the case of the missing time dimension. The consequence of this insight for example is, the objects which are formed with space-time curvature exclusively (like the gravitational waves) shouldn't move and propagate according to general relativity. The relativist time arrow has therefore a meaning only in very flat and steady-state world.
##### arom
1 / 5 (6) Aug 29, 2014
Didn't Einstein tell us it's all relative? Does anyone actually know what time it is? I mean, aside from figuratively, or in a political sense, or perhaps as part of rap performance from whence the power is being fought from, requiring the sick skills of a hype man wearing a clock around his neck on a big chain….

You have heard that everything is relative, usually we hear it from people who like to talk about "connections on many different levels", which is just nonsense.

But in physics "everything" is relative in a very particular way. Everything is relative to the speed of light, which is the same in every reference frame. Which is confusing and repeated enough that it can become meaningless….

Actually Einstein relativity theory is not so bad, what which seems crazy is just because in his time no one knows that vacuum space is not empty, so he had to sacrifice space-time in order to get the useful output we gained in modern physics today….
http://www.vacuum-mechanics.
##### Urgelt
4.1 / 5 (13) Aug 29, 2014
What hits me in the gut is how you would perceive time if you were a photon.

Answer: you wouldn't perceive any. You could travel across billions of light-years, but for you, no time would pass at all on your journey. You would depart and arrive instantaneously.

At least, that's according to Einstein's theory.

And photons are missing the whole cosmic show; for them there is no dance of galaxies, no ticking of clocks, no cosmic expansion, no rise or fall of self-proclaimed sapient species. Photons are emitted and absorbed in an instant, no matter how far we perceive them to travel.

Regarding the cosmos as enduring only for an instant and having no perceptible distance is rather mind-boggling. But that's a valid perspective - if you're a photon.
##### OceanDeep
5 / 5 (6) Aug 29, 2014
What hits me in the gut is how you would perceive time if you were a photon.

Answer: you wouldn't perceive any. You could travel across billions of light-years, but for you, no time would pass at all on your journey. You would depart and arrive instantaneously.

At least, that's according to Einstein's theory.

And photons are missing the whole cosmic show; for them there is no dance of galaxies, no ticking of clocks, no cosmic expansion, no rise or fall of self-proclaimed sapient species. Photons are emitted and absorbed in an instant, no matter how far we perceive them to travel.

Regarding the cosmos as enduring only for an instant and having no perceptible distance is rather mind-boggling. But that's a valid perspective - if you're a photon.

Yes, that is mind-boggling. Does that mean that from a photon's frame of reference, they don't move at all, but rather just blink in and out of existence at various locations in the universe?

##### Da Schneib
3.9 / 5 (7) Aug 30, 2014
Here's another way to think of it, OceanDeep: to a photon the universe has zero thickness. It has been FitzGerald/Lorentz contracted to zero because the photon is moving at the speed of light. It doesn't see places in the universe. It is absorbed at (to it) the same time it was emitted. Photons do not experience time. However, their paths can be curved by curvatures in space, such as gravity. To the photon that's not even a straight line; photons don't experience lines. They each experience a single point.
##### antigoracle
2.8 / 5 (6) Aug 30, 2014
They each experience a single point

Even when they pass through a double slit?
##### Mimath224
2.4 / 5 (5) Aug 30, 2014
Ref. photons? That is using Time as we USE the 'arrow' and we are thinking ideal conditions. But if a photon travels the universe it would lose energy so what photons 'experience' is that loss. And what would happen at infinity? However, what is more likely is that photons will interact at some point. Calendar Time is okay for our mundane purposes but hardly qualifies as a scientific 'entity' so perhaps Time on the quantum and/or GR scales is 'something more'; and our calendar or 'arrow' time is simply a manfestation of that 'something more' which has dimesions of its own...just a thought!
##### kevin_proudler_73
2.5 / 5 (8) Aug 30, 2014
Special Relativity and time may be confusing to many a folk, but if you discover Special Relativity by simply analyzing motion, it becomes easy to understand due to you having encompassed it's entirety.

Meanwhile, everywhere else in the world these days, all you will see are the complex explanations of Special Relativity which always include math, and NEVER fully encompassed Special Relativity's entirety.

However, when fully understood, Special Relativity can be explained in only 1 hour and 39 minutes. The absolute foundation that creates all the bizarre relativistic outcomes, is fully revealed.

See http://goo.gl/fz4R0I

This exposure is then violently opposed by those whom are caught up in relativistic circular reasoning. They refuse to accept any possible absolute cause of Special Relativity. In turn they continuously demand that there is an effect, but in no way is there a cause.
##### AmritSorli
2 / 5 (4) Aug 30, 2014
the only time in the universe is NOW
http://article.sc...3.11.pdf
##### Aligo
1 / 5 (9) Aug 30, 2014
The geometrization of space-time as proposed with Minkowski is one of the strongest points of relativity. It's symptomatic, Einstein didn't invent this idea - he was surprised with it and he even opposed it at its very beginning... But Einstein was sufficiently bright & flexible mind and he contributed even into theories, which he didn't like (quantum mechanics). So, once he recognized the power of space-time concept, he started to develop the general relativity upon it.

I do like this concept too and in AWT the space-time plays a role of density gradient of aether, similar (but not equivalent to) the gradient forming the water surface. The directions along which the transverse waves are spreading freely correspond the spatial dimensions. And the remaining direction perpendicular to it is the time dimension. This geometrization explains immediately, why the time dimension has an arrow (it's oriented parallel to density gradient of space-time) and why the space dimension haven't.
##### Aligo
1 / 5 (9) Aug 30, 2014
Needles to say, the space-time concept works only well in limited extent, in which the space is sufficiently flat and the energy spreads through transverse waves exclusively. Even at the water surface such a scope exist only in narrow range, where the surface waves propagate most slowly. From perspective of its observers such a scope is large enough, just because of low speed of energy transfer. Therefore the scope of roughly 4D space-time Universe appears so huge for us. But at the boundaries of this distance scale the scattering of light waves into extradimensions cannot be neglected anymore. It applies both to quantum scale, both into cosmological scale, but at the quantum scale the diversification of time arrows becomes most prominent and it subsequently leads into well known quantum indeterminism. The 4D space-time concept simply works well just until space-time remains four-dimensional only.
##### Aligo
1 / 5 (10) Aug 30, 2014
The unitarity of time arrow gets violated with every manifestation of high dimensions of 4D space-time, including the "common" space-time lensing. In this case the light of distant stars gets separated into multiple paths and it travels with different speed/distance, which breaks the time arrow in limited extent and you'll see the single process separated into multiple ones. The quantum indeterminism works in similar way, just the number of gravitational lenses (quantum fluctuations of vacuum) is much higher at the quantum scale and they're dynamic and volatile. But the principle of time arrow breaking works in similar way there. From general scope of AWT there is as many time dimensions, as dimensions of space-time. We can for example have one-dimensional space with two or more time dimensions along hole stripes within superconductors. In this case the charge of multiple electrons propagates chaotically.
##### Da Schneib
3.4 / 5 (5) Aug 30, 2014
They each experience a single point

Even when they pass through a double slit?

The analogy breaks down in the two dimensions that the photon is not moving in. I was going to mention it but figured I'd keep it clean and deal with that part if anyone asked. ;)

ETA: I can't believe someone gave you a 1 for that. You got a 5 from me. It was a great question and above all things, I respect good questions. Schneibing is asking good questions, and I am the Schneibster.
##### Da Schneib
4 / 5 (8) Aug 30, 2014
Ref. photons? That is using Time as we USE the 'arrow' and we are thinking ideal conditions. But if a photon travels the universe it would lose energy so what photons 'experience' is that loss.
This is incorrect. Planck proved that light is emitted in fixed sized packets that are called "quanta." Other than the Doppler effect, there is no interaction that changes the frequency of a photon "in flight." Even when entering or exiting refractive materials, the speed and the wavelength change, but the frequency does not; and it's very important to remember that frequency is the term that the Planck equation for determining the energy of a photon, not wavelength or velocity.

The direction of time's arrow is determined by the hyperbolically symmetric shape of time; it can go forward down the axis of the "front" of the hyperboloid of revolution, or it can go along the "back" hyperboloid, or it can skew out to the limits of the hyperboloid. But that is all.

contd
##### Da Schneib
3.9 / 5 (7) Aug 30, 2014
In the space between the limits of the branch hyperboloids defined by the curvature of time, exists a forbidden area. The equivalent of a "normal" (90°) in a hyperbolic geometry is the edge of the branch of the hyperbola you're in. The space between the hyperboloids of revolution that define "future" and "past" is forbidden. It either has an imaginary mass/length/energy/frequency, or an infinite one.

Remember also that for two observers in IRFs that are comoving, but not colocated, the frequency cannot change. Remember conservation of energy? That's why. Note however that this implies that energy is not a constant among IRFs that are not comoving. A lot of people who study relativity fail to get it at this point. It should be obvious; objects at different positions in a real gravity field have different potential energies, too. Energy is fungible among non-co-moving IRFs. It can be exchanged for velocity relative to its source.
##### Da Schneib
4.3 / 5 (6) Aug 30, 2014
And what would happen at infinity?
What's your procedure for getting to infinity?

##### Da Schneib
4.1 / 5 (9) Aug 30, 2014
Meanwhile, everywhere else in the world these days, all you will see are the complex explanations of Special Relativity which always include math, and NEVER fully encompassed Special Relativity's entirety.
This is incorrect. SRT is completely mathematical. You are confusing the real theory with explanations of the theory. English cannot properly express all of mathematics; that's why mathematics exists.

Just sayin'.
##### TechnoCreed
5 / 5 (6) Aug 30, 2014
@Da Schneib
This is incorrect. SRT is completely mathematical. You are confusing the real theory with explanations of the theory. English cannot properly express all of mathematics; that's why mathematics exists.
I gave a '5' to Kevin S. Prouler and wondered who could possibly give a '1' to this guy. So I was perplexed until I saw your comment. In your defence I must say that his comment is kind of misleading because his geometric demonstration is mathematic after all. I strongfully recommend that you view his videos. I did not watch it all (I am kind of lacking time at the moment) but the first tree parts were very good and will view the rest later tonight.
##### Irving13
2 / 5 (4) Aug 30, 2014
Don't think the universe reflects on time. There is only energy and matter in motion.
##### antigoracle
2.5 / 5 (4) Aug 30, 2014
And photons are missing the whole cosmic show

They are the cosmic show and if only they could see themselves.
##### Da Schneib
4.6 / 5 (10) Aug 30, 2014
Aligo, don't try to piggyback AWT on real physics.
##### Da Schneib
4.4 / 5 (7) Aug 31, 2014
And photons are missing the whole cosmic show

They are the cosmic show and if only they could see themselves.
They'd have to experience time to do so. ;)
##### Aligo
1 / 5 (6) Aug 31, 2014
don't try to piggyback AWT on real physics
Relativity doesn't provide the limits of itself. After all, as any other theory. Also, don't try to promote your own ideas on real physics without labeling them so.
##### Da Schneib
4.2 / 5 (5) Aug 31, 2014
Relativity begins with the nature of spacetime and eventually explains the field theory of gravity based on curvature of spacetime, as well as showing that there is more than one kind of such curvature. No less than three such curvatures are mentioned in the Einstein field equations. However, it does not describe the strong or weak nuclear forces. Nor does it describe electromagnetism. For those we have separate theories.

I'd say the limits of relativity are pretty obvious, myself.
##### Eddy Courant
4.8 / 5 (5) Aug 31, 2014
It's 4:20 somewhere ;-}-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
##### Benni
2 / 5 (3) Aug 31, 2014
"Part III: Considerations on the Universe as a Whole
Albert Einstein 97
If we are to have in the universe an average density of matter which differs from zero, however small may be that difference, then the universe cannot be quasi-Euclidean. On the contrary, the results of calculation indicate that if matter be distributed uniformly, the universe would necessarily be spherical (or elliptical). Since in reality the detailed distribution of matter is not uniform, the real universe will deviate in individual parts from the spherical, i.e. the universe will be quasi-spherical. But it will be necessarily finite. In fact, the theory supplies us with a simple connection 1) between the space-expanse of the universe and the average density of matter in it."

As Relativity explains the field theory of gravity based on the curvature of spacetime, the end result is Einsteins conclusion regarding the structure of the Universe as quoted directly above from his GR thesis.
##### antigoracle
2 / 5 (3) Aug 31, 2014
And photons are missing the whole cosmic show

They are the cosmic show and if only they could see themselves.
They'd have to experience time to do so. ;)

Don't they?
For example when they go for a swim.
##### swordsman
1 / 5 (4) Aug 31, 2014
All of which points to the fallacy of Einstein's theory regarding space-time. In fact, the Einstein-Minkowski relationship was a misinterpretation, as is shown by the eigenvector representation of electromagnetic radiation. The Minkowski equation appears in the exponent (eigenvalue). What is happening is that electromagnetic waves bend as the transverse velocity increases beyond the speed of light. You can see this in the plots of the antenna equation: www.science-site....cle.pdf.
##### Aligo
1 / 5 (3) Aug 31, 2014
What is happening is that electromagnetic waves bend as the transverse velocity increases beyond the speed of light
Yes, but this is a common aspect of all transverse waves in any material environment, once we observe the with the waves of this environment consequentially (i.e. in similar way, like we're observing the propagation of light waves through vacuum just with using of light waves).
This animation illustrates the shear of velocity vector for wake waves of boat, once it approaches the speed of surface ripples. The resulting contraction corresponds exactly the Lorentz contraction of special relativity.
##### Da Schneib
3.7 / 5 (3) Aug 31, 2014
As Relativity explains the field theory of gravity based on the curvature of spacetime, the end result is Einsteins conclusion regarding the structure of the Universe as quoted directly above from his GR thesis.
But don't forget the cosmological constant and the de Sitter solution. It's since turned out that in fact, the universe *can* be infinite and still be relativistic. See also FRWL solutions. Only the positive curvature universe is necessarily finite in extent; both the flat and negative curvatures are boundless. And the universe is very close to flat; so close that if it does turn out to have positive curvature it's enormous beyond reckoning (quite literally since we can only see some twenty billion light years and infer somewhat more than a hundred billion from physics considerations in the early universe).
##### Da Schneib
3.7 / 5 (3) Aug 31, 2014
And photons are missing the whole cosmic show

They are the cosmic show and if only they could see themselves.
They'd have to experience time to do so. ;)

Don't they?
For example when they go for a swim.
Smarty.

Besides, that's caused by their interactions with the molecules in the water, so the photon that emerges is not the same photon that entered the water.
##### Da Schneib
5 / 5 (2) Aug 31, 2014
Techno, thanks. I'll review the videos. Perhaps Kevin was having a bad day.
##### Da Schneib
5 / 5 (2) Aug 31, 2014
In fact, the Einstein-Minkowski relationship was a misinterpretation, as is shown by the eigenvector representation of electromagnetic radiation.
Prove it.

The Minkowski equation appears in the exponent (eigenvalue).
An exponent is not an eigenvalue. An eigenvalue is the amount by which an eigenvector must be multiplied in a mapping to yield the new eigenvector.

You are slinging words you don't understand around and pretending they "prove" your "theory." Scare quotes because you don't "prove" things in physics, only in math, and you don't have a theory, which has been tested by experiment, you have a conjecture that does not hold water when compared with reality.
##### Benni
1 / 5 (3) Aug 31, 2014
But don't forget the cosmological constant and the de Sitter solution. It's since turned out that in fact, the universe *can* be infinite and still be relativistic

.....well aware of those conjectures, and when I read about anyone conjecturing that there is an "infinite" parameter anywhere in the universe, I say to them "Show me one".

.....Standard Model- would result in a perfectly spherical universe, but Einstein proposed a "quasi-spherical" universe to account for "lumpiness" (galactic clusters)

the universe is very close to flat[

....but not flat.

so close that if it does turn out to have positive curvature it's enormous beyond reckoning

......exactly right, the translation being that the universe may be much older than 13.6 Gyrs with such small curvature. That complex integral used on redshift calculators
will need to have the limits changed, and I think it's the James Webb telescope that will prove this.
##### Da Schneib
4.2 / 5 (5) Aug 31, 2014
The redshift is confirmed by the supernova data.
##### Benni
2 / 5 (4) Aug 31, 2014
The redshift is confirmed by the supernova data.

I'm not talking about "redshift". I'm talking about the the "integral" used to "calculate" redshift, it has a limit set far too low for the size of a positively curved universe. Ever played around with one of those internet redshift calculators? That's what I'm talking about.
##### Whydening Gyre
5 / 5 (3) Aug 31, 2014
What time is it in the Universe?
Guess that depends on the "time zone" you're in...
That said, the "clock speed" is the same throughout...
##### Mimath224
5 / 5 (1) Aug 31, 2014
And what would happen at infinity?
What's your procedure for getting to infinity?

Didn't intend to suggest that I had a procedure just more of a modus p.p. thought. From a conventional point of view if the universe is expanding and photon v is max then photons enter the expansion before (slower) matter; but would that suggest photons create the expansion? Would that continue to ∞ ? Another point that I'd like help with is that space is not a vacuum but apparently full of energy (not to mention DE & DM) so would this constitute a 'medium' in which photon v would be slower than in a true vacuum? If that be the case then photons would 'experience' a finite period of travel.
##### TimLong2001
5 / 5 (1) Sep 01, 2014
Time is merely a metric that we have created to order relative motions and interactions. The Wheeler-DeWitt Equation clears this up nicely.
##### Reg Mundy
1 / 5 (5) Sep 01, 2014
And what would happen at infinity?
What's your procedure for getting to infinity?

Didn't intend to suggest that I had a procedure just more of a modus p.p. thought. From a conventional point of view if the universe is expanding and photon v is max then photons enter the expansion before (slower) matter; but would that suggest photons create the expansion? Would that continue to �ž ? Another point that I'd like help with is that space is not a vacuum but apparently full of energy (not to mention DE & DM) so would this constitute a 'medium' in which photon v would be slower than in a true vacuum? If that be the case then photons would 'experience' a finite period of travel.

Or maybe expanding photons are just an example of the expansion of all matter?
##### Reg Mundy
1 / 5 (4) Sep 01, 2014
Time is merely a metric that we have created to order relative motions and interactions. The Wheeler-DeWitt Equation clears this up nicely.

Very perceptive....
##### Uncle Ira
5 / 5 (4) Sep 01, 2014
What time is it in the Universe?
Guess that depends on the "time zone" you're in...
That said, the "clock speed" is the same throughout...

So right now it is 6:42 p&m.
##### AmritSorli
1 / 5 (4) Sep 02, 2014
Time in the universe EXISTS, but it has only a MATHEMATICAL EXISTENCE.
http://cosmology....Time.pdf
##### Reg Mundy
1.6 / 5 (7) Sep 02, 2014
Time is quantum and is created by us to explain the movement of the cosmos from one state to another. Thus, time is our path thru' chaos as dictated by the laws of physics.
##### apostolvictor999
5 / 5 (1) Sep 03, 2014
Can anyone explain to me in very simple terms why the speed of light is considered to be the highest in the Universe?
I know it is said something like: as the speed increases, you need more and more energy to move mass, toward infinite energy; so you need infinite energy to move to the speed of light.
Why is that? Because the speed of light is finite, not infinite, therefore the energy needed to reach it should be also finite.
Can you tell me were am I wrong?
##### Jixo
2 / 5 (4) Sep 03, 2014
why the speed of light is considered to be the highest in the Universe?
It's easy, because we still didn't observe something faster. This limit is valid for dense aether model as well under condition, it deals with deterministically observable phenomena. We can observe faster phenomena, but their determinism would be violated.
you need infinite energy to move to the speed of light
It's because of special rules of velocity composition in relativity, but the water surface analogy of AWT illustrates it too. At the water surface we can perceive the speed of objects as the speed of surface ripples, which are spreading from it, not as the speed of objects as such (illustration, animation). Therefore the whole mystery of special relativity is, we are observing the phenomena with the waves of the same environment, which is forming these waves (and us).
##### mahi
1 / 5 (3) Sep 03, 2014
why the speed of light is considered to be the highest in the Universe?
It's easy, because we still didn't observe something faster.

Even if we observe a particle travelling faster than light, we take that as proof of time dilation delusion. So obviously no particle can travel faster than light.

http://debunkingr...y-mania/
##### Jixo
2 / 5 (4) Sep 03, 2014
For example the gravitational waves, scalar waves (dark matter particles) or sterile neutrino would propagate with superluminal speed. But from the same reason these particles don't travel through vacuum along continuous path. They're doing a quantum jumps: they disappear from our sight and they emerge somewhere else along path of motion. Therefore we cannot observe their motion in deterministic way, but rather as a sequence of particles, which are newly created during each jump. This apparent violation of special relativity would be constrained to very subtle and lightweight particles in addition. We would rather observe various dark matter effects at distance, which would be mediated with these particles. But even if some gravitational anomaly would arrive immediately during solar eclipse from Sun to Earth, it still wouldn't violate the special relativity, because we wouldn't see its spreading directly.
##### mahi
1 / 5 (2) Sep 04, 2014
For example the gravitational waves, scalar waves (dark matter particles) or sterile neutrino would propagate with superluminal speed. But from the same reason these particles don't travel through vacuum along continuous path. They're doing a quantum jumps: they disappear from our sight and they emerge somewhere else along path of motion. Therefore we cannot observe their motion in deterministic way, but rather as a sequence of particles, which are newly created during each jump ----- .

As if our scientists have personally followed the photons all along, and closely watched them travelling in 'continuous paths' and not doing the weird jumps!!!
By the way Jixo, why isn't that a photon experience the above weird phenomena and do such weird jumps as it travels?
Without such dual standards, I am sure relativity and quantum physics won't survive.
##### Da Schneib
5 / 5 (3) Sep 12, 2014
The redshift is confirmed by the supernova data.
I'm not talking about "redshift". I'm talking about the the "integral" used to "calculate" redshift, it has a limit set far too low for the size of a positively curved universe. Ever played around with one of those internet redshift calculators? That's what I'm talking about.
The Hubble Constant was measured by the Hubble Telescope. It's what it was built to do and why it was named after Hubble. This was a done deal decades ago. There's no integral in the Hubble Constant. It's in (m/s)/ly. What "integral" are you talking about? We have two sets of data confirming it; one is the supernova data, and the other is galaxy brightness. Are you claiming the same "integral" (you should actually say "integration") is used to calculate both?
##### Da Schneib
5 / 5 (1) Sep 12, 2014
And what would happen at infinity?
What's your procedure for getting to infinity?

Didn't intend to suggest that I had a procedure just more of a modus p.p. thought. From a conventional point of view if the universe is expanding and photon v is max then photons enter the expansion before (slower) matter; but would that suggest photons create the expansion?
No. Expansion started with the impetus of the Big Bang, but would have stopped billions of years ago if not for dark energy, which is accelerating the expansion. It couldn't do that before seven billion years ago because there wasn't enough space, and therefore not enough dark energy. After space had expanded that much, there was.

Would that continue to ∞ ?
We can never find out. ∞ is beyond the horizon.

contd
##### Da Schneib
5 / 5 (3) Sep 12, 2014
Another point that I'd like help with is that space is not a vacuum but apparently full of energy (not to mention DE & DM) so would this constitute a 'medium' in which photon v would be slower than in a true vacuum?
Not measurably. The matter is too thinly spread in open intergalactic or even interstellar space to interact much with the light, and this is what slows the light down. And DE and DM don't interact with light; if they did we would be able to see their signature on the light, and we don't.

Good questions, Mimath.
##### Da Schneib
5 / 5 (2) Sep 12, 2014
Time is merely a metric that we have created to order relative motions and interactions. The Wheeler-DeWitt Equation clears this up nicely.
Tell us more. 8D
##### Da Schneib
5 / 5 (3) Sep 12, 2014
Can anyone explain to me in very simple terms why the speed of light is considered to be the highest in the Universe?
Yes. It's due to the degree of curvature of the hyperbolic time dimension with respect to the three spatial dimensions.

Time and the three space dimensions are all symmetric; but the symmetry of the time dimension is not circular, like the space dimensions; it is hyperbolic. This is what SRT tells us.

I know it is said something like: as the speed increases, you need more and more energy to move mass, toward infinite energy; so you need infinite energy to move to the speed of light.
Why is that?
Because mass increases with velocity, and acceleration decreases with mass.

Because the speed of light is finite, not infinite, therefore the energy needed to reach it should be also finite.
The energy to reach it depends not on light but on matter, and matter increases its mass exponentially as speed approaches lightspeed.
##### Whydening Gyre
5 / 5 (1) Sep 12, 2014
Schneib,
You said way earlier in the thread;
"...the speed and the wavelength change, but the frequency does not."

Isn't wavelength the frequency?
(perhaps I'm "quantumizing" on a way too general level)
##### Whydening Gyre
5 / 5 (1) Sep 12, 2014
and - this thread reminds me of an old Cheech n Chong skit.

"...if you had a watch, you'd know it was night time. An' night time ain't NO time to be in this here neighborhood..."