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Dark Energy......Or Slowing Time?

01/09/2008 1:03 PM

Here's an interesting article speculating that the apparent acceleration of the expansion of the universe could in fact be a result of time "slowing down". I'm not sure how I feel about this other than I hope someone figures this stuff out in my lifetime. Here is the article:

http://blog.wired.com/wiredscience/2007/12/scientists-time.html

Scientists: Time Itself May Be Slowing Down

By John Borland; December 28, 2007

For a decade, scientists have puzzled over a surprising phenomenon: Supernovae stars viewed at extreme distances seem to be moving away from us faster than those nearby.

Most researchers have assumed that the stars have somehow accelerated – or that, more precisely, the rate of the expansion of the post-Big Bang universe itself has accelerated over time.

This was particularly odd given that the universe was thought to be dominated by matter, which should, through the aggregate gravitational effect of each bit pulling on the others, have led to a decelerating expansion, rather than the opposite. Thus, scientists have postulated an unknown kind of energy, now known as "dark energy," which would be responsible for the acceleration.

But hold on just a minute.

A group of scientists from the University of the Basque Country in Bilbao, and Spain's University of Salamanca have offered a different idea. Maybe it's the passage of time itself that's slowing down, they say. The distant galaxies only look like they're accelerating because our deep-space telescopes are essentially looking back in time to see them, to when time was going faster.

The theory, outlined in the New Scientist and the UK Telegraph, and in a paper published in Physical Review D, is based on a complex bit of string theory that remains entirely speculative today. Under this theory, our entire universe is embedded in a multidimensional "brane," which itself is floating through a higher dimensional space that we can't detect.

Naturally, the theory has a few chilling conclusions. If time is slowing, it could – in billions of years – actually come to a complete halt, University of the Basque Country professor José Senovilla told New Scientist.

Would that mean everything freezes in place forever? Apparently. Does forever mean anything if time itself has literally stopped? Pass...

In short, a brain twister. Of course, there's a catch, which Senovilla says his group hasn't yet considered. Another group of physicists has postulated that there may actually be two dimensions of time, rather than just one we all know and fear. Which would explain where all that lost time goes, I suppose.

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#1

Re: Dark Energy......Or Slowing Time?

01/09/2008 4:08 PM

Now that makes sense. I know I've been slowing down as I've gotten older so why not the universe.

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#19
In reply to #1

Re: Dark Energy......Or Slowing Time?

01/10/2008 11:29 AM

Irving wrote: "Now that makes sense. I know I've been slowing down as I've gotten older so why not the universe."

No, no, I disagree! Time passed very slowly when I was two or three - think how long it was from one birthday present to the next...

Now that I'm old, time passes more quickly, too quickly...

So those scientists have it the wrong way round!

Jorrie

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#24
In reply to #19

Re: Dark Energy......Or Slowing Time?

01/11/2008 12:03 PM

Jorrie, I'm the old guy who loves Cosmology like you!

I totally agree! Things just didn't happen fast enough until I was twenty-one. Then holy mackerel by 63 (Now) they're flat whizzing by at an alarming rate.

Hey, "time warp by age" lets work on a theory for that! I have the song "Time Ain't On My Side"! We need to live in a black hole where time stands almost still and just evaporate into dark matter. Sounds like a way to be in the mix forever.

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#25
In reply to #19

Re: Dark Energy......Or Slowing Time?

01/11/2008 1:56 PM

So is this just a perspective thing? I agree time seemed to move slower when I was younger too but was that because I was moving faster? Now that I'm older and have slowed down maybe time just seems to be moving more quickly.

But I like your perspective better I think, its not me slowing down its time going faster so I'm okay. Also if time is going faster that means I'm not falling into a black hole so that's good too. Something else to celebrate.

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#2

Re: Dark Energy......Or Slowing Time?

01/09/2008 5:01 PM

Very interesting. When you think that time, as we know it is measured in the amount of time it takes the earth to revolve around the sun, and further broken down by counting the number of times the earth spins, (days) you can stretch this out to think if the earth stopped rotating... would my watch stop?

Better yet, would my wife stop nagging me?

Would my boss not pay me because I never completed the days work?

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#3
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Re: Dark Energy......Or Slowing Time?

01/09/2008 5:30 PM

... would my watch stop? -Yes

Better yet, would my wife stop nagging me? - Keep dreaming!

Would my boss not pay me because I never completed the days work? -No he wouldn't, but thats OK because the bills would never arrive in the mail!

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#4

Re: Dark Energy......Or Slowing Time?

01/09/2008 5:39 PM

Hello Roger Pink

The problem goes back further than we think.

The interpretation of time as being something which passes, is incorrect.

When I get an opportunity, I shall post what I am sure time really is.

Kind Regards....

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#7
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Re: Dark Energy......Or Slowing Time?

01/09/2008 11:14 PM

Hi Sparkstation:

"When I get an opportunity, I shall post what I am sure time really is."

There is no time like the present and the link to start a discussion it at the top right hand corner of this page.

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#9
In reply to #4

Re: Dark Energy......Or Slowing Time?

01/10/2008 1:52 AM

What? A sort of fizzy drink that uses Nutra-Sweet instead of neutrinos?

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#15
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Re: Dark Energy......Or Slowing Time?

01/10/2008 10:02 AM

Hi Sparkstation,


Thanks just not fair leaving us hanging with a comment like that.

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#5

Re: Dark Energy......Or Slowing Time?

01/09/2008 5:44 PM

If time is slowing down, how about the other dimensions? Could we ever know if everything is shrinking (locally)? Would it matter? (no pun intended).

(I haven't yet followed the link, so I'm sorry if I'm re-stating anything I've missed).

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#6

Re: Dark Energy......Or Slowing Time?

01/09/2008 8:00 PM

Where is Case when you need him........ I have experienced the ebb and flow of time way back in the days of my youth while listening to this:

http://www.youtube.com/watch?v=ntm1YfehK7U

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#8
In reply to #6

Re: Dark Energy......Or Slowing Time?

01/10/2008 12:01 AM

Time is an illusion. Just as words are illusions. Everything is an illusion. And we are left wondering: 'How did he do that?' I saw his hand move and I knew it was a trick, but I chose to ignore the facts. Now I have to agree with the whole act, or realise that I'm as stupid as everyone else. The truth will set you free, but that way lies madness.

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#10

Re: Dark Energy......Or Slowing Time?

01/10/2008 4:33 AM

It's time to bring in 'Jorrie' for help on this one, that's for certain.

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#20
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Re: Dark Energy......Or Slowing Time?

01/10/2008 11:34 AM

Hi PWS, "It's time to bring in 'Jorrie' for help on this one, that's for certain. "

Will have to read that paper first... If only time was not so fast... Sigh!

Jorrie

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#11

Re: Dark Energy......Or Slowing Time?

01/10/2008 4:49 AM

Hi Roger... First of all let's clarify a couple of things...

You said:"For a decade, scientists have puzzled over a surprising phenomenon: Supernovae stars viewed at extreme distances seem to be moving away from us faster than those nearby."... Well, this shows just an expansion of the space and not an accelerated expansion... Even with a stable rate of expansion (or even with a slightly decelarated expansion) over time, it's obvious that the faraway objects are moving away (from us) faster than the nearby objects... What the scientists observed (a decade ago) is that the Supernovae stars viewed at extreme distances seem to be moving away from us at a slower rate than it was expected... This shows that the "velocity" of the expansion of the Universe many billions years ago (faraway objects, i.e. those Supernovae) was smaller than it was supposed to be (by looking the "velocity" of the expansion at recent times, e.g. the velocity of the departure of the nearby objects)... So, we come to a conclusion that in the "far past" the expansion of the Universe was decelerated as opposed to the "near past" (and present time) where the expansion seems to be accelerated...

Apparently, this group of scientists in Bilbao say that as we observe the Universe in the "far past" it seems that is "moving slower" because the time is "running faster" (although its "velocity" maybe really high)... It seems, though, that there isn't a continuity in the evolution of the Universe... A change happened somewhere around (I think) 10 billion years ago... The expansion (initialy decelarated) became accelerated... If the "velocity" of the expansion is stable (or always decelarated) then this change must be took place in the behaviour of the "time" (I mean that we could consider that in the "far past" the time was "accelerated" and, nowadays, is "decelarated"... whatever this means...)... Anyway, I think that we, simply, transfer the problem of the "change of the status of the expansion": we transfer this problem from "space" to "time"...

Maybe, Jorrie could help a little bit here...

(By the way, where is Jorrie???... He has not posted anything for a long time...)

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#23
In reply to #11

Re: Dark Energy......Or Slowing Time?

01/11/2008 12:26 AM

Hi George, still around, just busy with some research work that zaps the energy!

You wrote: "What the scientists observed (a decade ago) is that the Supernovae stars viewed at extreme distances seem to be moving away from us at a slower rate than it was expected... "

Indirectly, you are right, but the direct observation that caused the issue was that those distant SN1ae were farther away than what they should have been, given their redshift. This can be "inverted" to read as you said, but I prefer the latter, because there was a time very shortly after the BB where the recession speeds of those regions were extremely fast, dark energy or no dark energy. The graph that I mentioned in reply to Roger illustrates this reasonably well.

Jorrie

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#12

Re: Dark Energy......Or Slowing Time?

01/10/2008 6:15 AM

Dear Roger,

I would like to offer my thought though I am not an expert in this field.

After the event of BigBang, if we imagine that stars and stellar matter started moving in all directions from the origin, then those stars movinng in the same direction as ours may appear moving slower as compared to the one which is moving in the opposite direction. Stars which are moving in the same or nearlysame direction as ours will appear slower compared to the one moving opposite eventhough their absolute velocities may be same. All the stars in our direction will remain relatively closer compared to the one moving in the opposite direction.

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#13
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Re: Dark Energy......Or Slowing Time?

01/10/2008 6:51 AM

Hi K.V.... I would like to remind you that the matter didn't derive and expand from an origin in the space (B.B.)... The space itself has derived and expanded with the B.B.... So, everything in the Universe is departed from everything else... (of course there are some exceptions... for example two galaxies may approach each other, like our Galaxy and Andromeda... but this is a "local" phenomeno... as I said, as an "average", everything is departed from everything else in a cosmic scale...)

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#16
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Re: Dark Energy......Or Slowing Time?

01/10/2008 10:05 AM

Hi G.K, Thanks for your comment. I understand that everything including space and time had the beginning at that moment [B B] and started expanding.But expansion taking place in two opposite direction should have higher speed than the one in the same direction.

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#18
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Re: Dark Energy......Or Slowing Time?

01/10/2008 11:23 AM

K.V. you said: "But expansion taking place in two opposite direction should have higher speed than the one in the same direction."... Again, you consider the origin of BB ( hence the creation and expansion of the matter, energy, space & time) into the space... The BB didn't happen somewhere into the space... The BB happened outside the space (as there were no space before the BB) creating the space itself... Another way to express this, is to consider that the expansion (of the space) is taking place in relation with a point (origin) not inside our space but "outside" our space (whatever this "outside" means)... A way to visualise (and probably understand) this is the expansion of a balloon... the expansion of its surphase is taking place in relation with the centre of the sphere-balloon, e.g. a point outside the surphase of the balloon... if you "live" on a point of the surphase of this balloon, you see all the other points around you to move away from you (as the surphase is expanded)... and, on all sides, every other point which has the same distance from you, is departed (away from you) with the same velocity... (no point of the surphase could be considered as the origin of the expansion... or, alternatively, every point of the surphase could be considered as the origin of the expansion... But, actually, both considerations are wrong, as the real origin of the expansion is the centre of the sphere...) The same happens when you observe the Universe around you: on all sides, every star, which has the same distance from you, is departed (away from you) with the same velocity... on all sides, the rate of the expansion is the same...

I hope that I helped you...

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#22
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Re: Dark Energy......Or Slowing Time?

01/10/2008 11:44 PM

Yes, G.K, Your explanation is great. Thanks a lot.

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#17
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Re: Dark Energy......Or Slowing Time?

01/10/2008 11:00 AM

Absolutely! I could not agree more. (though I would hope that something so obvious had already been considered)

Considering how short of a time (cosmically speaking) we have been observing the stars with any measurable precision (especially those at extreme distance), how much confidence can we have in the direction that we think these stars and galaxies are going in?

We all know that speed away from you can be figured from the red shift of the emitted light.

For the sake of argument, assume you are not moving and are looking in a given direction.

There are two stars, both moving with speed S (scalar quantity, not velocity which is a vector quantity) from the same starting point.

One moves directly away from you, the other is moving from right to left across you field of vision.

They both have the same speed relative to their starting point (but different velocities as they are moving in different directions), and so have the same red shift when viewed from that starting point.

From our observation point the one moving directly away from us will have a higher red shift than the one moving across our field of view, because their differences in direction relative to OUR observation point makes them appear to be moving at different speeds (relative to OUR observation point).

The end result is that the one that is further away seems to be moving faster than the one that is closer.

Because light travels at a finite speed, when we look at things far away, we cannot help but be looking back in time.

From the example above, when you do this, you see objects far away (both physically and in time) to be moving faster than objects that are close (both physically and in time)

So from the observation that distant objects have a higher red shift, it would seem like a reasonable assumption to say that in the past, things moved faster.

Seems reasonable, but is, in fact, dead wrong. Its an illusion based on OUR observing position.

Albert E strikes again, everything is relative. There is no need to mess with slowing time, though I do admire the "out of the box" thinking that would lead someone to propose such a concept.

Then again, I could be wrong.........

IPG

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#14

Re: Dark Energy......Or Slowing Time?

01/10/2008 8:46 AM

I never studied cosmology in any detail, but I get the impression that spacial (x,y,z) and time (c.t) coordinates are considered symmetrical in their properties. That is, there is no reason why one dimension has to be treated in any other way in the cosmological sense. If I'm wrong please correct me.

Given this, an idea (maybe stupid) crossed my mind now: why shouldn't we consider any of the four dimensions as liable to change - that is, even time can be affected - by dark energy or whatever other mysterious cause? To go even further, what if it isn't the scale factor of a dimension that changes, but there is in fact a rotation of the 4D reference system? In such a case, imagine an event in space-time mixing/exchanging some part of its spacial coordinates with time coordinates and vice versa, according to some rotation transformation. If someone elaborates more on this, could possibly be able to describe inflation and generally expansion as such a reference system transformation.

It sounds absurd at first (even to me!), but I cannot see why this is more absurd than proposing a change of the scale of the three spacial dimensions. At least in the latter approach, one has the extra burden to explain why that mysterious dark energy affects solely the spacial dimensions and not time.

But I must certainly be missing something here... Any idea?

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#21

Re: Dark Energy......Or Slowing Time?

01/10/2008 9:04 PM

Hi Roger.

I haven't read the paper yet, just the articles. The one you quoted from starts off on a false note, so it is not very promising: "For a decade, scientists have puzzled over a surprising phenomenon: Supernovae stars viewed at extreme distances seem to be moving away from us faster than those nearby."

This is standard, pre-1998 cosmology. What changed in 1998 is that the distant supernovae seem to be farther than they should be, because the nearer by universe (which is also the most recent) expands too fast! This sounds like a contradiction, but isn't. It is best seen in a curve like the one I plotted in my Blog on 'Cosmic Clocks' here.

There are a whole bunch of recent papers out there, some trying to explain the supernovae data by means of dark energy (cosmological constant) and some trying to fiddle with time to eliminate dark energy. This particular one that you referenced sounds a bit like the "tired light" hypothesis, only here it is "tired time".

Without reading the paper, I fail to understand the mechanism, because, like the quoted opening statement, it sounds wrong. It is the later universe that apparently expands faster, not the earlier one. With 'slowing time', we should have observed a totally different expansion curve than what we do.

Anyway, let's wait for the paper to become available...

Jorrie

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#26
In reply to #21

Re: Dark Energy......Or Slowing Time?

01/11/2008 7:20 PM

Good point Jorrie. I posted it more as a curiousity, and I wanted to hear your take on it. If I remember, I'll try to post the actual paper later on to see if this is bad journalism or bad science.

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#27
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Re: Dark Energy......Or Slowing Time?

01/11/2008 7:51 PM

Hi Jorrie,

I have a sincere question from an obvious novice.

I was reading an article in Scientific American, Dec. 2007, pg 61 regarding the "extreme universe".

Here's a short excerpt that I would like to ask you about:

"Historically, large leaps in measurement capability have often revealed unanticipated featues of nature, For instance, CGRO observed a very odd phenomenon in 1994. Seventy-five minutes after the onset of a gamma ray burst, the satelite detected a lone gamma photon with a whopping energy of 18 GeV, the most energetic gamma ever seen from a burst, Theorists have speculated ever since about what this event says about the physics of bursts."

My question is, how does one determine that a photon is singular? For that matter, how does one know exactly how many photons are in a source?

This is probably quite off topic but I'm really curious about this aspect of photons.

Thanks,

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#28
In reply to #27

Re: Dark Energy......Or Slowing Time?

01/11/2008 11:44 PM

Hi John, you wrote:

"My question is, how does one determine that a photon is singular? For that matter, how does one know exactly how many photons are in a source?"

AFAIK, it comes from the energy quantum of the single photon, which is hc/λ, where λ is the wavelength of the light you detect and hc is constant. You will find that for a specific λ, the energy can only go up in integer numbers of hc/λ, i.e. hc/λ, 2hc/λ, 3hc/λ, etc.

That way it is possible to count the number of photons (energy packets). This may be oversimplified, but I don't know more about it anyway...

Jorrie

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#29
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Re: Dark Energy......Or Slowing Time?

01/12/2008 8:07 AM

Thanks Jorrie.

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#32
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Re: Dark Energy......Or Slowing Time?

01/18/2008 4:11 PM

Hi Jorrie,

Let's see If I have understood what you said in your 'Cosmic Clocks' link. Is David Wilshire saying that our clocks are slowing because the gravity in our area is increasing relative to 'empty space', resulting in an illusion that the universe is expanding (because gravity slows time)? If so, might it be because the galaxy is accumulating matter, and the local group is coming together?

S

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#33
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Re: Dark Energy......Or Slowing Time?

01/18/2008 4:59 PM

In other words, our neigborhood of the universe is shrinking, rather than the rest of it expanding. Or, we are falling in to the black hole at the center of the Milky Way. Everything in our immediate vicinity is falling into the black hole at the same rate as we are, so we perceive our neighborhood as being dimensionally stable...? I think this is easier to cope with than the concept of an expanding universe and dark energy...

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#34
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Re: Dark Energy......Or Slowing Time?

01/18/2008 6:31 PM

This kinda harks back to my post #4, which I said more-or-less in jest.

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#35
In reply to #33

Re: Dark Energy......Or Slowing Time?

01/19/2008 12:44 AM

Uh, never mind, guys. Turns out someone forgot to wind the atomic clock.

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#36
In reply to #32

Re: Dark Energy......Or Slowing Time?

01/19/2008 12:48 AM

Hi S, you asked:

"Is David Wilshire saying that our clocks are slowing because the gravity in our area is increasing relative to 'empty space', resulting in an illusion that the universe is expanding (because gravity slows time)?"

Essentially yes. He reckons that most of the universe is empty (the voids) and there time must pass faster than here. He then modeled this and found that it looks very much like the apparent accelerating expansion that is observed. Wiltshire does however concede that the effect is not large enough to match observations.

"If so, might it be because the galaxy is accumulating matter, and the local group is coming together?"

AFAIK, only a few galaxies in our vicinity are approaching us. The outer dwarf galaxies of our local group are moving away from us a-la the Hubble flow. However, the whole local super-cluster still seems to be contracting, which may simply mean that the peculiar movements are larger than the Hubble expansion at these 'smallish' ranges. The Hubble flow positively dominates at ranges much larger than our Virgo supercluster.

The pesky Dark Energy explains such a large range of observations that I think only a modification of gravitation theory could fully take it away...

Jorrie

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#37
In reply to #36

Re: Dark Energy......Or Slowing Time?

01/19/2008 12:56 AM

Hi, Jorrie,

Did you hear about the honking big cloud of gas that's supposed to collide with our galaxy in about a million years. I think they said the cloud was about 11 light-years from us, and would cause a new, and intense period of stellar formation.

Also, if you got a minute, go check for my new thread, "The Back of my Head." I think you'll find it interesting!

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#30

Re: Dark Energy......Or Slowing Time?

01/12/2008 11:43 AM

Hi Roger,

I think they are grasping at straws. As other people have said, this doesn't explain why the rate changed a few billion years ago. I have wondered, though if the rate of time is linear. There is no good reason to believe it is. For some time I have wondered if the expansion of the universe causes time to pass. Come on Sparkstation, show us what you have!

I would like to hear more about what prompted the 2 dimensions of time theory.

S

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#31
In reply to #30

Re: Dark Energy......Or Slowing Time?

01/14/2008 2:34 AM

In Relativity, one learns that these mystical things called space and time are inextricably linked!

Time is measured using space and space is measured using time... What an entanglement!!!

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