# The Naked Scientists Forum

### Author Topic: What's the real speed limit of our universe?  (Read 10860 times)

#### lightarrow

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##### What's the real speed limit of our universe?
« Reply #25 on: 23/01/2009 13:24:54 »
Ah ok lightarrow lets see if I understand now its from the observers frame of reference not the spaceship or its crews frame of reference.I had it back the front.Yes?.

Cheers
what "its from the observers frame of reference" ?

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##### What's the real speed limit of our universe?
« Reply #26 on: 23/01/2009 13:43:50 »
To explain better: imagine that you and your friend are travelling with 2 equal starships in opposite directions; when you pass close to the other, you measure that his starship is shorter than your, even if they had the same lenght when still with respect to each other; in the same way, he measures that your starship is shorter than his.
When I observe his spaceship I am the observer and when he observes my ship he is the observer.
So from the observers point in each case the other persons spaceship would measure shorter.
Even though I might not be expressing it correctly I think I understand what you mean now.

Cheers

#### lightarrow

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##### What's the real speed limit of our universe?
« Reply #27 on: 23/01/2009 13:55:21 »
To explain better: imagine that you and your friend are travelling with 2 equal starships in opposite directions; when you pass close to the other, you measure that his starship is shorter than your, even if they had the same lenght when still with respect to each other; in the same way, he measures that your starship is shorter than his.
When I observe his spaceship I am the observer and when he observes my ship he is the observer.
So from the observers point in each case the other persons spaceship would measure shorter.
Even though I might not be expressing it correctly I think I understand what you mean now.

Cheers

Ok, however try not to use the word "observe" because it seems to imply that it's a kind of "optical illusion" while the fact is that you really *measure* that distance as shorter.

#### yor_on

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##### What's the real speed limit of our universe?
« Reply #28 on: 24/01/2009 01:53:40 »
Lightarrow, that is a very interesting thought.

If we define their length as seen from my 'galloping' spaceship at near 'c' from that frame seen, as being shorter.
And that the same would be true for all other frames 'distances'.

How would something 'living' 'moving' at that speed then see our universe?

As the universe is said to be 'bent' it could never come to any end, right?
And as 'time' for all other frames would be moving so much faster, the reference frames (if constantly taken by that object) would all be changed the next 'time' it would pass that same point, right?

So the universe would be seen to contain a lot of very small objects (suns and so forth:) that constantly was changing, but space would still be seen as being 'infinite'?

And what would happen when entropy had 'run out'?
Then it would be the only object still containing energy that could be transformed:)

And then distance is a measure of 'relative motion'.
So does it exist.

As if that velocity was almost :) at 'c'.

Where does 'distance' end, sort of.
And what is the 'relation' between distance, velocity, and gravity.
« Last Edit: 24/01/2009 02:02:29 by yor_on »

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##### What's the real speed limit of our universe?
« Reply #29 on: 24/01/2009 05:28:32 »
Thanks lightarrow
I just don't accept that about 300,000Km/s is the fastest anything can go in this vast universe.
A couple of billionKm/s maybe but 300,000 just seems way to slow.

Cheers

The laws of the universe don't care what you think.

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##### What's the real speed limit of our universe?
« Reply #30 on: 24/01/2009 12:56:39 »
The laws of the universe don't care what you think.
Or anyone else for that matter.

Cheers

#### Vern

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##### What's the real speed limit of our universe?
« Reply #31 on: 24/01/2009 13:53:47 »
Quote from: yor_on
As the universe is said to be 'bent' it could never come to any end, right?
And as 'time' for all other frames would be moving so much faster, the reference frames (if constantly taken by that object) would all be changed the next 'time' it would pass that same point, right?
We have to remember that the size reduction is not symmetrical. It only reduces in the direction of movement. So spheres would seem to become disks with dimensions perpendicular to movement undiminished. That is part of The Evidence that the universe is a photon-only construct.
Quote from the text:
Quote
Case Eight: No contraction perpendicular to direction of movement. A ball of photons, as in case five above, would not need to squeeze together in the direction perpendicular to movement to remain in the pattern. This is just as is predicted by the Lorentz transformations.

#### yor_on

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##### What's the real speed limit of our universe?
« Reply #32 on: 26/01/2009 22:03:04 »
It sure would make for a strange 'universe' though:)
Seeing that nothing stays the same I mean.

I wonder how they would explain it?

------

As I understand it they wouldn't have any 'gravity well' defined as they would be in a 'uniform motion' and not accelerating.

So 'Gravity' for them would be?
« Last Edit: 26/01/2009 22:06:58 by yor_on »

#### Vern

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##### What's the real speed limit of our universe?
« Reply #33 on: 26/01/2009 22:14:10 »
It sure would make for a strange 'universe' though:)
Seeing that nothing stays the same I mean.

I wonder how they would explain it?

------

As I understand it they wouldn't have any 'gravity well' defined as they would be in a 'uniform motion' and not accelerating.

So 'Gravity' for them would be?
I think the laws of physics would be the same, even if you were moving close to c. Stars might look like disks as you zipped past them

#### yor_on

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##### What's the real speed limit of our universe?
« Reply #34 on: 26/01/2009 22:23:35 »
Yes, you're right Vern.
But sometimes I can't help but wonder if there might be different ways to see the same 'results'.
And that goes back to how one look at things.

One could use acupuncture as a prime example for that.
In western society we use it mainly for pain relief.
In China they use it (or at least, used to use it) as a 'preventive' medical treatment.

Balancing your yin and yang as they saw/see it(?).
And for a lot of different 'permissive' medical treatments.

I mean, the way Einstein described our universe was rather new, wasn't it?

----
A thought, not a endorsement of yin and yang :)
I know all to little about that.
« Last Edit: 26/01/2009 22:28:40 by yor_on »

#### Vern

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##### What's the real speed limit of our universe?
« Reply #35 on: 26/01/2009 22:28:25 »
Quote from: yor_on
I mean, the way Einstein described our universe was rather new, wasn't it?
Yes; but not as new as many think; Lorentz and company had already published their transformation equations. Einstein derived those same equations by a different method. I like the Lorentz version of relativity better. It works in flat space-time.
« Last Edit: 26/01/2009 22:30:28 by Vern »

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##### What's the real speed limit of our universe?
« Reply #35 on: 26/01/2009 22:28:25 »