# Parallel universes again

1. Dec 25, 2007

### hammertime

Hey, I have another question about parallel universes. Are they synchronized, chronologically? For example, does the sun die out at the same time (in parallel universes containing our solar system)?

2. Dec 25, 2007

### starkind

Hans Reichenbach, in his book The Philosophy of Space & Time (1958, tr Maria Reichenback and John Freund, currently available in paperback by Dover Press) seems to me to be saying that synchronization of clocks is a matter of definition. Your question, in this light, seems to me to lack meaning.

To see this, you might rephrase it in geometric terms. Consider two parallel lines. Is a point on one line in the same place as a point on the other line? The possiblility is excluded by definition, at least in Euclidian space.

Keep thinking.

R

3. Dec 25, 2007

### Gokul43201

Staff Emeritus
How would one compare times between two universes?

4. Dec 25, 2007

### Chronos

Universal time, Gokul? The problem with parallel universes is . . . they are parallel [produce no observables in 'our' universe]. If they do result in observables, they are [at least to that extent] a part of 'our' universe, hence not parallel, but intersecting universes [but may still have unobservable features]. So, show me the observables produced by intersecting universes.

5. Dec 26, 2007

### setAI

look at the edge of any shadow

6. Dec 8, 2010

### ccrummer

According to Hugh Everett III, a new universe is born whenever a quantum interaction occurs. Example: When a photon is projected at a 45° angle to a half-silvered mirror. In the Copenhagen interpretation one would say that there is a 50% chance it will reflect and a 50% chance it will go through. For Everett (and Deutsch) a new universe is formed and each alternative happens. In "our" universe the photon does one thing and in the other it does the other. As soon as we look at our result, we know for a certainty that the other happened in the other universe. This looks sort of like entanglement but it's not. (Please critique this. I'm just saying it.) Entanglement occurs, for example, when two electrons scatter. In the S-state, their spins will be anti-aligned after the scattering. Both electrons are in our (one) universe. If we make a detection of the spin of one of them, we know for sure that the other, wherever IN OUR UNIVERSE it may be and if it hasn't interacted with anything else after the scatter, will have it's spin in the other direction. Due to this entanglement interesting experiments may be done... IN OUR UNIVERSE. Deutsch ADDS to Everett's theory the assumption that the particles in different universes can interact. Can someone explain how this interaction can happen?

7. Dec 9, 2010

### 36grit

Well, I'm no physicist, but I do give these matters a lot of thought. Personally I like to think that parallel universes act indepentely of each other with the exception of a new universe created inside of an old universe. I think the new "big bang" would create a gravitaional wave, traveling at the speed of the new "time", that would absorb all of the old universe to the extent of the energy released. But, I guess that's kindof a weird and unusual theory. I probably should have just kept it to myself. But I know myself, I'll hit the reply button because I just can't help myself.
The truth, I have a feeling we're about to observe this very phenominon. The expansion of a new and tiny universe growing in our own.
If this does happen, I guess we'll have a coverse instead of a universe.

I wonder if anybody else shares my insanity.

8. Dec 9, 2010

### Kevin_Axion

This thread is 3 years old, I question why the original poster would care about your answer at this point. Anyways the post is very much appreciated.

9. Dec 10, 2010

### ccrummer

Everett's work didn't get noticed for a long time after he published his thesis either. In the Copenhagen interpretation of Quantum Mechanics questions about what REALLY happens are considered nonsensical. Since then there have appeared several ontologies, e.g. Bohm and Everett. You could pretty much pick the one you like since they made no contribution to the calculation of Quantum Mechanical effects. With Deutsch's addition of inter-universe interaction, out of whole cloth it would seem, some of these ontologies, at least, would be wrong, not up for grabs. This is a big deal. Does anyone out there besides me think that Deutsch is blowing smoke?

10. Dec 10, 2010

### ninjanik18

Alan Guth said whatever can happen does happen therefore making the amount of possibilities ∞ taking advantage of infinity, if there are ∞ possibilities I think that there may be universes which are not synchronized in time but universes 0.00001th of a second before or after,a universe 1 second before or after ours, a universe 1 minute before or after ours...etc then within this there may be parallel universes which are differentiated with physical possibilities.

(I dont know if this may be correct but its worth a try) an equation which may be able to explain this?

..∞.......∞
( Σ Vn )
n=1
ignore the dots i couldnt get them to stay in that position

ps im 15

Last edited: Dec 10, 2010
11. Dec 10, 2010

### ccrummer

Universes are spawned "when" a quantum transition happens. We only know about our universe (unless David Deutsch is right). I guess when a new universe is created it inherits the time from the universe it split from at the instant of splitting. Because some quantum transitions have possibilities from a continuum of results, the many worlds (Hugh Everett III) story would say that there are a continuum of universes. That means uncountable in the sense that they cannot be put into a one-to-one correspondence with the integers. Where are these universes? If they are in other dimensions then the number of dimensions must be uncountable. "Between" (what can that mean?) any two dimensions there must be an uncountable number of dimensions. It's hard for me to make any sense at all of this, and it has to make sense otherwise it's just a story like Harry Potter. I think it's important to distinguish stories from physical theories.

12. Dec 16, 2010

### Grimstone

No. Because they are not tied together. as you are a smart and nice person. on the other parallel world you might be opposite gender, short, mean, poor, or dead, or even not born at all.