1. How did they prove that Universe doesn't know the outcome of a random experiment until we actually observe it?
This is like saying that nothing exist beyond our field of view?

2. Originally Posted by MaxPayne
How did they prove that Universe doesn't know the outcome of a random experiment until we actually observe it?
This is like saying that nothing exist beyond our field of view?
The statements are not logically equivalent. The first is about looking ahead in time. The second is about seeing things not in our field of view.

3. I've often wondered how lightening finds the fastest route to the ground....if that's not planned in advance what is?

4. Originally Posted by Jilan
I've often wondered how lightening finds the fastest route to the ground....if that's not planned in advance what is?
Various paths are explored until one reaches the ground.
Lightning captured at 7,207 images per second - YouTube

5. An amazing video, many thanks.

6. Originally Posted by mathman
The statements are not logically equivalent. The first is about looking ahead in time. The second is about seeing things not in our field of view.
Yes, so true!
What i meant was that "the universe doesn't know hence the event or it's aftermath doesn't happen unless we detect it through our senses".
If no one is around to watch something will that something ever happen?

7. Originally Posted by MaxPayne
If no one is around to watch something will that something ever happen?
You are referring to the notion of "counterfactual (in)definiteness". Counterfactual definiteness is something that we tend to assume, but in fact there can never be any evidence of it (because any observation that attempts to confirm counterfactual definiteness invalidates it). However, it should be stressed that even an indirect observation is sufficient as an observation with regards to counterfactual definiteness, thus indirect observations cannot confirm counterfactual definiteness. Bell's theorem says that quantum mechanics cannot be both local and counterfactually definite. However, since counterfactual definiteness is only an assumption, I see no reason to maintain that quantum mechanics is counterfactually definite.

8. I don't think you need to observe it. Schroedingers cat is alive or dead whether you open the box or not. It is the importance of having a boundry condition that allows an entropy increase in the system. Once the interaction takes place it becomes irreversible and the system changes whether you look at it or not.

9. Originally Posted by MaxPayne
Yes, so true!
What i meant was that "the universe doesn't know hence the event or it's aftermath doesn't happen unless we detect it through our senses".
If no one is around to watch something will that something ever happen?
Or more aptly, if a tree falls in the woods and no one is around to hear it (observe it) does it make a sound (does the super state become deterministic).

10. Originally Posted by Bergitor
Or more aptly, if a tree falls in the woods and no one is around to hear it (observe it) does it make a sound (does the super state become deterministic).
No, there is a difference between a real tree and a tree at quantum level. Relative determinism in the physical world is only a by product of high probability at quantum level.

The example of cat is different...the cat actually has a state which is highly probabilistic in nature, since it's state directly depends on a quantum process.

11. I don't think you need to observe it. Schrodinger cat is alive or dead whether you open the box or not. It is the importance of having a boundary condition that allows an entropy increase in the system. Once the interaction takes place it becomes irreversible and the system changes whether you look at it or not.
Cat will only know if it's alive only if it's alive. So it doesn't call the shots here.

Boundary condition??? That argument is only given to divert our attention from the inexplicable.
The boundary conditions are defined such that the cat would be dead if the process did happen.

12. Originally Posted by MaxPayne
Cat will only know if it's alive only if it's alive. So it doesn't call the shots here.

Boundary condition??? That argument is only given to divert our attention from the inexplicable.
The boundary conditions are defined such that the cat would be dead if the process did happen.
No, I think a forensic scientist would be able to establish pretty accurately the time of death from the temperature of said dead cat. What I mean by boundry condition is a condition in time that cannot be changed once it has occurred. The process becomes irreversible from that point on.

13. Originally Posted by Jilan
No, I think a forensic scientist would be able to establish pretty accurately the time of death from the temperature of said dead cat.
Hey, no one said that cat dies when you see it's dead body personally. Since it is quantum process the cat's reality becomes entangled with the process. It's the reality that changes when we look. hence the saying "mere observation can change the outcome of an experiment".

What I mean by boundary condition is a condition in time that cannot be changed once it has occurred.The process becomes irreversible from that point on.

14. Originally Posted by MaxPayne
Hey, no one said that cat dies when you see it's dead body personally. Since it is quantum process the cat's reality becomes entangled with the process. It's the reality that changes when we look. hence the saying "mere observation can change the outcome of an experiment":
So you believe in magic then?

15. Maybe we don't understand reality completely.

16. Originally Posted by MaxPayne
Maybe we don't understand reality completely.
Maybe that's true, but generally it's accepted that it's not the power of observation that makes the difference between the quantum and non quantum world. It the interaction with the world at large. If there is an increase in entropy that's it... time equals zero again and there is no going back.

17. Originally Posted by Jilan
Maybe that's true, but generally it's accepted that it's not the power of observation that makes the difference between the quantum and non quantum world. It the interaction with the world at large. If there is an increase in entropy that's it... time equals zero again and there is no going back.
So how do you explain spooky action at a distance? Magic?
I think we can change a past event if we haven't observed that event yet. Different observers can have different notions of time and sequence of events in a process. Regardless of this each one should observe the same result. I mean any unobserved event is not a real event but a probabilistic one. Anything thats recorded in history can't be changed, because the events have been observed by an observer or a group of observers.

18. Originally Posted by MaxPayne
I think we can change a past event if we haven't observed that event yet. Different observers can have different notions of time and sequence of events in a process. Regardless of this each one should observe the same result. I mean any unobserved event is not a real event but a probabilistic one. Anything thats recorded in history can't be changed, because the events have been observed by an observer or a group of observers.
In so far as the evolution of the system remains reversible then I would agree with you. But I don't agree that you need observers to record an event. A piece of photographic film or a dead cat will do just as well..... Unless of course you take the Many Worlds view. The consequence of that that is that you as an observer would need to tell someone about it or you would just become part of the superposition like the cat and it would still be undecided. In fact until you had told everyone in the universe you could never be sure!

19. Originally Posted by MaxPayne
So how do you explain spooky action at a distance? Magic?
Well it does appear as a type of magic to us non QM entities! I expect the answer will be related to the way quantum tunnelling is explained which is another type of spooky thing (as in going though walls.)

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