Do you believe the Universe is infinite?

[BlueBearBoots]

Nope

Incisive and succinct

I'm impressed

Damo will be along shortly to argue with my opinion :)


But I do agree that there doesn't have to be anything before the beginning because it was the beginning and what is there before the beginning?

 

[Damocles]

Damo said this earlier:

The speed of light in a vacuum has nothing special about it, it is just a substance that travels at the fastest possible velocity in the Universe. The fastest possible velocity would exist whether light travelled at that speed or not. Light just happens to have no mass thus travels at the speed limit. Basically the speed limit isn't light, light travels at the speed limit.

My question is what about entanglement? Because it would be much faster than "the speed limit" Or does this just not count as something "traveling"? This instantaneous effect.

One of the great things about physics is that sometimes the answer is as technical and scientific as it gets and other times the answer is as fun as

First thing to note here - the rule is that nothing that has mass can travel faster than light as the energy required to do would be infinite. Again there's nothing special about the constancy of the speed of light in a vacuum, it is just the maximum value where things of mass need an infinite amount of energy to accelerate them by a single m/s more as they theoretically hold an infinite mass (...sort of).

There is a rule that states that information cannot travel faster than the speed of light as then it would violate the law of causality as you could then receive a phone call before the other person actually rang you.

Quantum entanglement isn't a very well understood thing. There are a couple of decently supported hypotheses in terms of why what we see happens happens. However as it cannot be used to send any information then it doesn't violate relativity per se.

Basically entanglement is where you have a red and a black ball in a bag and then pick one out. If you pick out the red ball then the remaining ball HAS to be black, and vice versa. You can't actually send information in this way because the colours of the ball are predetermined and only by measuring one can you make any predictions about the other. But until you measure them both, they are of an unknown colour which just adds up to grey (do red + black = grey? Presume it does for arguments sake).

That's all it is really. You don't know which ball you're holding until you check the colour which then dictates that the other ball must be the other colour. Quantum entanglement is this over extremely large distances. It's a very interesting topic with lots of question marks about how this occurs but unfortunately not the time travelling spiritual stuff that many purveyors of woo make it out to be.

 

[BlueBearBoots]

Damo said this earlier:

The speed of light in a vacuum has nothing special about it, it is just a substance that travels at the fastest possible velocity in the Universe. The fastest possible velocity would exist whether light travelled at that speed or not. Light just happens to have no mass thus travels at the speed limit. Basically the speed limit isn't light, light travels at the speed limit.

My question is what about entanglement? Because it would be much faster than "the speed limit" Or does this just not count as something "traveling"? This instantaneous effect.

One of the great things about physics is that sometimes the answer is as technical and scientific as it gets and other times the answer is as fun as

First thing to note here - the rule is that nothing that has mass can travel faster than light as the energy required to do would be infinite. Again there's nothing special about the constancy of the speed of light in a vacuum, it is just the maximum value where things of mass need an infinite amount of energy to accelerate them by a single m/s more as they theoretically hold an infinite mass (...sort of).


So we don't know the answer to various puzzles, questions until we know at least one then we can maybe work out the rest? A bit like sudoku?
There is a rule that states that information cannot travel faster than the speed of light as then it would violate the law of causality as you could then receive a phone call before the other person actually rang you.

Quantum entanglement isn't a very well understood thing. There are a couple of decently supported hypotheses in terms of why what we see happens happens. However as it cannot be used to send any information then it doesn't violate relativity per se.

Basically entanglement is where you have a red and a black ball in a bag and then pick one out. If you pick out the red ball then the remaining ball HAS to be black, and vice versa. You can't actually send information in this way because the colours of the ball are predetermined and only by measuring one can you make any predictions about the other. But until you measure them both, they are of an unknown colour which just adds up to grey (do red + black = grey? Presume it does for arguments sake).

That's all it is really. You don't know which ball you're holding until you check the colour which then dictates that the other ball must be the other colour. Quantum entanglement is this over extremely large distances. It's a very interesting topic with lots of question marks about how this occurs but unfortunately not the time travelling spiritual stuff that many purveyors of woo make it out to be.

 

[Damocles]

Just to add a bit to that analogy.

When you have a bag of a red and black snooker ball, you don't know either colour of them. In fact you could suggest that they are in what is called a "superposition" of states where the balls are neither red or back until you measure them and all you know is that the whole bag together adds up to grey (or whatever red+black is).

Now if you close your eyes and pull out one of the snooker balls, the bag's contents have definitely changed but you don't know which ball you have in your hand because your eyes are shut. In this case you could say that the ball in your hand has a 50% probability of being red and 50% probability of being black. From this you can also infer that the bag's "colour" is no longer grey but either red or black. Again you cannot tell which of these they are without opening your eyes.

As soon as you open your eyes you can see that your ball is red and then can infer that the contents of the bag are then black. But you cannot confirm this until you ask your mate what the colour of the other ball is. You see no information actually travels faster than light, only the inference based on probabilities which then has to be confirmed via slower than light methods such as asking somebody.

Unfortunately when you try to make an analogy to explain anything at all you do lose some of the accuracy and the finer points of the idea but that's a broad strokes explanation of it.

 

[whp.blue]

Damo said this earlier:

The speed of light in a vacuum has nothing special about it, it is just a substance that travels at the fastest possible velocity in the Universe. The fastest possible velocity would exist whether light travelled at that speed or not. Light just happens to have no mass thus travels at the speed limit. Basically the speed limit isn't light, light travels at the speed limit.

My question is what about entanglement? Because it would be much faster than "the speed limit" Or does this just not count as something "traveling"? This instantaneous effect.

One of the great things about physics is that sometimes the answer is as technical and scientific as it gets and other times the answer is as fun as

First thing to note here - the rule is that nothing that has mass can travel faster than light as the energy required to do would be infinite. Again there's nothing special about the constancy of the speed of light in a vacuum, it is just the maximum value where things of mass need an infinite amount of energy to accelerate them by a single m/s more as they theoretically hold an infinite mass (...sort of).

There is a rule that states that information cannot travel faster than the speed of light as then it would violate the law of causality as you could then receive a phone call before the other person actually rang you.

Quantum entanglement isn't a very well understood thing. There are a couple of decently supported hypotheses in terms of why what we see happens happens. However as it cannot be used to send any information then it doesn't violate relativity per se.

Basically entanglement is where you have a red and a black ball in a bag and then pick one out. If you pick out the red ball then the remaining ball HAS to be black, and vice versa. You can't actually send information in this way because the colours of the ball are predetermined and only by measuring one can you make any predictions about the other. But until you measure them both, they are of an unknown colour which just adds up to grey (do red + black = grey? Presume it does for arguments sake).

That's all it is really. You don't know which ball you're holding until you check the colour which then dictates that the other ball must be the other colour. Quantum entanglement is this over extremely large distances. It's a very interesting topic with lots of question marks about how this occurs but unfortunately not the time travelling spiritual stuff that many purveyors of woo make it out to be.

Isn't that the Einstein argument of things were pre determined that has now been disproved ?

I can't believe I just wrote that BTW

 

[Damocles]

So we don't know the answer to various puzzles, questions until we know at least one then we can maybe work out the rest? A bit like sudoku?

Quantum entanglement being like sudoku is actually ten times smarter as an analogy than anything that I've said. In fact it's so genius that I'm stealing it from now on. Yes it's exactly like that in that you can infer the numbers in the box based on your knowledge of the total box (and the numbers in it) but cannot confirm it independently until you can accurately measure other boxes.

 

[BlueBearBoots]

So we don't know the answer to various puzzles, questions until we know at least one then we can maybe work out the rest? A bit like sudoku?

Quantum entanglement being like sudoku is actually ten times smarter as an analogy than anything that I've said. In fact it's so genius that I'm stealing it from now on. Yes it's exactly like that in that you can infer the numbers in the box based on your knowledge of the total box (and the numbers in it) but cannot confirm it independently until you can accurately measure other boxes.

But isn't that just science anyway? Or physics? We know the answer definitely to one thing and can work out the rest based on that rule?


Or you are just being sarcastic and if so I'm not playing anymore

 

[Damocles]

Isn't that the Einstein argument of things were pre determined that has now been disproved ?

Just a bad phrasing unfortunately. Einstein believed that there was hidden information that determined the colour of the balls which was always retained over long distances. We now know that this isn't true, it's just that the existing information can infer other information from the same system.

Unfortunately it's a bit more mundane as a topic than it sounds, I just can't find the right analogy for it.

Sudoku is a better one. Let's say that you have a completed Sudoku board with each line and box marked as "complete", if one number from one of the boxes "flies away" and marks the box "incomplete" then you can then infer that several other boxes will be marked as "incomplete".

If you have an entangled particle system and you destroy that system by measuring particle with an up spin then you can infer that the other entangled particle will have down spin. But you can't actually change what the spin is yourself of the escaping particle, only measure it which is why no information is travelling faster than light

 

[Damocles]

But isn't that just science anyway? Or physics? We know the answer definitely to one thing and can work out the rest based on that rule?
Or you are just being sarcastic and if so I'm not playing anymore

No I'm serious. The problem with trying to describe this is that entangled particles are a system of essentially random numbers that are ordered. When one of those random numbers escapes then the complete system is collapsed and you can know information about the rest of it based on the escaped particle if communicating with other observers. But each observer just sees a random number escaping.

The thing that appeals to me is that Sudoku is a game where people fully understand the idea of inter-connectivity and inference based on other information in each "system" like a box or a line.

It is how much of physics works. As I said, quantum entanglement is a little more mundane than others make it out on TV and the like. It's still fairly interesting though as we aren't sure of the details of how all of this works - the total value of the "system" doesn't seem to be pre-determined and instead the "collapse" of one part of it seems to determine the values of other parts.

 

[TangerineSteve17]

<a class="postlink" href="http://www.hawking.org.uk/does-god-play-dice.html" onclick="window.open(this.href);return false;">http://www.hawking.org.uk/does-god-play-dice.html</a>

I'll drop this here, I found it an interesting read, yet the outcome quite grim in a way.