Time before the Big Bang?: evidence.

Originally posted by @fabianfnas
I'm still waiting for the explanation why you synonymize 'when' and 'where'.
Don't bring up Lorentz, because this is way out of context.

I do recognize your knowledge about science.
But when it comes to explaining things, your not so good.

I provided a perfect explanation, you keep dismissing the important part. The Lorentz transform shows that space and time are one thing. So the distinction between spacelike and timelike coordinates has more to do with how we perceive the world than an actual distinction between the dimensions.

Originally posted by @deepthought
I provided a perfect explanation, you keep dismissing the important part. The Lorentz transform shows that space and time are one thing. So the distinction between spacelike and timelike coordinates has more to do with how we perceive the world than an actual distinction between the dimensions.

Let's stick with the 'when' and 'where' thing. You seem to avoid that question.
You say that they are synonymous. I say not.

Originally posted by @fabianfnas
Let's stick with the 'when' and 'where' thing. You seem to avoid that question.
You say that they are synonymous. I say not.

I have already answered it by pointing to the Lorentz transform. I'm not sure I should allow you to dictate the terms of debate, and you are pushing the bounds of politeness again accusing me of avoiding your "when and where" point. This is a discussion about science, not an eristic political squabble.

However, the distinction between space-like and time-like dimensions is similar to the distinction between altitude and latitude. I assume you don't think there's anything fundamental going on there. Different observers will disagree about when and where any given event happens, relative to some reference event they've agreed to measure distances and times from, the first observers "when" is a mixture of the second observers "when" and "where". In relativity the picture is one of a unified spacetime. When we say the nearest star is 4 lightyears away is that a measure of distance or time?

Originally posted by @deepthought
I have already answered it by pointing to the Lorentz transform. I'm not sure I should allow you to dictate the terms of debate, and you are pushing the bounds of politeness again accusing me of avoiding your "when and where" point. This is a discussion about science, not an eristic political squabble.

However, the distinction between space-like and ...[text shortened]... cetime. When we say the nearest star is 4 lightyears away is that a measure of distance or time?

Had to look up "eristic', new one for me😉
I wonder if there is some long forgotten hero fighting for justice, the "Eristic Kid'? WOuld he be an Eristocrat?

Originally posted by @deepthought
I have already answered it by pointing to the Lorentz transform. I'm not sure I should allow you to dictate the terms of debate, and you are pushing the bounds of politeness again accusing me of avoiding your "when and where" point. This is a discussion about science, not an eristic political squabble.

However, the distinction between space-like and ...[text shortened]... cetime. When we say the nearest star is 4 lightyears away is that a measure of distance or time?

I asked my grand-mother about the difference between 'when' and 'where', and the explanation of hers was clear and concise. I understood her explanation perfectly.
Then I showed her your explanation, and she began to laugh. She didn't really understand anything.

I know that you are better than she in science, you have my total respect there. But to explain things, she excels over you.

Originally posted by @deepthought
I provided a perfect explanation, you keep dismissing the important part. The Lorentz transform shows that space and time are one thing. So the distinction between spacelike and timelike coordinates has more to do with how we perceive the world than an actual distinction between the dimensions.

IMO you can't have time without space, and timelike coordinates can only be found on or alongside spatial coordinates... if that makes any sense. This would mean the universal stopwatch didn't start until space first appeared (big bang event).
I don't have formal training in physics so I'm sticking my neck out here, but it seems to me that you are both right. There is a difference between spatial and temporal, but you can't have temporal without the spatial, so perhaps it's because they are so closely tied together they appear to be equal parts of the same thing...?

Originally posted by @deepthought
I have already answered it by pointing to the Lorentz transform. I'm not sure I should allow you to dictate the terms of debate, and you are pushing the bounds of politeness again accusing me of avoiding your "when and where" point. This is a discussion about science, not an eristic political squabble.

However, the distinction between space-like and ...[text shortened]... cetime. When we say the nearest star is 4 lightyears away is that a measure of distance or time?

When we say the nearest star is 4 lightyears away is that a measure of distance or time?

To be fair it's both. It's a measure of distance using time as a measuring stick. We can say 4 lightyears from earth or we could say 23.5 trillion miles. (23,494,282,742,000 miles)*
We say the sun is about 93 million miles from earth, but It wouldn't make sense to denote distances to other stars and galaxies in terms of miles or kilometres.


* not sure if that number is right. My cheap little calculator only displays 8 digits, so I had to do the math the hard way.

Originally posted by @lemon-lime
[b]When we say the nearest star is 4 lightyears away is that a measure of distance or time?

To be fair it's both. It's a measure of distance using time as a measuring stick. We can say 4 lightyears from earth or we could say 23.5 trillion miles. (23,494,282,742,000 miles)*
We say the sun is about 93 million miles from earth, but It wouldn't make ...[text shortened]... right. My cheap little calculator only displays 8 digits, so I had to do the math the hard way.[/b]

God, how could you make such terrible errors? It is 23.2 trillion miles away🙂

Originally posted by @sonhouse
God, how could you make such terrible errors? It is 23.2 trillion miles away🙂

Actually I also did it the hard way and came up with 23.5😉
I used 186242 miles per second and 86400 seconds per day and then two cases, 365 days which clocks in at 23.49 or counting leap years making it 365.25 days which gives us 23.5 tril.
On extra dimensions, the evidence so far of deviations of gravitational inverse square law coming up empty and now this:

https://phys.org/news/2018-09-gravitational-dose-reality-extra-dimensions.html

They are saying sorry guys, no evidence yet and that is from two separate sets of experiments.

Goodbye hyperspace I guess. Sigh.

So maybe it's a good thing we or nobody else can go faster than c, it would protect us from REALLY bad guys in the galaxy😉

If shown true, no extra dimensions, that is going to bum out the string theory dudes!
Begging the question as to why string theory can be tuned to come up with our standard particle theory if there are in fact no extra dimensions? Just co-incidence or is there something deeper yet we are not sussing out?

Isn't just the fact that space and time itself is bendable showing there is something deeper we may have to call at least one extra dimension of spacetime?

Originally posted by @lemon-lime
IMO you can't have time without space, and timelike coordinates can only be found on or alongside spatial coordinates... if that makes any sense. This would mean the universal stopwatch didn't start until space first appeared (big bang event).
I don't have formal training in physics so I'm sticking my neck out here, but it seems to me that you are both ...[text shortened]... 's because they are so closely tied together they appear to be equal parts of the same thing...?

What I'm getting at is that although to us it appears that space and time are quite different, when one tries to put one's finger on why it's rather hard. In relativity there is a technical difference to do with the extension of Pythagoras' theorem to 4 dimensions, but that's about it.

In quantum theory there is a difference to do with the interpretation of the wavefunction. Essentially the probability of finding a given particle somewhere in the universe is 1, at any given time. This jars somewhat with the eternalist picture in relativity. This is called the Problem of Time and is a major problem in Theoretical Physics.

Originally posted by @deepthought
What I'm getting at is that although to us it appears that space and time are quite different, when one tries to put one's finger on why it's rather hard. In relativity there is a technical difference to do with the extension of Pythagoras' theorem to 4 dimensions, but that's about it.

In quantum theory there is a difference to do with the interpret ...[text shortened]... n relativity. This is called the Problem of Time and is a major problem in Theoretical Physics.

How will it effect the future of string theory or M or whatever else it morphs into if indeed it is proven there ARE no extra dimensions than the ones we recognize now? And doesn't it imply that the idea of time and space being malleable suggest there has to be another dimension for that to be able to bend into? If black holes hide their mass all inside themselves doesn't that imply the stuff went somewhere else than our own universe?

Originally posted by @deepthought
When we say the nearest star is 4 lightyears away is that a measure of distance or time?

I don't know from where you are, but I rather say that the nearest star is about 150 million km from us.
Not 'when', but 'where'.

Originally posted by @sonhouse
God, how could you make such terrible errors? It is 23.2 trillion miles away🙂

It was late and I was tired. Also forgot about leap year... 29 days in February instead of 28. So that would make it 365.25 days in a year instead of 365. But that would make the number higher, not lower.
Did you take leap year into account?

edit: Oops, just now saw your next post. You did take leap year into account.
Jolly good show!

Originally posted by @sonhouse
How will it effect the future of string theory or M or whatever else it morphs into if indeed it is proven there ARE no extra dimensions than the ones we recognize now? And doesn't it imply that the idea of time and space being malleable suggest there has to be another dimension for that to be able to bend into? If black holes hide their mass all inside themselves doesn't that imply the stuff went somewhere else than our own universe?

If black holes hide their mass all inside themselves doesn't that imply the stuff went somewhere else than our own universe?

I don't see how that follows. If I'm trucking through the wilderness and see a bear approaching, I might find a deep dark hole to hide myself in. It wouldn't mean I went somewhere else other than my own universe, it just means I hid my mass inside a black hole...
and lived to tell about it.

Originally posted by @sonhouse
How will it effect the future of string theory or M or whatever else it morphs into if indeed it is proven there ARE no extra dimensions than the ones we recognize now? And doesn't it imply that the idea of time and space being malleable suggest there has to be another dimension for that to be able to bend into? If black holes hide their mass all inside themselves doesn't that imply the stuff went somewhere else than our own universe?

It's a problem for supersymmetric theories of quantum gravity (SUGRA) as they don't work properly in low numbers of dimensions. Since M theory involves a collection of dualities between the various superstring theories and SUGRA. If SUGRA's broken then they are too. So I think that "only four dimensions" is a problem for these theories.

There is such a thing as the extended Schwartzschild solution, where the notion of white holes comes from. However, since we believe black holes undergo quantum evaporation all the mass energy is returned to this universe in the end. So it basically hasn't gone into a new one.