Time..

[rexbeccarox]

I miss David Tennant as the Doctor

[Thumpalumpacus]

"Get over" myself? This from the guy who expresses disappointment in online strangers because they don't use the same words he does?

Pot, kettle, etc etc.

FFS mate... one chance, one life... really.. you want a row? dear oh dear !!

If you don't want a row, don't take a tilt, that's what I say.

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I miss David Tennant as the Doctor

He was interviewed on NPR tonight. I've never watched the show, but he seemed like an extraordinary guy.

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I've always regarded time as the first dimension (inasmuch as you can enumerate dimensions meaningfully), since it must permeate every other dimension.

A fair correction. It's embarrassing that I should be brought up short so efficiently -- time and groove are the most important and basic parts of musicianship.

But I will confess to being visually oriented as well, and for me that means that the spatial dimensions and relationships are always near the front of my mind. It works for me, because often when I write and record songs I will use visual analogies to construct the piece.

A simple form of synesthesia, perhaps.

[Alex K]

Time is a parameter in our equations. Time and space seem to mix depending on the movement of observers, and are therefore not entierly different things. Time is that direction with respect to which entropy currently increases on average.

[BrianSoddingBoru4]

I miss David Tennant as the Doctor

I miss Tom Baker.

Boru

[lifesagift]

If you don't want a row, don't take a tilt, that's what I say.

Yeah, not worth falling out over. i'm happy to offer a handshake and move on.

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For me, the notion of a day is Earthbound. Calling the rotational period of any other planet around a star, a day. It's a bit like calling that star a Sun ! Wrong!

And if you hypothetically, were to sit in the middle of space, between galaxies, how would you measure time? Maybe by counting distance per heartbeat? but what if you passed close to a black hole?

But there's certainly no night and day if you aint orbiting a star.

[Jackalope]

And if you hypothetically, were to sit in the middle of space, between galaxies, how would you measure time?

Likely the same way that we establish time references - by measuring radioactive decay.

but what if you passed close to a black hole?

Are you concerned with the passage of time in your own reference frame? No problem, continue using whatever method you use until if and when spaghettification occurs. Worried about someone else's reference frame? Rosta ruck with that.

[Thumpalumpacus]

For me, the notion of a day is Earthbound. Calling the rotational period of any other planet around a star, a day. It's a bit like calling that star a Sun ! Wrong!

And if you hypothetically, were to sit in the middle of space, between galaxies, how would you measure time? Maybe by counting distance per heartbeat? but what if you passed close to a black hole?

But there's certainly no night and day if you aint orbiting a star.

That's exactly why I said I'm using human terms; days are a subjective subdivision of time, but they are equally as valid as any other subdivisions us humans care to define.

And according to relativity, every subdivision is equally relative, too.

In the middle of space, I'd imagine that counting the vibrations of a crystal -- or an atom -- would work as well as it does on Earth.

[JaceDeanLove]

The past is far behind us, and the future doesn't exist!

[robvalue]

I think of time as a man-made parameter to try and make sense of what is happening. A label for snapshots of existence.

I'm not happy about calling it a dimension. To me, it bears no resemblance to the other dimensions of space that we know. Rather, the other dimensions are functions of this parameter.

I see absolutely no reason to think that the past or future "exist" in any shape or form, it's science fiction, along with the nonsense of time travel. Travelling at super-high speeds so you then arrive somewhere so that more "time has passed" there than you seem to have experienced is not travelling to the future. I've never even heard a sensible definition of what time travel is.

I know that relativity is concerned with time "slowing down" and such stuff. I don't disagree with all the theory, but I am very uncomfortable with some of the labels and assumptions.

The way I look at it, there is one global "time" that applies throughout the universe. It is the reference number for the snapshot of the whole universe at that point. Rather than say time is relative, I would say that the ways the laws of motion work change. Kind of like if someone is trying to walk through water, their speed is reduced, it doesn't mean that time has slowed down.

I think it's mathematically convenient to think of time as being relative, but it doesn't sit right with me. I think the laws of motion are the things that are altering, so a modifying factor is needed to account for this as "time slows down".

This may be semantics, it may be I just don't understand it well enough. But as I see it, as an external observer to the whole universe, you could advance things one "frame" at a time, and that would be what I would call time. You would be able to observe what was happening, and where "time has slowed down" you would instead just see things happening slower than you would expect as you move the frames along. (Obviously I mean as a continuum, not as discrete pockets!)

I have this problem with just throwing time in as another dimension and saying that it changes. To me, that violate the very definition of time, which is meant to be an external, independent parameter for keeping track of universal change.

I'm not claiming any of that is actually true or even makes sense, so I'm not going to try and defend it any further than stating it. It's just the only way I can make sense of the ideas at the moment. I need to learn more about relativity and stuff.

[Alex K]

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I think of time as a man-made parameter to try and make sense of what is happening. A label for snapshots of existence.

I'm not happy about calling it a dimension. To me, it bears no resemblance to the other dimensions of space that we know. Rather, the other dimensions are functions of this parameter.

I see absolutely no reason to think that the past or future "exist" in any shape or form, it's science fiction, along with the nonsense of time travel. Travelling at super-high speeds so you then arrive somewhere so that more "time has passed" there than you seem to have experienced is not travelling to the future. I've never even heard a sensible definition of what time travel is.

I know that relativity is concerned with time "slowing down" and such stuff. I don't disagree with all the theory, but I am very uncomfortable with some of the labels and assumptions.

The way I look at it, there is one global "time" that applies throughout the universe. It is the reference number for the snapshot of the whole universe at that point. Rather than say time is relative, I would say that the ways the laws of motion work change. Kind of like if someone is trying to walk through water, their speed is reduced, it doesn't mean that time has slowed down.

I think it's mathematically convenient to think of time as being relative, but it doesn't sit right with me. I think the laws of motion are the things that are altering, so a modifying factor is needed to account for this as "time slows down".

This may be semantics, it may be I just don't understand it well enough. But as I see it, as an external observer to the whole universe, you could advance things one "frame" at a time, and that would be what I would call time. You would be able to observe what was happening, and where "time has slowed down" you would instead just see things happening slower than you would expect as you move the frames along. (Obviously I mean as a continuum, not as discrete pockets!)

I have this problem with just throwing time in as another dimension and saying that it changes. To me, that violate the very definition of time, which is meant to be an external, independent parameter for keeping track of universal change.

I'm not claiming any of that is actually true or even makes sense, so I'm not going to try and defend it any further than stating it. It's just the only way I can make sense of the ideas at the moment. I need to learn more about relativity and stuff.

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Yes, you should learn more about special relativity, it provides an important different perspective on your question. What's so fascinating is not only that time gets stretched or compressed a bit at high speeds, but that the geometry of special relativity tells you that space and time mix when you change reference frames, i.e. when you move at different speeds. What is time for an observer moving relative to you, is, in special relativity, a combination of what's time for you and the spatial direction in which she's moving relative to you. This situation can be quantitatively illustrated using minkowski-diagrams:

http://en.wikipedia.org/wiki/Minkowski_diagram

This is quite the puzzle since in quantum mechanics, time plays such a special role compared to space: the space coordinates x,y,z are so-called operators acting on the states of the physical system in complicated ways, whereas time is an ordinary parameter. This is precisely why the synthesis of quantum mechanics and special relativity, called quantum field theory, demotes x,y,z to ordinary numerical parameters again, like time.