Time Explained

[Farsight]

Clunk! That's my head hitting my desk. Now come on lpetrich, take a look at http://en.wikipedia.org/wiki/Lorentz_boost and pay careful attention to "It reflects the surprising fact that observers moving at different velocities may measure different distances, elapsed times, and even different orderings of events."

That's the textual evidence that you don't understand relativity theory because you only read wikipedia and don't study physics. Popular science accounts get caught up in "observer" talk, but it really doesn't matter.

No it isn't. It's the textual evidence that lpetrich doesn't. I've read the original Einstein remember? I'm the one quoting Einstein, and lpetrich is the one dismissing him.

What is the distance between the Earth and Alpha Centauri? The "real" distance, not the one distorted by our motion.

It's 4.37 light years with a little adjustment for the CMBR dipole anisotropy which says we're moving at 627 km/s with respect to the CMBR. You can also adjust for motion around the galaxy and sun, but they're small adjustments, so it's still 4.37 light years. Note that this is quoted in light years. That's the distance light travels whilst the earth travels once round the sun. Time and distance are measured using motion, and in the ultimate they're measured using the motion of light. When lpetrich is moving towards Alpha Centauri his motion alters his measurements, it doesn't change the space between here and Alpha Centauri to make it contract like a concertina.

[ChildInAZoo]

What is the distance between the Earth and Alpha Centauri? The "real" distance, not the one distorted by our motion.

It's 4.37 light years with a little adjustment for the CMBR dipole anisotropy which says we're moving at 627 km/s with respect to the CMBR. You can also adjust for motion around the galaxy and sun, but they're small adjustments, so it's still 4.37 light years. Note that this is quoted in light years. That's the distance light travels whilst the earth travels once round the sun. Time and distance are measured using motion, and in the ultimate they're measured using the motion of light. When lpetrich is moving towards Alpha Centauri his motion alters his measurements, it doesn't change the space between here and Alpha Centauri to make it contract like a concertina.

How do we know that this is the "real" distance? And if this is the "real" distance, does this mean that the "real" shape of the sun is similarly adjusted?

[lpetrich]

(about the Lorentz transformation / boost...)
Motion is nowhere in sight.

Clunk! That's my head hitting my desk. Now come on lpetrich, take a look at http://en.wikipedia.org/wiki/Lorentz_boost and pay careful attention to "It reflects the surprising fact that observers moving at different velocities may measure different distances, elapsed times, and even different orderings of events."

That's a side effect of space and time being coequal.

(attempt to explain WIkipedia's diagram...)
Farsight, if you insist on ignoring or misunderstanding the mathematics and making verbal descriptions mean what you want them to mean, you don't deserve to be taken seriously as a successor of Newton and Einstein.

And a metric is what you measure. ...

Another Gardnerian inversion. For all your Einstein-thumping, you have remarkably little understanding of Einstein's theories.

It's not Gardnerian, and it's nothing to do with Einstein. The metric isn't reality. It's merely how you measure reality. The distance from here to Alpha Centauri doesn't reduce just because you move towards it at a significant fraction at c. Your measurement of distance changes when you move through space, but I'm sitting here on earth along with 7 billion other people, and the distance hasn't changed one jot. You might claim it has, but it hasn't. And when you exclaim excitedly on the radio that you've encountered new space and new time, we sigh and tell you about Pythagoras' Theorem.

That's because you are still using your old coordinate system and I'm using a somewhat different one. It's sort of like rotation.

I showed why you can't use maths, because you can't use maths to define the terms you use in that maths. I demonstrated it with observable scientific evidence, what you class as mere "words". Maths is no substitute for this.

So you think that playing word games can make mathematics unnecessary?

"Hold your hands up, colubridae. See that gap between them? That's a space, and you can see it. Now waggle those hands. That's motion, and you can see that too. But can you see time? No. Spot the difference?"

It's that simple. Put your trust in the empirical scientific evidence you can see, not abstract things that you can't see like time flowing, and travelling through time, and time machines, and other such moonshine.

Except that the external world is equally abstract. We do NOT directly "see" it -- it is an interpretation made unconsciously and continually. Farsight, do you believe that clouds and rainbows are solid objects? Why do you believe what you believe about those entities?

Popular science accounts get caught up in "observer" talk, but it really doesn't matter.

No it isn't. It's the textual evidence that lpetrich doesn't. I've read the original Einstein remember? I'm the one quoting Einstein, and lpetrich is the one dismissing him.

What I'm dismissing is your stupid quote-mining and your refusal to take into account where Einstein believed something other than what you believe. Farsight, we don't do science by Maxwell-thumping or Einstein-thumping or Feynman-thumping or whoever-thumping. Doing so makes you seem much like a creationist.

[Twiglet]

Clunk! That's my head hitting my desk. Now come on lpetrich, take a look at http://en.wikipedia.org/wiki/Lorentz_boost and pay careful attention to "It reflects the surprising fact that observers moving at different velocities may measure different distances, elapsed times, and even different orderings of events." You haven't made new space, you're just moving through it. And as a result, your measurements are different. And by the way, when you measure time, you still use a clock, and that clock uses motion. You might use a parallel-mirror light clock, and then if you thought about it, you'd understand why your motion affected your measurements. See Simple inference of time dilation due to relative velocity.



See the right-angled triangle on the left? The diagonal is the light path, and we're using natural units wherein c=1. The base is your velocity as a fraction of c. The height √(1-v²/c²) or more simply √(1-v²) represents the Lorentz factor, with a reciprocal for time dilation as opposed to length contraction. Come on lpetrich, this is just Pythagoras' Theorem. It's kid's stuff. Wake up and smell the coffee instead of clinging to mysticism. And by the way, you've just demonstrated that you haven't even read the OP. Again. Clunk!

-snip-snip-snippety snip-snip- we sigh and tell you about Pythagoras' Theorem.

You think it's "about pythagoras"... because someone drew a triangle.......???

[Farsight]

How do we know that this is the "real" distance? And if this is the "real" distance, does this mean that the "real" shape of the sun is similarly adjusted?

Because we live in a real universe. And yes, that is the "real" shape of the sun, though we use the local space as our frame of reference and discount it.

You think it's "about pythagoras"... because someone drew a triangle.......???

No. Because this is how you can derive √(1-v²/c²), from Pythagoras' theorem and a beam of light. Surely you don't doubt this.

That's a side effect of space and time being coequal.

They are not coequal. You have freedom of motion through space, you have no freedom of motion through time.

Farsight, if you insist on ignoring or misunderstanding the mathematics and making verbal descriptions mean what you want them to mean, you don't deserve to be taken seriously as a successor of Newton and Einstein.

My explanation was correct. You can't fault it, so you respond with a dismissal. And what's with the successor to Newton and Einstein? I'm just a guy explaining a few simple things.

That's because you are still using your old coordinate system and I'm using a somewhat different one. It's sort of like rotation.

Your coordinate system isn't something real. It's an artefact of measurement which is affected by your motion through space.

So you think that playing word games can make mathematics unnecessary?

Not at all. How many times do I have to say mathematics is a vital tool for physics? And I'm not playing word games, I'm explaining the derivation of the mathematics.

Except that the external world is equally abstract.

No, it isn't abstract. It's real. Sheesh lpetrich, now I've heard it all.

We do NOT directly "see" it -- it is an interpretation made unconsciously and continually. Farsight, do you believe that clouds and rainbows are solid objects? Why do you believe what you believe about those entities? ...What I'm dismissing is your stupid quote-mining and your refusal to take into account where Einstein believed something other than what you believe. Farsight, we don't do science by Maxwell-thumping or Einstein-thumping or Feynman-thumping or whoever-thumping. Doing so makes you seem much like a creationist.

Enough. You can't handle Time Explained or the evidence that backs it up, and your dismissal and denial does you no credit.

[ChildInAZoo]

How do we know that this is the "real" distance? And if this is the "real" distance, does this mean that the "real" shape of the sun is similarly adjusted?

Because we live in a real universe. And yes, that is the "real" shape of the sun, though we use the local space as our frame of reference and discount it.

So you are saying that the "real" shape of our sun is a slightly flattened sphere? Interesting...