Four-vector in Relativity

Quote from: John Davis on April 28, 2010, 01:42:24 PM

Of course, the ball does travel in a straight line until it stops in RE physics too.

No, it travels in a straight line until acted upon by an outside force (that force mainly being gravity in this instance).  The force of gravity imparts acceleration to the falling object, causing it to form a parabolic curve.

I think will if you educate yourself on the works of Einstein you will find it travels at the speed of light in a straight line unless acted upon.

I think will if you educate yourself on the works of Einstein you will find it travels at the speed of light in a straight line unless acted upon.

A ball travels at the speed of light in a straight line unless acted upon?  Are you hearing yourself?

Quote from: John Davis on April 28, 2010, 01:55:19 PM

I think will if you educate yourself on the works of Einstein you will find it travels at the speed of light in a straight line unless acted upon.

A ball travels at the speed of light in a straight line unless acted upon?  Are you hearing yourself?

Yes what exactly did you have an issue with?

Yes what exactly did you have an issue with?

That an object with positive mass can travel at the speed of light.
Do YOU know about the very Einstein you speak of?

Quote from: John Davis on April 28, 2010, 01:59:38 PM

Yes what exactly did you have an issue with?

That an object with positive mass can travel at the speed of light.
Do YOU know about the very Einstein you speak of?

All objects with mass travel at the speed of light.  The magnitude of the 4-vector is always c.  Objects follow a straight line through space-time.

Do you even know of Einstein?

I'm sorry, John Davis, but again I must call BS.

All three of Einsteins equations involving the Lorentz factor do not allow things with positive mass to reach or exceed the speed of light.  This is because two of these equations involve DIVISION BY (remember that) the Lorentz factor (the other allows it, but that involves length becoming zero).  If you didn't know, the factor is: [1-(v/c)²]^½

You'll notice (I honestly pray you do) that if v equals the speed of light, you get the number 1.  We square it, then subtract it from the original number 1.  We then take the square root of that.  Guess what?  "Divide by zero error."  Do you understand that?  Do you get why you're wrong now?

Well, now I can see why you ran from the magnetism thread too. 
Anyone calls you on your BS and you fly like a bird.

No, you are still wrong.  I have company and have not been put on this earth to reply to you every chance I get.

Do you even know what a 4 vector is?

|(γc,γv)|=c

When I have more time I'll explain in more detail why you are wrong.

Edit: I have a second, thats all it takes.

Take an object.  Use its for.

v = (0,0,0)

Take its 4-vector:
(γc,γv)

Its speed (magnitude) (as shown above) is the speed of light.

Learn what you are talking about before you call BS.

Do you?  Your argument is that the ball, an object in space, is moving through space at the speed of light.  This is completely wrong.  4-vector says how it's moving through space, and how its perception of time to itself is unaltered.  4-vector is mainly just a bunch of ways of further proving that c is constant.

Edit: Ah, way to quickly edit your post.  To those just recently tuning in, what I said here was in response to his question, which merely asked if I knew what 4-vector was.

Edit again:  Well, he's just edited again.  How long are we going to keep this up?

Do you?  Your argument is that the ball, an object in space, is moving through space at the speed of light.  This is completely wrong.  4-vector says how it's moving through space, and how its perception of time to itself is unaltered.  All 4-vector is mainly just a way of proving that c is constant.

Edit: Ah, way to quickly edit your post.  To those just recently tuning in, what I said here was in response to his question, which merely asked if I knew what 4-vector was.

I was filling information for your ignorance.  Apologies, won't happen again because I'm done trying to teach you relativity.

An object travels at lightspeed through milowski space in a straight line.

This includes balls.

edit: milowski

And again I have to inform you that in the 3-dimensional space we're speaking of in the diagram, you're dead wrong.  I'm not talking about the object's speed through time.  I'm talking about its speed OVER time.

And again I have to inform you that in the 3-dimensional space we're speaking of in the diagram, you're dead wrong.  I'm not talking about the object's speed through time.  I'm talking about its speed OVER time.

When did I ever refer to the diagram or 3-dimensional space?  All I said is that all objects travel at the speed of light through space.   Admit you are wrong.

When did I ever refer to the diagram or 3-dimensional space?

Please see:

...you will find it (the ball we were speaking of) travels at the speed of light in a straight line unless acted upon.

Edit: Unless you meant a straight line through four dimensions, which we both know you didn't, I'm calling you out.

Quote from: John Davis on April 28, 2010, 03:11:42 PM

When did I ever refer to the diagram or 3-dimensional space?

Please see:

Quote from: John Davis

...you will find it (the ball we were speaking of) travels at the speed of light in a straight line unless acted upon.

Edit: Unless you meant a straight line through four dimensions, which we both know you didn't, I'm calling you out.

That is exactly what I meant and what I said.  I don't see why this is so complicated.  If one knew about relativity and read what I just wrote it would be painfully obvious what I meant.

Things travel in straight lines unless acted upon.  Gravity is a pseudoforce.  The ball is no exception.  Its magnitude is c.

Quote from: John Davis on April 28, 2010, 01:42:24 PM

ENaG is full of junk like this.  Its a important book for its time, and now, but much of it is incorrect.  Take the useful from it and throw away the crap, just like you Round Earthers do with Newton all the time.

So which bits of ENaG are not crap?  Rowbotham based his claim that the earth does not rotate on the erroneous "fact" that a ball thrown from a moving vehicle will expend all of its forward motion at the apex of its trajectory.  If his premise is flawed, then how can we trust his conclusion?

I wouldn't trust his conclusion to that, of course, but others may be worthwhile.  One must use their own judgement.  One should never trust any source beyond their own judgement.

I'll also take it that Eclipses (since he must use the same metric for judging himself as he does me) has run from the thread and conceded the point to me.  Balls travel at the speed of light in straight lines.

Gravity is a fundamental force, not a pseudoforce.  And no, it wouldn't be painfully obvious to ANYONE what you meant when you said that.  If you drove up to me and got out of a car claiming that you'd just gone (and are still going) at the speed of light, I'm going to call you an idiot for not knowing what you're talking about, and you're going to have to clarify that you don't use the word "speed" to mean what it does in its actual definition.

Let's be honest here.  When you said the ball was moving through space at the speed of light, you didn't mean its speed THROUGH time; you meant its distance OVER time, and were proven wrong.  I know this because you threw in the "unless acted upon by a force" part.  A force acting upon a four-dimensional vector?

What are you, a hypnotist?  You're trying to convince me you have some semblance of what you're talking about when the text clearly says the contrary, and I'm supposed to disbelieve my own eyes?  Your flagrant dishonesty is plain as day and clear for everyone to see.

Edit:
You did run from the magnetism thread, and I'm still eagerly awaiting a response.

I'll also take it that Eclipses (since he must use the same metric for judging himself as he does me) has run from the thread and conceded the point to me.  Balls travel at the speed of light in straight lines.

Well, I assume you mean Ellipses.  Just because he left the thread doesn't mean he is saying you're right.  Sometimes you just have to know when to stop arguing with idiots.

I'll also take it that Eclipses (since he must use the same metric for judging himself as he does me) has run from the thread and conceded the point to me.  Balls travel at the speed of light in straight lines.

I had no idea what you were referring to either.
In the context of the discussion, 3D space was assumed.  You really needed to specify what space the ball was moving at the speed of light in rather than leave that open.

Gravity is a fundamental force, not a pseudoforce.  And no, it wouldn't be painfully obvious to ANYONE what you meant when you said that.  If you drove up to me and got out of a car claiming that you'd just gone (and are still going) at the speed of light, I'm going to call you an idiot for not knowing what you're talking about, and you're going to have to clarify that you don't use the word "speed" to mean what it does in its actual definition.

Let's be honest here.  When you said the ball was moving through space at the speed of light, you didn't mean its speed THROUGH time; you meant its speed OVER time, and were proven wrong.  I know this because you threw in the "unless acted upon by a force" part.  A force acting upon a four-dimensional vector?

What are you, a hypnotist?  You're trying to convince me you have some semblance of what you're talking about when the text clearly says the contrary, and I'm supposed to disbelieve my own eyes?  Your flagrant dishonesty is plain as day and clear for everyone to see.

Within relativity, gravity is a pseudoforce.  Hence why balls travel in straight lines in non-euclidean space.  

I didn't say it would be painfully obvious to anyone.  I said it would be painfully obvious to anyone who knew what they were talking about.  You obviously don't.

I meant its 4-vector magnitude.  Do you honestly believe its a coincidence that I said balls travel at the speed of light in straight lines and that that is exactly what they do?

What exactly am I being dishonest about?  

Quote from: John Davis on April 28, 2010, 03:50:26 PM

I'll also take it that Eclipses (since he must use the same metric for judging himself as he does me) has run from the thread and conceded the point to me.  Balls travel at the speed of light in straight lines.

I had no idea what you were referring to either.
In the context of the discussion, 3D space was assumed.  You really needed to specify what space the ball was moving at the speed of light in rather than leave that open.

The ball is always moving through spacetime.  Are you suggesting balls move through different spaces depending on what we are talking about?

Gravity is a fundamental force, not a pseudoforce.

Gravity is a pseudoforce. I thought you understood Einstein?

Also,

http://en.wikipedia.org/wiki/Four-velocity

In other words, the norm or magnitude of the four-velocity is always exactly equal to the speed of light. Thus all objects can be thought of as moving through spacetime at the speed of light.

What exactly am I being dishonest about?  

You're pretending you meant "speed" through 4d space (rate of time passing) instead of 3d space (the definition we're all familiar with: DISTANCE OVER TIME).  It's obvious you meant 3d because you gave it away with the "acted upon by a force" part, unless you're talking about a thrown ball's motion through the fourth dimension somehow being altered by me applying a force to it.  Exactly how would that work?  What kind of force can I apply that stops the ball from traveling in a straight line THROUGH TIME?

You gave yourself away and are now grasping at straws to justify the statement and avoid conceding defeat.

Quote from: John Davis on April 28, 2010, 04:00:18 PM

What exactly am I being dishonest about?  

You're pretending you meant "speed" through 4d space (rate of time passing) instead of 3d space (the definition we're all familiar with: DISTANCE OVER TIME).  It's obvious you meant 3d because you gave it away with the "acted upon by a force" part, unless you're talking about a thrown ball's motion through the fourth dimension somehow being altered by me applying a force to it.  Exactly how would that work?  What kind of force can I apply that stops the ball from traveling in a straight line THROUGH TIME?

You gave yourself away and are now grasping at straws to justify the statement and avoid conceding defeat.

It would no longer be a straight line if acted upon by a force.

You repeatedly are calling me a liar with nothing to back it up with.  I deserve an apology and for you admit you were wrong.

Also, gravity is not a fundamental force within Einstein's relativity as Jack correctly points out again.   Do you still claim it is?  Or were you referring to something else.

You're not even reading my posts anymore, are you?   

You're not even reading my posts anymore, are you?  

You're not even understanding my posts anymore, are you?

I explained why it would no longer travel in a straight line if acted upon (great, now we've digressed to teaching you Newton.)

Do you still claim I'm a liar?

I was talking about a ball moving through three-dimensional space.  So were you.  When you said speed, you meant distance over time just like I did.  I called you out on it, and you moved the goalposts.  That's how you were being dishonest.

Edit: Will you stop with the multiple edits while I'm trying to reply?

I was talking about a ball moving through three-dimensional space.  So were you.  When you said speed, you meant distance over time just like I did.  I called you out on it, and you moved the goalposts.  That's how you were being dishonest.

I was talking about a ball moving through 3-dimensional space.  However, it is also moving through 4-dimensional space which is more accurately what I was talking about.  When I said speed I meant magnitude, specifically of the four-vector.  I've used this phrasing before here if you don't believe me you can do some research before making unfounded claims.

I didn't move any goalposts.  I meant what I said form the start.   Do you really think its a coincidence that I claimed it went in straight lines at c and that it really does?  

However, it is also moving through 4-dimensional space...

Duh, and so is the observer at basically the same rate.  Which is why we can talk about the ball's speed.  The spacial DISTANCE it covers over a length of TIME, which I assure you is nowhere near light's speed (and yes, I'm using the same definition for speed).

When I said speed I meant magnitude, specifically of the four-vector.

Funny how you didn't say magnitude to begin with.

Edit:  I guess what I mean is that saying what is essentially "they're both moving the same rate through time" is idiotic and missing the point of the concept presented.  They're not moving the same speed through space.  Their spacial relations are what is being dealt with.

Quote from: John Davis

However, it is also moving through 4-dimensional space...

Duh, and so is the observer at the same rate.  Which is why we can talk about the ball's speed.  The spacial DISTANCE it covers over a length of TIME, which I assure you is nowhere near light's speed (and yes, I'm using the same definition for speed).

Quote from: John Davis

When I said speed I meant magnitude, specifically of the four-vector.

Funny how didn't you say magnitude to begin with.

I said what I meant and I mean what I say.

Just admit you were wrong instead of trying to make this an ad hominem argument against me.