"Time is the speed of light."

[Brian]

ahhh - but only as far as an external stationary observer is concerned - if we do go faster, we don't feel time slowing, because for us it's not........

With implied quotes around "stationary," of course.

 

 

Two of the things my physics professors hammered on over and over were not forgetting that history shows anything we believe to be true is subject to change (as far as we know), and that sig figs & error analysis are your friend. I actually had a semester-long undergraduate course focused specifically on precision, error and uncertainty.

 

I suspect, Miffymog, that you are more deeply steeped in it than I am!

[Michael Sternbach]

Marblehead is the stationary observer here. He will watch us all slow down as we go faster and faster.

[Miffymog]

Marblehead is the stationary observer here. He will watch us all slow down as we go faster and faster.

 

Sorry Marblehead

 

Michael is saying that you're the slow moving object in this thread 

[Brian]

 

Marblehead is the stationary observer here. He will watch us all slow down as we go faster and faster.

As we watch him do likewise...

[Michael Sternbach]

Brain, I agree with you that we must be careful to think of ANY of our theories as THE truth. Actually, we already know situations in which the speed of light limit does not apply. (We may talk about those later, let's stick with time dilation a little longer.) Bottom line: Even though there is a lot of evidence in support of the Theory of Relativity, I suspect that it will eventually turn out to be no absolute truth but a subset of a yet more encompassing theory. So it may be relatively true.

 

Well, one way to evaluate the (relative) truth of a theory is to study whether it is at least consistent. I have heard many times that a trip at a velocity near c would mean that a watch on board of the space ship will considerably slow down relative to a "stationary" one back on Earth, so that (given that we could build such a ship), distant stars or even galaxies could be reached within the lifetime of the daring crew.

 

Of course, as seen by an external observer, the trip would still take just a little longer than light would take to travel that far. According to this, the astronauts, when arriving at their destination, will find that back on Earth thousands of years have passed.

 

But now you are telling me that for the astronauts, the external universe would slow down. So when arriving, less time will have passed in it than in their ship. Unless their watch mysteriously jumps forward once they come to a stop, this just doesn't make any sense.

 

[Michael Sternbach]

But I do try to keep my calm...

 

[Marblehead]

Don't give up. The faster we go, the more we will all slow down.

That doesn't sound very logical to me.

[Marblehead]

Marblehead is the stationary observer here. He will watch us all slow down as we go faster and faster.

Eventually y'all will burn up all your energy and then you will slow down.

 

Well, maybe not but that doesn't matter.

[Marblehead]

Sorry Marblehead

 

Michael is saying that you're the slow moving object in this thread 

That's okay.  My slow speed allows me to avoid collisions with other objects.  Less speed, more time.

[Marblehead]

As we watch him do likewise...

You won't see me moving too fast.  Ever!  I don't have to run because I know how to defend myself.

[Marblehead]

 Unless their watch mysteriously jumps forward once they come to a stop, this just doesn't make any sense.

Wait a minute.  The watch is a mechanical device that is going to do what it has to do.  It will not change how it displays the passage of time.

 

But then, if you plug a 220V clock into a 110V supply it will slow down.

 

Now stop trying to confuse me.

[Brian]

Brain, I agree with you that we must be careful to think of ANY of our theories as THE truth. Actually, we already know situations in which the speed of light limit does not apply. (We may talk about those later, let's stick with time dilation a little longer.) Bottom line: Even though there is a lot of evidence in support of the Theory of Relativity, I suspect that it will eventually turn out to be no absolute truth but a subset of a yet more encompassing theory. So it may be relatively true.

 

Well, one way to evaluate the (relative) truth of a theory is to study whether it is at least consistent. I have heard many times that a trip at a velocity near c would mean that a watch on board of the space ship will considerably slow down relative to a "stationary" one back on Earth, so that (given that we could build such a ship), distant stars or even galaxies could be reached within the lifetime of the daring crew.

 

Of course, as seen by an external observer, the trip would still take just a little longer than light would take to travel that far. According to this, the astronauts, when arriving at their destination, will find that back on Earth thousands of years have passed.

 

But now you are telling me that for the astronauts, the external universe would slow down. So when arriving, less time will have passed in it than in their ship. Unless their watch mysteriously jumps forward once they come to a stop, this just doesn't make any sense.

 

 

I'm the first to admit I don't keep up with all the excellent work being done at high energies but I am not aware of a single confirmed example of a violation of Lorentz invariance. I know there are a couple closely related experiments with neutrinos and antineutrinos which are currently being investigated but every prior case has turned out to be a false alarm or a misunderstanding of the principles involved.

 

In fairness, it has been my observation that most physicists don't really grasp and comprehend special relativity, much less general relativity. It is one thing to learn the math but something else entirely to abandon deep-seated assumptions about space and time. People far smarter that me have been saying, "That just can't be!" and have been banging their heads against it for over a century.

 

My expectation is that, just as special relativity integrated electromagnetism & motion to extend and expand Newtonian relativity while yielding results consistent with the latter within its scope of applicability, the next breakthrough will integrate relativity & quantum theory to yield something consistent with them both but reaching beyond either.

 

Go back up and read what I wrote about the astronaut traveling to the space station a light-year out. If you have read or been told things inconsistent with my description, you should probably go back to the drawing board.

 

I invite and encourage Miffymog and/or any other Bum who has practiced this particular gungfu to correct me (please!) or share their understandings.

[Marblehead]

I know there are a couple closely related experiments with neutrinos and antineutrinos which are currently being investigated but every prior case has turned out to be a false alarm or a misunderstanding of the principles involved.

 

 

Every time one of the theoretical physicists mention anti-matter I call bullshit on them.  So far I have heard nothing to suggest such a thing exists or ever existed.

[Brian]

With implied quotes around "stationary," of course.

 

 

Two of the things my physics professors hammered on over and over were not forgetting that history shows anything we believe to be true is subject to change (as far as we know), and that sig figs & error analysis are your friend. I actually had a semester-long undergraduate course focused specifically on precision, error and uncertainty.

 

I suspect, Miffymog, that you are more deeply steeped in it than I am!

As an aside, my teachers also stressed the importance of learning underlying principles rather than just memorizing formulas. Sure, I had formulas on the tip of my tongue (so to speak) when I was a student working problems with them on a daily basis but now, presented with a "two trains are traveling..." problem, I am likely to put pencil to paper and derive what I need from first principles (like F=ma) than to remember all the variations (although I must admit that I sometimes just use the Internet to jog my memory...)

[Brian]

Every time one of the theoretical physicists mention anti-matter I call bullshit on them. So far I have heard nothing to suggest such a thing exists or ever existed.

That's just because you reject things that you don't understand or that seem inconsistent with your personal beliefs about "how things are." (EDIT: This isn't meant as a dig -- this is just "human nature")

 

We've been producing antiprotons since 1955. Ever had a PET scan at the hospital? That's what the "P" stands for.

 

A few years ago, we discovered antimatter being generated in thunderstorms.

 

Heck! We've even trapped antihydrogen and antihelium.

[Miffymog]

I invite and encourage Miffymog and/or any other Bum who has practiced this particular gungfu to correct me (please!) or share their understandings.

 

I find it difficult enough explaining this stuff to some one face to face - doing it over a web forum is well beyond my abilities 

None-the-less, I've enjoyed reading this thread.

[Marblehead]

That's just because you reject things that you don't understand or that seem inconsistent with your personal beliefs about "how things are." (EDIT: This isn't meant as a dig -- this is just "human nature")

Oh, that is a fact.  I do not deny it.  I don't mind fair criticism.

 

We've been producing antiprotons since 1955. Ever had a PET scan at the hospital? That's what the "P" stands for.

Yeah, I just heard about that a couple days ago while watching one of the science documentaries.

 

A few years ago, we discovered antimatter being generated in thunderstorms.

Isn't it said that our sun also generates a little bit of it?

 

Heck! We've even trapped antihydrogen and antihelium.

Now that's weird.  Why?

 

That is always my question when presented with new information:  Why?

 

The creation of matter I can understand.  But why is there or has there ever been anti anything?

 

Yeah, creation and destruction.  But it's still not logical.

[Marblehead]

I find it difficult enough explaining this stuff to some one face to face - doing it over a web forum is well beyond my abilities 

None-the-less, I've enjoyed reading this thread.

Hey!  I'm having fun.  I don't know if I've learned anything though.

[Brian]

Oh, that is a fact. I do not deny it. I don't mind fair criticism.

 

Yeah, I just heard about that a couple days ago while watching one of the science documentaries.

 

Isn't it said that our sun also generates a little bit of it?

 

Now that's weird. Why?

 

That is always my question when presented with new information: Why?

 

The creation of matter I can understand. But why is there or has there ever been anti anything?

 

Yeah, creation and destruction. But it's still not logical.

The name is an unfortunate one, I think -- like "imaginary numbers."

 

"Why" almost always boils down to childlike curiosity. I suspect the same motivation led to finding out things like cooked elderberries are edible while raw one's are toxic. They make an interesting wine, too!)

[Michael Sternbach]

Go back up and read what I wrote about the astronaut traveling to the space station a light-year out. If you have read or been told things inconsistent with my description, you should probably go back to the drawing board.

 

I have a more simple solution: Let's just observe what happens when we move nearly at the speed of light!

 

[Marblehead]

You have left me in the dust.

[Stosh]

Aha! Now I know why, the faster I drive, the sooner I get to work.

[Marblehead]

Any more I travel at the speed of dark.

[Stosh]

Speed of dark being much faster? hmm dunno, if light travels at the speed its supposed to, a laser shone from the moon, from its point of view ,reaches its target as soon as its emmitted,,,,,,,, taking zero time, and travelling in a straight line through curved space. Right? But from its targets point of view, it has one and a third seconds to move out of the way. The light would have to hit its target instantly and miss it entirely.

[Marblehead]

In my mind the speed of dark is undefined.

 

If I recall correctly:

 

On one of the trips to the moon they put a mirror on the moon and here on earth they shoot a laser at it and depending on how long it takes the beam of light to travel to the moon and return to Earth they can determine the exact distance between the Earth and the Moon. 

 

So Yeah, I guess the light would travel a straight line to and back.  But it would still require a given amount of time.  That is how they determine the distance.