Relativity?

How does science work? And what's all this about quantum mechanics?

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davidm
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Re: Relativity?

Imagine a train and an embankment. The train is rushing past the embankment.

There is a kid on the train who rolls a marble. There is another kid on the embankment who rolls a marble.

This is a thought experiment, so it’s perfectly OK to imagine that the kid on the train and on the embankment roll their marbles at an identical rate of speed. In practice, this would be almost impossible to achieve except by dumb luck, but it’s OK for a thought experiment in order to illustrate a principle.

But even though the kid on the train and the kid on the ground have rolled their marbles at the same velocity, they are not ACTUALLY the same velocity. This is because, if both kids roll their marbles at one foot per second, the marble of the kid on the train will ADD the velocity of the train to the velocity of his marble. Hence, his marble will TRAVEL FASTER THAN the marble of the kid on the ground, even though both will measure, in their respective frames, the marble moving at one foot per second (the train must be an inertial frame — in constant uniform motion.)

In other words, the velocity of the marbles vary across frames. This is in conformance with the law of addition of velocities, or Galilean additivity.

Now, instead of a photon clock, we are going to build a marble clock. It works the same way as a photon clock, except that a marble, not a photon, goes down to the bottom and bounces back to the top. A round trip counts one second.

The marble clocks are synchronized in the ground frame. Each ticks off a second with military precision.

We put one marble clock on the moving train and leave the other on the ground. Will they remain synchronized?

Yes! Observe that on the train, the marble in the marble clock has a longer path to travel, to hit the bottom of the clock and return to the top, in order to tick off one second. It has a longer path to travel, because the bottom and tops of the clock are moving targets, unlike the marble clock in the stationary frame.

BUT, the marble in the moving train PICKS UP THE SPEED OF THE TRAIN! Because it does, the marble clock in the train and the marble clock on the ground remain in perfect synchrony — each agreeing on what constitutes one second.

Although the marble on the moving train has a longer distance to traverse than the marble in the ground frame, IT IS MOVING MORE QUICKLY.

THAT IS WHAT LIGHT DOES NOT DO.

Unlike the marble, the photon WILL NOT ADD THE SPEED OF THE MOVING FRAME. Thus, in addition to traversing a longer path than the photon in a photon clock on the ground frame, it will, from the point of view of the rest frame, take a longer time to trace that path.

Conclusion: a marble clock on a moving frame and a marble clock in the ground frame remain in synch.

But a photon clock on a moving frame and a photon clock on the ground frame do NOT remain in synch. The moving-frame clock ticks slower.

The marble clocks tick the same because of the variability of the speed of the marbles.

The photon clocks tick differently because of the invariability of the speed of photons!
Last edited by davidm on Mon Oct 30, 2017 1:28 am, edited 1 time in total.
Viveka
Posts: 369
Joined: Wed Sep 27, 2017 9:06 pm

Re: Relativity?

davidm wrote: Mon Oct 30, 2017 1:14 am Imagine a train and an embankment. The train is rushing past the embankment.

There is a kid on the train who rolls a marble. There is another kid on the embankment who rolls a marble.

This is a thought experiment, so it’s perfectly OK to imagine that the kid on the train and on the embankment roll their marbles at an identical rate of speed. In practice, this would be almost impossible to achieve except by dumb luck, but it’s OK for a thought experiment in order to illustrate a principle.

But even though the kid on the train and the kid on the ground have rolled their marbles at the same velocity, they are not ACTUALLY the same velocity. This is because, if both kids roll their marbles at one foot per second, the marble of the kid on the train will ADD the velocity of the train to the velocity of his marble. Hence, his marble will TRAVEL FASTER THAN the marble of the kid on the ground, even though both will measure, in their respective frames, the marble moving at one foot per second (the train must be an inertial frame — in constant uniform motion.)

In other words, the velocity of the marbles vary across frames. This is in conformance with the law of addition of velocities, or Galilean additivity.

Now, instead of a photon clock, we are going to build a marble clock. It works the same way as a photon clock, except that a marble, not a photon, goes down to the bottom and bounces back to the top. A round trip counts one second.

The marble clocks are synchronized in the ground frame. Each ticks off a second with military precision.

We put one marble clock on the moving train and leave the other on the ground. Will they remain synchronized?

Yes! Observe that on the train, the marble in the marble clock has a longer path to travel, to hit the bottom of the clock and return to the top, in order to tick off one second. It has a longer path to travel, because the bottom and tops of the clock are moving targets, unlike the marble clock in the stationary frame.

BUT, the marble in the moving train PICKS UP THE SPEED OF THE TRAIN! Because it does, the marble clock in the train and the marble clock on the ground remain in perfect synchrony — each agreeing on what constitutes one second.

Although the marble on the moving train has a longer distance to traverse than the marble in the ground frame, IT IS MOVING MORE QUICKLY.

THAT IS WHAT LIGHT DOES NOT DO.

Unlike the marble, the photon WILL NOT ADD THE SPEED OF THE MOVING FRAME. Thus, in addition to traversing a longer path than the photon in a photon clock on the ground frame, it will, from the point of view of the rest frame, take a longer time to trace that path.

Conclusion: a marble clock on a moving frame and a marble clock in the ground frame remain in synch.

But a photon clock on a moving frame and a photon clock do NOT remain in synch. The moving-frame clock ticks slower.

The marble clocks tick the same because of the variability of the speed of the marbles.

The photon clocks tick differently because of the invariability of the speed of photons!

Yes, I completely understand what you are saying. I summed up the SRT in a sentence. However, if it is true that the photons are invariate, why do they always 'hit the target' when they are in a light-clock? Because of the variance of space and time? I addressed this in my previous post that I feel you should read. I basically say that the reason why the light-clock always 'hits the target' is because of Galilean Transformations or Light-Anchoring.

Just because Light-speed is invariate supposedly means that there has to be length-contraction and time-dilation because you are taking the invariate speed of light, and then making time and space variate in order to keep the invariancy of the speed of light. That about sums up Special Relativity.
Last edited by Viveka on Mon Oct 30, 2017 1:37 am, edited 1 time in total.
davidm
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Re: Relativity?

Viveka wrote: Mon Oct 30, 2017 1:26 am Yes, I completely understand what you are saying. I summed up the SRT in a sentence. However, if it is true that the photons are invariate, why do they always 'hit the target' when they are in a light-clock?
I don't understand your question. If we consider the state of affairs from the point of view of the person who is in motion with respect to an "an rest" frame, then this person feels herself to be at rest -- and is perfectly entitled to do so. In an inertial frame (constant uniform motion) she does not detect any motion at all. She observes her photon clock. The clock is stationary. The photons bounce up and down, each round trip denoting one second. Why should these photons fail to hit the target?
Viveka
Posts: 369
Joined: Wed Sep 27, 2017 9:06 pm

Re: Relativity?

davidm wrote: Mon Oct 30, 2017 1:37 am
Viveka wrote: Mon Oct 30, 2017 1:26 am Yes, I completely understand what you are saying. I summed up the SRT in a sentence. However, if it is true that the photons are invariate, why do they always 'hit the target' when they are in a light-clock?
I don't understand your question. If we consider the state of affairs from the point of view of the person who is in motion with respect to an "an rest" frame, then this person feels herself to be at rest -- and is perfectly entitled to do so. In an inertial frame (constant uniform motion) she does not detect any motion at all. She observes her photon clock. The clock is stationary. The photons bounce up and down, each round trip denoting one second. Why should these photons fail to hit the target?
That's exactly what I've been wondering. You are saying that in order for light to go the same speed because of orthogonal motion to the path of light in a light-clock which means the light travels extra distance is the reason for space-time variance. Please read my long post on the previous page and respond to that. It makes sense according to what you've been saying.
thedoc
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Joined: Thu Aug 30, 2012 4:18 pm

Re: Relativity?

Lacewing wrote: Mon Oct 30, 2017 1:02 am Let us change the universe up a little. If Bob is on a train going nowhere, and he throws a clock out the window, how will he measure the time between repeating his posts?
Assuming it's the only clock he has, he will no longer be able to measure time, and will be left timeless. The clock will continue to measure time, (assuming it is not damaged on being thrown out) in what ever frame of reference it is in.
thedoc
Posts: 6473
Joined: Thu Aug 30, 2012 4:18 pm

Re: Relativity?

Viveka wrote: Mon Oct 30, 2017 1:26 am Yes, I completely understand what you are saying. I summed up the SRT in a sentence. However, if it is true that the photons are invariate, why do they always 'hit the target' when they are in a light-clock? Because of the variance of space and time? I addressed this in my previous post that I feel you should read. I basically say that the reason why the light-clock always 'hits the target' is because of Galilean Transformations or Light-Anchoring.

Just because Light-speed is invariate supposedly means that there has to be length-contraction and time-dilation because you are taking the invariate speed of light, and then making time and space variate in order to keep the invariancy of the speed of light. That about sums up Special Relativity.
Because the photon is aimed at the mirror even though that mirror is moving, the photon is aimed at where the mirror will be not at where the mirror is. The photon moves with the speed of the object that it is moving on, even though the speed of light is finite the distance is not, and the increased distance will require a longer time of travel.
uwot
Posts: 5068
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Re: Relativity?

Viveka wrote: Sun Oct 29, 2017 9:57 pm
uwot wrote: Wed Oct 11, 2017 9:52 pm What you have to remember is that special relativity describes what observers see when they pass each other with uniform relative velocity. If they continue with that uniform velocity, they will never know what the other's clock says, because they will simply be getting further and further away from each other.
Viveka wrote:In response to the bolded: Seriously? Whenever I move out of a room with a clock the clock stops working?
Well, if you can do that at the speed of light, then yes.
But seriously:
Viveka wrote:...why do they always 'hit the target' when they are in a light-clock?
That's yer basic optics: the angle of reflection is equal to the angle of incidence. Granted there are issues during acceleration, but you are taking this way too literally. No one, to my knowledge, has built such a light clock; much less a train that can travel at 0.6c. It is after all a thought experiment.
As I said before, you really should read my blog: http://willijbouwman.blogspot.co.uk Better still, buy the book: https://www.amazon.co.uk/dp/1521884722
I'm assuming that davidm still hasn't found time to do so, otherwise I'd knobble him for plagiarism, since his marble clock is more or less the example I use. I don't know which would pain me more.
Anyway, there's loads of pictures, and if you don't understand time dilation due to motion at the end of it, you never will.
ken
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Joined: Mon May 09, 2016 4:14 am

Re: Relativity?

davidm wrote: Sat Oct 28, 2017 9:48 pm Don't you have a anything better to do than spam this forum with your bullshit?
Where is the alleged bullshit?

davidm wrote: Sat Oct 28, 2017 9:48 pm
ken wrote: Sat Oct 28, 2017 9:22 pm
uwot wrote: Thu Oct 19, 2017 12:54 pm

Although cartography is basically the art of depicting a demonstrably spherical Earth on a 2D page, flat-earthers aside, there has been no serious attempt to describe the world as flat since Anaximander, in about 500BC. It is true that the Ptolemaic model is a mathematical description of a geocentric universe, and the reason it was so successful is that it is reasonably accurate; it actually predicts what can be seen with the naked eye very well.
My point WAS and IS that mathematical descriptions of physics can and do sometimes get shown to be wrong ...
Oh what a brilliant insight, genius! Uwot has VERY PLAINLY SAID THIS, particularly with his analysis of Ptolemy v. Copernicus, and so have I!
And I have said this first in very simple language, but that seemed to be overlooked, and then written in a way as though I had no idea of this.
davidm wrote: Sat Oct 28, 2017 9:48 pmThere's even a name for predicted theory failure, the pessimistic meta-induction, which I have also talked about.
Not all people know what all names mean, and you only talked about it after I very plainly said this.

Now human beings are predicting what parts of a theory will fail. Next they will make observatories and instruments to measure the predicted failures. And when they measure them, they conclude that the data Now proves this is correct. How much do human beings really love to try and be in control of things? As I continually ask, WHY not just look at and observe what IS?

This producing theories, and then going out making tools to ascertain if the theory is correct or not, or work out what parts are accurate and what parts fail, all being done with assumptions and beliefs playing a far bigger part and influencing the outcomes is all rather ridiculous and a complete waste of time and energy. Most human beings have not even worked out how they work yet, but try desperately to work out how every thing else works, they are trying in the wrong way I might also add.

Creating a theory and trying to work out if it fails it not, all the time while influencing the data, with in or sub conscious confirmation biases, along the way is like picking a side in the global warming issue, and then only looking for and finding any thing that fits in with and suits your "side" of the issue.

The truth is there is NO side. Like there is NO side on any issue, including creation/evoluton, nature/nurture, to name but just a couple. There is only a perceived side, which is solely made up by human beings. There only is what IS. If you want to find the actual truth of things, then just look at and observe that.
davidm wrote: Sat Oct 28, 2017 9:48 pmMoreover, we know that general relativity and quantum mechanics, one or both, must FAIL in some domain because they are IN CONFLICT.
AND where that conflict lays is very easy to find, and know.

As I have been repeatedly saying the truth and falsehoods is in all things. Learning HOW to be able to find, see, and distinguish them apart is extremely enlightening. I have partly explained this in detail before, but no person showed interested in that, so I let it be. People, like you, prefer to try and tell Me what is right instead, which I listen to, and then ask clarifying questions. This by itself shows what is known.
davidm wrote: Sat Oct 28, 2017 9:48 pm
Tell us, O genius, what IS, then, and how you know.
What Is WHAT, exactly?

And how I know WHAT, exactly?

If you want Me to answer clarifying questions, then you have to be able to clearly state what you are asking for.
davidm wrote: Sat Oct 28, 2017 9:48 pm
Which no one has denied. Do you have a point?
YES. You have clearly stated some things as being actual real and true facts. You have, therefore, denied any room for change. You are behaving like the person who believes some thing, and thus is not open to some thing else. That is My point.
davidm wrote: Sat Oct 28, 2017 9:48 pm
BUT WE DON'T SAY THAT.
BUT YOU DID SAY THAT.

There is no need to bring others into this as I have already pointed out that the other person does NOT do it as blatantly obvious as you do it.
davidm wrote: Sat Oct 28, 2017 9:48 pm
BUT HE DOES NOT SAY THAT, NOR DO I.
You do say it, intentionally. The other person, however, says it unintentionally or unknowingly.
davidm wrote: Sat Oct 28, 2017 9:48 pmEnough for now. It is increasingly difficult for me to stomach your trash, as it is for me to stomach the racists, sexists and evolution deniers here.
Maybe read from some thing else instead of the stomach.

But you can "stomach" that you, yourself, are racist and sexist, right?
davidm wrote: Sat Oct 28, 2017 9:48 pm Maybe I'll wade through the rest of your bilge later.
Enjoy.

Your ad homs and slander of uwot are really contemptible, but in addition to being utterly ignorant you are also utterly shameless. [/quote]

I have NEVER slandered any person here. If you read back what you have written about Me, then a reflection of one's own self, might mean some thing right now.

What am I supposedly ignorant of, or about, and shameless is a term that could be used.
davidm wrote: Sat Oct 28, 2017 9:48 pmHe is much more of a gentleman than I am, though, so he'll probably look at your insults and shine it all on.
I have NOT made one insult anywhere in this forum. People put their own perception of things into what is written by others, usually a bit or slot of self-reflection goes into that also.

Without first clarifying what another has written, then what is being suggested is only an assumption, which could well be absolutely WRONG. I much prefer to get clarification before I would want to make any assumption at all.

Also, trying to form separate groups and get others on your, perceived, "side" of things is not helping your case. In fact your words are just reaffirming and showing what I will say and will point out.
ken
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Re: Relativity?

davidm wrote: Sat Oct 28, 2017 10:02 pm
ken wrote: Sat Oct 28, 2017 9:41 pm
What happens if a human being could travel at the speed of light in a vacuum? If they could how would things happen for them?
How many times do we have to answer this quetion?
As many times as you like?

You claim that a human being would stop ageing, right?
davidm wrote: Sat Oct 28, 2017 10:02 pm
That EVERY thing is relative to the observer is a fact that can very easily be seen and understood. I have even stipulated this with absolutely EVERY thing is relative to the observer. Special relativity does not need to be known of to understand this.
But then we get this:
davidm wrote: Sat Oct 28, 2017 10:02 pm
Also are you absolutely sure that there is no one single unique reference frame that applies equally to all objects or observers?
No, we are not ABSOLUTELY SURE of this,
Great, but then we get this.
davidm wrote: Sat Oct 28, 2017 10:02 pmbut the point of relativity is, there is no evidence for such a frame, and tons of evidence against it. If there were such a frame, then things would NOT BE RELATIVE TO THE OBSERVER -- which you just agreed to above! You have NO IDEA what you're talking about!
Your assumptions led you to believe I have NO IDEA of what I am talking about.

You have NOT asked one clarifying question, SO every thing you say regarding this is just a complete assumption.

Does the laughter out loud at the end help you to feel more superior, in some way?

By the way how do you KNOW 'there is no evidence for such a frame'? Do you KNOW EVERY thing? Are you ABSOLUTELY SURE there is no evidence for such a frame?

If you had instead written some thing like, "I have not yet seen any evidence for such a frame", then I would NOT be pointing out your continual insistence that "current" knowledge is absolutely true, right, and unchangeable. You say you do not say things are absolute fact and true, but throughout your writings it is very plain for us to see.
davidm wrote: Sat Oct 28, 2017 10:02 pm
I have already, on quite a few occasions, actually stated one possible single unique frame of reference. But like as what happens what I write is not actually noticed and recognized, or just gets dismissed or rejected.
Oh, HAVE you?
YES.
davidm wrote: Sat Oct 28, 2017 10:02 pm Well, for us dummies, please reiterate what that unique frame of reference is

It is the unique frame of reference from EVERY thing as One, (observer).

There is nothing hard nor complicated in understanding this. In fact it is very simple, and obvious, really.

If human beings, individually and on the whole, stopped looking at things from their own perspective only, and instead started looking from Everything's perspective, as One, then being able to see things for what they really are becomes far simpler and easier.

Being completely open and observing from Everything's perspective allows ALL things to be known and understood, almost instantly. Far more can be seen and understood from a unified collective viewpoint then could ever be discovered from a separate individual viewpoint.
davidm wrote: Sat Oct 28, 2017 10:02 pm-- which would automatically invalidate your agreement, above, to the fact that there IS no such frame!
It does NOT invalidate it at all. Your assumption is once again WRONG. I NEVER agreed to there being no such frame. You just assumed that. Your beliefs led you to not being able to see things differently from what you assumed is true, right, and correct.
ken
Posts: 2075
Joined: Mon May 09, 2016 4:14 am

Re: Relativity?

davidm wrote: Sat Oct 28, 2017 10:06 pm To reiterate one more time, for the thick of wit.

1. If humans could travel at the speed of light, then relativity theory would be wrong,
Are you, in some way, here suggesting that relativity theory could NOT be wrong, in any way?
davidm wrote: Sat Oct 28, 2017 10:06 pm so the question of what humans would experience traveling at light speed is meaningless.
What is meaningless to you may not be meaningless to others.
davidm wrote: Sat Oct 28, 2017 10:06 pm How many times have this been explained to you?
From the outset I have only asked IF human beings could travel at the speed of light?

Thought experiments involve imagination, which it appears you are incapable of imagining with this scenario.

By the way if it is meaningless, TO YOU, then let it go. I will wait to see what answers other people, with imagination, give. I am certainly in no rush waiting for an answer.
davidm wrote: Sat Oct 28, 2017 10:06 pm What is actually WRONG with you?
Whatever you assume it to be. I can be as WRONG as you want Me to be.

I am sure with imagination you could make up all the WRONG you like.

But if you want the true answer to that question, then in what way, exactly, do you mean by WRONG?

Most of the time I am wholly and completely WRONG, to others, because I look at and see things differently.
davidm wrote: Sat Oct 28, 2017 10:06 pm2. Light speed is a degenerate or undefined frame, so the question of what ANYTHING would experience at light speed has no meaning in relativity theory.
Who really cares about a theory?

I find the truth far more fascinating then any theory, or story, that human beings have so far made up and told anyway.
ken
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Joined: Mon May 09, 2016 4:14 am

Re: Relativity?

davidm wrote: Sat Oct 28, 2017 10:08 pm
ken wrote: Sat Oct 28, 2017 10:04 pm

How long does a trip take, that travels four light years travelling at the speed of light?
See above. Reread the thread. This has been answered about 250 times by more than one person.
I looked. I can not find it. What was your answer again?
ken
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Joined: Mon May 09, 2016 4:14 am

Re: Relativity?

davidm wrote: Sat Oct 28, 2017 10:13 pm
ken wrote: Sat Oct 28, 2017 9:56 pm What I write is just a view I have. If what I write above is wrong or partly wrong, then just show that. If you disagree with it, then just show what part you disagree with and most importantly WHY you disagree.
We have done that. Repeatedly.
But I have not really said anything, yet, to disagree with. I have only really asked questions with the proviso IF IT WERE POSSIBLE.
ken
Posts: 2075
Joined: Mon May 09, 2016 4:14 am

Re: Relativity?

davidm wrote: Sat Oct 28, 2017 10:16 pm
ken wrote: Sat Oct 28, 2017 10:09 pm
davidm wrote: Sun Oct 22, 2017 4:24 pm

I've already answered this question -- several times. Scroll back and look for the answers. Good luck!
Whenever a person wants to deflect away from just giving an answer a "scroll back" or similar, response quite frequently given.

Why can you not answer the question now?
Why should I waste my time just repeating what I have already written? Scroll back and you will find my answers.
Why the "good luck" is it because you could not even be able to find it if you were to look for it?
No, it's because someone a thick as you will need a lot of luck to understand anything at all.
You have previously given two conflicting answers, which one do you want Me to accept?
And those "conflicting answers" were what, now?
"Scroll back", and you will find.
ken
Posts: 2075
Joined: Mon May 09, 2016 4:14 am

Re: Relativity?

davidm wrote: Sat Oct 28, 2017 10:18 pm
ken wrote: Sat Oct 28, 2017 10:13 pm Do you want to know, or do you just want to remain wondering?

Because if you want to know, then surely by now you know what the best thing is to do.
Why don't you just answer the question?
What question?

I have answered all your questions. If I have missed one, then do not be afraid to just ask again.
davidm wrote: Sat Oct 28, 2017 10:18 pm Do you think your Smart Phone''s GPS works by magic?
No.
ken
Posts: 2075
Joined: Mon May 09, 2016 4:14 am

Re: Relativity?

davidm wrote: Sat Oct 28, 2017 10:28 pm
ken wrote: Sat Oct 28, 2017 10:21 pm
davidm wrote: Sun Oct 22, 2017 8:51 pm Real-World Relativity: The GPS Navigation System

From the above link, bold mine:

Now tell us all about the “real truth,” Ken.
The real truth about what exactly?
You wrote:
Do you want to know, or do you just want to remain wondering?
Yes, O genius, I want to KNOW!!!!

Please ENLIGHTENUM us Lower Sods! Hurry up, I have a plane to catch!
You wrote;
davidm wrote: ↑Mon Oct 23, 2017 1:35 am
I wonder if Ken has a smart phone with a GPS device? If he does, I wonder what Ken infers from this?

My question; Do you want to know, or do you just want to remain wondering? Was in direct response to your quote here.

So, if you really want to KNOW, then yes I have a smart phone with a gps device, and, I infer from this, that this smart phone has a gps device.

Was there some thing else you were presuming I would infer from this?