126 replies to this topic

[Pliny]

[quote name='kimmy' date='16 October 2011 - 12:14 PM' timestamp='1318792461' post='719645']
Ultimately, your only argument against time dilation is that it contradicts what your "common sense" tells you, and your response to all these experiments that prove it happens is ... "well, there must be something wrong with the experiments!"
[/quote]
Actually, the argument is that light is a constant. Einstein's calculations are based upon light being a constant. His formulae will prove time dilation only if light is held as a constant. The doppler effect tells us it isn't a constant.

Energy shifts at different speeds used as a calculation, that is - a timer or clock, are thus not reliable unless light is a constant.

Here is the mathematical equation that proves time dilation.


[quote]Let us say that the clock at rest bounces light between mirrors separated by distance (d1).
So d1 = (c Dt1), where c is the speed of light, and Dt is the time it takes for a photon to
travel between the mirrors. Now we make an identical light clock, but have it move
normal to its light beam at close to light speed. Obviously the observer by the resting
clock sees the photons in the moving clock travel farther for each tick. The light clock
also seems to tell time slower because the photon seems to have to run farther in the
resting observer's space. We can call the apparent diagonal path of the photon in the
moving clock as seen by the observer at rest (d2) = (c Dt2), where (Dt2) is the dilated
time interval he measures. Taking (v) as the velocity of the moving clock, we get by the
Pythagorean relation:
* d1^2 = (c Dt2)^2 - (v Dt2)^2.
Here is where Einstein does his little trick. He multiplies the term (v Dt2) ^2) by the
factor (c^2 / c^2). This allows him to divide the whole equation by the factor (c Dt2)^2.
* d1^2 / (c Dt2)^2 = 1 - (v^2/c^2).
He then takes the square root of the whole thing and ends up with his famous factor.
* d1(c Dt2) = [1 - (v^2/c^2)]^1/2.
* Dt2 = (d1 / c) [1 - (v^2/c^2)]^-1/2.
Suppose, however, that we step back and leave out the little math trick. We still get:
* (Dt2 / Dt1)^2 = c^2 / (c^2 - v^2).
You can see from this that when (v) is very small, the ratio of time intervals (Dt2/Dt1) is
practically unity. However, as (v) approaches ©, (Dt2) gets much larger than (Dt1).
This is time dilation.
[/quote]
that from this site http://www.dpedtech.com/FTreview.pdf
[quote]

Has it ever occurred to you that your "common sense" doesn't really have any bearing on how things operate when they're traveling at near the speed of light?

Have you ever actually sat down with a textbook and a pencil and paper and tried to walk through the thought experiment that illustrates why events that appear simultaneous in one frame of reference don't happen simultaneously when viewed from a different frame of reference? Have you made any real attempt to understand any of this, or do you just sit there and say "that can't be true because it disagrees with my common sense" and flail around for some way of dismissing it to spare yourself the mental discomfort of dealing with a universe that contains things that are bigger and broader than you experience when you're driving your car to work?
[/quote]
My background is electrical so I know a little bit about physics. And because electrical theory has changed over time I know that a theory only has as much value as it can be practically applied.
The orignal theory of electricity has been proven to be incorrect by physics but it still makes a workable theory that we can apply practicably. When we have the exact theory we may even do more amazing things.

I am constantly amazed at what I find in physics. They have reasoned that the physical universe collapses and expands continually and have even calculated the rate. It's all theory of course.

But what you are saying is that the theory of relativity is all we have right now. And it is, even with all it's anomalies, correct. All I am saying is that it's anomalies are an indication it is not correct.
[quote]
Don't look now, but...
Dutch researchers solve the "speedy neutrino problem".

And you're going to love the explanation:

The CERN scientists used GPS satellites to synchronize the time at the sending station and receiving station. But since the satellites are moving 9000 miles per hour relative to the earth, the time sync signal at the receiving station came from a frame of reference where time is moving more slowly than in the scientists frame of reference.

Due to time dilation in the satellite frame of reference, the GPS told the scientists at the receiving station that the trip took less time than it actually had.

(common-sense analogy: my Malibu can do a 12-second quarter-mile... if you time it on a stop-watch that's running slow.)
[/quote]
So you are saying they made a mistake? Of course, it must be a mistake. But how could they have made a mistake like that. It seems a rather elementary mistake.
[quote]
Nope. It might not be explainable under current theories, but it does nothing to help your arguments against time dilation.
[/quote]
It is just common sense I guess.
[quote]
Actually, I'm thinking your inability to accept that there's no single absolute time reference is a lot like the church's refusal to accept a heliocentric solar system.

You'd like to imagine you're forward-looking, but your "open-mindedness" is actually just a result of your willingness to jump on any possible theory that lets you cling to your Flat-Earth-like opinion that time couldn't possibly be relative. It's not actually open-mindedness at all, it's the desperation of denial.
[/quote]
Yes it is desperation to claim general relativity a theory.
[quote]

It wasn't the scientific community that opposed Galileo, it was the church. The scientific community was already aware that a geocentric universe didn't explain observations about the movement of the planets as far back as the time of the ancient Greeks. The scientific community had already seen evidence by astronomers-- Kelper, Tycho-- showing that other planets must orbit the sun. The scientific community saw the heliocentric model by Copernicus. The science and astronomy communities were discussing heliocentric models of the solar system for a hundred years before Galileo got arrested.

In short, it wasn't the scientific community that considered Galileo's views radical. He was confirming stuff that astronomers and mathematicians had been talking about for a long time. It wasn't until Galileo published a best-seller that contradicted the church view that he got arrested. It wasn't the scientists who arrested Galileo. It wasn't scientists who made him recant. It wasn't scientists who banned his book.
[quote]
No. It was just scientists that didn't want to get locked up. They denied they knew anything. And for a few more decades or so they kept the truth a secret. Or did they keep on trying to explain it to the King? And what of scientists that were in the employ of the King and knew the truth? Would they deny it and save their own positions? Would they accept the truth?

It had to be scientists themselves that perpetrated the Copernican theory beyond it's time. We can conclude they either knew and lied by denying they knew or they simply didn't know and preferred it. You choose to believe they lied. I think they just didn't care to look because they were comfortably sitting at the King's council and all was well.

[quote]
I'm quite baffled by all of this. It seems as if you're arguing that life doesn't have any meaning unless you can find some way to convince yourself to believe in fairy-tales. I find that to be quite sad.
[/quote]
yeah. it's a pretty lonely world. Which is why I invented you.
[quote]
And that's just nonsense. The belief that there's a natural explanation for everything does not in any way imply that we know everything or discount the possibility of new and unexplained experiences.
[/quote]
We can't know everything. What would we do?
[quote]
My plans for myself certainly don't involve doing anything after I'm dead. And anybody who puts off making the most of their few decades on earth because they're expecting bigger things after they die is, in my opinion, making the biggest possible mistake.
[/quote]
Au contraire. you are more likely to attempt making the most of your few decades if you expect bigger things after. If you are just an animal or a body the prime and central theme of your life will be it's preservation. Not saying it isn't a part of everyone's life but it becomes one's only concern under that concept and we start worrying about things like politics and health instead of our potential.
[quote]
This is just inane. The believe in a natural explanation for everything doesn't in any way discount anything you experience.
[/quote]
There are rules.
[quote]
The truth is a grand and wondrous thing. It doesn't suck at all. And the more you learn about our universe, the more you'll appreciate how amazing it really is.
[/quote]
Couldn't agree more. But it is more realizing how amazing you really are.

[ToadBrother]

Actually, the argument is that light is a constant. Einstein's calculations are based upon light being a constant. His formulae will prove time dilation only if light is held as a constant. The doppler effect tells us it isn't a constant.

Einstein's calculations (and not just his calculations, but several important constants) are based upon the speed of light being a constant in a vacuum. The actual speed of photons themselves is not, however, guaranteed to be c.

Yes, the speed of light in a vacuum is constant.

[Pliny]

Einstein's calculations (and not just his calculations, but several important constants) are based upon the speed of light being a constant in a vacuum. The actual speed of photons themselves is not, however, guaranteed to be c.

Yes, the speed of light in a vacuum is constant.

Welcome to the conversation. kimmy mentioned you would be a worthy participant.

Where is light traveling through a vacuum?

[ToadBrother]

Welcome to the conversation. kimmy mentioned you would be a worthy participant.

Where is light traveling through a vacuum?

Well, intergalactic space is reasonably close, with matter and energy densities being extraordinarily low. Even interstellar space has low enough densities that a fair number of photons from any given source will travel at c. But even in earlier epochs, when the universe was much smaller and densities were absurdly high, c was still a constant, even if few photons could be expected to travel far.

Generally speaking what we're referring to here is the propagation of light. Different materials and mediums will effect that propagation, due to photons being absorbed and re-emitted. So when you talk about photon speed, or speed of propagation, in effect you are talking about something separate than c.

The fact is that "speed of light" is somewhat a sloppy term, as it can both refer to the speed of a photon and to the constant c. In a perfect vacuum, the two will always be identical, but obviously in the real world there are no lack of mediums through which photons have to travel which will effectively mean that they will propagate slower than c.

[Pliny]

Well, intergalactic space is reasonably close, with matter and energy densities being extraordinarily low.

Is it? What is light?

Even interstellar space has low enough densities that a fair number of photons from any given source will travel at c. But even in earlier epochs, when the universe was much smaller and densities were absurdly high, c was still a constant, even if few photons could be expected to travel far.

Generally speaking what we're referring to here is the propagation of light. Different materials and mediums will effect that propagation, due to photons being absorbed and re-emitted. So when you talk about photon speed, or speed of propagation, in effect you are talking about something separate than c.

The fact is that "speed of light" is somewhat a sloppy term, as it can both refer to the speed of a photon and to the constant c. In a perfect vacuum, the two will always be identical, but obviously in the real world there are no lack of mediums through which photons have to travel which will effectively mean that they will propagate slower than c.

Could light be something like sound only on an atomic level? Sound travels through a medium by creating a wave, essentially one molecule knocking the next molecule. Could light be atomic reactions of energy, say from the heat of the sun, just knocking the next particle? Upon reaching an atmosphere becoming a diffusion of atmospheric particles as they bump each other? You probably get the idea if I haven't expressed it well. The concept comes from Mark McCutcheon's Expansion theory which I find interesting.

[ToadBrother]

Is it? What is light?

Could light be something like sound only on an atomic level? Sound travels through a medium by creating a wave, essentially one molecule knocking the next molecule. Could light be atomic reactions of energy, say from the heat of the sun, just knocking the next particle? Upon reaching an atmosphere becoming a diffusion of atmospheric particles as they bump each other? You probably get the idea if I haven't expressed it well. The concept comes from Mark McCutcheon's Expansion theory which I find interesting.

Photons are both particle and wave; or more specifically a photon is a quanta of light. You're invoking an invalid analogy. That's not to say that photons cannot produce pressure, but it strikes me you're muddling together a number of different concepts here. The photons that you see coming from Andromeda were produced by Andromeda, and are not some nth generation of photons. A lot of the photons in certain regions may essentially be lost, in that the mediums through which they travel absorb light at certain frequencies, but those that make it through were the ones that started the journey from whatever radiation source gave birth to them.

At any rate, the fact remains that even if individual photons, because of the medium through which they travel, do not travel at c, the value of c itself is a constant, and more importantly a constant that is reflected in several other basic constants. If c is not a constant, then pretty much the entirety of the modern edifice of physics collapses, and I think we've confirmed enough of Relativity and QM to suggest that, while there are huge deficiencies in our knowledge, the speed of light being a constant is not among them.

[Pliny]

Photons are both particle and wave; or more specifically a photon is a quanta of light. You're invoking an invalid analogy. That's not to say that photons cannot produce pressure, but it strikes me you're muddling together a number of different concepts here. The photons that you see coming from Andromeda were produced by Andromeda, and are not some nth generation of photons. A lot of the photons in certain regions may essentially be lost, in that the mediums through which they travel absorb light at certain frequencies, but those that make it through were the ones that started the journey from whatever radiation source gave birth to them.

Fair enough.

We don't observe light until it reaches an atmosphere and light doesn't seem to get in the way of shadows.

At any rate, the fact remains that even if individual photons, because of the medium through which they travel, do not travel at c, the value of c itself is a constant, and more importantly a constant that is reflected in several other basic constants. If c is not a constant, then pretty much the entirety of the modern edifice of physics collapses, and I think we've confirmed enough of Relativity and QM to suggest that, while there are huge deficiencies in our knowledge, the speed of light being a constant is not among them.

Well, of course any different theory would collapse the modern edifice of physics.

[kimmy]

Actually, the argument is that light is a constant. Einstein's calculations are based upon light being a constant. His formulae will prove time dilation only if light is held as a constant. The doppler effect tells us it isn't a constant.

What?! "The Doppler effect tells us it isn't a constant"? What the hell are you talking about? I can't let that slide. Please expand on that idea.

I am constantly amazed at what I find in physics. They have reasoned that the physical universe collapses and expands continually and have even calculated the rate. It's all theory of course.

The collapse of the universe was a possibility, but it would only happen if there's sufficient mass to pull everything back to the center. But last I heard, they were only aware of a fraction of the mass required to "close" the universe, leaving the most likely outcome an eternal expansion and eventually entropy wins.

But what you are saying is that the theory of relativity is all we have right now. And it is, even with all it's anomalies, correct. All I am saying is that it's anomalies are an indication it is not correct.

What are these "all its anomalies" you keep talking about? By "anomalies" do you mean things that disagree with your "common sense"?

Yes it is desperation to claim general relativity a theory.

Gravity is "just a theory" too, but we know that if you drop a brick it'll land on the floor 100% of the time.

Relativity is "just a theory", but we know that time dilation is real just as surely as we know that bricks fall.

No. It was just scientists that didn't want to get locked up. They denied they knew anything. And for a few more decades or so they kept the truth a secret. Or did they keep on trying to explain it to the King? And what of scientists that were in the employ of the King and knew the truth? Would they deny it and save their own positions? Would they accept the truth?

You've got it wrong. Scientists of the day did explain it to the church, who were very interested in the theory because they were interested in accurate calendars. The church adopted the position that the heliocentric model was a useful predictive tool, but not theologically accurate.

Scientists weren't hiding stuff. They shared it with the church and with various nobles who were their patrons. It was only when Galileo shared it with the rubes on the street that the excrement hit the air circulator. You were allowed to study things... you just weren't allowed to let the people know that the church was wrong.

It had to be scientists themselves that perpetrated the Copernican theory beyond it's time. We can conclude they either knew and lied by denying they knew or they simply didn't know and preferred it. You choose to believe they lied. I think they just didn't care to look because they were comfortably sitting at the King's council and all was well.

"Perpetrated the Copernican theory beyond its time"? The Copernican theory was ahead of its time. The reluctance of some scientists was in some measure adherence to an idea they assumed to be correct (the earth must be the center of the universe because the Old Testament says so) and partly because of incomplete information.

Au contraire. you are more likely to attempt making the most of your few decades if you expect bigger things after. If you are just an animal or a body the prime and central theme of your life will be it's preservation. Not saying it isn't a part of everyone's life but it becomes one's only concern under that concept and we start worrying about things like politics and health instead of our potential.

If you sincerely believe this life is a prelude to a better one, why worry about your preservation at all? Why work? Why obtain money to pay for food or shelter? Why not just go starve to death so you can get to the main show?


While I do take great care to preserve my life and my health, that's hardly all-consuming. I take great pleasure in enjoying life as much as I can, because I believe in my heart that these few decades are all I have.


-k

[Pliny]

What?! "The Doppler effect tells us it isn't a constant"? What the hell are you talking about? I can't let that slide. Please expand on that idea.

Sorry - refraction. The Doppler shift doesn't seem to apply to light. Something about relativity?

The collapse of the universe was a possibility, but it would only happen if there's sufficient mass to pull everything back to the center. But last I heard, they were only aware of a fraction of the mass required to "close" the universe, leaving the most likely outcome an eternal expansion and eventually entropy wins.

It isn't a collapsing inward that I am talking about.

What are these "all its anomalies" you keep talking about? By "anomalies" do you mean things that disagree with your "common sense"?

You haven't heard of any anomalies?

Gravity is "just a theory" too, but we know that if you drop a brick it'll land on the floor 100% of the time.

It's a "theory" adopted to explain that phenomenon. There can only be two possibilities. Mass has an attractive force that causes objects to move towards it at 9m/sec^2 or the earth is expanding at a rate of 9m/sec^2. Any other theories you can think of that could make this happen?

Relativity is "just a theory", but we know that time dilation is real just as surely as we know that bricks fall.

Are bricks falling or is the Earth moving everything towards the brick? Time dilation is a nice thought experiment.

You've got it wrong. Scientists of the day did explain it to the church, who were very interested in the theory because they were interested in accurate calendars. The church adopted the position that the heliocentric model was a useful predictive tool, but not theologically accurate.

Scientists weren't hiding stuff. They shared it with the church and with various nobles who were their patrons. It was only when Galileo shared it with the rubes on the street that the excrement hit the air circulator. You were allowed to study things... you just weren't allowed to let the people know that the church was wrong.

Well, of course the church couldn't be wrong. So everyone "in the know" thought they would just lie to the rubes on the street is what you are saying. Galileo sort of let the cat out of the bag, kinda thing?
Is that it?

"Perpetrated the Copernican theory beyond its time"? The Copernican theory was ahead of its time. The reluctance of some scientists was in some measure adherence to an idea they assumed to be correct (the earth must be the center of the universe because the Old Testament says so) and partly because of incomplete information.

Boy! Caught me again. I meant the Ptolemaic system. Sorry about that.

If you sincerely believe this life is a prelude to a better one, why worry about your preservation at all? Why work? Why obtain money to pay for food or shelter? Why not just go starve to death so you can get to the main show?

It isn't a prelude to a better one. You have to earn it. There is no free lunch.

While I do take great care to preserve my life and my health, that's hardly all-consuming. I take great pleasure in enjoying life as much as I can, because I believe in my heart that these few decades are all I have.

Right! Ever consider climbing Mt. Everest? After all these few decades are all you have! Why risk that? There are better things to risk your life on like chocolate cheesecake. Pretty soon you have a public health care system and they start making laws that say you shouldn't be doing certain things that aren't healthy, like eating junk food. And you should weigh a certain amount
and you should exercise according to the exercise guide. These are all proper things you should be concerned about. If you are doing risky things with your life, like climbing mountains, or smoking or eating at MacDonald's, then public health will not cover any ill health or minimally there will be a premium to pay. You need to be concerned about your body and it can become all consuming. There is only so much your weak and frail self can take. Get out there and start working out with some non-competitive activities(competitive ones may not be good for your heart). And you could get cancer so get checked out for that, get your prostate checked, and that kinda stuff. Take what the good doc tells you and make sure you get those prescriptions filled! It's all common sense if you wish to live for a few decades.

If all you have is a body then that is what you will focus on. If you believe you have potential then that is what you will focus on. In your youth you might consider it romantic to flirt with death but a public health care system will do it's best to discourage you of that.

But we are talking about physics here.

[Bonam]

It's a "theory" adopted to explain that phenomenon. There can only be two possibilities. Mass has an attractive force that causes objects to move towards it at 9m/sec^2 or the earth is expanding at a rate of 9m/sec^2. Any other theories you can think of that could make this happen?

Why are you stuck on this "expansion" theory of gravity of yours? It absolutely does not explain commonly observed phenomena, such as the orbits of the planets around the Sun (or the orbit of anything around anything). Contrary to your earlier post, you can't turn a straight line into a circle/ellipse by this "expansion". Basic geometry.

Mass has an attractive force that causes objects to move towards it at 9m/sec^2

Though you are trying to describe the normal theory of gravity here, there are numerous errors just in this one sentence fragment. Given that you seem curious about physics, why not go pick up some actual legitimate books on the topic and learn something interesting, rather than confusing yourself with nonsense?

Edited by Bonam, 23 October 2011 - 12:24 AM.

[Bonam]

Sorry - refraction. The Doppler shift doesn't seem to apply to light. Something about relativity?

Of course the Doppler effect applies to light. In fact, the Doppler effect on light is one of our main tools for measuring the distances and velocities of distant galaxies.

Since you brought it up, do you know what the Doppler effect actually is? Without running to google/wikipedia to answer the question?

Edited by Bonam, 23 October 2011 - 12:22 AM.

[Bonam]

It's a "theory" adopted to explain that phenomenon.

General relativity is so widely accepted precisely because this is not at all the case. General relativity described phenomena that had never been observed. No one had ever thought of a black hole before, or seen one. But it popped right out of the equations of general relativity. And years later astronomers found black holes. Same with gravitational lensing and gravitational waves, among other examples.

When a theory can not only explain currently known phenomena, but predict entirely new, entirely unprecedented ones, that later turn out to really exist in reality, that lends great credence to that theory.

GR is quite possibly the most amazingly solid theory in all of physics.

Edited by Bonam, 23 October 2011 - 12:38 AM.

[kimmy]

Sorry - refraction. The Doppler shift doesn't seem to apply to light. Something about relativity?

Do yourself a favor and put down that Mark McCutcheon book for a while. Read about redshift.

You haven't heard of any anomalies?

I'm just curious as to why you're so non-specific about them. If these "anomalies" are the basis of your objection to relativity, you must be able to articulate them.

It's a "theory" adopted to explain that phenomenon. There can only be two possibilities. Mass has an attractive force that causes objects to move towards it at 9m/sec^2 or the earth is expanding at a rate of 9m/sec^2. Any other theories you can think of that could make this happen?

Are bricks falling or is the Earth moving everything towards the brick? Time dilation is a nice thought experiment.

Well, of course the church couldn't be wrong. So everyone "in the know" thought they would just lie to the rubes on the street is what you are saying. Galileo sort of let the cat out of the bag, kinda thing?
Is that it?

Copernicus and Kepler and Tycho didn't lie to the rubes on the street. They just didn't publish them in wildly popular books. The rubes on the street didn't really have access to the correspondence between the leading scientists of the day. They couldn't just go down to the magazine shop and buy an Astronomy Society Journal.

Right! Ever consider climbing Mt. Everest? After all these few decades are all you have! Why risk that?

I don't plan on climbing Mt Everest because it would be a highly inefficient use of my limited time and resources. What about you? As a liberated spirit-being with unlimited potential, you must be planning to climb Mt Everest any day now, right?

There are better things to risk your life on like chocolate cheesecake. Pretty soon you have a public health care system and blah blah blah blah

What a bizarre rant. The notion that disbelief in an afterlife inevitably argues for for some sort of restricted code of behavior state interventionism is inane and disjointed. It should be pointed out, however, that every formalized belief in an afterlife (that I'm aware of, at least) imposes restrictions on your behavior in this current life; if you don't follow the rules in this life you don't get the big present after you die (or, as you put it, "you've got to earn it.")

-k

[Pliny]

General relativity is so widely accepted precisely because this is not at all the case. General relativity described phenomena that had never been observed. No one had ever thought of a black hole before, or seen one. But it popped right out of the equations of general relativity. And years later astronomers found black holes. Same with gravitational lensing and gravitational waves, among other examples.

When a theory can not only explain currently known phenomena, but predict entirely new, entirely unprecedented ones, that later turn out to really exist in reality, that lends great credence to that theory.

GR is quite possibly the most amazingly solid theory in all of physics.

The theory of electricity harnessed it's energy for us and made many things predictable. It gave us practical application but the original theory of electrons moving along a wire wasn't what was happening on a molecular level at all.

GR has to ignore certain phenomena to remain intact. It states that energy can neither be created or destroyed but merely changes form one form to another. So gasoline gets burned and creates heat and a vehicle will move down the road. But there are obvious energy sources that do not get drained, there is a constant force and no seeming depletion of that force.

[ToadBrother]

The theory of electricity harnessed it's energy for us and made many things predictable. It gave us practical application but the original theory of electrons moving along a wire wasn't what was happening on a molecular level at all.

GR has to ignore certain phenomena to remain intact. It states that energy can neither be created or destroyed but merely changes form one form to another. So gasoline gets burned and creates heat and a vehicle will move down the road. But there are obvious energy sources that do not get drained, there is a constant force and no seeming depletion of that force.

Please do tell us where these infinite sources of energy are. I can tell you right now that Thermodynamics applies to everything, even the Universe, and perpetual motion machines are quite impossible. Entropy rules all.