Existence

Hi ICANT,
Permit me to butt in again before departing for the depths once more... The answer to your conundrum should be glaringly obvious if you had ever cared to read anything about relativity. You see, time dilation (terrible word that) does not stand alone, there is also length contraction (another bad choice of word). If you're travelling at c/2, the distance you travel in your frame of reference is also reduced, coincidentally by the same amount that the time is "dilated" in that frame.So the opening statement of the quote is WRONG - and of course, the rest then just falls apart.If you execute your turn-around at a pre-determined point one light-year from the Earth (as measured FROM EARTH), then you'd arrive earlier than you expect - your odometer would read 0.87 light years and your dash clock only 1.75 years.... on your return, you'd only have been travelling for 3.5 years, although 4 years would have elapsed on Earth. And if you'd planted a flag at the turn-around point, when you return to Earth you'd see it's really 1 light year away after all!Oh, and before you get clever with me, if you'd gone on for the whole 2 years so that your odometer read 1.0 ly before turning, then 4.6 years would have elapsed on Earth and measurements would show that you've planted the flag 1.15 light years away.Hard to twist your mind around, but no contradiction, no paradox. As I've said earlier it's mathematically INEVITABLE if the speed of light is to remain constant in all inertial frames - only you won't do the maths, will you? And it's been experimentally proven - as others have already told you, you really should read up about the cosmic-ray muon problem, which you've also been avoiding.And I'll leave you with a quotation, from worthier lips than mine - there are none so blind as those who WILL NOT see.

Yes as viewed from the ground clock reference frame. However, the clock on the satellite would no longer reflect the passage of time on the satellite.

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If the speed of c is constant how could I close the gap between our ages?

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I haven't checked the math, but fizz57102's posts describes the SR effects properly. The short answer is that SR is not just about rulers shrinking and clocks slowing. It's about length contraction and actual time dilation. Yes, I see Monti's claims that Michelson was a pathological liar and a fool, and that Einstein was an incompetent failue. The problem is that the Michelson's experiments have been repeated and poured over by doubters who would have caught the errors Monti claims exist.The second problem is that SR and GR make predictions that are matched by experiment. Monti won't be credible until he takes all of those things on.Monti further claims that Eddington's eclipse observation results were a swindle. This claim may have some support, but Eddington's experiment was repeated by others on many occasions. The results confirm GR.Further, Monti claims that the perihelion advance was corrected from 43 seconds or arc per century to 50.9 in 1930. This is an outright fabrication. The current accepted value for the anomaly is 42.98 arc seconds per century, matching the values predicted by GR.Further the values for Venus and Earth, 8.6 and 3.8 arc seconds per century, respectivrly, match the values predicted by General Relativity. Relativistic Perihelion Precession of Orbits of Venus and the EarthR. Monti's claims don't seem to hold water, IMO.

You experience less than four years of travel time because the speed of light is constant for all observers.Suppose that just at the same time you reached 1/2 c on your space bike, a bullet traveled by the Earth towards you at .8 c. Your stationary wife on Earth observes it pass by the Earth at .8 c, but from your perspective, as a result of your velocity in the same direction as the bullet, you observe it's speed to be .3 c (.8 - .5). That's because the relative velocity of objects depends on their velocities relative to each other. That's a perfectly sensible and Newtonian way to describe motion in the universe.But, light is apparently different. Suppose instead of a bullet, it's a photon. Your wife sees it pass the Earth at 1 c, the speed of light. But here's the thing - you also see it approach from your hindquarters at 1 c. Again, the isotropic nature of the speed of light is both mathematically inescapable and experimentally verified.But since speed is distance over time, the only way it works out that you and your wife see the speed of the photon as identical regardless of your individual velocities is if velocity itself has a corresponding effect on distance and time. And, experiments have verified that this is the case - your velocity of .5 c results in time slowing down for you personally, such that you experience things in other reference frames happen at increased rates. People looking into your reference frame from outside see things happening on your space bike at decreased rates.This time dilation is a necessary consequence of the speed of light being the same for all observers.

Hi fizz,Welcome to EvC. It is only wrong if you believe in magic.Light year equals the distance light can travel in 365.2425 mean solar days.So at 1/2 c it would take 730.485 mean solar days to travel 1 light year.If you went back and read my design for the trip you will notice I designed it with a turn around that does not require slowing from 1/2 c.The light year would be completed at the half way point through my turn around making it an equal light year back to earth.At this point in my journey 730.485 mean solar days have passed.Since the speed of light is constant it will take 365.2425 mean solar days for the image of my turn around to reach my wife. At which time I will be half way back to earth.At which point the images of my return trip will all be cramed into my final 365.2425 mean solar days. So my wifes preception would be that I was now traveling at the speed of light.My total trip would take 1460.97 solar days unless the speed of light changes.But you and others tell me "you'd only have been travelling for 3.5 years, although 4 years would have elapsed on Earth".That is magic, not science.Since I did not take an atomic clock with me I don't know how many solar days it would represent had passed.I do know if I had carried one that the further I got from earth the faster the tick rate would have been. What I don't know is what effect the gravatational field of the sun would have on the clock nor do I know what effect the gravatational field of the planet I circled would have on the clock.A clock runs slower the lower it is in a gravatational field.

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From the principle of equivalence, Einstein predicted that clocks slow down in a gravitational field.

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http://docs.google.com/viewer?a=v&q=cache:kVTIff-pBE8J:ar...Notice the clock slows down not time.

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For GPS satellites, GR predicts that the atomic clocks at GPS orbital altitudes will tick faster by about 45,900 ns/day because they are in a weaker gravitational field than atomic clocks on Earth's surface.

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SourceNotice that the clock ticks faster not that time passes faster.

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The experimental evidence shows that the gravitational potential affects: (1) the rate at
which clocks run;

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SourceNotice that gravitational affects the rate at which the clock ticks (runs) at, and not the speed at which duration passes.Hatch has worked in the GPS industry since he graduated from college. He holds a dozen patents, and is responsible for most of the software used in GPS systems including the one used by construction companies to build grades and control equiptment to be able to cut a grade within 1/4 inch. That has to be pretty accurate computations, which means he knows what he is talking about or is very lucky. Except those who have their heads buried in the sands of dogma and refuses to even look at the evidence.God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

Hi crash, So the speed of light is not a constant speed.God Bless,

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"John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."

You're still thinking of c as comparable to a moving object on Earth.If you stand on a train that's moving at 60 MPh, and another train is coming towards you at 60MPh with me standing on it, you and I will see each other approaching at 120MPh. We'll see the ground being passed by at 60MPh.But if we shine lasers at each other from our respective trains, we'll both observe the speed of light moving at exactly c. Not c plus or minus 120MPh, but exactly c. Even though we're approaching each other and the velocity of anything we "throw" at each other should have the cumulative velocity of the throw plus the speed of the trains, the speed of light does not. It moves at exactly c (for the purpose of this example, imagine there's no atmosphere; the light is "slowed down" in a medium, not because c changes, but rather because light is absorbed and re-emitted as it passes through a medium like air).Even when our trains pass each other and we're moving away from each other, c stays the same. Both of us measuring the laser light's speed as we first move towards each other at 120MPh and then after we pass and we move away from each other at 120MPh will still record the light's speed as c.The same would happen if we were on rockets moving at 1000MPs, or 10,000MPs, or even at .5c.The speed of light is measured identically regardless of the frame of reference of the observer.The speed of light is the only constant frame of reference. It's everything else that gets measured differently.These things have been proven in countless different experiments.Once again you show that you don't know a damned thing about the topic you're discussing.

Please refrain from insulting religious people.
Thank you.

Your entire post is simply denial. We all know that if you use simple classical mechanics you are going to get answers that do not reflect the effects of relativity. Why do you think presenting such calculations advances your position in any way? Do you think we disagree with you because we are not able to do arithmetic? You mean because you deny SR you are not going to speculate.
Gravity is not the only thing that causes time dilation. In fact, the gravitational effect on the time/clocks is pretty much negligible for this problem compared to the effects from SR (given any reasonable assumptions). ICANT, is it really your position that no evidence in favor of SR/GR has been presented or discussed in this thread?Edited by NoNukes, : No reason given.

Hi ICANT,
I note that you've responded in your (thankfully) inimitable style. Your post is so full of errors, irrelevancies and misunderstandings that one doesn't know where to start responding. So rather than a line-by-line rebuttal, which would only lead to an ever-lengthening ping-pong between us, I'm going to focus on just one point. I won't forget the others, though, but we need to get some things clear first.You tell me: but you tell crashfrog: Can you please make up your mind on this? Once you've decided which position to take, we can proceed.Edited by fizz57102, : removed parting shot in the hope ICANT will focus on the question.Edited by fizz57102, : Complete rewrite to prevent another possible weasel-out

In general? No, the speed of light is slower in different media than it is in a vacuum. That's the physical principle behind refraction by lenses, for instance.But, no, the speed of light in a vacuum is the same for all observers regardless of their velocity. For that to be the case, time and dimension (as well as mass, as it turns out) have to be relative to your inertial reference frame.I'm not sure how it is that you read my statement and decided that it was saying the exact opposite of what it said, but to correct you: no, the speed of light in a vacuum is a constant speed C that is the same for all observers regardless of their inertial reference frame.

Your wife will witness a 2 year trip, but using the same clock she is using you will observe a much shorter trip. This difference in the passage of time increases as your velocity increases. If you are travelling at 0.99c a travel distance of one light year will take about 51 days by the clock used by the traveller. This has all been confirmed by the Hafele-Keating experiment that I linked to before. It has nothing to do with the gravitational force on the clock mechanism. Time ticks at different rates in different interial frames. This was confirmed in the Hafele-Keating experiment where both planes flew at the same altitude. The clocks went out of synch based on which direction they flew (east vs. west) compared to the stationary clock on Earth. The plane flying with the rotation of the Earth did not show as much time dilation as the plane flying against the rotation of the Earth. The effect of altitude is removed from this experiment. False. Time itself moves faster.

That is the experiment I was trying to think of.
Thanks for posting it.I wait to see if ICANT's "clocks are effected by gravity" hypothesis can explain why two planes flying at the same height experience different "clock speeds".

Obviously ICANT's hypothesis is useless to explain either time dilation or clock rate changes when there is no change in the gravitational potential.The aircraft experiment has been mentioned at least one other time. Data from a partial repeat of the experiment has also been presented. I don't believe ICANT has ever acknowledged, let alone attempted to explain, either experiment.Generally speaking, evidence of time dilation predicted by SR has been ignored by ICANT. He simply keeps repeating is mantra about gravity affecting clocks even when that isn't at issue.Yet ICANT has the sac to insist that his detractors are the ones ignoring evidence.

I concur (but I am willing to be proved wrong). It is a long thread. I skipped a few pages...

Does your God exist? If so, is existence eternal or did it begin to exist?If existence has to be either/or and your god exists and the universe also exists then the question can be equally posed to either idea.Yes, as far as we can detect the universe had a beginning, but we know that the universe exists. Therefore, all we know of existence is what began at the beginning of time. If your god exists, it has to be part of existence and therefore, had to begin to exist (or, as per your logic, doesn't exist).Or (again, as per your logic) all existence is eternal and your god has no special place.Or does Yahweh get a special pass because he said so?

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"You are metaphysicians. You can prove anything by metaphysics; and having done so, every metaphysician can prove every other metaphysician wrong--to his own satisfaction. You are anarchists in the realm of thought. And you are mad cosmos-makers. Each of you dwells in a cosmos of his own making, created out of his own fancies and desires. You do not know the real world in which you live, and your thinking has no place in the real world except in so far as it is phenomena of mental aberration." -The Iron Heel by Jack London"Hazards exist that are not marked" - some bar in Chelsea