Philosophy ILP style

Right.

As the linked Scientific American article explains, a star six light years distant from the earth is 4.8 lights years distant for someone traveling toward the star at 0.6 c. So for the traveler the journey takes eight years by his clock because the distance is shorter, whereas the earth observer sees it as taking ten years by his clock. Time dilation and length contraction are both real.

According to the theory - if you take a 1 meter stick and somehow accelerate it up to extreme speeds and get it to pass back by you - that same stick - as it passes - will measure shorter than 1 meter.

Things that are passing by very very fast - will actually measure as shorter than they would if they stopped moving relative to you. That is the theory.

It isn’t about perspective nor about the Doppler effect mentioned in that article.

What several people here seem to be missing is the very fundamental concern of Special relativity.

Special relativity postulates that there is no “actual/absolute/objective” measure of space or time - “all is relative”. That means that things are only big compared to something small - something is bent only compared to something straight - something is fast only compared to something slow. And that idea came from Galileo - long before Einstein.

When someone discovered that light has an upper limit to its speed and nothing could be any faster - things got confusing - Newtonian physics suddenly seemed insufficient (and they were right about that). After some thought it was revealed (Einstein got the credit) that the effort to measure things is complicated by how fast the observer is moving - and no matter how fast the observer is moving - light will always be measured as moving at the same speed away from the observer = “c”.

So if one observer leaves another at high speed and lights his torch - both observers will measure the light leaving the torch at the same speed from themselves. The speeds do not linearly add - the light doesn’t leave the torch at the 2nd observer’s speed plus the speed of light - light always leaves at c and measures as such to both observers. And that means that even though the observers are moving with respect to each other - they both still see the light leaving the torch at c - mystifying but necessarily true.

Further complication that stems from that is that any and all measures of time and distance are dependent on how fast the observed/measured object is traveling with respect to the observer. The observed object will be both smaller and internally slower (slower time) - the faster it travels with respect to the observer.

The end result of all of that is “There is no absolute frame of reference” - so there is no “actual speed, actual length, actual duration” - there is only “speed, length, duration relative to something in the same frame” - nothing else exists.

Personally I am not totally sold on the truth of that - yet - but it is the current theory (James’ reports excluded).

The entire theory is just a bunch of rubbish that results from a false 2nd postulate. I’ve proved it over and over again.

Until somebody finds an error in my MD’s Box you are simply repeating rubbish! You are spreading BS!

Closing your eyes to the facts doesn’t make it go away.

With your reasoning you could probably prove that the Earth is flat and no one can walk on the Moon.

[list]“Obviously the Earth is flat else people would fall off!!

SEE – PROVED IT!!![/list:u]

To Who? I haven’t seen ANYone say that you proved it to them.

Simpler than that.

Put a metre stick in space. Fly past in the direction of the length of the stick and it will be shorter.

Is the direction important? Yes. If you placed it perpendicular to the direction of flight, then it would be 1 metre long. (But it will be thinner.)

Distances are only shorter in the direction of travel.

Why does this happen? Because space and time are intimately connected.

Correct. I’m just trying to clarify for MagsJ that a traveler on a spaceship at relativistic speed won’t see HIS OWN clock ticking slow, or HIS OWN meter stick shortened. In constant uniform motion, he may judge himself at rest with respect to the earth observer, and if he were to look back with a telescope at earth, he’d see clocks ticking slow and meter sticks shortened on earth.

Yes.

If I think of time as how quickly things around me are changing compared to me - the faster they change compared to me - the slower I age compared to them - my time scale becomes slower. If I speed through those changes around me - they change even faster compared to me - making my aging slower still - compared to them.

And also if I speed toward the changes - those changes seem not only faster but more compressed - shorter in length - in the direction I am traveling.

But what about behind me? Why would the changes that I am traveling away from seem to change any faster or seem more compressed. It seems reasonable that what is behind me would be the opposite - slower changes and more drawn out - the Doppler effect of a siren passing by.

So does SR say that only things in front of the motion are shorter and faster?

Yes - SR only applies to observing things that are in motion relative to the observer - although the traveler still ages less due to his travel - something still seems incomplete about that thought.

That’s true in Relativity, because Einstein says length contraction occurs in the direction of travel, but not perpendicular to the direction of travel.

That is his FUDGE FACTOR to claim that length contraction occurs, which is why it only occurs along the direction of travel. It’s total BS to make his numbers add up.

Look at my box, there is NO LENGTH CONTRACTION, and the numbers add up PERFECTLY. You see how the box is traveling along the x axis, and it takes light so much more time to reach the x receiver than it does for it to reach the z receiver?

In order for the numbers in Relativity to work, he had to create some fudge to solve that issue, so he FABRICATED the concept of length contraction, to make the numbers work. But he COULDN’T do it in two directions, it would NEVER WORK!

LENGTH CONTRACTION IS TOTALLY FABRICATED BS!!

Anyone with any sense knows it’s impossible for a stick to be both a meter long and shorter than a meter at the same time! It’s total BS!

Look how obvious it is that any man would fall off of the Moon! Walking on the Moon is total BS!! :astonished:

:icon-rolleyes:

OH LOOK, the Moon is length contracted in the x direction but not the z direction. LOL

We see the Moon as round on a full moon night, but in actuality it’s really a rectangle if you go there. It’s only round because it’s length contracted in one direction and not the other!! (/sarcasm) Laughin my f’n ass off!!!

Don’t do that mate - you won’t be able to eat.

:obscene-smokingweed:

Things moving away are also shorter.

That’s because of what is happening when you do the measurement.

You look at the one end of the metre stick at certain point in time and space t0,p0. You then look at the other end at another point in time and space t1,p1. In the amount of time between t0 and t1, that end has moved towards the first position that you looked at (p0). When you make the measurement p1-p0 is not equal to 1 metre for you.

That is the Doppler effect concerning the light coming at you - that doesn’t count - a separate issue. The theory isn’t supposed to be dependent on how a measurement is being made.

…and once again, the length of the meter stick does not depend on who is looking at it, and what velocity they are traveling, just like a rotation of the Earth around the Sun does not depend on who is looking at it and what speed and direction of travel they are traveling.

Likewise, 1 complete rotation of a crankshaft does not depend on if you look at it and from how far away, or what speed direction you look at it. One complete rotation of the crankshaft is ABSOLUTE! It does not depend on who you ask, and a meter stick’s length does not depend on who you ask!

And by the way, if your tachometer is accurate and claims the crankshaft is rotating at the rate of 3,000 RPM, then if the crankshaft completes 3,000 revolutions, that TIME is exactly 1 MINUTE, regardless of who you ask or how fast they are traveling! 3,000 RPM IS EXACTLY 3,000 complete revolutions in EXACTLY 1 minute!

Check out this video:
[youtube]https://www.youtube.com/watch?v=-Poz_95_0RA[/youtube]

MD - if you somehow instantly changed all motion throughout the entire universe - making it slower to half speed - would time still be the same?

Nah - that is the second video I have seen from that bloke where he makes an invalid argument.

There is no requirement to make the measurements of position from end to end of the stick at different times - there is such a thing as parallel processing - both operations happening at the same time.

There has to be a better explanation. And his synchronicity issue is invalid also (separate issue).

He is just pulling a Biden.

Yes, the time (duration) would still be the same. Earth would only travel 1/2 the distance in the same duration of time. So it would take twice as much time to complete 1 lap around the Sun.

Since a “year” is 1 lap around the Sun, a “year” would be a different duration of time. A year would be twice the duration of time that it currently is. It is a clock running slow, according to the current standard of time that we call a “year.”