So does anyone else see the meter definition as silly

| "Spaceman" wrote | > In fact, in all the experiments I have read about. | > I do not see one that actually has an observer heading towards | > the lightsource.(they all seem to be opposite that in thier | > operation factors) | | There's a variety of experiments that all work on the basic principle of | measuring the light reflected off heavenly bodies at two points in their | orbit (usually 180 degrees opposite). The body is going in the opposite | direction (relative to us) on each side of the orbit so you get one | measurement with the lightsource moving away and one moving closer. Just do | a Google on "light speed experiment" and you'll find several.
Those type experiments are still questionable along with the "doppler effect" reasoning used to determine the differences.
| > They all seem to have the lightsource moving toward the observer | > and they measure the lightsource speed to the observer. | | There's no difference between the lightsource moving towards the observer | and the observer moving towards the lightsource.
Actually there would be, the lightsource will always emit at c. the object heading towards it is what I think would not read such a c.
| That's just basic vector | math. The experiments where you saw the lightsource moving towards the | observer *are* experiments where the observer was heading towards the | lightsource.
No, It is not the same.
| > But of course if you used sound the same way, | > sound could be considered constant to all also like such, | > since it can not leave the source at any different rate no | > matter it's speed also. | | Speed of sound depends on temperature and material.
So does light. Light also travels through mediums at different speeds and is effected by heat etc.. (ever see a hot roadway with light passing above it?). One needs a single medium and an object towards the lightsource experiment to see about a c speed being detected by the object heading towards the lightsource.
| Observers experimenting | on the same material at the same temperature will always get the same speed | of sound. Just like observers experimenting on light in a vacuum (assuming | all vacuums are the same, which they pretty much are by definition).
No actually, observers traveling towards the sound source will find a relative speed change "doppler effect" and the speed is the only thing causing such change of frequency.
| The | difference is that sound requires a transmission medium, so you have to | measure speed of sound against the transmission medium. Light doesn't need | a transmission medium, so motion between the observer and the vacuum is | irrelevant.
Sound doppler has nothing to do with the medium when the medium is not moving.
If an object is traveling towards light real fast, it also incurs a doppler effect of the light. I suggest this effect is caused by the change in relative speed. and I can not find any Earth based experiment that has tested this type of motion. (object moving towards lightsource)
Reply to
Spaceman
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Hello James,
Your interpretation of the definition of a meter is erroneous. Using your style, the equation should be as follows:
a meter (d) = a distance per time (d/t) * the specific time 1/299,792,458 (t)
The "distance per time (d/t)" is the speed of light, also known as c.
Simplified, the equation becomes d = d.
You may not be comfortable with this definition for the meter, but this definition produces a more consistent distance than most methods for documenting distance standards. This definition is not altered by temperature, pressure, etc.
Reply to
John Eric Voltin
| You may not be comfortable with this definition for the meter, but this | definition produces a more consistent distance than most methods for | documenting distance standards. This definition is not altered by | temperature, pressure, etc.
Ok, Actually I jumped the gun on the d= d/t thing. (my bad) But the fact that a standard meter (dimension of length) is being corrupted by something that uses a speed (d/t) should be a simple reason for such spacetime mix mixing dimensions in the standards really makes spacetime stuff fit almost anything it states since the standards in my opinion are now corrupted to fit it.
Reply to
Spaceman
Dear Spaceman:
It had been a pleasure to talk with you before you had to have everyone agree with you. Thanks for playing. Now that you are back in rant mode...
Goodbye.
David A. Smith
Reply to
N:dlzc D:aol T:com (dlzc)
I'm not certain I understand the subtleties of your argument, but you seem concerned about using a speed to define a distance. Generally, your concern is quite valid, but the definitition of a meter is a special case. This definition is accepted because the speed of light (c) is accepted to be a constant. If the speed of light is not treated as a constant, then the definition of a meter becomes problematic. I can't claim to be an expert on topics such as the speed of light, but much experimentation and research went into this topic before the speed of light was accepted as a constant. This result is definitely counter-intuitive and inconsistent with classical physics (Is it formally called Newtonian physics? I don't remember.). I still remember sitting in freshman physics class and thinking my professor, Dr. Austin Gleeson, must be confused because this aspect of physics made no sense to me. After careful thought and much review of the experimental evidence, I began accepting such counter-intuitive aspects of physics.
I would be interested in learning more about your concerns. Please correct me if I mis-interpreted your posting.
Reply to
John Eric Voltin
The other potential variable is of course time. Time is apparently relative so the length of the SI reference will vary depending on the observer. I'm sorry but thinking about that sort of thing makes my brain hurt unless I've had a lot of alcohol to drink before-hand.
Reply to
Bernd Felsche
If I want to open out the hole I drilled 1 3/32", can I use my 1 5/64" drill, ..... no, then it's not needed.
BTW, what diameter drill do I use to fit a 1.1" shaft through...
I have just thought of where to put my 1 5/64" drill.... :-)
Regards Jonathan
Reply to
Jonathan Barnes
"N:dlzc D:aol T:com (dlzc)" wrote in message news:2ZwIf.32764$jR.25033@fed1read01... | Dear Spaceman: |
| > | > "N:dlzc D:aol T:com (dlzc)" | > wrote in | > message news:anuIf.32754$jR.1230@fed1read01... | > | Sorry Nature does not agree with you. If you can learn Her | > | lessons, She will not be forced to break your leg, or end | > your | > | life in favor of a member that can learn it. | > | > Dear David, | > Please take your "know it all" attitude and stick | | It had been a pleasure to talk with you before you had to have | everyone agree with you. Thanks for playing. Now that you are | back in rant mode...
Thanks for ignoring the facts presented after. It is a good sign. :)
Reply to
Spaceman
| I'm not certain I understand the subtleties of your argument, but you seem | concerned about using a speed to define a distance. Generally, your concern | is quite valid, but the definitition of a meter is a special case. This | definition is accepted because the speed of light (c) is accepted to be a | constant. If the speed of light is not treated as a constant, then the | definition of a meter becomes problematic. I can't claim to be an expert on | topics such as the speed of light, but much experimentation and research | went into this topic before the speed of light was accepted as a constant. | This result is definitely counter-intuitive and inconsistent with classical | physics (Is it formally called Newtonian physics? I don't remember.). I | still remember sitting in freshman physics class and thinking my professor, | Dr. Austin Gleeson, must be confused because this aspect of physics made no | sense to me. After careful thought and much review of the experimental | evidence, I began accepting such counter-intuitive aspects of physics. | | I would be interested in learning more about your concerns. Please correct | me if I mis-interpreted your posting.
Hi John, I am very much aware of the "accepted" constant, The problem I see is the experiments that are the supposed proof. Each end every experiment I see could have actually used sound (in air) as a constant speed also. Each and every Earth based experiment never had an object heading towards the lightsource. If an object heading towards the light source occured I find it very hard to believe that the basic math of such occuring is wrong and that the light will still pass the object heading towards it at c, In fact it would basically have to ignore relativity itself to do such.
Reply to
Spaceman
| The other potential variable is of course time. Time is apparently | relative so the length of the SI reference will vary depending on | the observer. I'm sorry but thinking about that sort of thing makes | my brain hurt unless I've had a lot of alcohol to drink before-hand.
Time changing rate is a malfunction of a clock, In fact if you replace "time changed rate" with "the clock malfunctioned". There is no problem with such a statement at all being just as true and the clock malfunctioning fits better since any good engineer would know that if a timing device did not match another, there is a problem with the timing device and what it is going through.
So time changing rate is really not even a good cause found by SR since it actually ends up being stated as time changed rate in the moving objects frame because time changed rate. and that circular reasoning is not even a cause finding in reality. :)
Reply to
Spaceman
This is the Newtonian physics interpretation of the situation; it has been proven wrong several times by experiment. You may not accept that light speed is a constant but it absolutely does not obey Newtonian physics, as you're suggesting.
The source will emit light at c. The observer will always see it at c, for one of two reasons: 1) If the observer is stationary relative to the source, they will get c, obviously 2) If the observer is moving relative to the source, the observer will experience time dilation relative to the source, causing them to observe the same value of c despite the speed difference between source and observer.
Time dilation exactly counteracts the shift in c that you'd expect under Newtonian physics. Time dilation is a very well documented and tested phenomenon, and it applies to things other than photons. Or do you suspect the time dilation experiments as well?
Yes, it is. The only way that it can be different is if there is an absolute reference frame to measure both source and observer against; nobody has ever discovered such a reference. Otherwise there is no physical difference since you can't tell which one is "stationary".
Yes, which is why we're talking about speed of light in a vacuum (which is a defined material with a defined temperature).
They will *not* see a speed change relative to the medium of transmission. They will see a frequency shift. Doppler effect relates to frequency, not propagation velocity. Light undergoes the same thing (red shift). Light does *not* have a constant frequency between moving observers, only constant velocity.
The effect your talking about (frequency shift) *is* caused by change in relative speed. But it has nothing to do with calculating c.
Why does the experiment have to be Earth based? There's a whole lot of convenient vacuum out there...
Tom.
Reply to
Tom Sanderson
| > | There's no difference between the lightsource moving towards the | > observer | > | and the observer moving towards the lightsource. | > | > Actually there would be, the lightsource will always emit at c. The | > object heading towards it is what I think would not | > read such a c. | | This is the Newtonian physics interpretation of the situation; it has been | proven wrong several times by experiment.
It has never been tested in that way that I can find anywhere. and Tom, It is also a relativity based situation so relative speeds are being ignored as a cause in such?. Sch a test with an observer moving towards the lightsource has not been done. If you can find such, please do post a link.
| The source will emit light at c. The observer will always see it at c, for | one of two reasons: | 1) If the observer is stationary relative to the source, they will get c, | obviously | 2) If the observer is moving relative to the source, the observer will | experience time dilation relative to the source, causing them to observe the | same value of c despite the speed difference between source and observer.
Tom, Are you actually an engineer? If you are an engineer, I find it very hard that you can not realize that a time dilation is a clock malfunction and nothing more than such.
| Yes, it is. The only way that it can be different is if there is an | absolute reference frame to measure both source and observer against; nobody | has ever discovered such a reference. Otherwise there is no physical | difference since you can't tell which one is "stationary".
The lightsource is "at rest" compared to Earth. I am not picking an absolute, I am picking a known rest frame. With such rest frame, the ship is moving towards the light.
And for your info. Let's take a brick wall and a bullet hitting it. If you say we don't know if the brick wall is moving or the bullet is moving. How come the end result shows us it was the bullets speed doing the damage, and not the massive brick wall hitting the bullet. If a 1 ton brick wall hits the bullet how much energy would be hitting the bullet? The end result does show you a basic fact of what was doing the motion compared to the other.
Another example could be 2 identical cars. heading towards each other at a relative speed of 100 mphs. We can find the actual speeds by the end result of the crash. If all the parts are thrown behind one car, that car was technically stationery and the other car was doing 100mph. End results do show, what was moving, so relativities they are both moving crap, is null and void when such end results can find such facts about the actual motion.
| They will *not* see a speed change relative to the medium of transmission. | They will see a frequency shift.
Frequncy shift occurs from a relative motion difference.
| Doppler effect relates to frequency, not | propagation velocity.
Wrong. the propagation velocity is what changes the frequency by changing the time the wavelength goes by the object. It is the only physical reason for doppler shift without a medium in motion.
| Light undergoes the same thing (red shift). Light | does *not* have a constant frequency between moving observers, only constant | velocity.
A constant speed to all would mean no doppler ever.
| The effect your talking about (frequency shift) *is* caused by change in | relative speed. But it has nothing to do with calculating c.
It is a reason to question the constant speed of light, since it can not be a speed of c and also come up with a frequency change.
| Why does the experiment have to be Earth based? There's a whole lot of | convenient vacuum out there...
Because using a "rest frame" compared to lots of other things in such rest frame makes it easy to figure out what is actually moving compared to the Earth itself. (see the 2 cars, and bullet and wall, statements above)
Reply to
Spaceman
It has never been tested in a way you accept. That's different.
No, relativity based speeds are what cause c to be a constant. They're intimately included in the experiment.
Yes.
As others have done, and I should have, this conversation has to be dropped. You don't understand special relativity. Time dilation isn't a clock malfunction, simple as that, since it will occur even with a perfect clock.
That's the problem...there's no such thing as a rest frame. That's the whole underpinning of relativity.
The end result does not show that. If you mount the brick wall on a conveyor going bullet-speet (say, 1500 fps) and run it into a stationary bullet, you will get *exactly* the same result.
You're talking about kinetic energy, which only has meaning when measured against a reference point. The kinetic energy isn't an absolute, it changes depending on your reference point. It's meaningless to determine which object is in motion based on kinetic energy, because you can always pick a reference point for which KE is zero for any object.
A crash is a horrible example, since as soon as you bring acceleration into it several parts of relativity don't apply. The physics just aren't the same as what we've been talking about elsewhere. Ditto for the bullet & the brick, now that I think about it.
The physical reason for doppler shift is motion between the observer and the source...doppler shift will occur regardless of the propagation speed of the wave (provided it is finite).
No. Light undergoing a dopper shift still moves at c.
Yes, it can. It does.
I'm out.
Tom.
Reply to
Tom Sanderson
| > It has never been tested in that way that I can find anywhere. | | It has never been tested in a way you accept. That's different.
It is not a matter of testing it in a way I accept, It is a matter of testing it in a different way then it has been tested.
| > It is also a relativity based situation so relative speeds are being | > ignored as a cause in such?. | | No, relativity based speeds are what cause c to be a constant. They're | intimately included in the experiment.
How can you include a "constant c" to find out if it is not constant, That is silly. If you already make it a constant, how would it change at all.
| Yes. | | > If you are an engineer, I find it very hard that you can not realize | > that a time dilation is a clock malfunction and nothing more than such. | | As others have done, and I should have, this conversation has to be dropped. | You don't understand special relativity. Time dilation isn't a clock | malfunction, simple as that, since it will occur even with a perfect clock.
Wow, You truly are not an smart engineer. A smart engineer would know a perfect clock would never change rate ... ever.
| > Let's take a brick wall and a bullet hitting it. | > If you say we don't know if the brick wall is moving | > or the bullet is moving. | > How come the end result shows us it was the bullets speed | > doing the damage, and not the massive brick wall hitting the bullet. | | The end result does not show that. If you mount the brick wall on a | conveyor going bullet-speet (say, 1500 fps) and run it into a stationary | bullet, you will get *exactly* the same result.
So the energy from a moving wall (say a 1 ton wall) would have the same impact on a bullet, that a bullets total energy would have on the wall? KE does not like that situation.
| > If a 1 ton brick wall hits the bullet how much | > energy would be hitting the bullet? | | You're talking about kinetic energy, which only has meaning when measured | against a reference point. The kinetic energy isn't an absolute, it changes | depending on your reference point. It's meaningless to determine which | object is in motion based on kinetic energy, because you can always pick a | reference point for which KE is zero for any object.
Not in an impact you can't. There is nowhere in the universe that the "bullet hitting the wall experiment" would show no KE occured to the bullet or the wall. Sheesh, For an engineer, you are truly brainwashed by relativity.
| > Another example could be 2 identical cars. | > heading towards each other at a relative speed of | > 100 mphs. | > We can find the actual speeds by the end result of the crash. | | A crash is a horrible example, since as soon as you bring acceleration into | it several parts of relativity don't apply. The physics just aren't the | same as what we've been talking about elsewhere. Ditto for the bullet & the | brick, now that I think about it.
Relativity applies fine, you just have to allow it to have a "rest" frame.
| > | Doppler effect relates to frequency, not | > | propagation velocity. | > | > Wrong. the propagation velocity is what changes the frequency | > by changing the time the wavelength goes by the object. | > It is the only physical reason for doppler shift without a medium | > in motion. | | The physical reason for doppler shift is motion between the observer and the | source...doppler shift will occur regardless of the propagation speed of the | wave (provided it is finite).
The propagation speed of the wave WRT the object passing through it, is what causes the change in frequency. Doppler can not occur if the wave does not pass by the object slower or faster than a 0 relatvie motion.
| > A constant speed to all would mean no doppler ever. | | No. Light undergoing a dopper shift still moves at c.
No, it can't. If it did, no frequency change could occur.
| > It is a reason to question the constant speed of light, since | > it can not be a speed of c and also come up with a frequency | > change. | | Yes, it can. It does.
No, it can't, and it does not.
| I'm out.
You should be, You don't understand basic doppler shift.
Reply to
Spaceman
Perhaps you need a refresher course in special relativity. A "perfect" clock moving relative to a "perfect" reference clock, will "tick" more slowly relative to the reference clock. When the moving clock is brought to a standstill relative to the reference clock, less time will have elapsed on the clock that was moving.
IIRC; Apollo 13 astronauts are about 300 milliseconds younger because they went so fast; for a fairly long time.
If the clock is moving relative to the observer noting the distance travelled by light over the interval, then the dilation will lead to a longer distance for the interval.
To account for special relativity, the specification of the metre need only require that the clock not be moving relative to the observer.
Reply to
Bernd Felsche
| Perhaps you need a refresher course in special relativity. | A "perfect" clock moving relative to a "perfect" reference clock, | will "tick" more slowly relative to the reference clock. When the | moving clock is brought to a standstill relative to the reference | clock, less time will have elapsed on the clock that was moving.
You seem to need a refresher course in how clocks function. The clocks were not perfect. The end results are of SR tests are actual proof.they are still not perfect.
| IIRC; Apollo 13 astronauts are about 300 milliseconds younger | because they went so fast; for a fairly long time.
You have a problem with that one, Nasa has to make the astonauts exercise, If they do not exercise they actually will somewhat age quicker in some places, because of the lack of use of certain muscles.
Reply to
Spaceman
"N:dlzc D:aol T:com (dlzc)" wrote in message news:LCSIf.32849$jR.5880@fed1read01... | You might be interested in this: |
formatting link
When you can not attack the post itslelf, attack the poster. I used to have that problem, and now it seems it is the opposite now. :) At least I learn from my posting mistakes. :)
Reply to
Spaceman
| | >Dear Bernd Felsche: |
| >... | >> Perhaps you need a refresher course in special relativity. | | >You might be interested in this: | >
formatting link
| | OK... make that a PERCUSSIVE refresher course in special relativity.
So, you accept someone elses webpage about me and take it as fact, no wonder you can't grasp a clock funtion problem, you must have been brainwashed to think the clocks are perfect, even though they could not be since if they were, there would be no time difference at all... ever.
Reply to
Spaceman
That's not the basis for determining your thickness.
You adequately display total lack of comprehension of relativity.
>take it as fact, no wonder you can't grasp a clock funtion >problem, you must have been brainwashed to think >the clocks are perfect, even though they could not be >since if they were, there would be no time difference >at all... ever.
Reply to
Bernd Felsche

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