about Bob's article on absolute or relative time

[chair]

... Real scientific of you, chair. We shouldn't do anything because it will just show us what we already know.

Quite scientific. I don't mean things that we already "know" in our heads. I means things that we don't already know from other simpler, more precise experiments. What can we learn from the proposed experiment that we don't already know from previous experiments or that could be learned from other simpler, doable experiments?

Part of science is designing an experiment so that you learn something from it.

 

[Stripe]

Quite scientific. I don't mean things that we already "know" in our heads. I means things that we don't already know from other simpler, more precise experiments. What can we learn from the proposed experiment that we don't already know from previous experiments or that could be learned from other simpler, doable experiments?

Part of science is designing an experiment so that you learn something from it.

Really?

What experiments have you done that show people will live longer if they travel faster?

 

[chair]

Really?

What experiments have you done that show people will live longer if they travel faster?

Ah. That is why I asked (post #411) what the point of the experiment is. OK. So now we have finally defined the purpose of the experiment:

To test if the statement "people will live longer if they travel faster" is true.

Fair enough.

So I propose that we do the following:
1. Consider whether the existing experimental data already answers that question.
2. Assuming that the answer to #1 is no, let's think of how to do an experiment that will answer the question.

My thoughts:
1. There is existing experimental evidence for the relativistic effects on time. If these effects occur, then they occur for all systems, and there is no need to check them over and over again for different types of "clocks"
2. Assuming that there is some doubt about the experiments, or that they apply to humans, how can we do this experiment?
Since "metabolic rates"- actually aging, as the question was posed, takes a long time and a lot of energy, are there simpler systems that would satisfy us? For example, how about two chicken eggs? Keep one stationary, fly the other around at high speeds, bring it back to earth next to the first egg, and see which one hatches first. This would take less energy and less time than a human experiment (though I doubt that it is doable) Would this be convincing, or in order to check whether humans age faster, we have to measure humans aging, and nothing else.

If we are choosing biological systems, then maybe bacteria should be used. measure how fast they divide or something. Lighter, cheaper, faster. Would that be convincing?

Besides the energy and time restraints, there is the control issue. How can you be sure that biological systems aren't affected by something else in this experiment?

 

[Memento Mori]

Ah. That is why I asked (post #411) what the point of the experiment is. OK. So now we have finally defined the purpose of the experiment:

To test if the statement "people will live longer if they travel faster" is true.

Fair enough.

So I propose that we do the following:
1. Consider whether the existing experimental data already answers that question.
2. Assuming that the answer to #1 is no, let's think of how to do an experiment that will answer the question.

My thoughts:
1. There is existing experimental evidence for the relativistic effects on time. If these effects occur, then they occur for all systems, and there is no need to check them over and over again for different types of "clocks"
2. Assuming that there is some doubt about the experiments, or that they apply to humans, how can we do this experiment?
Since "metabolic rates"- actually aging, as the question was posed, takes a long time and a lot of energy, are there simpler systems that would satisfy us? For example, how about two chicken eggs? Keep one stationary, fly the other around at high speeds, bring it back to earth next to the first egg, and see which one hatches first. This would take less energy and less time than a human experiment (though I doubt that it is doable) Would this be convincing, or in order to check whether humans age faster, we have to measure humans aging, and nothing else.

If we are choosing biological systems, then maybe bacteria should be used. measure how fast they divide or something. Lighter, cheaper, faster. Would that be convincing?

Besides the energy and time restraints, there is the control issue. How can you be sure that biological systems aren't affected by something else in this experiment?

I see the muon observation as satisfying your situation because we know for a fact that they "live" for a very specific amount of time when stationary but when traveling at close to the speed of light they "live" much longer. Even though it is not biological, it satisfies the wont of the experiment.

 

[chair]

I see the muon observation as satisfying your situation because we know for a fact that they "live" for a very specific amount of time when stationary but when traveling at close to the speed of light they "live" much longer. Even though it is not biological, it satisfies the wont of the experiment.

I would agree, but apparently there are those here who are not satisfied by that experiment- not that I have seen a real argument as to why that experiment doesn't prove the point.

Frankly, I view the "let's see if humans age faster" bit as more of a parlor trick than a proper experiment.

 

[Stripe]

I see the muon observation as satisfying your situation because we know for a fact that they "live" for a very specific amount of time when stationary but when traveling at close to the speed of light they "live" much longer. Even though it is not biological, it satisfies the wont of the experiment.

How do we know for a fact that they live for a specific amount of time again?

 

[Yorzhik]

Why do you want to do this particular experiment? It is extraordinarily difficult, perhaps impossible, and won't prove anything beyond what has already been shown in other experiments.

This type of experiment would be best. Obviously, if humans cannot travel that fast, we can consider the closest alternative. However, we need to try and accomplish the best test and scale back only when it becomes unfeasible. BTW, if we can do the human test, add the egg and the bacteria and see how they compare. So how fast can we go?

P.S. MM, we realize that nothing inside the atmosphere can go very fast.

 

[Johnny]

How do we know for a fact that they live for a specific amount of time again?

Did you really just ask that? Are you so damn lazy you can't flip back a few pages in this thread yourself?

No one answer him. Make him flip back himself.

 

[Gerald]

Well, I guess in order to argue with Relativity, one has to undermine all of science, and reality for that matter.

How very postmodern! :jump:

 

[pozzolane]

Did you really just ask that? Are you so damn lazy you can't flip back a few pages in this thread yourself?

No one answer him. Make him flip back himself.

It's not that he's lazy. He has no integrity.

 

[Stripe]

Did you really just ask that? Are you so damn lazy you can't flip back a few pages in this thread yourself?

No one answer him. Make him flip back himself.

Calm down, dude. I only want us to clearly understand what we're talking about.

The mean life of the positive muon has been measured to a precision of 11 ppm using a low-energy, pulsed muon beam stopped in a ferromagnetic target, which was surrounded by a scintillator detector array. The result, 2.197 013(24) [microseconds], excellent agreement with the previous world average.

So now we observe muons reaching the earth's surface and calculate that they can travel faster than that.

Right?

 

[Memento Mori]

Calm down, dude. I only want us to clearly understand what we're talking about.

The mean life of the positive muon has been measured to a precision of 11 ppm using a low-energy, pulsed muon beam stopped in a ferromagnetic target, which was surrounded by a scintillator detector array. The result, 2.197 013(24) [microseconds], excellent agreement with the previous world average.

So now we observe muons reaching the earth's surface and calculate that they can travel faster than that.

Right?

Travel faster than what?

As for everything else, yes.

 

[Stripe]

Travel faster than what?

Faster than the result, 2.197 013(24)\mu$s, [microseconds]

Not sure what the scale is. http://arxiv.org/abs/0704.1981v1

 

[Memento Mori]

Faster than the result, 2.197 013(24)\mu$s, [microseconds]

Not sure what the scale is. http://arxiv.org/abs/0704.1981v1

Ok, so we agree that muons decay in 2.197013 microseconds?

 

[Stripe]

Ok, so we agree that muons decay in 2.197013 microseconds?

Depends on the conditions. Clearly they can survive longer in conditions other than those in the lab.

 

[Johnny]

Calm down, dude. I only want us to clearly understand what we're talking about.

You're just as capable as any of us at finding a definition or a paper. Stop asking us to do all the work.

Clearly they can survive longer in conditions other than those in the lab.

This is a half-life, which is a property of the fundamental force interactions (just like everything else). They survive longer because their motion is extremely fast relative to us. And it's not just 'outside of lab conditions'. The same thing happens if you accelerate them in a particle accelerator in laboratory conditions. Einstein's relativity predicts not just that their half-life will "increase" relative to a stationary observer, but it predicts exactly how long their half-life will increase based on their relative velocity to us. In other words, special relativity can tell us the factor by which half-life will increase based on what speed the muons are traveling.

The fundamental forces are carried at the speed of light, and thus for particles in motion relative to a stationary observer, the forces must travel a longer distance, and therefore any physical process will occur slower from the vantage point of the stationary observer (if the speed of light is constant, and the distance to travel increases, then the length of time it takes to travel that distance will increase, and all interactions will thus be slower from the vantage point of the stationary observer). Yet from the vantage point of the particle in motion, the forces does not have to travel a longer distance, and thus everything occurs at intervals as if the particle is at rest. In other words, from the point of the particle, the half-life never changed.

This is just the twin paradox in action. Create pairs of muons. Accelerate one of them around near the speed of light, and watch it far outlive its twin.

It's a wonderful experiment for the time dilating effects of special relativity.

 

[Clete]

Well, I guess in order to argue with Relativity, one has to undermine all of science, and reality for that matter.

You're an idiot if you think that's what I was doing.

I was arguing the EXACT opposite! It was Johnny who said that he wasn't sure that his perceptions have anything to do with reality, not me. I'm only pointing out that if you can't know that, you can't know anything at all - at all! It is Johnny (and anyone who accepts contradiction in the name of "science") who is undermining all of science and reality!

Resting in Him,
Clete

 

[Stripe]

This is a half-life, which is a property of the fundamental force interactions (just like everything else). They survive longer because their motion is extremely fast relative to us. And it's not just 'outside of lab conditions'. The same thing happens if you accelerate them in a particle accelerator in laboratory conditions. Einstein's relativity predicts not just that their half-life will "increase" relative to a stationary observer, but it predicts exactly how long their half-life will increase based on their relative velocity to us. In other words, special relativity can tell us the factor by which half-life will increase based on what speed the muons are traveling.

How does one use relativity to calculate the change? Is there a named constant that multiplies with the speed?

The fundamental forces are carried at the speed of light, and thus for particles in motion relative to a stationary observer, the forces must travel a longer distance, and therefore any physical process will occur slower from the vantage point of the stationary observer (if the speed of light is constant, and the distance to travel increases, then the length of time it takes to travel that distance will increase, and all interactions will thus be slower from the vantage point of the stationary observer). Yet from the vantage point of the particle in motion, the forces does not have to travel a longer distance, and thus everything occurs at intervals as if the particle is at rest. In other words, from the point of the particle, the half-life never changed.

A change in distance has nothing to do with the dilation of time or what we are discussing. You do not attribute sonic booms to relativity, why do you attribute it here? Why do you even bring it up? Relativity either accounts for the muon's capacity to travel longer distances or it doesn't. No need to involve a "stationary observer".

This is just the twin paradox in action. Create pairs of muons. Accelerate one of them around near the speed of light, and watch it far outlive its twin.

That's just stupid. Of course something that travels faster will travel further in the same amount of time. You're going to have to find a much clearer way of explaining your ideas.

It's a wonderful experiment for the time dilating effects of special relativity.

Or it's another example of how gravity affects physical things. :idunno:

 

[Memento Mori]

How does one use relativity to calculate the change? Is there a named constant that multiplies with the speed?

Well here's the equation for time dilation: Delta-t' = Delta-t ( 1 / sqrt[1 - v^2/c^2]). If we put in 99%c (the average speed of a muon particle [that I could find on short notice]) for v and 2 microseconds in for Delta-t. Then, Delta-t' becomes 15.6 microseconds (this is to us). However, this many microseconds still isn't enough for the muon to reach earth: 5940m (as opposed to our previously stated 9000m). This is where length contraction comes into play. The equation for length contraction is
L = Lo sqrt(1 - v^2/c^2) (where Lo is the "proper length" [so called by physicists] and L is the contracted length). So put in 9000m and 99%c and you should come up with about 1260 meters which is more than enough of a contraction for a muon to make it. This is why we find so many muons at earths surface and can be found quite deep in the earth too

That's how you calculate it.

A change in distance has nothing to do with the dilation of time or what we are discussing. You do not attribute sonic booms to relativity, why do you attribute it here? Why do you even bring it up? Relativity either accounts for the muon's capacity to travel longer distances or it doesn't. No need to involve a "stationary observer".

Actually, length contraction has everything to do with time dilation. Sonic booms travel at the speed of sound which is no where near the speed of light (343m/s vs 300,000,000m/s). And you need to involve a stationary observer because if you just go from the muon's perspective it only lives 2.19... microseconds. From our perspective the muon lives much longer.

That's just stupid. Of course something that travels faster will travel further in the same amount of time. You're going to have to find a much clearer way of explaining your ideas.

He's saying the muon traveling closer to the speed of light will live longer than the inert one. If Relativity were untrue both would "die" at the same time regardless of speed. But this is not what is observed.

Or it's another example of how gravity affects physical things. :idunno:

I think that smilie says it all.

 

[Stripe]

That's how you calculate it.

Oh, right.

Actually, length contraction has everything to do with time dilation. Sonic booms travel at the speed of sound which is no where near the speed of light (343m/s vs 300,000,000m/s).

We do not invoke relativity to explain the fact that sound waves are at a higher frequency from an object travelling towards us. Neither do we need to invoke relativity to to explain lightwaves at a higher frequency when they are from an object travelling toward us.

If we look at a clock moving toward us it will appear to move faster the closer to the speed of light it gets. That is because the lightwaves are arriving at a higher frequency. A very simple physical explanation that is very easily understood. There is no need to talk about "time dilation".

He's saying the muon traveling closer to the speed of light will live longer than the inert one.

I know what he's trying to say.

If Relativity were untrue both would "die" at the same time regardless of speed. But this is not what is observed.

What is observed is that muons can travel at speeds that can be averaged out. What is further observed is that muons arrive at the Earth's surface and this returns a much faster speed (using standard calculations). You account for this faster speed by invoking time dilation. I would explain the difference by the change in gravity acting upon the muon.

I see no reason why this observation is any different from any of the others we have discussed. Gravity affects real things. It does not affect non-physical, abstract concepts like time and space.