speed of light?

[Mingon]

Heh, you sound like my dad. And you, too, rant on about how scientists are stupid because they think about things that are different from what you think about. Since you're the engineer you should have explained to the chemist what the conditions were. That's your job. It's the chemist's job to design a glue to stick two things together, not to figure out what the people managing the project are not telling her about her design constraints.

As we both had the same requirements the same brief on what was to bedevolped, the fault was with the chemists not understanding the implications of what was required

 

[grant2]

Originally posted by: Mingon
Wow your ignorant, perhaps we should have a P*ssing competition. I am 28, spent 9 years developing, designing and testing military equipement, and have spent the last 2 years teaching. I have studied engineering for 9years at various levels as well as business and project management. If you can match that then fair enough if not take your dumbarse comments elsewhere. :disgust:

How much of the equipment you've developed tests the speed of light within a cesium atmosphere? My safe assumption is "none".

Why don't you take your "pissing contest" off to the scientists' who's work you're calling "rubbish"? Or at least explain how you know innately know something that these scientists have been labouring to investigate?

 

[Mingon]

Ok well tell me what part of 'light has a finite speed, it cannot leave before it has entered it will always be an amount of time latter despite how small the amount of time is.' you disagree with and we can get back on topic. I think what I said is true and would be more than happy for you to try to disprove it.

 

[rjain]

Originally posted by: Mingon
Ok well tell me what part of 'light has a finite speed, it cannot leave before it has entered it will always be an amount of time latter despite how small the amount of time is.' you disagree with and we can get back on topic. I think what I said is true and would be more than happy for you to try to disprove it.

That's exactly what I'm talking about. You're taking the theories religiously. This shouldn't be a battle of egos. Just accept that just because you or someone else says something, it doesn't have to always be right. People acted the same way about Newtonian mechanics 100 years ago. It's been since "disproven".

 

[Mingon]

That's exactly what I'm talking about. You're taking the theories religiously. This shouldn't be a battle of egos. Just accept that just because you or someone else says something, it doesn't have to always be right. People acted the same way about Newtonian mechanics 100 years ago. It's been since "disproven".

I agree with what you are saying, to a point (that point being dont accept theories as truth). But I cannot see time travel as being possible (going back in time at least) and that is what something arriving before it has left is describing - this is my opinion not taken from anyone else. Even if we start to think about multiverses (ala timeline by micheal crichton - just in post production I hear) I dont believe that a particle is somewhere before it has left.

 

[rjain]

Originally posted by: Mingon

That's exactly what I'm talking about. You're taking the theories religiously. This shouldn't be a battle of egos. Just accept that just because you or someone else says something, it doesn't have to always be right. People acted the same way about Newtonian mechanics 100 years ago. It's been since "disproven".

I agree with what you are saying, to a point (that point being dont accept theories as truth). But I cannot see time travel as being possible (going back in time at least) and that is what something arriving before it has left is describing - this is my opinion not taken from anyone else. Even if we start to think about multiverses (ala timeline by micheal crichton - just in post production I hear) I dont believe that a particle is somewhere before it has left.

Maybe time isn't what you think it is. Maybe the experiment was screwed up. Maybe you shouldn't just dismiss things using "common sense". How "common sensical" do you consider ANY of quantum mechanics to be? Ever try to drive through a wall? Particles do that every day and don't get a scratch... and they end up on the other side of the wall without breaking through it. I could imagine someone like you yelling and screaming that it's impossible back when it was first observed. That's the beautiful thing about progress. The conservatives get left behind, with sore throats, no less.

 

[Mingon]

Who's screaming I just find unjustified comment rather irratating when all I was doing was expressing a belief - and not exactly a highly controversial one at that. As penance I will get a rjain herratic hat and sit in the corner

 

[rjain]

Originally posted by: Mingon
Who's screaming I just find unjustified comment rather irratating when all I was doing was expressing a belief - and not exactly a highly controversial one at that. As penance I will get a rjain herratic hat and sit in the corner

I didn't specifically say you were screaming, but I haven't ruled out the possibility that you'd want to scream if you were within earshot. But keep on ignoring what I really said.

The belief that the Earth is flat isn't controversial either (in 1300)... The fact that you think that heresy has anything to do with what's being discussed here shows that you don't take the behavior of the world around you very scientifically.

Please get out of the religious mode and let's discuss science and experimental technique, not harp on about theories that were developed when we knew less than we know now.

 

[Mingon]

I didn't specifically say you were screaming, but I haven't ruled out the possibility that you'd want to scream if you were within earshot. But keep on ignoring what I really said.

In all honesty I am starting to lose track of what your exact point is, you seem to both agree and disagree with yourself in different threads.

The belief that the Earth is flat isn't controversial either (in 1300)... The fact that you think that heresy has anything to do with what's being discussed here shows that you don't take the behavior of the world around you very scientifically.

The Heresy joke was just linking to the fact that galileo was accused of heresy for his theories on terrestrial dynamics- and found guilty (not cleared formally until 1992). In fact I was using it to support your own argument, but excuse me if you did not understand the cut of my gib so to speak

Please get out of the religious mode and let's discuss science and experimental technique

This I dont understand, I am perhaps the least religous person I know so I dont know what angle you are coming from.

not harp on about theories that were developed when we knew less than we know now

And as you say 'dont accept that just because you or someone else says something, it doesn't have to always be right'

If you want to wax lyrical you could say we in fact know less now than we ever have, but again that is off topic.

 

[Mark R]

"The light travels so fast that the main part of the light pulse exits the chamber even before it enters. Theoretically, this means that you could see a moment in time before it actually takes place."

Although it sounds bizarre, the pulse does appear to leave the chamber before it has even entered.

The key to understanding this is to visualise the pulse of light as being made up of a large number of seperate wavelength waves which sum together to produce a pulse. These waves must exist before and after the peak of the pulse.

As these waves enter the cesium chamber the velocities of the individual frequencies are changed so that the peak of the pulse appears a considerable distance downstream of where it would appear before it entered the chamber. An important point is that the pulse is long (3.7 us), whereas the *peak* of the pulse only appears 62ns early.

The scientists who performed the experiment have an excellent explanation here

 

[f95toli]

Thanks for a great link. I have heard of similar experiments before so I wasn't that surprised when I read the news. It is pretty interesting that the "rule" is that you can not transfer information FTL, in every experiment/theory I have heard of in this field (and that includes quantum cryptography and quantum teleportation) the best way to understand it has been to look at what is happening to the information.
I don't think anyone knows why "information" (whatever that is) seem to have this property, it is an interesting question.

 

[grant2]

Originally posted by: Mingon
Ok well tell me what part of 'light has a finite speed, it cannot leave before it has entered it will always be an amount of time latter despite how small the amount of time is.' you disagree with and we can get back on topic. I think what I said is true and would be more than happy for you to try to disprove it.

If you have something to prove or disprove, go to it. I have nothing prove, just an open mind.

My rhetoric was not meant as a personal attack, but as an analogy that preconceptions can be proven wrong.

You believe "time travel is impossible" based on your own deductions. Because of this belief, you label the quoted article as "rubbish" because it contains evidence to the contrary... This strikes me as a backwards way to learn.

Shouldn't we derive our conclusions from all evidence, rather than choose some evidence based on our conclusions?

 

[Mingon]

You believe "time travel is impossible" based on your own deductions. Because of this belief, you label the quoted article as "rubbish" because it contains evidence to the contrary... This strikes me as a backwards way to learn.

no I said 'sounds like rubbish' their is a slight difference, and then offered a reason why I thought as I did. This is in no way a backwards way to learn, it is simply me offering a reason why I disagreed. If I had of said just 'rubbish' I could understand your response - but I didnt

My rhetoric was not meant as a personal attack, but as an analogy that preconceptions can be proven wrong.

BUt inverersely preconceptions are often proved right, science is not about proving a theory is right or wrong it is about understanding a concept.

Or do you only arbitrarily discount scientific study done AFTER your birth/adolescence?

Its this part I feel was offensive, but I am english and you are from canada so I will accept it was crossed wires.

 

[Hasse]

Hmm I thought this discussion was about the article .. Anyway isn't there something about this stated in the superstring theory. About different dimensions particles move in, and other dimensions have different physical properties, which will allow a particle to move faster than light in another dimension, even particles with mass. As regarding to the statement regarding particles passing through the earth and seemingly solid things: We all know that lead stops most radiation, and is used to shield against it in heavy radiation enviroment. But even lead is fairly spaced at an atomic level, and that's how they discovered neutrinos. They placed a huge water tank underground, way under ground. They sealed it completely, but installed alot of light sensitive cameras, now any light erupting in the water would have to be a result of particles colliding with the atoms and thus releasing energy (light). Every now and then, not often, there would be smal flashes of light in the tank, that's how they really discovered that there are particles that move through the earth and rarely colliding with anything. Ahh well I think science is marvoulus, but I find most scientists to take to the relativity to some kind of holy grail of science, but to state that nothing can move faster than light is just oo simple an answer to why.
Another brief note of science matters: Quarks are created in pairs, and they have a funny property, no matter huge the distance is between a pair, if one is stopped (and thus no longer exists), the other one no longer exists, this way one could send information relatively fast, but you'ld have to have some quark pairs at the ready.. which I find funky.

Ahh well I'm ranting here.... hmm a common mistake among researchers or scientists and engineers is that both groups seems to take the other for ignorant fools, whilst they both require each other...

Bahh

Take care folks

 

[iuvas]

And do you also think the world is flat & supported on the backs of elephants & that all matter is made up of 4 elements? Or do you only arbitrarily discount scientific study done AFTER your birth/adolescence?

Turtles, not elephants. It's turtles all the way down.

 

[rjain]

Originally posted by: Hasse

Ahh well I think science is marvoulus, but I find most scientists to take to the relativity to some kind of holy grail of science, but to state that nothing can move faster than light is just oo simple an answer to why.

Very good point. It seems that Lorentzian Relativity is a better theory of relativity with what we've seen so far, and GR only takes what's common between SR and LR. (http://www.ldolphin.org/vanFlandern/gravityspeed.html)

However, I have no idea where your points about moving through lead come from other than my mention of infinite potential barriers, where you might have mixed-and-matched parts of my analogy to get this idea.

Another brief note of science matters: Quarks are created in pairs, and they have a funny property, no matter huge the distance is between a pair, if one is stopped (and thus no longer exists), the other one no longer exists, this way one could send information relatively fast, but you'ld have to have some quark pairs at the ready.. which I find funky.

This isn't quite true. For one, nature abhors naked color: Quarks can't move singly. Also, entanglement doesn't apply to interaction in general, it applies to conservation laws (AFAICT). That is, if the angular momentum of one of the pair is in one direction, the other must be in the opposite direction (or whatever is required to conserve the angular momentum of the particle(s) that gave rise to the two moving away). But this has nothing to do with light moving anywhere. In fact, nothing really moves anywhere in this process other than the two photons moving at normal light speed.

 

[rjain]

Originally posted by: Mingon

Sounds like rubbish, light has a finite speed, it cannot leave before it has entered it will always be an amount of time latter despite how small the amount of time is.

Originally posted by: Mingon

You believe "time travel is impossible" based on your own deductions. Because of this belief, you label the quoted article as "rubbish" because it contains evidence to the contrary... This strikes me as a backwards way to learn.

no I said 'sounds like rubbish' their is a slight difference, and then offered a reason why I thought as I did. This is in no way a backwards way to learn, it is simply me offering a reason why I disagreed. If I had of said just 'rubbish' I could understand your response - but I didnt

Your reason was that it conflicted with what your teacher told you. What your teacher tells you isn't the truth, it's just one theory that has been upheld reasonably well by the scientific method. (Actually it hasn't held up that well, but mostly because of socio-political (on the personal level) issues and misconceptions, it's been assumed to be true).

My rhetoric was not meant as a personal attack, but as an analogy that preconceptions can be proven wrong.

BUt inverersely preconceptions are often proved right, science is not about proving a theory is right or wrong it is about understanding a concept.

So what you said could be right and could be wrong and you don't provide any evidence either way.

 

[Mingon]

Your reason was that it conflicted with what your teacher told you. What your teacher tells you isn't the truth, it's just one theory that has been upheld reasonably well by the scientific method. (Actually it hasn't held up that well, but mostly because of socio-political (on the personal level) issues and misconceptions, it's been assumed to be true).

Sorry you must have me mistaken for someone who actually listened during class. I have (slight) Asberger's syndrome which leaves me with very little concentration span, hence school was a bit of a nightmare - when I attended. I learnt most of my information from reading books articles etc. and then deciding which I believed to be true.

So what you said could be right and could be wrong and you don't provide any evidence either way.

We are talking about a subject that is still not fully understood and yet you expect me to offer 100% reliable evidence

, unfortunately I dont have the time due to work restriction nor wish to provide quotations etc. instead I offered a theory I believed to be correct. If you disagree fair enough but dont start spouting things about someone you dont know - the UK education is far removed from yours, time to grow up and stop the personal attacks Rjain.

 

[rjain]

Originally posted by: Mingon

Sorry you must have me mistaken for someone who actually listened during class. I have (slight) Asberger's syndrome which leaves me with very little concentration span, hence school was a bit of a nightmare - when I attended. I learnt most of my information from reading books articles etc. and then deciding which I believed to be true.

And now those beliefs are set in stone and anything different looks like rubbish to you, ok.

So what you said could be right and could be wrong and you don't provide any evidence either way.

We are talking about a subject that is still not fully understood and yet you expect me to offer 100% reliable evidence

, unfortunately I dont have the time due to work restriction nor wish to provide quotations etc. instead I offered a theory I believed to be correct. If you disagree fair enough but dont start spouting things about someone you dont know - the UK education is far removed from yours, time to grow up and stop the personal attacks Rjain.

Excuse me? Because it's not fully understood means that you can assume that what contradicts with your current beliefs is rubbish? This isn't a place to promulgate your latest dogma. Please try to engage in intelligent conversation here. The UK education is far better than that in the US, so I don't know what your point is there, and if you don't want your personal religion to be disapproved of, please don't bring it up in a scientific discussion.

 

[Mingon]

And now those beliefs are set in stone and anything different looks like rubbish to you, ok.

Well heres an idea stop with the thread cr@pping and start offering an alternative suggestion? I said that specific article sounded like rubbish, NOT, any others. If you offer me an alternative theory and if I believe it to be true then I will be a convert - so far you have offered nothing.

Excuse me? Because it's not fully understood means that you can assume that what contradicts with your current beliefs is rubbish? This isn't a place to promulgate your latest dogma. Please try to engage in intelligent conversation here. The UK education is far better than that in the US, so I don't know what your point is there, and if you don't want your personal religion to be disapproved of, please don't bring it up in a scientific discussion.

So you know all about the UK education now do you

the UK further education might be of a higher standard (i.e. degree level only), but in no way is the rest any better. Try going to denmark and seeing the schools out their. And quit with the religon talk it is offensive.

 

[rjain]

Originally posted by: Mingon

And now those beliefs are set in stone and anything different looks like rubbish to you, ok.

Well heres an idea stop with the thread cr@pping and start offering an alternative suggestion? I said that specific article sounded like rubbish, NOT, any others. If you offer me an alternative theory and if I believe it to be true then I will be a convert - so far you have offered nothing.

There has been a good deal of serious discussion here. You just chose to chime in right away and scoff at the concept. It would have been nice if you followed this advice in the first place.

Excuse me? Because it's not fully understood means that you can assume that what contradicts with your current beliefs is rubbish? This isn't a place to promulgate your latest dogma. Please try to engage in intelligent conversation here. The UK education is far better than that in the US, so I don't know what your point is there, and if you don't want your personal religion to be disapproved of, please don't bring it up in a scientific discussion.

So you know all about the UK education now do you

the UK further education might be of a higher standard (i.e. degree level only), but in no way is the rest any better.

Shrug, maybe my mom just went to a fancy school or maybe it's degraded there to the level of the US. Oh well. I don't care how your education was anyway, I learned most of what I know (and all of what I know about modern physics outside of waves&optics in college showing me how exactly Heisenberg uncertainty comes out of particle-wave duality (of course, that wasn't their intent, but they did it anyway)) outside of any formal schooling.

And quit with the religon talk it is offensive.

Ehm, I thought I was the one asking you to do that... Well, if that's an apology (an empathetic one, at that, although I don't find religion offensive, just interesting, but off topic here), it's accepted and we'll move on.

 

[Mingon]

There has been a good deal of serious discussion here. You just chose to chime in right away and scoff at the concept. It would have been nice if you followed this advice in the first place.

You can only do one of three things when given an article, you either agree, disagree or stand on the line, My response was to disagree, and I still stick by what I said. Please offer me an alternative suggestion by all means.

Shrug, maybe my mom just went to a fancy school or maybe it's degraded there to the level of the US. Oh well. I don't care how your education was anyway, I learned most of what I know (and all of what I know about modern physics outside of waves&optics in college showing me how exactly Heisenberg uncertainty comes out of particle-wave duality (of course, that wasn't their intent, but they did it anyway)) outside of any formal schooling.

Whereas I learnt from practical physics i.e. engineering, it gives a great insight into how and why things work and what factors effect things in the real world.

Ehm, I thought I was the one asking you to do that... Well, if that's an apology (an empathetic one, at that, although I don't find religion offensive, just interesting, but off topic here), it's accepted and we'll move on.

And again I cannot see any mention in my posts of religon, perhaps you can pick it out for me as I am amazed at the sugestion frankly. And I still cant see where you are getting it from, I personally prefer people to have an opinion and state it rather than people who frankly try to disagree for the sake of it.

So as I know you require the final word offer a theory that is different to what I suggested, that is all I ask. no more arguing disagree thread picking just stay on topic and answer the question on a light pulse being able to exit before it has entered.

I await with baited breath...

 

[rjain]

Originally posted by: Mingon

There has been a good deal of serious discussion here. You just chose to chime in right away and scoff at the concept. It would have been nice if you followed this advice in the first place.

You can only do one of three things when given an article, you either agree, disagree or stand on the line, My response was to disagree, and I still stick by what I said. Please offer me an alternative suggestion by all means.

You can analyze it and say something intelligent about your opinion or just sit back and see what others have to say and compare that to what you thought. Then, if that provokes some idea, by all means, please share it with us. But there's no need to just snicker at something just because it doesn't agree with your preconceptions.

Ehm, I thought I was the one asking you to do that... Well, if that's an apology (an empathetic one, at that, although I don't find religion offensive, just interesting, but off topic here), it's accepted and we'll move on.

And again I cannot see any mention in my posts of religon, perhaps you can pick it out for me as I am amazed at the sugestion frankly. And I still cant see where you are getting it from, I personally prefer people to have an opinion and state it rather than people who frankly try to disagree for the sake of it.

So as I know you require the final word offer a theory that is different to what I suggested, that is all I ask. no more arguing disagree thread picking just stay on topic and answer the question on a light pulse being able to exit before it has entered.

I await with baited breath...

You don't have to mention religion in order to be religious about your beliefs. It seems to me that YOU are the one who was disagreeing for the sake of it, since you didn't have anything intelligent to contribute to the disucssion other than a haughty attitude about things you don't even understand in the first place.

 

[rjain]

OK, here's a page that actually has some intelligent commentary on what was happening there, but doesn't go deep enough for me. However, it basically confirms that SR wasn't violated at all. Nothing moved faster than the speed of light, it's just that the shape of the pulse was warped so that the peak "moved" faster than the speed of light. In fact, the exiting wave peaked before the peak of the entering wave made it into that chamber. Nothing interesting here. Move on.

Without seeing the exact time-series of the amplitudes of the pulses and then seeing what exactly this cesium gas's exitation state was, I can't say whether anything moved faster than the speed of light.

What I think might have happened is that the leading edge of the pulse triggered the emission of photons in the same quantum state from the cesium atoms. This caused the peak to arrive very early, as the following parts of the incoming pulse didn't have much more "excitation" to feed off.

 

[Mickjc]

...and so we argue ouselves round in circles. Read the start of this thread.

Mick.