No, this fact merely establishes that nerve signal are not transmitted by photons in a vacuum. It does not establish whether the signal is transmitted by electrical or chemical means, or indeed by a combination of the two.
The observed speed in medium being less than c is a result of charge interaction between matter and the EM wave (or polaritons from the QM perspective). "Light" (photons in QM) travel at c. Period.
These two statements are self contradictory: photons are an EM wave. In a material the photons interact with the EM fields and so do not propagate at te same speed as they would in vacuo.
I was responding to the claim that because no charge flows in part of the circuit no electrical current can flow. This is not correct because you can have a charge build up which creates a reverse potential as was known pre-Maxwell.
You also don't get the Maxwell equations correct. Instead of "mag-flux" you should have "magnetic field"(=B) and "e-flux" should be "electric displacement field"(=D). A magnetic flux is the magnetic field multiplied by an area and typically denoted using a capital phi. Also "div D" is equal to the electric charge density and the differentials are partial not full ones as you indicate.
The EM fields of course move at c, and since the signals propagating through the nerves move a lot slower than that, we probably should conclude that AC isn't the mediator of the signals.
Absolutely incorrect. There is a reason that 'c' is called the "speed of light in vacuo". That reason is because a vacuum is the place where EM radiation travels that fast. In different media there is no requirement that the speed be this great. Indeed if you buy coax cable you will find that the rated signal speed is ~60-70% of 'c' although you can get special air-core cables with speeds of 80-90% 'c'. Clearly on a coax cable the signal is being transmitted by the EM field. Indeed there is a form of radiation, called Cherenkov, that is emitted by particles travelling faster than the speed of light in the local medium.
Might I suggest that instead of studying EM fiercely you study it carefully?
The photo shown in the article is that of the Large Hadron Collider (LHC) which will (when operational) circulate two beams of protons at 7 TeV. The total energy in the beam is 360MJ so I really doubt that you will want to use that to cure a brain tumour....although if you did I suppose it would be the first time where particle physics literally made someone's head explode!
Yes, however were you to actually use a gram of antimatter to treat a patient you will generate a 42.8 kiloton blast. While this would be certain of destroying all the cancer cells the side effects of this treatment would be a little severe!
The last time I checked there weren't any US tanks rolling through Canadian streets.
Perhaps not but there are a good few rolling wherever they are using fuel made from Canadian oil. So lets make a deal: you don't tell us what we can do with your movies and we won't tell you what you can do with our oil.
Just a slight update. The gluon having zero mass is just a theorectical value and a mass as large as a few MeV is not precluded according to the particle data group. So in fact we don't even know that the strong force is transmitted at the speed of light.
All 4 basic forces: electromagnatism, gravity, strong nuclear, and weak nuclear (not Nukular; bite me, George) forces propogate at the speed of light in their reference frame.
Not at all correct. First the weak force is transmitted by W and Z bosons which have mass and therefore CANNOT propagate at the speed of light. Secondly in their own reference frame, by definition the weak force bosons will not propagate at all since your own reference frame is defined as the frame you are at rest in. Thirdly massless particles have no reference frame of their own.
I know you were quoting someone else but please pick someone who at least has a clue what they are talking about!
So at this rate it won't be long before we will need real Exabyte tapes. I always thought the original ones should qualify for the award of world's most misleading name since their capacity was 500 million times less what their name suggested.
You laugh but TeX was almost the base language of the web instead of HTML. Apparently Tim Berners Lee used SGML for document typesetting unaware that the rest of the field he was developing the web for (particle physics) used LaTeX until it was too late to change....or at least that's a story I heard at CERN once.
One of the reasons I was so glad to leave the US is that they do exactly that: they refuse to let your kid go to school unless they have had the required vaccinations. Most of them were very sane an sensible ones but there was one we objected to (chicken pox) based on advice from a doctor who explained that the protection of the vaccine was only thought to last 10 years and that chicken pox is a lot more serious if you get it as an adult (it is called shingles). So either you caught the disease as a kid (with risk of serious complications comparable to the vaccine) and had lifelong protection from it or you take the vaccine and MUST get a booster every 10 years or risk getting shingles with a very large risk of serious, life threatening complications.
The WHO's advice on the vaccine was that developed countries might want to consider it based on the economic cost savings of not having parents take days off work to look after their sick kids. Sorry but slight economic advantages are not worth any risk to my children's health. For any medical procedure to be worthwhile there has to be a clear, proven improvement to the recipient's health. Making it compulsory to have particular medical procedures to be allowed to go to school is, in my opinion, highly unethical unless there is a significant risk to other pupils health.
Then why not spend the money educating the general population instead of what looks like bribing a government which then forces its decision on everyone? I want to make my own decisions about my and my families healthcare because I think I can do a better job than them. Even if this is a very sensible vaccine it should never be forced on someone.
Several years ago I managed to crash an in flight entertainment system on a united flight completely inadvertently. The system in question required only had a few games for free with the rest costing money to unlock. Since I objected to having to pay for the games I restricted myself to the free games until suddenly in the middle of a game of pong it got more and more sluggish until the screen freezes, goes black and the system reset itself. I went back into pong, cranked up the number of balls to the max allowed (4 IIRC) and noticed that now it would crash within a minute or two.
Playing around (there really was nothing better to do) I found that quickly wiggling the bat around with 4 balls on the screen would crash the system. After about the 4th or 5th crash the system came back up but this time with all the games enabled! After that I was careful not to crash the system but still about 30 minutes from landing it crashed again and came back up with only the free games.
I wondered at the time how such an easily triggered failure could have been overlooked. Unlike the article my crash only affected my screen...but at least there was some beneficial affect!
Does anyone else think that creating a black hole on earth might be a bad idea?
Apparently nature doesn't because if the LHC can produce black holes the Cosmic rays do too so were they that dangerous we would not be here to debate the point.
Large Extra-Dimensions are a set of theories inspired by string theory...sort of like a Hollywood movie that is "inspired by" true events. While finding them would certainly make people take more interest in string theory, they would not confirm nor deny string theory - just like you may get a hint of the "true events" from a Hollywood movie but it is in no way an accurate picture of what really happened. So sorry to disappoint you but this would still not confirmation of strings - just a hint that maybe we are on the right track.
Ah, yes! It's time once again for that favorite pastime of obnoxious, unsocialized nerds: telling other people what you think they should and should not be offended by.
I'm flattered that you think that my point of view is SO important that people will feel that they should be agreeing with it. I realise that English may not be your first language but there is a difference between expressing a point of view (as I did) and issuing an instruction (as you think I did). It might also be worth pointing out that expressing points of view (without the implication that everyone MUST agree) is generally how enlightened discussion progresses in places like Europe, Australia and Canada although I know that some other countries have trouble with this concept.
CE and BCE have the advantage of not being religion-based.
No they are religion based because of the choice of zero year. Renaming them does not alter that and to be honest seems more insulting because it seems to suggest that a non-christian will somehow be stupid enough not to notice what you are doing!
All the major religions have their own system of years so either we ought to use one and call it that for cultural reasons or else choose a non-religious event of world significance (invention of printing press, landing on the moon spring to mind) and use that as zero. Renaming them "BCE" and "CE" is just stupid and from my point of view infinitely more insulting to a non-christian.
On the plus side the first time I saw "BCE" I was in Canada and briefly thought that this must be the Canadian equivalent of "BC"...."Before Christ Eh?"
It has come to our attention that you are currently the head developer of an operating system called Linux. Please cease and desist these efforts immediately as they are in direct conflict with the new Windows Vista EULA.
According to Microsoft's EULA: "You may not work around any technical limitations in the software"
Just wait until we hear, "I'm sorry sir but installing Linux on your machine to get around the technical limitations of Windows is now against the EULA".
Slashdot Mirror
No, this fact merely establishes that nerve signal are not transmitted by photons in a vacuum. It does not establish whether the signal is transmitted by electrical or chemical means, or indeed by a combination of the two.
The observed speed in medium being less than c is a result of charge interaction between matter and the EM wave (or polaritons from the QM perspective). "Light" (photons in QM) travel at c. Period.
These two statements are self contradictory: photons are an EM wave. In a material the photons interact with the EM fields and so do not propagate at te same speed as they would in vacuo.
This bears all the hallmarks of strong backing by the US president. Dubious ethics and even more dubious english!
I was responding to the claim that because no charge flows in part of the circuit no electrical current can flow. This is not correct because you can have a charge build up which creates a reverse potential as was known pre-Maxwell.
You also don't get the Maxwell equations correct. Instead of "mag-flux" you should have "magnetic field"(=B) and "e-flux" should be "electric displacement field"(=D). A magnetic flux is the magnetic field multiplied by an area and typically denoted using a capital phi. Also "div D" is equal to the electric charge density and the differentials are partial not full ones as you indicate.
The EM fields of course move at c, and since the signals propagating through the nerves move a lot slower than that, we probably should conclude that AC isn't the mediator of the signals.
Absolutely incorrect. There is a reason that 'c' is called the "speed of light in vacuo". That reason is because a vacuum is the place where EM radiation travels that fast. In different media there is no requirement that the speed be this great. Indeed if you buy coax cable you will find that the rated signal speed is ~60-70% of 'c' although you can get special air-core cables with speeds of 80-90% 'c'. Clearly on a coax cable the signal is being transmitted by the EM field. Indeed there is a form of radiation, called Cherenkov, that is emitted by particles travelling faster than the speed of light in the local medium.
Might I suggest that instead of studying EM fiercely you study it carefully?
No I would not. By that definition no circuit with a capacitor in it has a current which is clearly not correct using ANY sense of electrical current.
The photo shown in the article is that of the Large Hadron Collider (LHC) which will (when operational) circulate two beams of protons at 7 TeV. The total energy in the beam is 360MJ so I really doubt that you will want to use that to cure a brain tumour....although if you did I suppose it would be the first time where particle physics literally made someone's head explode!
Yes, however were you to actually use a gram of antimatter to treat a patient you will generate a 42.8 kiloton blast. While this would be certain of destroying all the cancer cells the side effects of this treatment would be a little severe!
The last time I checked there weren't any US tanks rolling through Canadian streets.
Perhaps not but there are a good few rolling wherever they are using fuel made from Canadian oil. So lets make a deal: you don't tell us what we can do with your movies and we won't tell you what you can do with our oil.
Just a slight update. The gluon having zero mass is just a theorectical value and a mass as large as a few MeV is not precluded according to the particle data group. So in fact we don't even know that the strong force is transmitted at the speed of light.
All 4 basic forces: electromagnatism, gravity, strong nuclear, and weak nuclear (not Nukular; bite me, George) forces propogate at the speed of light in their reference frame.
Not at all correct. First the weak force is transmitted by W and Z bosons which have mass and therefore CANNOT propagate at the speed of light. Secondly in their own reference frame, by definition the weak force bosons will not propagate at all since your own reference frame is defined as the frame you are at rest in. Thirdly massless particles have no reference frame of their own.
I know you were quoting someone else but please pick someone who at least has a clue what they are talking about!
So at this rate it won't be long before we will need real Exabyte tapes. I always thought the original ones should qualify for the award of world's most misleading name since their capacity was 500 million times less what their name suggested.
You laugh but TeX was almost the base language of the web instead of HTML. Apparently Tim Berners Lee used SGML for document typesetting unaware that the rest of the field he was developing the web for (particle physics) used LaTeX until it was too late to change....or at least that's a story I heard at CERN once.
One of the reasons I was so glad to leave the US is that they do exactly that: they refuse to let your kid go to school unless they have had the required vaccinations. Most of them were very sane an sensible ones but there was one we objected to (chicken pox) based on advice from a doctor who explained that the protection of the vaccine was only thought to last 10 years and that chicken pox is a lot more serious if you get it as an adult (it is called shingles). So either you caught the disease as a kid (with risk of serious complications comparable to the vaccine) and had lifelong protection from it or you take the vaccine and MUST get a booster every 10 years or risk getting shingles with a very large risk of serious, life threatening complications.
The WHO's advice on the vaccine was that developed countries might want to consider it based on the economic cost savings of not having parents take days off work to look after their sick kids. Sorry but slight economic advantages are not worth any risk to my children's health. For any medical procedure to be worthwhile there has to be a clear, proven improvement to the recipient's health. Making it compulsory to have particular medical procedures to be allowed to go to school is, in my opinion, highly unethical unless there is a significant risk to other pupils health.
Then why not spend the money educating the general population instead of what looks like bribing a government which then forces its decision on everyone? I want to make my own decisions about my and my families healthcare because I think I can do a better job than them. Even if this is a very sensible vaccine it should never be forced on someone.
'DVD' Jon breaks quantum encryption, APS sues claiming its against the laws of physics.
We'd have a lawyerocracy instead
Too late - we already do. Look at how many politicians come from a legal background.
Several years ago I managed to crash an in flight entertainment system on a united flight completely inadvertently. The system in question required only had a few games for free with the rest costing money to unlock. Since I objected to having to pay for the games I restricted myself to the free games until suddenly in the middle of a game of pong it got more and more sluggish until the screen freezes, goes black and the system reset itself. I went back into pong, cranked up the number of balls to the max allowed (4 IIRC) and noticed that now it would crash within a minute or two.
Playing around (there really was nothing better to do) I found that quickly wiggling the bat around with 4 balls on the screen would crash the system. After about the 4th or 5th crash the system came back up but this time with all the games enabled! After that I was careful not to crash the system but still about 30 minutes from landing it crashed again and came back up with only the free games.
I wondered at the time how such an easily triggered failure could have been overlooked. Unlike the article my crash only affected my screen...but at least there was some beneficial affect!
Does anyone else think that creating a black hole on earth might be a bad idea?
Apparently nature doesn't because if the LHC can produce black holes the Cosmic rays do too so were they that dangerous we would not be here to debate the point.
Large Extra-Dimensions are a set of theories inspired by string theory...sort of like a Hollywood movie that is "inspired by" true events. While finding them would certainly make people take more interest in string theory, they would not confirm nor deny string theory - just like you may get a hint of the "true events" from a Hollywood movie but it is in no way an accurate picture of what really happened. So sorry to disappoint you but this would still not confirmation of strings - just a hint that maybe we are on the right track.
That this woman ended up on the short end of the stick still doesn't affect the validity of her tail...
Good grief!! If she now has a tail it's no wonder she is critcising the surgeon!
Ah, yes! It's time once again for that favorite pastime of obnoxious, unsocialized nerds: telling other people what you think they should and should not be offended by.
I'm flattered that you think that my point of view is SO important that people will feel that they should be agreeing with it. I realise that English may not be your first language but there is a difference between expressing a point of view (as I did) and issuing an instruction (as you think I did). It might also be worth pointing out that expressing points of view (without the implication that everyone MUST agree) is generally how enlightened discussion progresses in places like Europe, Australia and Canada although I know that some other countries have trouble with this concept.
CE and BCE have the advantage of not being religion-based.
No they are religion based because of the choice of zero year. Renaming them does not alter that and to be honest seems more insulting because it seems to suggest that a non-christian will somehow be stupid enough not to notice what you are doing!
All the major religions have their own system of years so either we ought to use one and call it that for cultural reasons or else choose a non-religious event of world significance (invention of printing press, landing on the moon spring to mind) and use that as zero. Renaming them "BCE" and "CE" is just stupid and from my point of view infinitely more insulting to a non-christian.
On the plus side the first time I saw "BCE" I was in Canada and briefly thought that this must be the Canadian equivalent of "BC"...."Before Christ Eh?"
It has come to our attention that you are currently the head developer of an operating system called Linux. Please cease and desist these efforts immediately as they are in direct conflict with the new Windows Vista EULA.
Yours sincerely,
Microsoft Lawyers
According to Microsoft's EULA: "You may not work around any technical limitations in the software"
Just wait until we hear, "I'm sorry sir but installing Linux on your machine to get around the technical limitations of Windows is now against the EULA".