Einstein for ever?

[wobblycogs]

The formula E=mc^2 would probably not hold if neutrinos travel FTL. I don't know there theory in enough depth to say for sure but if neutrinos travel FTL you would probably see a larger mass loss that expected (assuming you could do sufficiently accurate experiments) as the neutrinos would require more energy when leaving. The formula would probably become something like: E = mc^2 + nx^2 where m is the mass of regular mass, c is the speed of light, n is the mass of the neutrinos and x is the speed of the neutrinos.

As I said at the beginning: this is going to be a systematic error in the way they are recording the result that is leading to a 60ns difference from theory. What is interesting is that these people are professional scientists and they have a result that appears very valid at first glance. As a scientist I have to remain open to the possibility that they have discovered a real phenomenon but at the same time I rate it right up there with pots of gold at the end of rainbows and finding faeries at the end of the garden!

As for what did Einstein say, blimey what a question. His big work was special relativity (1905) which deals with how bodies move under special conditions (excluding gravity). He then followed this up with general relativity (1916) which takes special relativity and incorporates gravity - very clever. Both pieces of work discuss the speed of light at length and require it to be an upper limit.

Our current understanding makes the speed of light the hard upper limit for any item with mass due to the fact that it would require infinite energy to accelerate anything with mass to c. Going beyond c would therefore require more than infinite energy which doesn't make sense.

The pedant in me has to point out that by convention lower case c is reserved for the speed of light and lower case m for mass.

 

[Karl]

As I recall from my student days Karl Einstein had no difficulty with things moving beyond the speed of light, only how to accelerate them, the mass/energy conversion makes such impossible.

Not so - the speed of light is the maximum universal speed. If you could beat the speed of light, time travel would become possible, thereby giving Causality a few headaches. But that's another arguement.

Cheers

Karl

 

[Digit]

Not so Karl E=MC2 is a mass/energy formula, nothing in it forbids the existance of particles that have a normal velocity beyond light speed.
The reasoning from that is if they lose velocity down to LS, they would give up their energy and vanish!
Neutrinos?
Remember, Karl, that Albert started his reasoning from the assumption that light was constant in velocity, an unproven view at that time.

Roy.

 

[Karl]

Not so Karl E=MC2 is a mass/energy formula, nothing in it forbids the existance of particles that have a normal velocity beyond light speed.

No - the c in e=mc2 is a universal maximum speed. The speed of light.

 

[wobblycogs]

The speed of light, technically, isn't constant it depends on the medium it is travelling though a phenomenon that gives rise to the sparkle of diamond and fibre optic broadband (amongst other things). The constant c is the speed of light in a perfect vacuum and it is the fastest anything can travel. The c in E=mc^2 specifically states that it is the speed of light in a vacuum.

While papers have discussed the possibility of FTL particles they are currently nothing more than speculation. There is no real evidence of them they are just one persons interpretation of some extremely complex mathematics. The trouble is the media is very poor at getting across the fact that this is total blue sky research not proven fact.

 

[Digit]

ie Cherenkov radiation eh ws? Beautiful colour.
The Tacyon is a hypothetical partical, agreed, so was the atom and sub-atomic particles.
The Tacyon, if it exists I grant you, and if E=MC2 is to run, then the Tacyon would have a lower speed limit of C/Light and would gain velocity as it lost energy would it not?
I've got a head ache.

Roy.

 

[Jonzjob]

An there were me thinkin that if man exceeded the speed of an 'orse at 18 mph it would rip yer lungs owt and man cuuu't servive?

How science gows forward :?

All you have to do is to read J Clarksons "A Short History Of Time", or was that Stephen Hawkins? And you would see what I mean. As a matter of interest, I have read it. I don't say that I understood a lot of it, but enough 8) 8) 8)

 

[Digit]

To change the subject briefly John there was programme on TV some time ago demonstrating how man left Africa 70000yrs ago and that we all developed from that. The one off OOA theory has been on life support for some time now, but it is still trotted out 'cos people haven't kept upto date.
God knows how many school kids have been lectured on Dinosaurs being slow moving, lethargic, lizards, or Neandertal Man the cretinous cave dweller.
One good reason for writing books on such subjects is that science is advancing probably faster now than at any time in the past and books on these subjects are damn near out of date before publication, so you write a new one every few years!

Roy.

 

[barkwindjammer]

A book that I still keep in my toilet to this day Roy had this rather spine chilling view of the future
http://i.imgur.com/cO4QA.jpg

 

[RogerS]

Mr Schrodinger? Has your cat been bothering next door again?

 

[Jonzjob]

Digit said "so you write a new one every few years!"

Roy! I have a problem writing me own name there daze?

One of the most fascinating walks I have ever made was round the NINA ring at the SRC Darsbury, somewhere up Norf in Cheshire? A 1/4 mile circumfre-thingy and reckoned not to have moved more than a couple of mm metrik bits in the past 10,000 years! Who the hell measured it?

The magnets that controlled it were about 12 foot high and wide and longer. It was flat and round to within what you and I would know as a knats thingy, you now, the thingy it uses to make more bleedin knats. I had to get a likkle round ally disk tht had to be returned before the thing could be fired up, because the life expectancy of any poor sod in there if it were fired up with then in there was about 15 seconds!

And the use? To accererate tiny bits that you couldn't see till they got as near to the speed of light as makes no difference to the average Mini driver wheel spinning away from the traffic lights and fire them at something else you couldn't see and measuring the impact that you also couldn't see!

But, impressive? Well, the price was.

They flogged it to the Japs, lock, stock and smoking magnets :?

I must admit that the walk impressed me more than a little. Shame I didn't have me camera though?

 

[Digit]

Unfortunately BWJ books that predict a new Eden don't sell.
I still have a 1950's copy of Day of the Triffids, great tale IMO.
The problem with pure research John is you have no way of knowing the outcome. Albert was dead against the A bomb that his ideas fathered. The Laser was once described as an invention looking for a use.
Faraday is supposed to have stated that the electro magnetic affect that he demonstrated had no practical use.

Roy.

 

[Jonzjob]

"Faraday is supposed to have stated that the electro magnetic affect that he demonstrated had no practical use."

Not true though! It keeps my watch on good time :wink:

 

[Shultzy]

Surely as speed = distance / time there are only two variables to check. Either the times wrong or the distance is wrong (by about 18m), or is this too simplistic?

 

[wobblycogs]

It's a bit simplistic but not by a huge amount. The problem is that neutrinos are very very difficult to detect because they rarely interact with matter - don't forget the neutrinos in this experiment have just passed through 732km of solid rock unscathed.

Most detectors are huge tanks of heavy water surrounded by highly sensitive cameras but even then only a few neutrinos will be detected and those detections will be scattered throughout the tank. The event that creates the neutrinos has a certain size and it isn't instantaneous so there is some error in both distance and time. For example, was the neutrino you just spotted created at the start or the end of the event? This error is minimized by repeated runs of the experiment to build a statistical picture and thus reduce the error margin. What makes this interesting is that the scientists have run this experiment so many times now the error margin is tiny. Under normal circumstances the error is so small they would just publish their results but because they are suggesting something so outlandish they are having the physics community check their experiment first.

 

[Jonzjob]

Been done..

http://www.bbc.co.uk/news/science-environment-15017484

 

[sparkymarky]

there`s a many things i dont understand about the speed of light and einsteins theories, however i do understand that light can be bent by a gravitational pull (i know the light doesnt actually bend but follows the space that is bent, if that makes sense) so can neutrinos be affected by gravity of a large nature like passing through the earths crust. if the neutrinos could be affected by the spinning earths gravitational pull could they not of been `slingshot` in affect to give a false reading. surely to make sure the readings are correct they would have to switch the sensors and fire the neutrinos other way to test whether the earth affects the readings.

also are the neutrinos fired in a dead straight line or do they follow a set distance from the earths central point so in affect do they curve as could gravity pull then in to the center of the earth and shorten the distance they travel very slightly??

i do hope this isnt completely stupid and sort of makes sense .

 

[Digit]

Personally, I've no idea, but I do have simple question. How did they measure the distance?

Roy.

 

[wobblycogs]

Not only does it make sense I think it's a great bit of scientific thinking.

Neutrinos interact with gravity and the weak nuclear force (they don't interact with the strong nuclear force or electromagnetism which is why they are so hard to detect). Therefore they would be affected by the gravitational pull of the earth but the effect would be tiny due to the speed they are travelling and the strength of the interaction, I doubt it would be measurable.

The earth couldn't accelerate the particle up to super-luminal speeds using a slingshot effect for the same reason you can't make any item to go at ligth speed - the energy required would be infinite. Imagine a piece of string with a small weight attached. Holding the string you spin the weight above your head and it goes at a a certain speed. The longer you make the string the faster the weight goes but the more energy you have to put in to keep it spinning. The string represents the attraction by gravity so even if the interaction with the neutrino was brief you would you would still need to apply infinite energy to accelerate it.

We commonly measure speeds above c but there are special cases where an item is moving almost towards us at a speed close to c (say 97% or more of c). The measured speed is then apparently some multiple of c, I know of at least one measurement of 4*c. Of course this is an artefact of how the speed was measured not an actual true reading. The reason I mention it is because this is something that would need to be accounted for in the measurements. The earths rotation could cause an apparent increase in the speed of the neutrinos. If I'm honest though I don't think this effect would be anywhere near large enough for account for this discrepancy.

The circumference of the earthis 40075.16km so at the equator the velocity is 1669.8km/h (which is 463.8333m/s). The neutrino took 0.0024 seconds to travel the distance from the source to the detector so the earth rotated during the travel time of the neutrino was: 1.1m. Note that this is an absolute worst case where the neutrino source and detector were on the equator and they neutrino had to follow the surface of the earth. IIRC the discrepancy would have to be about 18m to account for the odd measurement.

Edit. the distance is probably measured with gps and then corrected by calculation for relativistic effects.

 

[LuptonM]

Does anyone know the significance of E=mc^2? As I understand, energy is mass and mass is energy such that at high speeds the kinetic energy of a particle makes it 'heavier' (ie mass increases) and thus more energy is needed to accelerate it. Is the speed of light the velocity at which no matter how much energy you input into the system the particle just gets heavier and speed remains constant?

If a neurtino has gone faster than light then energy is not equal to mc^2 and must be some other term right?