[Mars]

What would be the implications or issues if the speed of neutrinos were actually the new maximum speed?

Relativity was wrong

[Scourge of Ages]

Relativity was wrong

It wouldn't just need a footnote? "Except for neutrinos, which go about 60ms faster?"
Or you replace all instances of c with whatever letter they decide on for speed of neutrinos?

[watsisname]

It would require an explanation for why the speed of electromagnetic radiation is always constant despite not traveling at the maximum speed.  If the maximum possible speed were indeed faster then you'd expect to be able to see variability in light's speed depending on the relative motion with respect to the source, but we have never observed that.

It'd be a really awkward situation if this ends up getting verified.

[redsniper]

More like a really INTERESTING situation, amirite?

[achtung]

The barkeep says 'We don't serve faster-than-light particles in here'. A neutrino walks into a bar.

-- Too many people on slashdot.

[Grizzly]

Light is how we define time. So travelling faster then light allows us to travel faster then time. Or something.

[Herra Tohtori]

Light is how we define time. So travelling faster then light allows us to travel faster then time. Or something.

No, light is how we define distance.

Time is defined through the oscillations of the ground energy state of Caesium-133 atom (one second is exactly the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom, as quoted from Wikipedia).

Now that we know the duration of a second, we can measure how far a photon goes in one second, and that is defined as exactly 299,792,458 seconds.


Therefore one metre is defined as the distance that a photon travels in 1/299792458 seconds, which corresponds to 30.663319 periods of ground state oscillation of Ce-133 atom.


Now, special relativity assumes that the speed of light is invariable (same for every observer) and therefore should be the speed of causality in the universe.

If there are faster than light particles, then clearly light's speed can't be invariable to them as they would observe photons moving backwards compared to our observation of them.

Weird things start happening in special relativity with superluminal objects, and that's an understatement of the century. Lorentz transformations obviously fail when c=0, but mathematically you can get them working when c>0, you just need to use imaginary numbers for that because you need to take square roots out of negative numbers; what implications this would have for such particles in reality are something I don't really even want to think of.

Regardless, faster than light particles would be very problematic for the base assumptions of special relativity, as it would mean time is not as relative as we have thought.

Considering all the previous observations that have directly supported relativity, it's at this moment unlikely that this neutrino anomaly will prove to be anything but a glitch in the matrix. prove to be anything but a glitch in the matrix.


Now, personally I would gladly welcome any observation that breaches the iron grip of relativity on all known physics, because that would perhaps mean barriers such as light speed are not as unbreakable as have been assumed. And I really want us to get away from Earth at one point... preferably before it's rendered unsuitable for human occupation, either by our own actions or something outside our control such as comet or asteroid impact. Or, at the latest, the Sun's expansion.

Need to get that FTL working, you know...

[Nuke]

what exactly happens when a neutrino hits another particle? does it kinda phase on though? or does it do some kinda teleport magic? im kinda curious if space actually exists within a particle (assuming these particles have dimension). could it be possible that space does not exist where ever a particle may be? if you assume that it does not, and considering that what we perceive is solid rock is mostly empty space, with an occasional particle in it, so when the neutrino actually hits some other particle, i'm curious if this doesn't result in the neutrino instantly moving from once side of that particle to the other, without actually moving through space. so as this particle moves along, each time it hits something it might jump a very short distance to cross the particle. then these (tiny) distances add up to reduce the length of travel and shave a few nanoseconds off the particles journey at velocity c. i thought about this way back when i used to smoke a lot of weed, but wrote it off as a stupid idea. a product of alaskan dope and a documentry on string theory.

[deathfun]

Light is how we define time. So travelling faster then light allows us to travel faster then time. Or something.

This gave me an idea for a physicists clock

[Herra Tohtori]

There's no such thing as "collision" in quantum mechanics, so the question isn't really relevant.

In the standard model, particles are typically dimensionless (although their wave function of probable existence in points of space can have variable spread based on the properties of the particle, making the particle have an apparent "size").

Also, you have to remember that in quantum level there is no such thing as "solid". Every interaction happens via gauge bosons. For example, in macroscopic world a football doesn't phase through your foot because the surfaces meet each other; on quantum level this means a LOT of electromagnetic interactions that simply don't apply to single particles in quite the same way.

So, no, dimensionless particles do not "collide" or "phase through" each other. However when they get close enough to each other, they can interact with each other, and usually do. An example would be of two deuterium nuclei approaching each other. As they approach each other they experience a repulsive force through electromagnetic interaction - that is, their electric charges repel each other through virtual photons (I am not making this up).

If their initial velocity is high enough, they can get close enough to each other that the so-called strong interaction becomes more powerful than the Coulomb force. Strong interaction or strong nuclear force is transmitted via particles called gluons and it is by far the most powerful force of nature in the scale of atomic nucleus. When the strong interaction starts to pull the particles together, they fuse to form one combined particle - in this case it would be an alpha particle, or Helium-4 nucleus consisting of two protons and two neutrons, held together by the strong nuclear force.

In the context you speak of, particles never collide with each other; only their spheres of influence get close enough to each other that noticeable interactions are transmitted through them, and interesting things consequently happen.



Of course, there is the Pauli exclusion rule that posits that no two fermions can occupy the same quantum state at same space and time. In case you wonder what fermions are, they are particles that follow the Fermi-Dirac statistics; the other type of particles known are the bosons which deliver the interactions between particles. Neutrinos are, at the moment, classified as fermions, and more specifically leptons.

Neutrinos are a curious breed of particles because the only known way for them to interact with anything is through so called weak interaction, and more specifically since neutrinos have neutral electric charge, the interaction is transmitted by the so-called Z-boson (Z-bosons are have neutral electric charge, while W⁺ and W^- -bosons have electric charge).

The probability of a neutrino interacting with a more typical particle such as electron (or proton or neutron for that matter) is rather unlikely, so you need a lot of neutrinos passing through your detector (which is not a problem at all since those things are everywhere) and a BIG detector with good way to observe the very weak flashes of light caused by neutrino interactions with matter.

You also need a way to exclude other possible sources of flashes of light such as cosmic radiation, so the best place for neutrino detector is deep underground.


Deathfun... be welcome to try and invent new and better ways to measure time, but beware of redundant definitions sneaking up on you.

[Dragon]

IIRC, you can measure time using distance units (physicists sometimes do that). This simplifies a lot of calculations, and if you take a unit in which c=1, Lorentz transformation (and relativistic calculations in general) suddenly becomes really simple. In one book I read (I can't recall the title), the author even proven that you could measuring energy (and of course, mass) with that very same unit. Perhaps physicists working on relativity also do that (outside of that book, I never really heard about that though, so it's possible that it's impractical).

[Herra Tohtori]

IIRC, you can measure time using distance units (physicists sometimes do that). This simplifies a lot of calculations, and if you take a unit in which c=1, Lorentz transformation (and relativistic calculations in general) suddenly becomes really simple. In one book I read (I can't recall the title), the author even proven that you could measuring energy (and of course, mass) with that very same unit. Perhaps physicists working on relativity also do that (outside of that book, I never really heard about that though, so it's possible that it's impractical).

That only works if you have a calibrated measuring stick whose length is known...

...and you measure length based on how long a photon travels in an unit of time, so you need a definition for unit of time first to calibrate your measuring equipment.


This doesn't change what is being measured, but you really rather need to take great care to avoid redundant definitions and circular logic.


And I think the book you mention was referring to the use of natural units, which are a way to simplify a lot of equations in, say, special relativity - just substitute c with 1. Same stuff is often done in quantum physics with Planck constant, and there's also a special unit of mass called atomic mass unit (amu, or dalton) that is used in chemistry, defined as one twelwth of the mass of carbon-12 atom in its ground state, and it's approximately the mass of proton or neutron (though not quite), just so that chemists and nuclear physicists could use "1" for the approximate mass of protons and neutrons when dealing with isotope masses.

Heck, particle physicists started using electronvolt as an unit of energy simply because it was a handy way of describing the energy that an electron would get in a particle accelerator when it traveled through one volt electric potential difference; 1000 volt potential would give one electron the energy of 1 keV, etc.

For more information on natural units and what natural constants are used to define them, consult the book of knowledge.

[Dragon]

I'm pretty sure that this one book specifically brought every value that matters in physics to one unit. Could have been "Hyperspace" by Michio Kaku, but I'm not sure. I'm sure that spacetime can be measured using one unit (heck, I can even quote):

For example, in special relativity space and time are so closely related that it can be useful to not specify whether a variable represents a distance or a time.

I can't find in which book it was, but I think that energy was brought to the same unit by exploiting how it warps spacetime. The author did that mostly to show how neatly equations start to look when such simplifcation is made.
EDIT: I was simply thinking of this: http://en.wikipedia.org/wiki/Natural_units#.22Natural_units.22_.28particle_physics.29
Still didn't checked the book, but I'm sure that for demonstration purposes it used either seconds or meters as a "base" unit instead of eV, but it was mentioned both there and in wiki that any unit will do.

[jr2]

...it's at this moment unlikely that this neutrino anomaly will prove to be anything but a glitch in the matrix. prove to be anything but a glitch in the matrix.

* jr2 sees what you did thar... 

[Kolgena]

^ Nice.

[watsisname]

One of my physics prof's just published a critique of the super-luminal neutrino observation, which can be found here on arXiv.  Might be an interesting read for the physics-inclined viewers around here.

[Ghostavo]

Whoops...

[CommanderDJ]

One of my physics prof's just published a critique of the super-luminal neutrino observation, which can be found here on arXiv.  Might be an interesting read for the physics-inclined viewers around here.

Good read. There's a typo in one of the headings, though. Neutrino is spelt as nwutrino.

[watsisname]

Whoops...

Boy would that be embarrassing if neglecting to account for special relativistic effects from the GPS satellites ends up being the explanation for this. :<

[MR_T3D]

Whoops...

note that he's not sure, it could be that's already been accounted for when they said they "accounted for all relativistic effects" and even our link friend says so.

jury's out until the guys that did this note it.