Just about two days ago I warned that there will be a lot of nonsense about relativity coming out these days, and promptly there are already three articles here on Science2.0 alone that are exactly what I feared: Physicists with only basic knowledge about relativity claiming that particles cannot possibly go faster than light and portraying anybody who holds otherwise as a moron (not literally, but that seems to be the gist). Wake up guys – it is 2011 – modern physics has come a looooong way since Albert.
In modern physics, it is well understood how particles can travel with superluminal velocity without violating special relativity or causality. I will discuss such a mechanism here and the novel experiments it suggest in case the recent neutrino physics observations do hold up to scrutiny.
One possibility is very intuitive: Our three dimensional universe may well be due to a three (or more) dimensional membrane inside a higher dimensional, so called bulk space. This is called “universe on a membrane” or short “membrane universe” (MU). This is a well known scenario in string theory but not restricted to string theory. In the MU scenario, our light velocity c is the maximum velocity of excitations inside the MU membrane, the latter being by the way the very reason for why the MU universe observes Einstein relativity inside of it. That velocity c may be very small compared to the maximum velocity of particles that are not bound to our MU membrane, those that speed freely through the bulk space.
If, as was reported, neutrinos actually went faster than light from CERN to OPERA (Oscillation Project with Emulsion-tRacking Apparatus) in Italy’s Gran Sasso, they can do so without any violation of relativity as follows:
(Remark: I wrote this article before I saw Dimension hop may allow neutrinos to cheat light speed, which is saying something very similar to what I point out in the following here and have pointed out before for a number of years now. HOWEVER: My use of extra dimensions here is rather a didactic tool. As explained here, they are not necessary for the main arguments to go through just the same.)
In very high energy collisions, excitations may be shot out into the bulk space. They leave the MU, much like when rogue waves on the ocean hit each other and water splashes far above the surface of the ocean. The splashed water can travel much faster than any of the waves ever could inside the ocean. Our light velocity c, which is the maximum velocity for our universe’s “low energy” excitations in the MU, is much lower than the maximum for those particles that are not attached to the MU. That should not surprise: The maximum velocity for ocean waves is also much lower than the velocity of light c, the latter here being the maximum velocity for the splashed water that is not bound to the ocean. In fact, c is for all practical purposes infinite as far as ocean waves are concerned. In general ‘condensed state physics type’ of emergent gravity scenarios, a large difference between our c and the maximum velocity valid for the bulk space that contains our universe is expected (not in the string theory scenarios I have come across though).
The only sketch of the MU that I found today - a string theoretical example: Notice that the closed strings (gravitons) can reach outside of the membrane while the standard model forces (open strings) are attached to the membrane universe. Neutrinos have only weak interactions; whatever precedes them may come off of the membrane more easily than say muons. It would be thus expected to observe such mechanisms first with neutrinos, as may have happened now.
If this is what has now been observed, then it goes as follows: At CERN, where the high energy collision happens, MU neutral excitations without electro-magnetic or strong interactions are bound weakly enough to the MU that their energy is above the limit below which they would still “feel” the MU. They spread out into all directions, mostly away from the MU into the higher dimensional bulk space. They may travel or jump ‘above’ the MU membrane for perhaps tens of meters along the MU before they re-enter it. How much they on average travel along the orthogonal directions (perpendicular to the MU) depends on the specifics of why they re-enter the MU membrane, which I will discuss below.
Traveling only three to 30 meters parallel along our MU means that they re-enter our universe still inside CERN (!). It also means that about ten to 100 nanoseconds seem to be missing; this would account for the about 60 nanoseconds that the neutrinos are reportedly early.
Why do bulk excitations re-enter our universe? There are several possibilities that could be perhaps distinguished in the data, two of which are:
1) While electro-magnetic, strong, and so called weak interactions are bound to the MU, gravity is universal and reaches out into the bulk space. Gravity may pull them back into the MU (this is a common string theoretical assumption). Gravity is very weak, but since CERN may just be at the threshold energy for this effect, the 'splashed stuff' may sta
In modern physics, it is well understood how particles can travel with superluminal velocity without violating special relativity or causality. I will discuss such a mechanism here and the novel experiments it suggest in case the recent neutrino physics observations do hold up to scrutiny.
One possibility is very intuitive: Our three dimensional universe may well be due to a three (or more) dimensional membrane inside a higher dimensional, so called bulk space. This is called “universe on a membrane” or short “membrane universe” (MU). This is a well known scenario in string theory but not restricted to string theory. In the MU scenario, our light velocity c is the maximum velocity of excitations inside the MU membrane, the latter being by the way the very reason for why the MU universe observes Einstein relativity inside of it. That velocity c may be very small compared to the maximum velocity of particles that are not bound to our MU membrane, those that speed freely through the bulk space.
If, as was reported, neutrinos actually went faster than light from CERN to OPERA (Oscillation Project with Emulsion-tRacking Apparatus) in Italy’s Gran Sasso, they can do so without any violation of relativity as follows:
(Remark: I wrote this article before I saw Dimension hop may allow neutrinos to cheat light speed, which is saying something very similar to what I point out in the following here and have pointed out before for a number of years now. HOWEVER: My use of extra dimensions here is rather a didactic tool. As explained here, they are not necessary for the main arguments to go through just the same.)
In very high energy collisions, excitations may be shot out into the bulk space. They leave the MU, much like when rogue waves on the ocean hit each other and water splashes far above the surface of the ocean. The splashed water can travel much faster than any of the waves ever could inside the ocean. Our light velocity c, which is the maximum velocity for our universe’s “low energy” excitations in the MU, is much lower than the maximum for those particles that are not attached to the MU. That should not surprise: The maximum velocity for ocean waves is also much lower than the velocity of light c, the latter here being the maximum velocity for the splashed water that is not bound to the ocean. In fact, c is for all practical purposes infinite as far as ocean waves are concerned. In general ‘condensed state physics type’ of emergent gravity scenarios, a large difference between our c and the maximum velocity valid for the bulk space that contains our universe is expected (not in the string theory scenarios I have come across though).
The only sketch of the MU that I found today - a string theoretical example: Notice that the closed strings (gravitons) can reach outside of the membrane while the standard model forces (open strings) are attached to the membrane universe. Neutrinos have only weak interactions; whatever precedes them may come off of the membrane more easily than say muons. It would be thus expected to observe such mechanisms first with neutrinos, as may have happened now.
If this is what has now been observed, then it goes as follows: At CERN, where the high energy collision happens, MU neutral excitations without electro-magnetic or strong interactions are bound weakly enough to the MU that their energy is above the limit below which they would still “feel” the MU. They spread out into all directions, mostly away from the MU into the higher dimensional bulk space. They may travel or jump ‘above’ the MU membrane for perhaps tens of meters along the MU before they re-enter it. How much they on average travel along the orthogonal directions (perpendicular to the MU) depends on the specifics of why they re-enter the MU membrane, which I will discuss below.
Traveling only three to 30 meters parallel along our MU means that they re-enter our universe still inside CERN (!). It also means that about ten to 100 nanoseconds seem to be missing; this would account for the about 60 nanoseconds that the neutrinos are reportedly early.
[Warning: MATH! If they jump those first meters with a velocity of maybe ten or hundred times c, they practically spend no significant time jumping, because the rest of the travel time for the 730 km to Gran Sasso is much longer. Without jumping, the neutrinos must spend additional time t traveling along the jump path with at most the speed of light c instead. Those that do not first jump for example 20 meters would need to spend
20 m / c = 20 m /(299792458 m/s) ~ 60 nanoseconds
longer to get to Gran Sasso.]
Why do bulk excitations re-enter our universe? There are several possibilities that could be perhaps distinguished in the data, two of which are:
1) While electro-magnetic, strong, and so called weak interactions are bound to the MU, gravity is universal and reaches out into the bulk space. Gravity may pull them back into the MU (this is a common string theoretical assumption). Gravity is very weak, but since CERN may just be at the threshold energy for this effect, the 'splashed stuff' may sta
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