Update: October 17 00:00 UTC: whether this supposed explanation out of at least 80+ different papers attempting to debunk the neutrino FTL results has a shred of truth will take a while for the physics community to sort out. Regardless, the point of this post was to show that the frontier science journalism/communication falls victim to “viral theories” that have not been adequately tested. In this day and age, anyone with access to a computer and the internet can engage a global audience with their cockamamie ideas on physics or perhaps climate change or medicine. The moral of the story is that with any new discovery which may challenge conventional wisdom is to be patient and keep an open mind. — Ryan Maue.
Not so fast little neutrinos. Turns out that the discovery of superluminal or faster-than-light (FTL) neutrinos at CERN has been “explained”. Before reading the explanation, here’s a tidbit of information that would have probably tipped off a lot of skeptics from the start: to measure the “speed” of the neutrinos from point A to point B, the scientists used our constellation of GPS satellites in earth orbit. Turns out Einstein’s theory of relativity comes in handy to explain those missing 60 nanoseconds over 730 km distance…
I won’t spoil the explanation any further: from an open source Physics journal: Faster-than-Light Neutrino Puzzle Claimed Solved by Special Relativity
— somehow I’m betting the real explanation is still out there…
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What no reviling of these consensus shakers, no conspiracies to keep them out of publishing. What are these wimpy physicists thinking? This cannot be real science.
So are we certain it was the same neutrino?
I agree this is a poor explanation. As pointed out in the earlier thread, SN87a showed that neutrinos do not travel faster than light. The most likely error IMO is the distance measurement. The receiver is deep undeground, so the location can’t be direcvtly measured by GPS. Is there an article that describes exactly how the position of the receiver was determined?
A simple case of relativity!
Would the speed of sound be the theoretical universal speed limit in a universe in which humans are blind and can’t perceive light? 🙂 In other words, is it possible there are ‘things’ in our reality we can’t perceive, and those ‘things’ travel faster than light?
Morris Minor says:
October 15, 2011 at 11:30 pm
The neutrino says, “Am I late?”
Bartender says, “I don’t know, the photon isn’t here yet.”
Well, it IS an explanation. I have some doubts, The trouble, I see, is that if this correction is applied to previous experiments (for all light speed particles) and clocks, a new error would appear in those experiment’s calculation. Like a tile setter, once you shift one tile, you must shift all the other tiles.
I don’t think we have heard the last of this experiment. GK
Scottish Skeptic:
“Anyway, the argument for relatively is hardly convincing: “The speed of light is a constant therefore space and time must vary”. All you need do is define a new variable “speed of light” which varies to allow space/time to be constant, and you have a Universe which is identical but where a new set of metrics vary to allow other metrics to remain the same.”
“the argument for relatively is hardly convincing” is one of the more uninformed statements to come out of this web-site in a long while!
May I recommend this Youtube series on Special Relativity from Stanford University
Or this one, if you’re in a hurry
The CERN result still stands. I think its hilarious that a pompously written article that mentions a relativistic correction is immediately taken as “disproof”. I read the beginning of the article, and, I can assure you that it was written for maximum density. It was poorly written.
It’s easy to figure out whether the clocks at the emitter and detector sites are synchronized. The issue is whether the distance is 730 km or 730 km plus 20 meters. It could be that they used a spherical approximation to the earth (which is an irregular prolate spheroid) as part of the GPS measurements. However, that “debunking” article should not be taken as proof. I’m waiting for Penn Jillette to entry the fight.
The article states in the final paragraph: ” Finally, making all calculations from the correct reference frame might also lead to further improvement of the accuracy of GPS systems as the errors reported here for the time-of-flight amount to a ±18 m difference in location”
This is already corrected for in basic GPS algorithms. The error budget for the standard positioning service is on the order of several meters, where as for precise GPS it is on the order of cm.
For more details on precise GPS algorithms and accuracies see:
http://igscb.jpl.nasa.gov/igscb/resource/pubs/UsingIGSProductsVer21.pdf
Scottish Sceptic,
“All you need do is define a new variable “speed of light” which varies to allow space/time to be constant, and you have a Universe which is identical but where a new set of metrics vary to allow other metrics to remain the same”
No, the universe would not be identical. If the speed of light was not constant then you would observe all kinds of anomolies that aren’t observed. For example, if a distant body started moving towards you, the light would be approaching you faster than the light that left before the change in motion occurred. This would result in light that was emitted later overtaking light emitted earlier. To the observer, this would appear as if events were running backwards. I am sure it was realisations like this that led Einstein to conclude that the speed of light must be constant under all frames of reference. He then had to show how.
If GPS processors did not account for relativity (S&G) your car satnav would be out by tens of metres. An experiment carried out millions of times every day.
There must be another explanation (perhaps related to the uncertainty principle, applied to particles of “negligable” mass?).
TerryS says:
October 16, 2011 at 1:20 am
Very well said. You distinguished the spirit of science from the spirit of !@ur momisugly#$%-science.
A further thought – I wonder if the GR correction to GPS was applied to surface geometry? Subsurface locations for source and emitter would encounter lower gravitational fields than those at the Earth’s surface.
Tom_R: I was thinking along these lines too. It seems to be a distance measurement problem. They cannot have received GPS signals at the bottom of a 1km deep shaft. If they projected a surface GPS position vertically down (i.e. radial to the centre of Earth) from the top of the shaft that would be wrong. But surely CERN wouldn’t make an error that basic! The position of the receiver would have to be projected to the surface via a line that was a) normal to the straight line through the earth from Cern to G. Sasso (this defines a plane); b) vertical only in the normal plane defined in a).
Roger Longstaff says:
October 16, 2011 at 8:40 am
A further thought – I wonder if the GR correction to GPS was applied to surface geometry? Subsurface locations for source and emitter would encounter lower gravitational fields than those at the Earth’s surface.
—————————————————
Roger,
I believe your assumption is based on a spherical earth of constant density. If you are talking about changes in the measured speed of light over 720 km then I doubt those two assumptions are correct. I recall a friend taking gravity measurements in a mine underground and the values were higher than on the earth’s surface several hundred meters directly above the drift.
Why wouldn’t they use a fiber-optic cable to connect the two sites? Then they wouldn’t have to burn a hole in the rock 😉
All I can say is, of course. Faster than light? The universe could not exist. Albert never stirred one bit, but I’ll bet he’s now chuckling at the reason.
I think the thing to do is to watch the Lecture given at CERN about the experiments:
http://cdsweb.cern.ch/record/1384486
Here you can see all the things they did & didn’t do, and how they got the accuracies they claim for distance & time measurement.
The general feeling seems that the distance is known better than the time
– i.e. there are a lot more possibilities for error in the timing of the detection of the neutrino burst (whereas the distance measurement is believed to be less prone to error)
For example, one of the tables shows a 1ns delay through an FPGA
– well that was my understanding
– if so, this can’t be right, as the delays through an FPGA are many times that…
It is still most likely a timing calculation error, in my opinion.
(Sorry, I mis-read the chart on the FPGA delay – it’s actually a believable number)
This “paper” is just one paragraph from my widely read September 24th blog entry,
http://motls.blogspot.com/2011/09/potential-mistakes-in-opera-research.html#clocks-thirty-nanoseconds
including the description of the problem and the 30-nanosecond result etc. Please check it; I personally think it’s more likely than not that the author has simply copied this calculation of mine and made an arXiv preprint out of it. It’s silly, Anthony, for you to promote this one possible explanation about dozens of potential explanations to a full-fledged WUWT article, especially if you completely ignored all the other analyses and discussions of people who know 50 times more about the stuff than the Dutch guy, such as myself.
Yes, you’re probably right that this is probably not the mistake they have done. GPS just doesn’t work in this way. The satellites’ reference frame plays no role and the events on Earth are given their full 4 spacetime coordinates, from an Earth reference frame, regardless of the motion of the satellites.
60 nanoseconds light travels 1.8m or so (am I right). As a geologist/engineer I would suspect the elasticity of the earth’s crust, tidal effects, seismic vibrational effects, tectonic effects (flexing) could make 1.8m an error bar for the 730,000m the neutrino travelled. Using a constantly moving medium to measure this accurately seems like a poor choice for a very costly infrastructure. The engineer in me advises that this experiment be repeated about 30 times and the average taken.
My shot at the neutrino joke:
“We dont serve Neutrinos that travel faster than light!” and the reason is:
A neutrino walks into a bar………………but he left before he got there.
Interesting article from when this story first broke. http://www.forbes.com/sites/alexknapp/2011/09/23/faster-than-light-neutrinos-dont-bet-on-it/
Based on viewing the CERN presentation
http://cdsweb.cern.ch/record/1384486
they seem to have considered all the time and space variables in great detail. They spelled them out for the entire scientific community to evaluate possible errors in measurement or analysis. Snide critique of CERN based on the anti-science posture of the official Climate Team is unwarranted, IMHO.
Most likely there is some subtle error not yet exposed and understood. If not, the apparent result is correct and, under certain circumstances, neutrinos may be superluminal, and travel, or appear to travel, faster than light seems to travel.
On the other hand, we know that Space/Time curves, perhaps quite tightly in some of its several dimensions. So, what if, under certain conditions, light and neutrinos, etc., go straight (or more directly) and are not affected (or less affected) by this curvature? Might that explain how the most careful experiment could come up with a superluminal result?