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JustAnEngineer
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Re: Huge Physics News

Thu Oct 06, 2011 5:56 am

Sometimes the guys who are ridiculed are right:
http://news.yahoo.com/vindicated-ridicu ... 56852.html
 
Common Sensei
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Re: Huge Physics News

Fri Oct 14, 2011 5:47 pm

Happily, a pretty good suggested explanation has been found:

http://arxiv.org/abs/1110.2685

A description of the proposed solution:

http://www.technologyreview.com/blog/arxiv/27260/
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notfred
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Re: Huge Physics News

Fri Oct 14, 2011 6:02 pm

Interesting, the suggestion is just a Lorenz Contraction based on the GPS satellites flying in approximately the same direction as the neutrino beam.
 
ChronoReverse
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Re: Huge Physics News

Fri Oct 14, 2011 6:48 pm

Ugh, surely they accounted for this and used a local atomic clock or something?

Still, it's uncanny how this would produce a 64ns discrepancy where the measured faster than light time is 60ns.
 
just brew it!
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Re: Huge Physics News

Fri Oct 14, 2011 7:13 pm

ChronoReverse wrote:
Ugh, surely they accounted for this and used a local atomic clock or something?

I think the time scales we're dealing with here are getting down to the level of accuracy of atomic clocks. How do you verify that the clocks are in fact synchronized closely enough to measure stuff like this? (Answer: Probably by using GPS...)
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ChronoReverse
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Re: Huge Physics News

Fri Oct 14, 2011 7:57 pm

just brew it! wrote:
ChronoReverse wrote:
Ugh, surely they accounted for this and used a local atomic clock or something?

I think the time scales we're dealing with here are getting down to the level of accuracy of atomic clocks. How do you verify that the clocks are in fact synchronized closely enough to measure stuff like this? (Answer: Probably by using GPS...)


[edit]nvm[/edit]
I guess so =)
 
notfred
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Re: Huge Physics News

Sat Oct 15, 2011 8:33 am

When dealing with time there are two concerns, precision and accuracy. Atomic clocks will get you very precise i.e. a 1 second tick is 1 second +/- a very tiny amount (10^-15 to 10^-16 according to Wikipedia). If you have two separate clocks then you need to synchronise them for accuracy, it's no good if they both tick 1 second precisely if they are set to different times (e.g. 1pm and 1:05pm). GPS is the best way so far of synchronising separated clocks.
ChronoReverse wrote:
Ugh, surely they accounted for this and used a local atomic clock or something?

The time scale of the error is quoted in the paper as 64ns so that's 10^-9. Given that the atomic clocks are meant to be 10^-15 then the problem is going to be the accuracy of the clocks and not the precision.
Last edited by notfred on Mon Nov 21, 2011 8:40 am, edited 1 time in total.
 
just brew it!
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Re: Huge Physics News

Sat Oct 15, 2011 8:50 am

I don't know whether *all* atomic clocks have 10^-15 precision, or just the best ones. Or whether they had access to such clocks for this experiment. But as you've noted, the issue is likely to be accuracy of synchronization, not precision.
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derFunkenstein
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Re: Huge Physics News

Sat Oct 15, 2011 6:47 pm

Maybe not feasible, but couldn't they eliminate clocks as a factor by sending particles in both directions? Once you average the times, you'll have a better idea of whether or not it's possible it actually worked, right?
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notfred
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Re: Huge Physics News

Sat Oct 15, 2011 7:40 pm

The problem is that the neutrino beam is coming from CERN, big particle accelerators cost a lot. :-)
 
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Re: Huge Physics News

Sun Oct 16, 2011 12:28 am

Send photons down the same pathway. If they arrive before you expect them to, then you know you have a measurement error. Compare the transit times with the neutrino tests, and you can confirm or disprove those findings. Why is this so hard?
 
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Re: Huge Physics News

Sun Oct 16, 2011 1:25 am

Lol, because they're shooting the neutrinos *through* the earth...
 
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Re: Huge Physics News

Sun Oct 16, 2011 11:41 am

cheerful hamster wrote:
Send photons down the same pathway. If they arrive before you expect them to, then you know you have a measurement error. Compare the transit times with the neutrino tests, and you can confirm or disprove those findings. Why is this so hard?

Anomymous Gerbil wrote:
Lol, because they're shooting the neutrinos *through* the earth...

Yeah, that's the first problem. The reason experiments like this are possible in the first place is that neutrinos interact very weakly with ordinary matter, so shooting them through several hundred miles of solid rock barely affects them. This is also the reason neutrino detectors are large and expensive -- it is difficult to detect something that tends to not interact with the detection apparatus much! :wink:

The second problem is that photons only travel at maximum speed (what we commonly refer to as "the speed of light") when they're in a vacuum, so not only would you need a perfectly straight 500 mile tunnel through the Earth from Switzerland to Italy, you would need to maintain a near-perfect vacuum in the tunnel.
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notfred
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Re: Huge Physics News

Fri Nov 18, 2011 9:10 am

A re-run of the experiment with tweaks to improve the timing has repeated the results:
http://www.telegraph.co.uk/science/scie ... esult.html
 
Captain Ned
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Re: Huge Physics News

Fri Nov 18, 2011 9:20 am

notfred wrote:
A re-run of the experiment with tweaks to improve the timing has repeated the results:
http://www.telegraph.co.uk/science/scie ... esult.html

Still looks like they're ignoring the relativistic effects of the GPS signals' differing time-of-flight (and GPS is their key timing "constant").
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just brew it!
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Re: Huge Physics News

Sun Nov 20, 2011 3:57 pm

Has anyone come up with a credible rebuttal to the GPS time-of-flight question?
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notfred
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Re: Huge Physics News

Mon Nov 21, 2011 8:45 am

I'm not sure, I would have thought that if that was it they would have found it in all the peer review by know.

I did see someone else point out that they basically get a neutrino beam by stopping everything else with a plate whose thickness happens to line up with the discrepancy - i.e. 64 light-nanoseconds.
 
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Re: Huge Physics News

Mon Nov 21, 2011 9:59 am

derFunkenstein wrote:
Maybe not feasible, but couldn't they eliminate clocks as a factor by sending particles in both directions? Once you average the times, you'll have a better idea of whether or not it's possible it actually worked, right?


Exactly. Just need to build a duplicate of CERN at the target site.
 
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Re: Huge Physics News

Mon Nov 21, 2011 10:34 am

just brew it! wrote:
Has anyone come up with a credible rebuttal to the GPS time-of-flight question?



From the latest article:

There are more checks of systematics currently under discussion, one of them could be a synchronisation of the time reference at CERN and Gran Sasso independently from the GPS (Global Positioning System), using possibly a fibre.
 
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Re: Huge Physics News

Mon Nov 21, 2011 11:09 am

Crayon Shin Chan wrote:
Yet another "physics breakthrough" article from a major tabloid. These tend to be the types of places where you also hear about new "free energy" breakthroughs. When will people ever learn?


For a "tabloid" it is rather unlike so and is followed in establishment circles on both sides of the Atlantic. The Daily Mail, on the other hand...
 
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Re: Huge Physics News

Mon Nov 21, 2011 11:48 am

Perhaps the fundamental question is whether the least error-prone concept of light vectored along time is that of a least-distance or a least-annihilation pathing model. If the latter, then we might have possibility of at-c particles "threading" experimental filters just as they might be doing so around gravitational nodes prior to final attenuation. Or so I've heard elsewhere, from mathematicians as well as physical scientists.

Then again, maybe this cosmos and us and all we describe in it, it's all just math at "bottom", a virtual construct underlying and thus modeling visible matter everywhere and surpassing it in complexity from before instantiation, animated at sub-quantum levels by an instrumentality or agency empirically unobtainable to our like. And like us, the scientists are each just mathematically temporalized sets of material and personal phenomena. Who curiously attempt to relate to and explain further sets of material phemomena yet wind up stumbling in the conceptual boundaries dividing and nesting in the current incomplete theoretical schemas. Where the limits of sapient sensorium and intelligence begin to factor as speculation evolves, and where wisdom is scarcer than a Higgs event.
Last edited by trackerben on Mon Nov 21, 2011 12:13 pm, edited 1 time in total.
 
StefanVonS
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Re: Huge Physics News

Mon Nov 21, 2011 12:11 pm

That's exactly what I was thinking... :wink:
 
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Re: Huge Physics News

Mon Nov 21, 2011 1:21 pm

trackerben wrote:
Then again, maybe this cosmos and us and all we describe in it, it's all just math at "bottom", a virtual construct underlying and thus modeling visible matter everywhere and surpassing it in complexity from before instantiation, animated at sub-quantum levels by an instrumentality or agency empirically unobtainable to our like. And like us, the scientists are each just mathematically temporalized sets of material and personal phenomena. Who curiously attempt to relate to and explain further sets of material phemomena yet wind up stumbling in the conceptual boundaries dividing and nesting in the current incomplete theoretical schemas. Where the limits of sapient sensorium and intelligence begin to factor as speculation evolves, and where wisdom is scarcer than a Higgs event.


That may just be the most verbose way of saying our current understanding of quantum mathematics may not be adequate to correctly describe the physical behavior of the really, really small stuff. :P

This particular observation seems mostly likely expalined by a clock synchornization issue, as discussed above.
 
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Re: Huge Physics News

Mon Nov 21, 2011 3:09 pm

trackerben wrote:
Then again, maybe this cosmos and us and all we describe in it, it's all just math at "bottom", a virtual construct underlying and thus modeling visible matter everywhere and surpassing it in complexity from before instantiation, animated at sub-quantum levels by an instrumentality or agency empirically unobtainable to our like. And like us, the scientists are each just mathematically temporalized sets of material and personal phenomena. Who curiously attempt to relate to and explain further sets of material phemomena yet wind up stumbling in the conceptual boundaries dividing and nesting in the current incomplete theoretical schemas. Where the limits of sapient sensorium and intelligence begin to factor as speculation evolves, and where wisdom is scarcer than a Higgs event.


You reminded me of Architect's speech in "The Matrix Reloaded" which I saw last Saturday on TV.
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Re: Huge Physics News

Mon Nov 21, 2011 3:30 pm

Sure, why not? Perhaps quantum mechanics is just the physical manifestation of roundoff errors in the universe's floating-point representation, and black holes are the manifestation of an overflow.
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Captain Ned
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Re: Huge Physics News

Mon Nov 21, 2011 6:39 pm

just brew it! wrote:
Sure, why not? Perhaps quantum mechanics is just the physical manifestation of roundoff errors in the universe's floating-point representation, and black holes are the manifestation of an overflow.

Ah, so the universe (and that nasty charge/parity violation between matter & antimatter) is nothing more than the macroscopic manifestation of the FDIV bug.

It's a bit tough to describe the first 13 billion years or so but after that the curve fits really well.
What we have today is way too much pluribus and not enough unum.
 
just brew it!
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Re: Huge Physics News

Wed Feb 22, 2012 3:20 pm

Looks like it was a problem with the synchronization of the atomic clocks after all: http://news.sciencemag.org/scienceinsid ... aster.html
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Glorious
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Re: Huge Physics News

Wed Feb 22, 2012 3:35 pm

JBI wrote:
Looks like it was a problem with the synchronization of the atomic clocks after all: http://news.sciencemag.org/scienceinsid ... aster.html


Oh. Great.

MORE news I could have used back before I bought and started modding a Delorean.

:evil:
 
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Re: Huge Physics News

Wed Feb 22, 2012 4:00 pm

So...
Science wrote:
After tightening the connection and then measuring the time it takes data to travel the length of the fiber, researchers found that the data arrive 60 nanoseconds earlier than assumed.
These guys literally had a screw loose? ;)
Glorious wrote:
MORE news I could have used back before I bought and started modding a Delorean.
Well, 80s fashions are coming around again so maybe you can sneak right in with the leg-warmers-and-gratuitous-zippers crowd.

Besides, overclocking of flux capacitors is still something of a black art (just look at the power required!), and I don't think the neutrino guys were looking at that at all.
 
ChronoReverse
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Re: Huge Physics News

Wed Feb 22, 2012 4:24 pm

just brew it! wrote:
Looks like it was a problem with the synchronization of the atomic clocks after all: http://news.sciencemag.org/scienceinsid ... aster.html


Well, I'm glad I didn't hold my breath for this one.

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