do neutrinos keep travelling in a straight line after passing through the first detector?
I detect a circular argument (pun intended), so I will take a moment to clarify.
First, you question if they travel in straight lines:
So, it means they might not travel in a straight line.
When an explanation is provided, you switch to question the relative location of the experiment, now apparently accepting the straightness.
Beam neutrinos, as is heavily implied by the name, are man made beams of neutrinos. Rather like the LHC at CERN beam beams of protons are accelerated to high energies. Unlike CERN the beams are collided with a solid target even less like CERN the resultant beam of muon neutrinos is aimed into the ground. Why the madness a sane person might ask? Well as I mentioned in the solar neutrino thread neutrinos do not interact strongly, infact they barely interact at all. Where as a gamma ray from nuclear radiation will penetrate a few feet of lead a neutrino will penetrate a few light years of lead. So for these experiments we need lots of neutrinos and big detectors. The sun provides lots of neutrinos but that is a long way away, so we'd rather make our own and target them exactly where we want them to collect lots more quickly. So we aim the neutrinos into the ground and build a big detector where they re-emerge from the ground. So this isn't really a tricky particle physics question is more of a geometry question. A beam of neutrinos is fired into the ground to be detected elsewhere. How do you do this with a flat surface. Keep in mind that they dont really interact so they don't bend, at least not unless your talking about cosmological distances (real ones not FE ones).
Please tell us the locations from where they are emitted and where they are detected. I suspect this is highly possible according to FE.
Then you questioned the authenticity of the experiment information:
Google for the "long baseline neutrino experiment".
http://www.google.com/search?hl=en&ei=fvyiSsPCJIKknQeA59WFBQ&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=long+baseline+neutrino+experiment&spell=1
The first page of search results is dominated by government or somehow related sources.
Then you tried to show that the experiment could be done on a flat Earth:
The only important quantity for our purposes I found was L = 250 km. This is not a very long distance and, according to RE, the 'bulge' between the two points is:
h = R*[1 - cos(L/(2*R))]
With a RE radius R = 2*10,000 km/π = 6,366 km, we get a height of h = 1.2 km. The depth of the instruments (Super-Kamiokande. for example) is estimated to be 1,000 m.
Which I feel that I successfully answered:
The point is that the neutrino's are shot into the ground at a downward angle. For them to be detected 300km away on a flat earth with a downward angle of 1 degree:
depth = 300km * sin(1[degree]) = 5.236km
So for Super K to see the neutrinos from Tokai it would have to be ~5km deep...
Then for some reason (this makes it much easier for me), you appeared to agree based on UA that neutrinos would travel in a straight line:
The UA has influence even on neutrinos just as on everything else, because its effects are due to changing of reference frames. However, because the neutrinos travel at speeds very close to the speed of light, their deflection in the vertical direction is negligible. Namely, if neutrions are fired horizontally, then, at a point that is at a distance D, they would have a vertical deflcetion of approximately (t = D/c, h = g*t2/2):
h = g*D^2/(2*c^2),
or, if we express D in kilometers and h in micrometers, we get:
h/(um) = 5.46 x 10-8 x (D/km)2.
For the above case D = 250 km, we get a vertical deflection of h = 0.0034 um = 3.4 nm, which is just of the order of one wavelength for soft X-rays. That's pretty straight.
Then, when asked again, you went back and attacked the idea that the angle is downward with this post:
Like this?
Which is missing the third point on the line, the below sea level near detector. I replied with this picture:
http://t2k-information.googlegroups.com/web/General+Neutrino+Detector+Diagram.jpg?hl=en&gda=gQtfqFcAAACRTuUW9np5-UAIyR2Eir-sJ0Ok0tEziVbbPG5GIe4snYxv0q0VZhjKiWMs9yi7adzMY-wpAXVKhiwImBIOO5DiJey9J-K9TpVnNBVqJ8Vj4u10aVPw-pIVf8OUHFYczcUEdit: Photo source changed from Google Groups to Flickr
Now you are back to questioning if neutrinos travel in a straight line:
do neutrinos keep traveling in a straight line after passing through the first detector?
Before continuing, I am going to make a habit of including my current assumptions in the beginning of my post, to avoid confusion. It is great to debate, and I enjoy it, but it becomes frustrating when there is a lack of agreement on a definition or premise.