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thisonehasalittlehat - 13 Jul 2018 12:04:37 (#1 of 21)

It's not hard. You've got a trail that is left by the particle that's so long. You simply extrapolate out forever. Bit like in CSI when they put lasers in bullet holes to find the source of a gunshot. In fact, I bet that's what they did. Anyone could do it. Don't know what the fuss is about.

It is fortunate that nutrinos go straight. If it had been a bullet it would have wobbled all over the place and you would stand a chance. Although those effects are not really visible within a crime scene. I think they're working to slightly larger tolerances on CSI.

indlovubill - 13 Jul 2018 12:07:39 (#2 of 21)

Truly fucking amazing, could solve all of our problems at a stroke.

Brunothecat - 13 Jul 2018 12:10:36 (#3 of 21)

Extraordinary. I am still often struggling to trace where I put the kitchen scissors and they are considerably closer. Usually.

FredDee - 13 Jul 2018 12:11:59 (#4 of 21)

already covered in the Science News And Comment thread.

phantlers - 13 Jul 2018 12:12:36 (#5 of 21)

It is fortunate that nutrinos go straight.

Is there any such thing as a straight line across the vastness of the known universe though?

johnnythesailor - 13 Jul 2018 12:14:07 (#6 of 21)

Technically straight lines are geodisics but yes, because neutrinos don't really interact with anything, they do.

phantlers - 13 Jul 2018 12:16:23 (#7 of 21)

But everything is in motion all the time so what starts as a straight line gets distorted through spacetime's natural expansion in all dimensions.

head explodes

johnnythesailor - 13 Jul 2018 12:19:03 (#8 of 21)

Hence geodisics.

phantlers - 13 Jul 2018 12:20:05 (#9 of 21)

further reading required, thanks

johnnythesailor - 13 Jul 2018 12:46:11 (#10 of 21)

It's just the shortest distance between 2 points but those points don't need to be on a flat surface e.g. the earth's surface or spacetime.

phantlers - 13 Jul 2018 12:52:01 (#11 of 21)

The universe is a dynamic thing though and the two points shift in position even as the figurative line is 'drawn'. I understand the geodesic part but that seems prrdicated on a snapshot of the relative positions of, in this case, the Earth and the originating distant galaxy.

Please don't spend any great length of time trying to explain this this any more simply, I may just be a bit thick.

tasselhoff - 13 Jul 2018 13:01:39 (#12 of 21)

That makes sense to me. But we may be both at the same level of incompetence.

Brunothecat - 13 Jul 2018 13:09:30 (#13 of 21)

If the particle moves in a straight line, then where it ends up is pure chance surely? And all its fetching up in Ponders End or whatever means that happens to be in that same straight line for a period. Or am I too completely up the creek?

mentranilvavin - 13 Jul 2018 13:17:05 (#14 of 21)

If the universe is 14 billion years old, then how can a particle have got here from somewhere 37 billion light years away?

widenation - 13 Jul 2018 13:18:02 (#15 of 21)

Because it's expanding?

Sabacious - 13 Jul 2018 13:19:37 (#16 of 21)

Because it 3.7 billion lighte years away.

Brunothecat - 13 Jul 2018 13:19:57 (#17 of 21)

then how can a particle have got here from somewhere 37 billion light years away?

That only works if the universe is completely static. If it is expanding in all directions fast, distances will be have been increasing enormously for 14 billion years.

mentranilvavin - 13 Jul 2018 13:20:56 (#18 of 21)

Because it 3.7 billion light years away.

Ah yes- the URL in the header says 37bn

johnnythesailor - 13 Jul 2018 13:28:26 (#19 of 21)

Though the *observable* universe is thought to be 91 billion light years across due to said expansion.

If the particle moves in a straight line, then where it ends up is pure chance surely?

Yes. It was pure chance that we were in its way.

phantlers - 13 Jul 2018 13:32:21 (#20 of 21)

I certainly understand that much. Does this raise any interesting questions about non locality or the fact of such an observation (of the neutrino) and entanglement over such, heh, astronomical distances?

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