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  1. Standard member sonhouse
    Fast and Curious
    23 Nov '17 10:25
    https://phys.org/news/2017-11-earth-high-energy-neutrinos-tracks.html

    It has been found these highest energy neutrinos DON"T pass through the Earth like a knife through butter but in fact don't make it all the way through at all.

    My question is this: is there a way to understand or visualize somehow the difference between high and low energy neutrinos?

    Like it is of course very well known EM radiation is easy to understand in terms of energy, higher energy basically just means smaller wavelengths.

    What is an analogy for Neutrinos?
  2. Standard member mchill
    Green Lantern
    23 Nov '17 12:07
    Originally posted by @sonhouse
    https://phys.org/news/2017-11-earth-high-energy-neutrinos-tracks.html

    It has been found these highest energy neutrinos DON"T pass through the Earth like a knife through butter but in fact don't make it all the way through at all.

    My question is this: is there a way to understand or visualize somehow the difference between high and low energy neutrin ...[text shortened]... , higher energy basically just means smaller wavelengths.

    What is an analogy for Neutrinos?
    This is a bit out of my league, but the best I could do in defining the difference between high and low energy neutrinos are in the links below.


    High:
    https://www.nobelprize.org/nobel_prizes/themes/physics/hulth/

    Low:
    http://iopscience.iop.org/article/10.1088/1742-6596/718/2/022012/pdf
  3. Standard member lemon lime
    blah blah blah
    24 Nov '17 04:22
    Originally posted by @mchill
    This is a bit out of my league, but the best I could do in defining the difference between high and low energy neutrinos are in the links below.


    High:
    https://www.nobelprize.org/nobel_prizes/themes/physics/hulth/

    Low:
    http://iopscience.iop.org/article/10.1088/1742-6596/718/2/022012/pdf
    High:
    https://www.nobelprize.org/nobel_prizes/themes/physics/hulth/

    "... a star in the Large Magellanic Cloud exploded as a supernova, which was later named SN1987. The neutrinos from the inner part of the collapse reached the earth after a journey of 170,000 years, a few hours before the arrival of light."


    The neutrinos were travelling faster than light?
  4. 24 Nov '17 07:44
    Originally posted by @lemon-lime
    High:
    https://www.nobelprize.org/nobel_prizes/themes/physics/hulth/

    "... a star in the Large Magellanic Cloud exploded as a supernova, which was later named SN1987. The neutrinos from the inner part of the collapse reached the earth after a journey of 170,000 years, a few hours before the arrival of light."


    The neutrinos were travelling faster than light?
    No, they started earlier.
  5. Standard member sonhouse
    Fast and Curious
    24 Nov '17 17:56
    Originally posted by @lemon-lime
    High:
    https://www.nobelprize.org/nobel_prizes/themes/physics/hulth/

    "... a star in the Large Magellanic Cloud exploded as a supernova, which was later named SN1987. The neutrinos from the inner part of the collapse reached the earth after a journey of 170,000 years, a few hours before the arrival of light."


    The neutrinos were travelling faster than light?
    Neutrinos have a small amount of mass and therefore cannot go even at c but they get close. The large Magellanic cloud is about 160,000 light years away and it is reasonable for the Neutrinos to take 170,000 years to get here. No superscience here, walk away folks.
  6. Standard member DeepThought
    Losing the Thread
    25 Nov '17 06:06
    Originally posted by @sonhouse
    https://phys.org/news/2017-11-earth-high-energy-neutrinos-tracks.html

    It has been found these highest energy neutrinos DON"T pass through the Earth like a knife through butter but in fact don't make it all the way through at all.

    My question is this: is there a way to understand or visualize somehow the difference between high and low energy neutrin ...[text shortened]... , higher energy basically just means smaller wavelengths.

    What is an analogy for Neutrinos?
    Higher energy means means shorter wavelength for neutrinos and for that matter any particle. As a rule scattering cross-section decreases with energy, so one would expect the higher energy neutrinos to interact even less than low energy ones.
  7. Standard member sonhouse
    Fast and Curious
    26 Nov '17 04:53
    Originally posted by @deepthought
    Higher energy means means shorter wavelength for neutrinos and for that matter any particle. As a rule scattering cross-section decreases with energy, so one would expect the higher energy neutrinos to interact even less than low energy ones.
    But the electromagnetic field of photons have two parts, a magnetic part and an electric field part, welded together but still it is easier to understand the wavelength bit that way.

    What is it about neutrino's that would lead to a wavelength? What is 'waving'?
  8. Standard member lemon lime
    blah blah blah
    04 Dec '17 04:06
    Neutrinos have energy and momentum... hence, wavelength.
    λ = h/p
  9. Standard member sonhouse
    Fast and Curious
    04 Dec '17 19:26
    Originally posted by @lemon-lime
    Neutrinos have energy and momentum... hence, wavelength.
    λ = h/p
    But they are not electromagnetic waves. What kind of waves then? Plancks constant divided by momentum. Fine, that tells you the physical picture of the size of the wavelength but what is waving? In and out of existence? What?
  10. Standard member lemon lime
    blah blah blah
    05 Dec '17 04:27 / 4 edits
    Originally posted by @sonhouse
    But they are not electromagnetic waves. What kind of waves then? Plancks constant divided by momentum. Fine, that tells you the physical picture of the size of the wavelength but what is waving? In and out of existence? What?
    After a bit of reading and contemplation (and a headache) I can now confidently say I have no idea what is waving, or why it's waving.
    (it's waving bye bye to the supernova?)

    I have a different question:

    Is the Magellanic cloud 170,000 light years away now, or was it 170,000 light years away at the time of the supernova?

    The reason I ask is because if we witness an event happening 170,000 years ago, and the universe is expanding at an accelerated rate, does this mean light must have traveled more than 170,000 light years before reaching earth?
  11. 05 Dec '17 07:47 / 2 edits
    Originally posted by @sonhouse
    But they are not electromagnetic waves. What kind of waves then? Plancks constant divided by momentum. Fine, that tells you the physical picture of the size of the wavelength but what is waving? In and out of existence? What?
    It is a very long time since I studied quantum physics and my memory of it is a bit rusty but if my memory from my university physics studies a few decades back serves me well enough, according to quantum physics, ALL particles have a 'frequency' or 'vibration' associated with them, including photons, electrons, protons, etc and thus I assume this must surely include neutrinos. I could be wrong but I took that to mean that this 'vibration' generally occurs in space so all particles vibrate in space including neutrinos.
    So, I could be wrong but, a possible answer to your question is; what is 'waving' in this case is the neutrino itself and it is specifically 'waving' in physical 3D space.

    ANYONE;
    Please correct me if I got that wrong.
  12. Standard member sonhouse
    Fast and Curious
    05 Dec '17 12:41
    Originally posted by @humy
    It is a very long time since I studied quantum physics and my memory of it is a bit rusty but if my memory from my university physics studies a few decades back serves me well enough, according to quantum physics, ALL particles have a 'frequency' or 'vibration' associated with them, including photons, electrons, protons, etc and thus I assume this must surely ...[text shortened]... s specifically 'waving' in physical 3D space.

    ANYONE;
    Please correct me if I got that wrong.
    I was trying to picture this 'vibration' and wonder if it is connected to the way Gravitational waves work? A stretching and pulling of spacetime somehow inherent in all particles.