What is the Interaction of Solar Neutrinos with Matter?

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Discussion Overview

The discussion revolves around the interaction of solar neutrinos with matter, specifically focusing on how many solar neutrinos interact with the human body per second or over a lifetime. Participants explore the nature of neutrinos, their interaction rates, and related concepts in quantum field theory.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • Some participants propose that approximately 100 billion neutrinos pass through a human thumbnail every second, leading to only one or two neutrino-induced reactions in a lifetime.
  • Others argue that neutrinos do not significantly interact with biological organisms, suggesting that there has not been a serious study on their interaction with human bodies.
  • A participant mentions that it takes about 100,000 years for gamma rays from the Sun's core to reach its surface, while neutrinos arrive at Earth in about eight minutes due to their rare interactions with matter.
  • There is a question about whether neutrinos can pass through dense objects like neutron stars or if they would be affected by strong gravity.
  • Some participants discuss the potential gravitational effects on neutrinos, noting that while they have non-zero mass, their interactions are primarily influenced by weak forces.
  • One participant corrects a previous claim about the travel time of neutrinos and clarifies the distinction between neutrinos and other particles like neutrons.
  • Another participant expresses uncertainty about the wording of a source regarding solar activity visibility and its implications.
  • There is a mention of an estimation approach to understand neutrino interactions with dense matter, such as neutron stars.
  • One participant suggests a different estimate of 65 billion neutrinos per second interacting with the human body.

Areas of Agreement / Disagreement

Participants express a range of views on the interaction of solar neutrinos with matter, with no clear consensus on the specifics of interaction rates or the implications of neutrino behavior in extreme environments.

Contextual Notes

Some claims about interaction rates and travel times are challenged or corrected, indicating potential misunderstandings or misinterpretations of the underlying physics. The discussion includes various estimates and interpretations, reflecting the complexity of the topic.

hhhmortal
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Hi, I'm trying to find out the total number of solar neutrinos that interact with the human body per second or per lifetime. I know we are exposed to many, most which pass straight through us, but I'm interested to know how neutrinos interact with matter.


Thanks.
 
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why do you want to know? or rather, how MUCH do you want to know? if you want to know how they interact with matter from a quantum field theory approach I/we can guide you to resources.

I think it is 1 or so ..
 
hhhmortal said:
Hi, I'm trying to find out the total number of solar neutrinos that interact with the human body per second or per lifetime. I know we are exposed to many, most which pass straight through us, but I'm interested to know how neutrinos interact with matter.


Thanks.

To my knowledge, there has never been a serious study on solar neutrons interacting with human bodies. Nor a present need for such a study.
They just don't affect biological organisms to any known significant degree at all.

A "neutron bomb", on the other hand, can cause severe biological damage.
 
pallidin said:
To my knowledge, there has never been a serious study on solar neutrons interacting with human bodies.

He's asking about neutrinos, not neutrons.

The OP can find information about calculating rough estimates of interaction rates here:

Neutrino cross section (Hyperphysics)
 
Last edited:
Coincidentally, I just happened to read the answer to this a couple of days ago.
ansgar said:
I think it is 1 or so ..

Yup. From the second edition of Introduction to Elementary Particles by David Griffiths:

"John Bahvall, who was responsible for most of the calculations of solar neutrino abundances, like to say that 100 billion neutrinos pass through your thumbnail every second; and yet they are so ethereal that you can look forward to only one or two neutrino-induced reactions in your body during your entire lifetime."
 
George Jones said:
"John Bahvall, who was responsible for most of the calculations of solar neutrino abundances, like to say that 100 billion neutrinos pass through your thumbnail every second; and yet they are so ethereal that you can look forward to only one or two neutrino-induced reactions in your body during your entire lifetime."

HOLY CRAP, that's amazing. Would neutrinos go right through very dense objects like neutron stars? Or would they simple get sucked in by its strong gravity?
 
Dav333 said:
HOLY CRAP, that's amazing. Would neutrinos go right through very dense objects like neutron stars? Or would they simple get sucked in by its strong gravity?

gravity can't bound them, but you can do an order of estimation, scale the mean-length for a neutrino in lead, divide with the density of neutron star, the result is order of meters... in lead.. light years
 
Neutrinos don't interact with matter, that's why they pass through objects such as the human body. It takes 100,000 years for neutrinos to travel from the sun's core to it's surface, and only 8 minutes to travel from the sun's surface to earth. It's estimated that 50 trillion neutrinos pass through the human body per second.
 
blackemerald said:
It takes 100,000 years for neutrinos to travel from the sun's core to it's surface, and only 8 minutes to travel from the sun's surface to earth.

That's not correct.
 
  • #10
Vanadium 50 said:
That's not correct.

Yeah, I was about to jump on that myself.
 
  • #11
my mistake-

"It takes about a hundred thousand years that the gamma ray generated by the nuclear fusion in the center of the Sun appears on the surface. On the other hand, solar neutrinos arrive at the Earth in about eight minutes because neutrinos rarely interact with the matter. Therefore we see the solar activity a hundred thousand years ago by the visible lights, however, it is possible to see the inner of the Sun in real-time by neutrinos."
source:http://www-sk.icrr.u-tokyo.ac.jp/sk/physics/solarnu-intro-e.html
 
  • #12
blackemerald said:
my mistake-

"...Therefore we see the solar activity a hundred thousand years ago by the visible lights..."
source:http://www-sk.icrr.u-tokyo.ac.jp/sk/physics/solarnu-intro-e.html

Hmmm... that seems poorly worded to me. Maybe a translation/grammar issue.
Or, maybe it's just me.
 
  • #13
It is poorly worded, so imagine my embarassment when I went back, read it and realized my misinterpretation. But the information IS from the official Super-Kamiokande website, who the last time I checked is on the forefront of neutrino research.
 
  • #14
ansgar said:
gravity can't bound them, but you can do an order of estimation, scale the mean-length for a neutrino in lead, divide with the density of neutron star, the result is order of meters... in lead.. light years

Neutrinos do have non-zero mass; so I imagine that you would see at least some gravitational effect.

Normally for low-mass elementary particles like electrons you never observe gravitational effects because they're completely swamped by the electromagnetic force, but for a neutrino, which isn't coupled to the strong force or electromagnetism, I imagine you could observe some gravitational deflection in the presence of an extremely strong gravitational field, eg. a neutron star or black hole.
 
  • #15
I think the number of neutrinos is 65 000 000 000 neutrinos for seconds...
 

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