From my very limited understanding of astrophysics, there are various particles zipping about the universe at all times. If they have mass, does that mean that when they hit a solid object – say, for example, a 140kg male H sapiens – do they pass through with no damage? Or do they bounce off?
At whatever speed those objects are moving through the universe, what speed would they have to be going before they did some kind of noticeable damage to me (such as drawing blood)?
Neutrinos have mass and are constantly going through you.
Neutrinos are ghostly particles that barely interact with the world at all. Look at your hand—there are about a trillion neutrinos from the Sun passing through it every second.
From here.
About a hundred trillion per second for a human body; and about a 25% chance that one neutrino interacts with you in your lifetime.
Just how often are you hit by a neutrino? | symmetry magazine
So obviously…
Yo mama so fat she interacted with 3 neutrinos last week.
Haha!!
Back to the OP, that link is an amusing take, but it has a lot of great information, including how many neutrinos you’d need to have damage (spoiler: a LOT).
I don’t think there are other particles routinely moving through you, but I could be wrong.
This well known story also comes to mind, although it’s not about cosmic rays.
The most important answer to your question is that cosmic rays contribute to DNA mutation - thus cancer, and germline mutations that are passed to the next generation.
In terms of damage done by these high-speed particles, I wonder if they are the cause of random DNA errors that can lead to diseases happening de novo (spontaneously). AIUI, all it would take is for a single particle to interact with a single DNA base in a germ cell to cause a disorder that gets passed on to a new generation… or do we know these high-speed particles are not the cause of DNA mutations?
Also, I once traveled a lot overseas on business, and I was once told that flying at 36,000 feet for a dozen hours exposes you to a lot more high-speed particles passing through your body compared to being down on earth. I suspect that’s more urban legend, but I’m curious if, in fact, it’s true, and what implications it has for airline pilots who spend many hours far off the surface of the planet.
Muons are apparently moving through our bodies at all time. The April 23 Science News doesn’t say how many but it describes them as plentiful enough to muonography studies of pyramids and volcanoes. It includes the disturbing sentence, “The difference between an electron and a muon passing through matter is like the difference between a bullet and a cannonball … A wall may stop a bullet, but a cannonball passes through.”
Found later it says one muon a minute through your thumbnail.
I found this info that again illustrates how little they interact with mass:
The problem with neutrinos is that they have a very low probability of interacting with matter. A neutrino could pass through a light year of lead and not be stopped by any of the lead atoms!
And since the OP asked about “how fast”, neutrinos move at so close to the speed of light that we can’t measure the difference.
It is true. Here is just one study that turned up on the first page of a Google search. Flight crews are at a higher risk for skin cancer, and possibly other cancers, than people who don’t fly everyday.
People living at high altitude are also at a higher risk for skin cancer than people living closer to sea level.
Most of the damage will be from gamma radiation though, not particle radiation.
No, it’s particle radiation that does most damage.
Typical secondary cosmic ray particles include protons, neutrons, positive and negative pions , and positive and negative kaons .
https://letstalkscience.ca/educational-resources/backgrounders/what-are-cosmic-rays
I stand corrected. I somehow disregarded all I know about particle radiation beyond alpha and beta.
The Master Spoke:
It’s likely that dark matter particles are passing through your body more or less constantly, but they’ll never interact.
And we don’t know how many dark matter particles, because we don’t know how much mass each one has. One of the many, many things we don’t know about them.
Ignorant question, sorry: If Neutrinos are so reluctant to interact, how do we know they are so plentiful?
One of those things being if they even exist at all.
A new study suggests that maybe dark matter doesn’t exist. The study suggests an incomplete scientific understanding of gravity is behind what appears to be the gravitational strength of galaxies and galaxy clusters, rather than vast clouds of dark matter.
That might mean mathematics, and not invisible matter, could explain why galaxies behave as they do, said study co-author Stacy McGaugh, who heads the astronomy department at Case Western Reserve University in Cleveland.
They were predicted in 1930 by Pauli on theoretical grounds. They were proven to exist only 26 years later, using the huge flux of neutrinos that were predicted to be generated by a nuclear reactor if the theory was correct. The theory is solid, and made specific predictions - and the results of the experimental detection were exactly what theory predicted, including the quantitative prediction for the (very small) probability of interaction. So that was compelling evidence that the theory is correct and that all the undetected ones are there too.
They had predicted a cross-section for the reaction to be about 6×10−44 cm2 and their measured cross-section was 6.3×10−44 cm2.
And obviously there’s a whole lot of subsequent experimental results, all consistent with theory.