If one atom of iron was shot at my head . . .
Sept 25, 2021 16:34:40 GMT -5
RWA3006 and hummingbirdstones like this
Post by 1dave on Sept 25, 2021 16:34:40 GMT -5
Do you ever see sparks or trails of light?
Answer by Robert Meservy -
Follow B.A. in Physics & Biomath, Utah State University (Graduated 2007)Updated October 16, 2020
To expand on Doug Hensley's answer to If one atom of iron was shot at my head at a speed of 28,000 km/h, would it affect me?, your chosen speed is too dang slow.
28,000 kmph may sound impressive to you and, sure, if I had a car or motorcycle that could hit those speeds I would be impressed, but for an atom or a subatomic particle you’re not even close to breaking into relativistic effects.
Cosmic rays regularly impact the earth and create showers of muons with energies of ~1.4TeV. At 207 (206.768 2830) times the mass of an electron (rest mass); they’re much lighter than your iron nucleus/atom but they are very common.
Typical values at sea-level are 1 muon/cm2/minute, though it gets higher with elevation.
The area of the top of a human head is around 150cm2.
So, every minute 150 of these suckers zip through your brain with a velocity in the 0.998c+ range.
Since Doug did the Joule calculation for your iron scenario I’m going to just steal it:
3*10(-18)J. Since an electron Volt (eV) is 1.6*10(-19)J the conversion is straight forward:
3*10(-18)J / 1.6*10(-19) = 18.75eV << Again, you’re not even trying to hurt yourself are you?
1 muon is carrying the energy equivalent of 1*10^12/18.75 = 53 *10^9 of your iron atoms. Taking into account the area of the top of your head (150cm2), we get 150 (events) * 53*10^9 (energy equivalence) = ~8*10^12
So the universe does your experiment on your head 8 Trillion times every minute of every hour of every day. So far you seem (relatively) unaffected.
First of all, thanks to everyone for reading, upvoting and sharing this. Since a lot of people are interested in physiological effects I’d like to add some small factoids.
On average the muons zip through your body with minor interactions, a sea-level dweller accumulates about 10 chest X-rays/year from muon exposure
.
Low-level increases in cosmic ray muons are believed to increase cloud formation leading to global cooling. A find of Fe-60 (an unstable iron isotope) in the deep ocean dates back to 2.6MYA and is only formed within Supernovas. This suggests that ~2.8MYA a Supernova exploded somewhere within 150 light years of us
. This coincides with the Pliocene-Pleistocene boundary Mass Extinction Event (2.8MYA) which is linked with a rapid decrease in global temperatures. (The Fe-60 arriving ~200,000 years later at a slower than light speed).
Astronauts working outside the boundaries of our magnetosphere report flashes of light
that vary in frequency depending on the mission and correlate with measured cosmic ray activity. One astronaut sought shelter behind the Lead-Acid batteries when the flashes were interfering with sleep but found no change.
Researchers are currently unsure whether they are caused by Cherenkov Radiation
within the vitreous humor or direct activation of optic nerves by high energy particles but experiments on earth where subjects had high energy particle beams shone at their eyes (!) suggest that what astronauts are experiencing is direct stimulation.
I’ve seen flashes of blue-white light out of the corner of my eyes too, it’s not at the 2.9 minute mark as seen by Apollo astronauts or the 6.8 minutes reported by Near Earth inhabitants. But at around 1 unexplained event/year (discounting pressure, dizziness, vertigo, etc), maybe…just maybe…I’m seeing a muon.
Edits:
Clarified the eV calculation slightly
Corrected typo in requested speed
Corrected mass of muon from 270 to 207me [Pranjal Ralegankar]
Clarified “equivalence” calculation [Jeff Templeton]
Added 2nd section
Answer by Robert Meservy -
Follow B.A. in Physics & Biomath, Utah State University (Graduated 2007)Updated October 16, 2020
If one atom of iron was shot at my head at a speed of 28,000 km/h, would it affect me?
To expand on Doug Hensley's answer to If one atom of iron was shot at my head at a speed of 28,000 km/h, would it affect me?, your chosen speed is too dang slow.
28,000 kmph may sound impressive to you and, sure, if I had a car or motorcycle that could hit those speeds I would be impressed, but for an atom or a subatomic particle you’re not even close to breaking into relativistic effects.
Cosmic rays regularly impact the earth and create showers of muons with energies of ~1.4TeV. At 207 (206.768 2830) times the mass of an electron (rest mass); they’re much lighter than your iron nucleus/atom but they are very common.
Typical values at sea-level are 1 muon/cm2/minute, though it gets higher with elevation.
The area of the top of a human head is around 150cm2.
So, every minute 150 of these suckers zip through your brain with a velocity in the 0.998c+ range.
Since Doug did the Joule calculation for your iron scenario I’m going to just steal it:
3*10(-18)J. Since an electron Volt (eV) is 1.6*10(-19)J the conversion is straight forward:
3*10(-18)J / 1.6*10(-19) = 18.75eV << Again, you’re not even trying to hurt yourself are you?
1 muon is carrying the energy equivalent of 1*10^12/18.75 = 53 *10^9 of your iron atoms. Taking into account the area of the top of your head (150cm2), we get 150 (events) * 53*10^9 (energy equivalence) = ~8*10^12
So the universe does your experiment on your head 8 Trillion times every minute of every hour of every day. So far you seem (relatively) unaffected.
First of all, thanks to everyone for reading, upvoting and sharing this. Since a lot of people are interested in physiological effects I’d like to add some small factoids.
On average the muons zip through your body with minor interactions, a sea-level dweller accumulates about 10 chest X-rays/year from muon exposure
.
Low-level increases in cosmic ray muons are believed to increase cloud formation leading to global cooling. A find of Fe-60 (an unstable iron isotope) in the deep ocean dates back to 2.6MYA and is only formed within Supernovas. This suggests that ~2.8MYA a Supernova exploded somewhere within 150 light years of us
. This coincides with the Pliocene-Pleistocene boundary Mass Extinction Event (2.8MYA) which is linked with a rapid decrease in global temperatures. (The Fe-60 arriving ~200,000 years later at a slower than light speed).
Astronauts working outside the boundaries of our magnetosphere report flashes of light
that vary in frequency depending on the mission and correlate with measured cosmic ray activity. One astronaut sought shelter behind the Lead-Acid batteries when the flashes were interfering with sleep but found no change.
Researchers are currently unsure whether they are caused by Cherenkov Radiation
within the vitreous humor or direct activation of optic nerves by high energy particles but experiments on earth where subjects had high energy particle beams shone at their eyes (!) suggest that what astronauts are experiencing is direct stimulation.
I’ve seen flashes of blue-white light out of the corner of my eyes too, it’s not at the 2.9 minute mark as seen by Apollo astronauts or the 6.8 minutes reported by Near Earth inhabitants. But at around 1 unexplained event/year (discounting pressure, dizziness, vertigo, etc), maybe…just maybe…I’m seeing a muon.
Edits:
Clarified the eV calculation slightly
Corrected typo in requested speed
Corrected mass of muon from 270 to 207me [Pranjal Ralegankar]
Clarified “equivalence” calculation [Jeff Templeton]
Added 2nd section
grainy structure 
