Has Anyone Seen a Subatomic Particle With Their Naked Eyes?
Most recent answer: 10/22/2007
- Zandi (age 19)
University of the Western Cape, South Africa
Hi Zandi,
[scroll down to follow-up #16 for possible explanation!]
Good question! Subatomic particles, the hadrons and leptons you ask about, are so small they are difficult to detect individually, and elaborate apparatuses are designed for detecting the presence of and measuring the properties of individual particles. Here is a describing a fairly typical, large detector for subatomic particles. These detectors are designed to measure the effects of particles when they pass. They may leave a trail of ionized gas, for instance, or a flash of light when they collide with leaded glass. People have seen with their eyes these flashes of light and sparks one can make with the ion trails. An older technique is to expose a liquid just about ready to boil to high-energy particles, and then to take a picture as the bubbles left in the path of the particle start to expand. Here is a describing one particularly large bubble chamber, along with a photograph of bubble trails left by subatomic particles.
Electrons are the most common lepton, and protons and neutrons are the most common hadrons (see our description of . Everything we look at is made up of these things, and so we are looking at them all the time, it's just a question of whether we've seen only one of them at a time. To "see" something with a naked eye you need to shine light on it and observe the photons with the eye (and then one can argue that all you're "seeing" is the photons, a secondary consequence of the electron being there.) Electrons don't weigh very much, so when you shine light on one it will bounce away unless it is held down somehow.
So the answer is no, not to my knowledge, has anyone shined light on just one of these particles and then unambiguously observed the light with their eyes and determined that it came from only one electron or proton. The smallest I remember seeing a picture of is that of a single sodium atom sitting in an atomic trap, fluorescing laser light.
Tom
(published on 10/22/2007)
Follow-Up #1: More on detecting particles with your eyes
- Jeff (age 26)
University of Kansas
There could also be other things going on, such as cosmic ray interactions with not just the retina but possibly neurons involved in visual processing. In our high-energy physics experiments we put sensitive amplifiers and digitizing electronics on the ends of the sense wires of our detectors. Sometimes we get showers of particles from the accelerator that strike the electronics and then you get signals from the electronics even if the detector is not sensitive (like when the high voltage is switched off). You might imagine that random flashes of light perceived by astronauts might be cosmic-ray interactions with any piece of the visual processing chain, including the brain. This is one reason why these flashes were initially some concern, because exposure of astronauts brains to high-energy penetrating radiation in the form of hadron showers was not investigated at the time and could lead to unknown damage.
Tom
(published on 10/22/2007)
Follow-Up #2: Seeing sub-atomic particles is difficult
- Onyx (age 18)
Detroit,MI, USA
I was stupid, I could have fried my eyeballs.
LeeH
(published on 03/26/2009)
Follow-Up #3: "Seeing" particle trajectories?
- Ron Branscombe
Tallinn, Estonia
LeeH
(published on 08/01/2009)
Follow-Up #4: seeing moving dots
- leslie (age 32)
ks
We don't know but are posting this along with several related questions to try to find out from our readers.
Mike W.
(published on 01/30/2013)
Follow-Up #5: seeing particles
- Joseph (age 33)
Menifee, ca, USA
Mike W.
(published on 03/03/2013)
Follow-Up #6: seeing light particles
- Anmol (age 31)
Nottingham UK
Mike W.
(published on 03/26/2013)
Follow-Up #7: seeing rain-like patterns
- Marc (age 39)
London, UK
Mike W.
(published on 04/21/2013)
Follow-Up #8: Floaters?
- sheren (age 26)
ny
I think I have an explanation for at least some of the effects that our readers are pointing out: .This well-documented effect occurs when small particles floating in the eye are detected by the retina, usually when illuminated against a clear backdrop (like the sky on a clear day).
These floaters are easiest to see if you are gazing into empty space with your eyes unfocused. At least for me, this requires a bit of relaxed concentration, and a clear blue sky helps make them visible. They tend to slowly sink within the eye, in a sort of light rain. In addition, when I flick my eyes lightly, all the floaters move in the direction of the flick, with a small time delay.
These effects certainly give the impression of an invisible rain of particles controlled only by your mind. However, floaters are basically harmless, intriguing, and useless irregularities in the eye.
Interestingly, I'm pretty sure you can observe white-light diffraction around the edges of the floaters. This is why their edges aren't sharply defined, but instead fuzzy, tiny, alternating light and dark bands.
Hopefully this explanation resonates with at least some of our readers.
Let us know!
David Schmid
(published on 05/05/2013)
Follow-Up #9: Seeing Antimatter and Subatomic Particles
- orla (age 59)
Ireland
Hi Orla,
Perceiving such effects is quite common. Many of our readers (and several of our staff) can relate.
However, there is no reason that this phenomena is linked to subatomic particles or antimatter. There are several possible explanations; see above for some discussion.
Cheers,
David Schmid
(published on 01/11/2014)
Follow-Up #10: visible dots flying around
- orla Bradley (age 59)
Ireland
We remain stumped, but are hopeful that some alert reader will help explain this common observation.
Mike W.
(published on 01/12/2014)
Follow-Up #11: visual particles
- Daniel (age 42)
Guntersville, AL, USA
We're happy to pass on these data in the hope that some reader may help figure out the explanation. One thing we're sure of: it's not neutrinos. They just don't interact enough with our type of matter.
Mike W.
(published on 05/18/2014)
Follow-Up #12: visual sparkles
- Ms. Rodleen Getsic (age 39)
Smokey Point, WA, USA
We're happy to include your contribution. Perhaps someone who understands the brain's visual processing system will notice and contribute some explanation of this common phenomenon.
Mike W.
(published on 08/13/2014)
Follow-Up #13: seeing tiny drops
- Vince (age 36)
San Diego
We'll put this up to help further the discussion.
Mike W.
(published on 10/20/2014)
Follow-Up #14: Seeing single photons
- Anonymous
Great point! However, it's not actually clear that frogs or any other animal can "see" individual photons. What we know is that some of the light-sensing photoreceptor cells in the eye are sensitive enough to detect single photons. This has been confirmed by experiments with individual photoreceptor cells from frogs and from monkeys, and it's thought to be true for humans, too.
The pathway from these cells to the brain, where conscious perception happens (at least for humans) is much more complicated, and tiny signals from single photons might be filtered out or lost somehow. Or they might not be—no one knows for sure. The research group I work with here at the University of Illinois is actually whether humans can see single photons, using a light source that can generate one photon at a time.
Rebecca Holmes
(published on 10/23/2014)
Follow-Up #15: seeing sparkling things in sky
- khaber (age 19)
zakho,kordistan,iraq
Hi Khaber- We don't know what you're seeing. All we do know is that it sounds very much like what many other readers from around the world have described.
The way our eyes produce signals and our brain interprets them is complicated. Probably someone who studies those processes could give a better answer than our group of physicists.
Mike W.
(published on 11/11/2014)
Follow-Up #16: fun with floaters
- Blair (age 49)
Montreal, Canada
Thanks.
My own floaters are big lumbering things which interfere with clear vision and never do anything fun.
Mike W.
(published on 01/29/2015)
Follow-Up #17: see sparkling dots
- Erick Hartman (age 62)
Tacoma, WA, USA
Thanks! You've cleared up a question many of our readers had asked about.
Mike W.
(published on 01/31/2015)
Follow-Up #18: seeing particles?
- Lorena Whelan (age 42)
Seoul, Seoul, South Korea
It's definitely not neutrinos. They just don't interact enough with our type of matter. Check follow-up 16 for a posible explanation.
Mike W.
(published on 02/14/2015)
Follow-Up #19: more visual dots
- Radhika (age 22)
Coimbatore,India
You're right that they can't be air molecules, which are too small and interact very weakly with light.
We're happy that you've added more data to the discussion.
Mike W.
(published on 03/10/2015)
Follow-Up #20: seeing dancing light spots
- Amanda Francis (age 42)
Lennox Head NSW Australia
Welcome to the club! I've put this in a thread with related observations.
Mike W.
(published on 06/21/2015)
Follow-Up #21: seeing moving dots
- Andrea (age 48)
Washington State
I don't see how it could be particles from the Sun or farther. They'd be zipping along at close to the speed of light.
I'm not sure why you rule out white blood cells, which a knowledgable reader suggested as an explanation. They're present throughout the blood, and blood flows to all the cells at the back of the eye.
Mike W.
(published on 07/06/2015)
Follow-Up #22: moving visual dots
- Andrew (age 21)
Lithuania
We don't know, but one reader thinks that white blood cells are likely.
Mike W.
(published on 07/09/2015)
Follow-Up #23: more dots seen
- sylvia carlson (age 65)
salzburg
Well, it's more data.
Mike W.
(published on 09/03/2015)
Follow-Up #24: seeing bright spots
- Keithen Odom (age 33)
Pembroke, NC
We don't close discussions here, so your story is welcome. We still don't understand the phenomenon. Since your mother could see it too, it sounds like there could have been something in the air scattering the light. Individual water molecules, however, are far too small. Maybe you're on the right track thinking of little slat particles picking up water or something like that. I can't think of any specific story that would work.
Mike W.
(published on 07/02/2016)
Follow-Up #25: seeing particles
- Joshua Gibson (age 34)
48461
From your description, you just need to replace the word "molecules" with "dust particles". There are a lot of them in ordinary air, and perhaps your eyes are sensitive enough to see many of them under the right conditions.
Mike W.
(published on 01/22/2017)
Follow-Up #26: seeing little particles
- Robert (age 48)
Lovelady, TX, US
We will just post this for readers' thoughts.
Mike W.
(published on 03/23/2017)
Follow-Up #27: more particle viewing
- Liz (age 30)
UK
Yes, something like this seems very common, and perhaps not well understood. How well do your observations fit the explanation one of our readers gave in follow-up 16?
Mike W.
(published on 02/18/2018)