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Q & A: Seeing and instruments

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Most recent answer: 10/22/2007
All the things we know about our universe through physics we are aware of because of our senses. I know we can "see" things we cannot see in many scientific ways, but is it possible that we lack senses that would make it possible for us to better understand or "see" the universe?...even with the aid of scientific instruments.
- Josh (age 18)
Miami, FL
Hi Josh,

Great question. Physics is an experimental science, and we test our models and hypotheses against observations to check to see if they are favored or excluded. Observations can take a large variety of forms. Many observations which can be done with our built-in senses have been done many times over, and so the discovery of previously undiscovered physical principles usually involves the use of some kind of equipment or other. Although you certainly can discover stuff with your own senses! Like a new comet (telescopes help, but for the most part it just involves someone looking in the right direction at the right time), or a new species of plant or animal. Or you can measure important things, like the length of your shoes, without complicated equipment.

But some phenomena require apparatus which extends our ability to perceive stuff. I work in the field of experimental elementary particle physics, and we require sensitive electronic devices, and sometimes big piles of steel and lead, all arranged with high voltage and electronics, to pick up the faint traces that individual particles leave. If some interaction or phenomenon has any impact at all on something else, then it can be detected in some way with some piece of apparatus. Example: even if we cannot see evaporation, we can infer it by its effect on a glass of water (the effect is easier to see if we let something sit out and evaporate for a long time). Even though we cannot see X-rays, we can detect them with photographic film or electronic detectors. Even though we cannot see neutrinos, and they only very seldom interact with anything, we can amass a large quantity of water in a tank and look for individual flashes of light created by the electrons or muons created during one of the rare neutrino interactions. Or we can put a whole bunch of gallium together, and screen it chemically after waiting a while, to see how much of it has been chemically altered by neutrino interactions.

So -- our ability to perceive stuff is really limited by our imagination and available technology. If we would like to perceive something which interacts with something else in any way whatsoever, all we have to do is put together the right piece of equipment and devise the right way of interpreting its results.


p.s. of course it would be cool to directly 'see' things by other senses, the way bats 'see' things by sound or platypus' 'see' things electrically. Unfortunately we can't really imagine what those sensations are like. As for getting information information about some side of nature that can't be reached by any instruments, that seems far-fetched. Anything that interacts, directly or indirectly, with ordinary stuff should someday be detectable by instruments, as Tom wrote. Now if there were something that had no interaction of any type with ordinary stuff, it wouldn't make much sense to talk about it. Mike W.

(published on 10/22/2007)

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