What is the Smallest Piece of Matter We Can Observe?

[kyphysics]

I was just recently listening to a radio program, where a scientist said that we cannot observe electrons visually, but know they exist from their effects. That got me wondering...

What is the smallest piece of matter that we DO have the capability of seeing? And, also, how much of what exists is beyond our current scope of observation?

 

[DennisN]

What is the smallest piece of matter that we DO have the capability of seeing? And, also, how much of what exists is beyond our current scope of observation?

The answer to this question depends on if you mean "see/observe with our eyes" or "observe/examine with instruments (i.e. equipment)". So which of these do you mean?

 

[UltrafastPED]

Look up atomic force microscope, and related images.

 

[ZapperZ]

I was just recently listening to a radio program, where a scientist said that we cannot observe electrons visually, but know they exist from their effects. That got me wondering...

What is the smallest piece of matter that we DO have the capability of seeing? And, also, how much of what exists is beyond our current scope of observation?

What you are being asked to explain here is elaborate if you mean by seeing as in with the naked eyes, unassisted by any other means.

If this is yes, then the answer is the the size of the shortest wavelength in the visible spectrum of light. This is because to "see" something with your eyes, the object must either have its own light, or is able to reflect light from an external source. And the smaller the object, the shorter the wavelength of light that is needed to detect that object. Since we are using our eyes, then it will be the shortest wavelength that our eyes can detect, which is towards the violet/indigo region.

If you are asking about what we can see/detect in general with assistance of devices, then STM/AFM techniques have allowed use to look at Angstrom scale resolution.

Zz.

 

[CWatters]

I was just recently listening to a radio program, where a scientist said that we cannot observe electrons visually...

Technically that's correct but see...

http://io9.com/the-first-image-ever-of-a-hydrogen-atoms-orbital-struc-509684901

 

[russ_watters]

I was just recently listening to a radio program...

Interesting...how do you know radio exists if you can't see it...?

 

[CWatters]

What is the smallest piece of matter that we DO have the capability of seeing? And, also, how much of what exists is beyond our current scope of observation?

I still think you have to define "seeing". We can't see some galaxies using visible light. If we use a radio telescope to convert the radio data to a visible image does that count as seeing?

If you want to know what the smallest thing is you can see with regular visible light perhaps try..

http://www.nanowerk.com/spotlight/spotid=33865.php

A conventional optical microscope equipped with an oil immersion objective can resolve objects no smaller than about 200 nanometers – a restriction known as the diffraction limit. The diffraction limit, which typically is half the width of the wavelength of light (λ) being used to view the specimen, represents the fundamental limit of optical imaging resolution.

Breaking this limit is possible by very sophisticated techniques and costly instrumentation. Now, though, researchers in Switzerland have found that when putting a transparent dielectric particle on top of an object with nanoscale features, details of that object with a size corresponding to ∼λ/7 can be resolved using a conventional microscope objective.

As others have pointed out, you can make images of smaller objects using SEM and the like but is that "seeing" according to your definition?

 

[kyphysics]

The answer to this question depends on if you mean "see/observe with our eyes" or "observe/examine with instruments (i.e. equipment)". So which of these do you mean?

Haha! Let's say both! That'd be neat to know!

What you are being asked to explain here is elaborate if you mean by seeing as in with the naked eyes, unassisted by any other means.

If this is yes, then the answer is the the size of the shortest wavelength in the visible spectrum of light. This is because to "see" something with your eyes, the object must either have its own light, or is able to reflect light from an external source. And the smaller the object, the shorter the wavelength of light that is needed to detect that object. Since we are using our eyes, then it will be the shortest wavelength that our eyes can detect, which is towards the violet/indigo region.

If you are asking about what we can see/detect in general with assistance of devices, then STM/AFM techniques have allowed use to look at Angstrom scale resolution.

Zz.

Interesting. Out of curiosity, what are some things that are on the "Angstrom" scale of size?

Also, have we ever "seen" (with either human eye or a device assisting it) things like atoms before?

 

[Maxo]

Interesting. Out of curiosity, what are some things that are on the "Angstrom" scale of size?

Actually it's spelled Ångström, with "Å" and "ö", which are different letters than "A" and "o". Just a side note.

 

[Matterwave]

Interesting. Out of curiosity, what are some things that are on the "Angstrom" scale of size?

An angstrom is 10^-10 meters. This is roughly in the molecule/single atom size (where the electrons orbit) range.