The tiniest of things

[Daisho]

Really curious here. What is the smallest thing ever seen by the human eye using microscopes?

[liquoricemad]

As a guess, I would say a cell organelle, something like a mitochondrion. Any advances on that?

[stevie21]

EDDIE51, in that case you're only measuring the limits of technology rather than the inital idea which I believe hinged on only eyeballs and lenses being used.

We can all look at a TV picture of something which, in reality, would never be visible to the naked eye.

[Daisho]

Many thanks for all your answers. So, is an atom pretty much the smallest thing known?

[Clanad]

"Known" is sometimes a theoretical term... We "know" that atoms are made up of even smaller particles (protons, neutrons and electron) and then in 1963  Murray Gell-Mann proposed his quark theory. Gell-Mann believed that each proton and each neutron is made up of three even smaller particles -- particles he named quarks (there are different types of quarks). Finally, quantum physics describes the subatomic world as one that cannot be depicted in diagrams -- particles are not dots in space, but are more like "dancing points of energy."  These are theoretical, as of now, with much work left to trupy understand the phenomena... simply put...

[Peter Pedant]

Optical microscopes are limited by something called resolution - this depends on the wavelength of the light being used. basically you end up with a blur, and on turning up magnigication, the blur just getts larger.

Cell organelles and some large viruses - small pox viruses are big enough to be seen, and I think are called paschen bodies.....

[Phantaxus]

Scanning Tunneling Microscopes (STM) can resolve and manipulate individual atoms

[Phantaxus]

see http://www.almaden.ibm.com/vis/stm/gallery.html

[Daisho]

Thank you for sharing your knowledge with me. Appreciated.

[Porkboy]

The previous post was quite right to distinguish between optical microscopy (ie visible light) and other forms of microscopy (electron, tunnelling and atomic force microscopy, for example). Whilst the resolution of these latter techniques allows the imaging of single atoms the mechanism by which the image is produced is completely different from that used by the eye to 'see'. The optical diffraction limit, as mentioned earlier, governs the resolution we can distinguish. This is roughly half the wavelength of the incident light, in practice this is approximately 200nm. However, it is possible to obtain a resolution of better than 100nm by using a technique called SNOM (scanning near-field optical microscopy), or NSOM if you're American.

[dothawkes]

how come noone had had the foresight or sense of danger to say that it might be deesels big sweaty pal? Cowards the lot on ye