: Sorry to get off the subject here but I am facinated and confused by this photo. If this is an atom lattice then am I to understand that those little roundish bumps are individual atoms? Yep.
: My layman's understanding of modern physics is that atoms are not actually little interconnected balls - that this depiction is just a model that physicists use to describe the atomic world just as wave models are used to describe the same; that no one knows what atoms really look like - only that they exhibit particle AND wave-like behavior.
No-one knows *exactly* what they look like; since we've never seen one unaided. however, STM is analogous to running a needle a few atoms thick over the surface and measuring the results that come out; similar in a way to a stylus on a record player touches a record; albeit much more sensitive.
Atoms do indeed display particle-like and wave-like properties at the same time, as the great physicist Louis de Broglie demonstrated; building on the work of the quantum pioneers. De Broglie demonstrated that *everything* has a certain amount of fuzziness associated with it; and is capable of acting like a wave; the only reason that we don't see it in day-to-day life is that Planck's Constant is very very small. If Planck's Constant was 1, then a human being walking through a doorway would be diffracted in the same way that light is in the slit experiments (Young's slits and the single-slit diffraction).
However, atoms also display particulate properties on a certain scale; what we're looking at here are effectively individual atoms in a latticework; they are fuzzy, but not on a scale which prevents them from forming noticeable peaks on an STM trace.
: Can someone straighten this out for me or recommend me to a forum that would clear this up? How can the things in this photo be atoms?
The thing is that, to measure the wave-like properties of atoms, you have to perform an experiment that works on the basis of atoms possessing wave-like quantities; to perform an experiment on atoms as particles, you have to design your experiment to elucidate the particular properties.
It's bizarre, I agree; it's one of the most counter-intuitive things about quantum physics; the one that gives quantum mechanics its fearsome reputation as Hard Science. It is difficult to visualise something as having both wave-like and particle-like properties at the same time because everything seems so concrete in the everyday world.
However, it is the simplest explanation that fits all the observed phenomena, it is falsifiable and it has stood up to every experiment yet performed.
Basically, everything that exists is the superposition of a number of mathematical possibilities; all of which combine to form what we know as 'matter'. For each particle (e.g. an electron e) there are a number of mathematical eigenvalues* (L) for its energy status; the Copenhagen Interpretation of Quantum Mechanics basically says that the total energy of the electron is equivalent to the combined eigenvalues of the possible quantum states; and that the probability of the electron being in a particular quantum state is equal to the prominence that that energy state has in the total energy state.
(Which is basically known as the Schrödinger Wave Equation, or S.W.E. for short.)
It's something that generally does require a bit of reading around the subject, though; looking at the paragraph above, most people I know will be scratching their heads; it's not the easiest or most obvious bit of physics.
I'd recommend this site and this site and here is a good background and working of the Schrodinger Wave Equation; they should be simple enough to give you a reasonably good grasp of the subject.
To answer the question, though; yes, those are atoms; or the nearest we can get to actual physical proof of them.
We can't ultimately prove that they exist in much the same way that you can't ultimately prove your neighbour's car exists; there is evidence to support the theory; and we can do experiments that would show us if they didn't exist.
Such experiments have not shown us that they don't exist, so we go with the theory until a better one comes along.
Gideon.
*Eigenvalues; a set of equally valid solutions to a matrix multiplication equation; there's an excellent explanation here
