If we can control single atoms and electrons, why can't we take a picture of them?

Status
Not open for further replies.

totalnoob

Golden Member
Jul 17, 2009
1,389
1
81
Just wondering..Is there something in quantum mechanics that absolutely prevents a high resolution picture of a fundamental particle? I think it would be fascinating to see one of the "building blocks" of everything up close. The closest we seem to be able to get is a picture of a molecule (pentacene).
800px-IBM_Zurich_Press_Release_AFM_Image_Penacene_Aug_2009.jpg


http://www.dailymail.co.uk/sciencet...n-times-smaller-grain-sand-pictured-time.html

That shows the beautiful symmetry of the chemical bonds BETWEEN the atoms, we really can't see what the atoms look like themselves..

Then there is this..supposedly a photo of an atom, but it looks more like a blob than anything else..
1zf63v9.jpg
http://www.insidescience.org/research/first_detailed_photos_of_atoms

We are able to create precise transistors down to the nm scale, and we are able to control single electrons perfectly in the large hadron collider, so why can't we hold an electron or proton in place and snap a high res photo of it (or at least it's general vicinity..It is bound to pop into frame eventually.) ;)
 

bobsmith1492

Diamond Member
Feb 21, 2004
3,875
3
81
A typical picture involves measuring photons that reflected or were emitted from an object. However, photons move with a wavelength too large too use them to "see" atoms or even molecules.

So, we use scanning or tunneling electron microscopes: instead of "seeing" with photons they see with electrons instead.

Now, how can you use an electron to see an electron? You can't bounce an electron off another to see where it was...

Basically there aren't any particles small enough to look at electrons without completely disturbing their positioning.

Read here... http://en.wikipedia.org/wiki/Observer_effect_%28physics)
 

totalnoob

Golden Member
Jul 17, 2009
1,389
1
81
Thanks for that. Obviously electrons are out of the question with our current method..but what about much larger particles like protons/neutrons? In the second picture I posted, if we could somehow "strip away" the electron cloud, we should get a good picture of the nucleus, no? :)
 
May 11, 2008
19,300
1,129
126
Thanks for that. Obviously electrons are out of the question with our current method..but what about much larger particles like protons/neutrons? In the second picture I posted, if we could somehow "strip away" the electron cloud, we should get a good picture of the nucleus, no? :)

Unfortunately it is not that easy.

atoms look big because of the electron cloud around the atom. If you take out the electrons, there really is not that much left.

Here is a nice link and text of a "photographed" electron.

http://discovermagazine.com/2009/jan/070

It is kind of controversial and under debate, but you might want to look up on spherical standing waves.
 
Last edited:

bobdole369

Diamond Member
Dec 15, 2004
4,504
2
0
Also I always wondered about the actual shape of protons and electrons. I know there is a theory that electrons are point sources, so I picture a little bit of lightning floating around orbiting the nucleus. When I started learning about valance shells and energy levels I thought about it as a nested concentric lightning.

Then I thought about things the same way for the nucleus, i.e.a blob of matter with "6 protons and 9 neutrons" worth of charge. It works until you split the nucleus, in which case they pretty much have to become point sources again. BUT if you treat it as a quantum superposition (i.e. we don't know what it is until observed) it works, and the instant a free neutron hits the nucleus it splits as expected and you get 3 spare neutrons.

Why do you always get that, why not 2 sometimes and 4 others, and why does the nucleus always split evenly? How come it never fractures into a billion hydrogens?

Well back to the point, I think maybe we can't see protons and neutrons because they really don't follow the traditional model.
 

beginner99

Diamond Member
Jun 2, 2009
5,208
1,580
136
Electrons (and even molecules) can also act like "waves" depending on the experment you preform. Same holds true for light waves (or any other magentic waves). Sometimes it's right to talk about photons sometimes about waves and wavelength depending on context.

Then it depends what you mean by picture.
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
49,606
166
111
www.slatebrookfarm.com
Think about what forms an image - for visible light, it's photons of light that are bounced off the object that you want an image of.

Imagine you want to take a picture of a horse by bouncing something off the horse - doesn't have to be photons. Pretend we can't see the horse at all with our eyes. We could bounce a lot of basketballs off the horse to get an idea of what is where & the relative shape of the horse. Better: bounce tennis balls off the horse - that would allow us to get some more detail. Better yet: bounce ping pong balls off the horse to get a clearer picture of what is in front of us. Now, if you're looking at a large object, such as a building, you can get a pretty good idea of what its shape by bouncing ping pong balls off it. But, if you want to get an idea of the relative shape of an insect, the ping pong balls aren't going to work. Such is the problem using visible light to see objects. You can only get so small before the light is useless (relates to the wavelength.) So, electron microscopes use something smaller. But, even that has limitations.
 

Red Squirrel

No Lifer
May 24, 2003
67,197
12,025
126
www.anyf.ca
I've always wondered this too, but the problem is, even if you could make a lens that was powerful enough to zoom in that deep, you would probably start seeing molecules of the lens itself. In fact once you get to the atomic level, the properties that make a lens work are probably shot out the window.
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
49,606
166
111
www.slatebrookfarm.com
I've always wondered this too, but the problem is, even if you could make a lens that was powerful enough to zoom in that deep, you would probably start seeing molecules of the lens itself. In fact once you get to the atomic level, the properties that make a lens work are probably shot out the window.

I think you're missing the point - there is a lower limit to the size that can be viewed by visible light. THAT'S why they make electron microscopes. Those too have a lower limit, again dictated by the laws of physics.
 

silverpig

Lifer
Jul 29, 2001
27,709
11
81
We can see atoms. You can do it via STM and TEM with AFM getting close. here's an image of a carbon film with a hole in it I took with a TEM. You can see the little dots. Those are individual atoms.

atoms.png
 

KIAman

Diamond Member
Mar 7, 2001
3,342
23
81
If you really want to get complicated, trying to take a picture of the smallest particles will result in the Observer effect. Basically, even if we were able to figure out how to use something smaller than an electron to map out something smaller, you can't trust the image.

One has to also keep in mind that "visual" is a man made concept. Some things in nature have no "visual" property at all. But because we need a reference for conceptualization, we assume a visual aka artist rendition.
 

Rubycon

Madame President
Aug 10, 2005
17,768
485
126
That first pic the blue images look like a 473nm laser with a mode hopping problem! Left is TEMoo (good) and right is TEM01 (not good).

Silverpig's pic is really from a car with a bad paint job. (orange peel)

:p

Sorry, could not resist!

That said atomic force microscopy is fascinating. :)
 

Hacp

Lifer
Jun 8, 2005
13,923
2
81
To take a picture of an atom, you need something an order of magnitude smaller than the atom.
 
May 11, 2008
19,300
1,129
126
I wonder if there is a way by using multiple wavelengths. The interaction and refraction would tell something. Today lasers seem to exist that can shoot single photons or use extremely short wavelength. Shoot a bunch of them of different wavelenghts and at different times(phase) and some information should be found about the build up. Use some magnetic control as well. But a series of test experiments must be done first. Because you have to contain the atom. Because you contain it, you already are changing the information you would receive when shooting it with photons. Everything you do to manipulate the atom must be taken into account as well. Then you can backtrack and elimate all influences on the atom and some useful information should arise.
Never had a truly "No that is not going to work" about that idea...

I mean you know you are going to influence that atom in any way you look at it. Now if you do a series of influences like above, you expect a series of results. When those results differ, those results tell you something about the atom itself. Especially if the proper wavelengths and timings are used.
I mean, i still keep finding it interesting that the electron orbitals of an atom look so much like the radiation patterns of antenna's...

Or am i forgetting something ?
 
Last edited:
Status
Not open for further replies.