Page 2 of 2 FirstFirst 12
Results 16 to 22 of 22

Thread: Picture of a single Atom

  1. #16
    Originally Posted by Ashnak View Post (Source)
    What you actually see is a finely tuned flourescense. The atom is illuminated by a (violet) laser, which is energizing the outer shell electron(s). When they relax to their ground state, they emit violet light themselves. Very faint, but apparently just visible with the naked eye, and recordable by a camera in a long time exposure.

    ---

    Edit:
    And since this is a digital image, what you actually get is the pixel (the pixels?) that are triggered by the light emitted form this single atom, modified by the Airy disc of the lens.

    Actually - that would make a great tool to determine the actual resolution of a lens-sensor combination....
    Great explanation! o7!

  2. #17
    Originally Posted by Ashnak View Post (Source)


    Guy at Oxford University takes a picture of a single Strontium atom (ok, ion...) caught in an ion trap: https://www.epsrc.ac.uk/newsevents/n...ons-top-prize/
    Sorry but this is utter rubbish no matter how it is spun. Nothing can see an atom and definitely not a normal camera.

    There is absolutely no evidence that there is a single atom because nothing can detect a single atom, how do they know there are not two of them?

  3. #18
    Originally Posted by StiTch View Post (Source)
    Unless understanding has changed since I studied you cannot actually perceive single atoms regardless of magnification ability.
    Not with visible light, which has a wavelength multiple order of magnitude larger than atoms, but other methods can image single atoms.

    Originally Posted by Gortron View Post (Source)
    Sorry but this is utter rubbish no matter how it is spun.
    The blue point of light is emitted by a single atom.

    Originally Posted by Gortron View Post (Source)
    Nothing can see an atom and definitely not a normal camera.
    https://en.wikipedia.org/wiki/Scanni...ing_microscope

  4. #19
    Originally Posted by Morbad View Post (Source)
    Not with visible light, which has a wavelength multiple order of magnitude larger than atoms, but other methods can image single atoms.



    The blue point of light is emitted by a single atom.



    https://en.wikipedia.org/wiki/Scanni...ing_microscope
    Ok that is interesting. I find the idea that is possible to identify a single atom very hard to believe / verify but it is interesting.

    Not saying you are telling me lies... just that I didn't know that microscopes could see atoms.

  5. #20
    Originally Posted by Gortron View Post (Source)
    Ok that is interesting. I find the idea that is possible to identify a single atom very hard to believe / verify but it is interesting.

    Not saying you are telling me lies... just that I didn't know that microscopes could see atoms.
    Check out https://en.wikipedia.org/wiki/Field-emission_microscopy . The German page has a few more pictures how that beast actually looks like - and how old that one is. Over here, such a tube is (or at least was) standard equipment for a high shool (Gymnasium) physics lab. It'll only show the structure of a crystal (i.e. the tip of the electrode) at atomic (or close to) resolution.

    "Real" atomic resolution came up with the various types of essentially mechanical raster microscopy - scanning probe microscopy. Rather like reading braille - you run a tip over a surface and detect the "roughness" (which might be expressed as electrical current as in the raster tunnel microscope or, later on, even as mechanical force in the raster force microscope). I can remember this picture going around the world when I was a student: https://www-03.ibm.com/ibm/history/e...506VV1003.html

    Of course, "see" is a bit far fetched here, as you're not dealing with any form of light. Any "light" that could work on this kind of scale would basically destroy the stuff it was sent to illuminate. As e.g. in the XFEL facility, which works with X-rays to probe molecular structures.

  6. #21
    Originally Posted by Ashnak View Post (Source)
    Check out https://en.wikipedia.org/wiki/Field-emission_microscopy . The German page has a few more pictures how that beast actually looks like - and how old that one is. Over here, such a tube is (or at least was) standard equipment for a high shool (Gymnasium) physics lab. It'll only show the structure of a crystal (i.e. the tip of the electrode) at atomic (or close to) resolution.

    "Real" atomic resolution came up with the various types of essentially mechanical raster microscopy - scanning probe microscopy. Rather like reading braille - you run a tip over a surface and detect the "roughness" (which might be expressed as electrical current as in the raster tunnel microscope or, later on, even as mechanical force in the raster force microscope). I can remember this picture going around the world when I was a student: https://www-03.ibm.com/ibm/history/e...506VV1003.html

    Of course, "see" is a bit far fetched here, as you're not dealing with any form of light. Any "light" that could work on this kind of scale would basically destroy the stuff it was sent to illuminate. As e.g. in the XFEL facility, which works with X-rays to probe molecular structures.
    If I'm honest I'm at the limit of my intellectual capacity when I talk about this stuff but I do have very strong understanding of particle physics. My specalisit supject isn't taking pictures of atoms..... which I considered impossible

  7. #22
    Originally Posted by Ashnak View Post (Source)
    "Real" atomic resolution came up with the various types of essentially mechanical raster microscopy - scanning probe microscopy. Rather like reading braille - you run a tip over a surface and detect the "roughness" (which might be expressed as electrical current as in the raster tunnel microscope or, later on, even as mechanical force in the raster force microscope). I can remember this picture going around the world when I was a student: https://www-03.ibm.com/ibm/history/e...506VV1003.html
    My wife does a lot of work with atomic force microscopy. She's a geomicrobiologist and this method allows imaging of living cells, in situ, rather than having to use specially prepared (and usually very dead) samples for TEM. The hardware she works with doesn't quite have atomic scale resolutions, but it's about the best you can get in something you can carry out into the field with you: https://www.nanoscience.com/products/afm/traxafm/ .

    Originally Posted by Ashnak View Post (Source)
    Of course, "see" is a bit far fetched here, as you're not dealing with any form of light.
    The whole point of these tools is to exceed the limitations of our own senses and our previous tools to get an accurate representation of objects that would otherwise be beyond our perception.

    We may need to translate the data, but 'see' is still apt.

Page 2 of 2 FirstFirst 12