Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Atoms and Space

  1. Jun 29, 2004 #1
    First post and let me just say that after viewing this forums rules and it's warning system, I very much appreciate your efforts to keep this area within a realm of discussion instead of name-calling like you see on the usenet groups. Ok, now that cheesy statement is over let me get on with my question.

    With the scanning tunneling microscope we are able to see, visually, the energy shells that surround the nucleus of an atom. Given our knowledge of how small the atomic nucleous is in relation to the electron cloud, isn't it slightly ironic that the electrons that move inside this cloud are actually microscopic in comparison to the size of a single proton which makes up the whole of the nucleous.

    I found that relation to be puzzling. This statement came about while I was thinking of the nature of 'space' and how matter exists within it.

    The 'why' of my line of thinking is due to my dislike of the idea of dark matter and dark energy as well as my disbelief that there is such a thing as a 'graviton' or any particle that can be defined as belonging to gravity. I think the photon holds the throne on that theory.

    Anyhow, I'm interested in learning or hearing others opinions about the nature of space on both a quantum and universal scale. First there's the space that is contained within the electron cloud of an atom. This space is obviously different than the space contained outside, else why is there a cloud? What is going on inside? Sure there's measurable amounts of energy that we can push into the cloud to cause the electron to change to a higher energy state but is this binding energy only a relationship between the subatomic particles alone or is there some property of the space these particles reside in that also contributes to the total energy needed to keep the particles from flying apart.

    I've always envisioned space literally as a fabric made of threads which are weaved together. Each intersect of thread creates a point and many points to create a plane. Throw in some atoms and the fabric begins to stretch. At this point I'm not sure which is happening, is the fabric being displaced outward by the atom or is it being compressed?

    When cosmologists say that regular matter accounts for only about 4% of the total mass of the universe are they also taking into consideration the volume of space inside the electron cloud? A space that is flexible, stretchable, and compressible?

    I'm looking forward to listening to other's ideas.
     
  2. jcsd
  3. Jun 29, 2004 #2

    chroot

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The space inside the electron cloud is no different from any other region of space. It just happens that some electrons have a non-zero wavefunction there.

    - Warren
     
  4. Jun 29, 2004 #3

    ZapperZ

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    I wouldn't have responded to your post here except for the fact that you seem to have based the remainder of your hypothesis/question based predominantly on this STM result. Since I know quite a bit about STM, I thought I should respond here.

    You need to be careful in what you mean by "able to see, visually...". STM in an imaging mode (as opposed to spectroscopy mode), collects either variation in the tunneling current or variation in potential difference as it scans over an area of the surface. So the STM image that one normally sees being splashed on the front cover of magazines and on various websites are such variations. The "energy shells" that you supposedly saw are actually the valence bonds of a solid (you can't do this on free atoms).

    Zz.
     
  5. Jun 29, 2004 #4
    Ok, I certainly didn't think about the bonding that occurs between the atoms in a molecule.

    I am still trying to understand how a group of atoms can get together in the void of space and ultimately become massive enough to exert a gravitational tugging on the space around it leading, in some circumstances, to the gravitational lensing that we can see in galaxy clusters.
     
  6. Jun 29, 2004 #5

    chroot

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    It takes a heck of a lot of atoms! There's really no way the human mind can contend with visualizing the number of atoms in a galaxy.

    - Warren
     
  7. Jun 29, 2004 #6
    a few more than 10...

    K_
     
  8. Jun 30, 2004 #7
    Aye, too true. May as well measure the size of the universe with a tape measure.

    Of course gravitational lensing is something that is observed on a massive scale.

    I guess one of my questions is: is gravity derived from the size of an object or from it's density? I know astronomers have found a few asteroids in our solar system that even though small, also have their own satellite(s) that revolve around them.

    I know that this stuff is likely trivial knowledge and had I studied physics in college I'd probably not even be asking these questions. I do appreciate learning.

    I suppose I could just say:
    Space is to gravity as a conductor is to electricity.

    What does that have to do with nuclei and particles? I think that these particles are the cornerstone to this relationship, without the atom, there is no gravity, just space.
     
  9. Jun 30, 2004 #8

    chroot

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Gravity only depends on the total mass of a body. From a distance, gravity acts as if all mass were concentrated into a point.

    - Warren
     
  10. Jul 1, 2004 #9
    So, if you measure out 1 gram of nickle and 1 gram of lithium, (despite the size of samples which 1. should differ due to the difference in atomic number and 2. contain a different amount of atoms per 1gram sample), they each would exert the same gravitational pull on it's surroundings?
     
  11. Jul 1, 2004 #10

    ZapperZ

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    If you look at how gravitational force is described, it explicitly depends on the amount of mass of the object, not the TYPE or element of the object. The only other factor that will make them differ is if the geometry for each one of them is different, i.e. one is like a flat plane while the other is a sphere. But if you make them have the same geometrical shape (not necessarily the same size), then the value of the gravitational force outside of the object at some field point is identical.

    Zz.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Atoms and Space
  1. Heavy Atoms (Replies: 8)

  2. Atomic partons? (Replies: 7)

  3. Atom strucutre (Replies: 3)

  4. Empty space of Atoms (Replies: 19)

  5. Decay and atoms (Replies: 2)

Loading...