most dense object?

Discussion in 'General Science & Technology' started by hiimwayne, Dec 12, 2002.

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  1. Sputnik Banned Banned

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    And just to round up the force of gravity ...(forgetting the socalled negative pressure from "Dark Energy " ) ..... on this learned thread ...... (I so far counted the word retard beeing used at least 3 times here on the thread ) ............

    An object of matter has gravity ? .... right ?
    But if the same amount of matter turns into pure energy ... then the gravity of this energy is Zero ???? ....Right ? ..... or is it right ???

    Anyway, I wish you all a very Happy New Year ....

    http://www.wikiality.com/Gravity

    :m:

    Please Register or Log in to view the hidden image!

     
    Last edited: Jan 1, 2007
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  3. superluminal . Registered Senior Member

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    I always knew the truthiness of gravity was highly suspiscious.
     
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  5. MetaKron Registered Senior Member

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    Dubya isn't the most dense object?
     
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  7. eburacum45 Valued Senior Member

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    Wrong. Next question?
     
  8. Odin'Izm Procrastinator Registered Senior Member

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    at room temperature, generally solid hydrogen is about 3 times more dense.
     
  9. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    That is interesting - something I did not know already. Do you know its structure? I.e. Is it crystalline? If so, the unit cube spacing must be small compared to H2's molecule separation, I would think.* I have a hard time understanding this but am thinking it must be the electrons are not bound to any proton, (Thus would be a very good conductor** - Is it?) and the protons can get relatively close to each other (the electron "cloud" shielding one from another until they get to small separation and repel each other) - Is how it can be true?
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    *This because I have read that there is more hydrogen in gallon of liquid NH3 than in gallon of liquid Hydrogen, H2. This and because decomposition of Ammonia is exothermic have made me wonder and suggest that Ammonia may be the way to transport / store Hydrogen for cars with fuel cells.
    **As the phonons must be very rare at solid H temperature, perhaps it is also the most electrically conductive “normal substance” known? (Super conductors excluded of course and assuming it is not also a super conductor, or at least has some small temperature range where it is solid and normal.) I know essentially nothing about solid hydrogen - tell more, or I will be forced to search.
     
  10. MetaKron Registered Senior Member

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    The gravity of that energy is the same as it was when it was matter.
     
  11. superluminal . Registered Senior Member

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    Under normal ambient conditions (temperature and pressure) osmium is the densest naturally occurring substance.

    Under varying artificial conditions I can make anything "the densest".
     
  12. superluminal . Registered Senior Member

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    Solid hydrogen at room temperature?
     
  13. Alastor Registered Member

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    Solid hydrogen...?
    Time to do a Google search.
     
  14. phlogistician Banned Banned

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    Dwayne has it right, it's Iridium, if we are talking about an element.

    Neutron stars and black holes are dense, but we have no direct measurements of them of course, just calculated figures, so I think Iridium is your answer.
     
  15. Chatha big brown was screwed up Registered Senior Member

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    So wait...
    most dense object - Neutron stars/ atomic nuclei
    most dense element- osmium/iridium
    most dense gem- platinum
    most dense enviroment- black holes(unspecified)
     
    Last edited: Jan 3, 2007
  16. Prince_James Plutarch (Mickey's Dog) Registered Senior Member

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    Chatha:

    Are you sure Aggregated Diamond Nanorods are the most -dense-? And not simply the -hardest-?
     
  17. geeser Atheism:is non-prophet making Valued Senior Member

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    I saw this whilst passing, and in answer to op question, isn't the most dense object lightgigantic.
     
  18. Odin'Izm Procrastinator Registered Senior Member

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    no. closer to absolute zero.

    carrying on from Osmium -> yes at room temperature. But in general solid hydrogen is about 3 times denser. it's density is 70.6 g/cc osmium is 26 I think. And no you can't make anything densest. If we asume that a material X is densest as a solid than a gas or a liquid; Hydrogen is the densest material on earth in it's solid form as it has the smallest atomic mass. This works, by using the metaphor for balls in a jug, if we fill the jug with larger spheres they will leave alot of space open, the smaller the sphere the less space is left inside the jug... It's not that hard to understand is it.
     
  19. Odin'Izm Procrastinator Registered Senior Member

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    Yes, When solid, the crystal structure is hcp (hexagonal close-packed).
     
  20. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    This may be part of the reason, but surely something else is main cause. Perhaps what I guessed in post 142.

    For example, He4 has four times the mass of Hydrogen and its two electrons are also both in the same n=1 orbital as hydrogen‘s one electron. As each is attracted to the nucleus by two positive charges, not just the one of hydrogen, if anything* the He4 atom should be slightly smaller and four times heavier. It is not the nucleus that determines the volume each atom must occupy. It is the size of the outer orbital.
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    *I am just reasoning, and could be wrong; someone can look up the radius of the Helium atom and compare to the Bohr radius (the hydrogen radius' name), but I would be very surprised if it is large enough to compensate for the factor of four mass advantage Helium has.
     
  21. Chatha big brown was screwed up Registered Senior Member

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    Thanks
     
  22. Chatha big brown was screwed up Registered Senior Member

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    I get your point- smallest atomic mass. I am confused though. If the mass of hydrogen's proton and neutron(atomic mass) is smaller than most other elements... what about the volume? Remember density is m/v. So a smaller mass doesn't make more density. Care to explain?
     
    Last edited: Jan 3, 2007
  23. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    This is an extension to post 157 (I just returned from my swim and was thinking more on the relative density of isolated atoms while swimming):

    I bet that some of the later noble gases (filled outer shells or orbitals) are even denser than He4 despite having electrons in shells more distant from the center. This because the ratio of neutron to protons in the nucleus is larger than unity.
    From my dictionary:
    Radon, Rn, has 86Ps and atomic weight of 222 or 126Ns.
    Lawrencium, Lw, has 103Ps and atomic weight of 257 or 154Ns

    I doubt is any one has measured the radius of Lw, but surely Radon's is known and it is 222 times heavier than Hydrogen. Thus if radon's radius is not more than cube root of 222 times the Bohr radius, it is denser than Hydrogen on an atom by atom basis. For example: If the diameter of Radon atom is only 6 times larger than Hydrogen's, then Radon is denser than Hydrogen atom by atom. Anyone willing to dig out the facts?

    If solid Hydrogen is a good electrical conductor (and I bet it is), then I am reasonable sure my guess in post 142 as to why it is so dense is basically correct. (But, quantum mechanics is not doubt making the full answer/ reason more complex.) I.e. the consideration being offered by others about "hydrogen being the smallest /lightest" etc. play little, if any, role in the explanation of solid Hydrogen's high density; however, the fact that when you free hydrogen's one electron from being bound to a particular nucleus (proton) and let it belong to the entire crystal, then there is no electron left to make the protons stay at least two Bohr radii apart. That is very important, if it happens, and a unique feature of hydrogen.

    That is why high electrical conductive, if it exists, is evidence for my POV in post 142. (If it is highly conductive, it might be best to regard solid Hydrogen as an "ordered plasma" as the positive ions are at regular sites, not randomly "flying around.")
     
    Last edited by a moderator: Jan 3, 2007
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