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  1. #1
    Dr. Buzz Killington
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    Most Distant Galaxy Record Broken & New Mass of Milky Way

    I always love hearing about new astronomical/cosmological discoveries.


  2. #2
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    Because the universe is expanding so fast, we will never see the edge, or the farthest galaxies.

  3. #3
    Dr. Buzz Killington
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    Quote Originally Posted by Cinelli 82220 View Post
    Because the universe is expanding so fast, we will never see the edge, or the farthest galaxies.

    Well, that assumes the universe has an edge, because for all we know it could be infinite. However, there is a physical limit to what we can see, and that's the "wall" created by the cosmic microwave background. As we peer further into space, we're looking further back in time. When the universe was really young, it was so hot up until about 100 000 years old that matter couldn't remain neutral. What existed was a charged plasma of protons and electrons, and plasmas are opaque to radiation. That means any light of any wavelength emitted would be absorbed and re-emitted back in the direction it came. Therefore, if you were outside the universe looking inward you wouldn't see anything because light couldn't escape. The furthest we could therefore see is when the universe was about 100 000 years old, because that would be the last scattering surface before the universe was cool enough to become transparent to radiation. As an aside, this last scattering surface predicted that we should be able to see radiation coming at us from all directions as a signature of the Big Bang, and it also predicted that we'd measure it in the microwave spectrum due to redshift. In 1964 this radiation was discovered accidentally by two American radio astronomers who had no idea what they were doing, but they won the Nobel physics prize anyway.

  4. #4
    Call me a Fred
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    I had a girl friend who like new cosmetics.
    Mike

    -----------------------------------------------------------------------------------
    You may starch my jumper
    Hang it upside your wall
    You know by that, baby
    I need my ashes hauled.

    Sleepy John Estes

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  5. #5
    Dr. Buzz Killington
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    Quote Originally Posted by MikeBiker View Post
    I had a girl friend who like new cosmetics.
    Any more intellectual insights for us?

  6. #6
    half-fast
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    Quote Originally Posted by MikeBiker View Post
    I had a girl friend who like new cosmetics.
    Was she like, far out?

  7. #7
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    Quote Originally Posted by SauronHimself View Post
    However, there is a physical limit to what we can see, and that's the "wall" created by the cosmic microwave background.
    Not a physical barrier IMHO. The limit is caused by the distance and time it takes for the light at the edge of the universe to reach us. The "subluminal" universe is the universe we will never see.
    In 1964 this radiation was discovered accidentally by two American radio astronomers who had no idea what they were doing, but they won the Nobel physics prize anyway.
    Penzias and Wilson are all too frequently dismissed as lucky instead of talented. Nobody else knew about the background radiation either, but they are criticised for not recognising it. None the less, Dicke and his group at Princeton should have got the Nobel. Both teams' papers appeared in the same issue of the Astrophysical Journal, so there isn't much issue of primacy.

  8. #8
    Dr. Buzz Killington
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    Quote Originally Posted by Cinelli 82220 View Post
    Not a physical barrier IMHO. The limit is caused by the distance and time it takes for the light at the edge of the universe to reach us. The "subluminal" universe is the universe we will never see.

    Penzias and Wilson are all too frequently dismissed as lucky instead of talented. Nobody else knew about the background radiation either, but they are criticised for not recognising it. None the less, Dicke and his group at Princeton should have got the Nobel. Both teams' papers appeared in the same issue of the Astrophysical Journal, so there isn't much issue of primacy.
    I used the term "wall" in quotes to signify that it isn't necessarily a physical barrier. Penzias and Wilson had constructed a horn-shaped antenna to detect radio waves bounced off echo balloon satellites, and they cooled the receiver with liquid helium to reduce noisy interference, which of course eliminated all the noise except for that coming from the CMB. In one sense they were talented to build the technology, but it was still an accidental/lucky discovery since that wasn't their intent.

  9. #9
    Master debator.
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    One day Chuck Norris decided that a certain galaxy was pissing him off. He roundhouse kicked it nearly out of existence, but let it live as long as it stayed away. It has only recently been rediscovered.
    "I felt bad because I couldn't wheelie; until I met a man with no bicycle"

  10. #10
    Frog Whisperer
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    The most surprising element in that video to me was the concept of light "stretching " which changes the wavelength. I had never considered the elasticity of light. Forwarding to my daughter....... kinda nice having my own personal astronomer.

    edit: I guess i had never heard I'd explained that way before)

    edit 2: DOH..........I are an idjuct.... THAT is what they mean when they refer to the "shift" re: light.......NOW......it all makes more sense..... That image i am seeing in the mirror in the morning is all bent and twisted because of the "shift" of the light.....i don't REALLY look that way!!!!

    that's my story and i'm sticking to it!
    Last edited by Touch0Gray; 12-17-2012 at 04:40 AM.

  11. #11
    Frog Whisperer
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    and from what i understand, the velocity is actually increasing.
    Of course I'm sure...that doesn't mean I'm right......

  12. #12
    Dr. Buzz Killington
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    Quote Originally Posted by Touch0Gray View Post
    and from what i understand, the velocity is actually increasing.
    If you're referring to the universe's expansion, then yes that speed is increasing. In fact, space will one day expand faster than light, so any light coming from galaxies at a certain distance will never reach us. Before any of you armchair physicists step in and say that nothing can travel faster than light, remember that Einstein proved that nothing can travel through space faster than light. Space can do whatever it wants.

  13. #13
    Seat's not level
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    I'm not recognizing any new 'discoveries' until they bring pulto back...
    Bad decisions make great stories - JP

    He can compress the most words into the smallest idea of any man I know. -- Abraham Lincoln, Unknown , Unknown

  14. #14
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    Quote Originally Posted by SauronHimself View Post
    If you're referring to the universe's expansion, then yes that speed is increasing. In fact, space will one day expand faster than light, so any light coming from galaxies at a certain distance will never reach us. Before any of you armchair physicists step in and say that nothing can travel faster than light, remember that Einstein proved that nothing can travel through space faster than light. Space can do whatever it wants.
    Can space kick Chuck Norris' A$$?

  15. #15
    feh
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    Quote Originally Posted by SauronHimself View Post
    In fact, space will one day expand faster than light, so any light coming from galaxies at a certain distance will never reach us.
    Assuming I understand what you're saying here, you may have forgotten Carl Sagan's commandment #1 of the Cosmos: thou shalt not add (or subtract) the speed of a light-emitting object to/from the speed of light.
    What's the Matter with Kansas?

  16. #16
    Dr. Buzz Killington
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    Quote Originally Posted by feh View Post
    Assuming I understand what you're saying here, you may have forgotten Carl Sagan's commandment #1 of the Cosmos: thou shalt not add (or subtract) the speed of a light-emitting object to/from the speed of light.
    This applies to special relativity, and once again it refers to objects traveling through space. Space itself is allowed to expand faster than light.

  17. #17
    Seat's not level
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    yes, but it requires a sense of humor...
    Bad decisions make great stories - JP

    He can compress the most words into the smallest idea of any man I know. -- Abraham Lincoln, Unknown , Unknown

  18. #18
    Mad-one...
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    Quote Originally Posted by SauronHimself View Post
    Any more intellectual insights for us?
    Were you expecting a serious conversation on cosmology on a cycling forum? :-)
    There is NO rehearsal - this is the real thing.

  19. #19
    Frog Whisperer
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    Quote Originally Posted by Chain View Post
    I'm not recognizing any new 'discoveries' until they bring pulto back...
    THIS!!!!!!!!!
    we want Pluto.....we want Pluto....we want Pluto
    Of course I'm sure...that doesn't mean I'm right......

  20. #20
    Frog Whisperer
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    yes....the velocity of the expansion.

    A tip to the new boy in town.....the term "armchair physicists" is pretty condescending, particularly in light of the fact that there are quite a few very highly educated folks here, including several pHD's in physics, just saying.

    I was also under the impression that while all signs and indications point to Einstein's theory being true, but to the best of my knowledge it has not been proven.
    Of course I'm sure...that doesn't mean I'm right......

  21. #21
    Dr. Buzz Killington
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    Quote Originally Posted by Touch0Gray View Post
    yes....the velocity of the expansion.

    A tip to the new boy in town.....the term "armchair physicists" is pretty condescending, particularly in light of the fact that there are quite a few very highly educated folks here, including several pHD's in physics, just saying.

    I was also under the impression that while all signs and indications point to Einstein's theory being true, but to the best of my knowledge it has not been proven.
    When you refer to a theory pejoratively like that and in the context you've placed it, you clearly don't know what a theory is. Let me be the first to say that no theory can be proved 100% true, and the reason this is the case is because theories are based upon grounds of observation. Therefore, the only way to prove a theory 100% true is to observe an infinitely large amount of data, which is physically unfeasible. A 100% true theory is called a theorem, and only mathematics have those because we've already defined the constraints. It's a different story when nature is defining the constraints and one is trying to determine what they all are. A theory is much more than a hypothesis; it's a collection of verifiable facts that have made predictions which, in turn, have been experimentally tested and yielded consistent results. These results have also been put under the highest scientific scrutiny by third-party peer review and verified to hold water. Only then can a measly hypothesis become a theory. This is consequently why we don't teach things like alchemy, astrology, and creationism in schools because these things have failed to successfully survive the gauntlet of the scientific method.

    By the way, the Big Bang Theory was originally proposed by the Catholic priest Georges Lemaitre who was also a physicist. He solved Einstein's equations for General Relativity and discovered that the theory only allowed for an expanding universe that began from a point, which he dubbed the "primeval atom". Einstein actually balked at this notion until a few years later when lawyer-turned-astronomer Edwin Hubble discovered observationally that the universe is expanding.

  22. #22
    Frog Whisperer
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    Right or wrong, your condescension continues at an accelerated rate. Rather than give you the additional fuel and satisfaction...........bye bye........unsubscribed.......
    Of course I'm sure...that doesn't mean I'm right......

  23. #23
    Dr. Buzz Killington
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    Quote Originally Posted by Touch0Gray View Post
    Right or wrong, your condescension continues at an accelerated rate. Rather than give you the additional fuel and satisfaction...........bye bye........unsubscribed.......
    What you see as condescension will not further your education, and leaving the argument neither concludes it nor grants you any sort of victory even if it's personal satisfaction. You can choose scientifically literacy or delusion, but only one will bring you empirical understanding.

  24. #24
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    /cue crickets

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