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Red Shift - the universe may not be as big as it seems

Discussion in 'Space' started by seabhcan, Jan 15, 2016.

  1. seabhcan

    seabhcan Member Political Irish

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    ASASSN-15h_.jpg

    Astronomers see most stars as single points of light even in the most powerful telescopes. And stars are of all different brightness levels, so how do they know how far away the most distant stars and galaxies are? The answer is surprising and complex.

    The theory goes that the universe is expanding, and the farther away something is, the faster it is moving away from us. They measure how fast something is moving, by looking at how red it is. Just like how the sound of an ambulance changes when it is moving away, the colour of stars become more red the faster they are moving away.

    But some stars are red anyway - so how do they know which ones are naturally red, and which ones just look red due to motion? They look for 'standard candles' - stars in distant galaxies that look like they are of a particular stable type, which we know the colour of by examining them in our galaxy. Then they examine how red these stars look in other galaxies and compute how fast they are moving, then they use that to figure out how far away they are (assuming that fast = far away). Complex.

    But what if something else, some unknown process, makes some stars shift red even if they aren't quite so far away as it seems?

    This is important because we keep finding impossible events when we look deep into space. There is an example in the press today:

    https://www.siliconrepublic.com/innovation/2016/01/15/assassin-supernova-asassn-astronomy-hubble

    An impossibly bright supernova - brighter than 570 billion stars - twenty times brighter than our whole galaxy? The astronomers admit, physics says such a bright star is impossible. But how do they calculate how bright it is? Its all based on the red-shift of nearby 'standard candles' and an assumption that fast = far away.

    On the other hand, if the red-shift theory is flawed, and this supernova is not as far away as it seems, then it is smaller and less bright, and all the physics works out neatly.

    120370.jpg
     
  2. Flamer

    Flamer Member Political Irish

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    Who really knows anything about the Universe, Its all guess work anyhow.

    If you look at the theory we evolved from the big bang, that the biggest load of horse shyte ever, imagine telling your science teacher you were going to create a universe from a spec of sand. You would be locked up and yet this is the crap scientists believe.

    The expanding universe theory is equally as crazy, what the hell are we expanding into?

    More to the truth that what is really happening we dont know.
     
  3. OP
    seabhcan

    seabhcan Member Political Irish

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    The universe probably is expanding, but not as fast or quite as big as it seems.
     
  4. Quantum

    Quantum New Political Irish

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    Good video on the subject here





    [font=Verdana, Arial, Helvetica, sans-serif]In the biggest survey ever conducted using the Hubble Space telescope, 446,000 galaxies were studied to see how matter was distributed throughout the universe and how quickly it had expanded.[/font]

    [font=Verdana, Arial, Helvetica, sans-serif]And the astronomers found that the universe was growing faster and faster with time, as predicted by Einstein in his theory of general relativity. [/font]

    [font=Verdana, Arial, Helvetica, sans-serif]Scientists claim that the universe is made up of three different components – normal matter, which is the physical objects in the universe such as the planets – dark matter, which is invisible matter that creates the gravitational pull that causes galaxies to form – and an unknown energy referred to as "dark energy", the force which causes the universe to expand.[/font]

    [font=Verdana, Arial, Helvetica, sans-serif]Einstein's theory of general relativity claims that space and time are a geometrical structure which can be changed by the behaviour of the matter inside it.[/font]

    [font=Verdana, Arial, Helvetica, sans-serif]So proof that the expansion of the universe is speeding up shows that the contents of the universe, such as the "dark energy" causing it to inflate, are influencing its structure.[/font]

    [font=Verdana, Arial, Helvetica, sans-serif]Ludovic Van Waerbeke, of the Department of Physics and Astronomy at Leiden University in the Netherlands, said: "Our results confirmed that there is an unknown source of energy in the universe which is causing the cosmic expansion to speed up, stretching the dark matter further apart exactly as predicted by Einstein's theory.[/font]
     
  5. OP
    seabhcan

    seabhcan Member Political Irish

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    Or... there is no 'dark energy' but something is skewing red shift in some galaxies, making them appear farther away than they really are.
     
  6. bobsecret

    bobsecret Member Political Irish

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    Great thread guys, love reading this stuff.