• Question: how many galaxys are their

    Asked by beastlyboy197 to Alexander, Aron, Jess, Neil on 19 Mar 2014.
    • Photo: Aron Kisdi

      Aron Kisdi answered on 19 Mar 2014:

      We do no know.
      We can only observe a part of the universe. Also the way we observe the universe at the moment means we are observing waves travelling the speed of light. So when we look at distant objects the “light” we see took many years (or many 1000s or millions of years) to get to us so that object might not exist anymore.
      We are only making models and predictions to shape physics and our understanding of the universe based on things we can observe. That is why we need new space missions to observe more of the universe and understand it better.

      To put things in scale: http://scaleofuniverse.com/

    • Photo: Alexander Finch

      Alexander Finch answered on 19 Mar 2014:

      How many galaxies? Lots… and lots and lots and lots. In fact, we don’t know how many there are because we can’t count or see them all! We guess that there are maybe 500 billion galaxies that we should be able to see. That’s a lot – almost enough for 100 galaxies per person on the Earth! And you have to remember that each galaxy is already huge, with billions of stars in – so the number of stars is incredibly big. The Universe is a big place…

    • Photo: Neil Bowles

      Neil Bowles answered on 19 Mar 2014:

      Billions of ’em. I had a chat with a colleague how worked on the Herschel Space telescope that could measure the faint heat traces from distant galaxies and their comment was that the sky was ‘carpeted’ with faint galaxies.

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