• Question: how was the big bang discovered

    Asked by dentrenator to Adam, Catherine, Karen, Leila, Nazim on 13 Mar 2012.
    • Photo: Adam Stevens

      Adam Stevens answered on 12 Mar 2012:

      The idea for the big bang came from Edwin Hubble’s discovery that the universe is expanding in every direction.

      If you follow this discovery back, then the universe must have started at a single point and moved apart from this point. The phrase ‘Big Bang’ was originally meant to poke fun at this idea, so it isn’t very descriptive. It wouldn’t have been an explosion like we’re used to, especially since space was created at this point at well.

      Since then people have done lots of theoretical treatments of the Big Bang, so we think we know quite a lot about it. Particle accelerators are the only experiments able to get anywhere near the energy you would need to probe the Big Bang, so we don’t have that much hard data to tell us about it yet.

      Some people still don’t think that the Big Bang is real either!

    • Photo: Leila Battison

      Leila Battison answered on 12 Mar 2012:

      The Big Bang is the best way to explain a bunch of different observations in the universe, including the ‘cosmic background radiation’.

      Cosmic background radiation raises the temperature of deep space to three degrees above absolute zero. −270.15° celcius. It also makes up 1% of the white noise you see on an untuned TV. It is the leftover heat from the Big Bang, about 14 billion years ago.

    • Photo: Catherine Rix

      Catherine Rix answered on 12 Mar 2012:

      I think the idea of the universe begining in a ‘big bang’ came about because all the stars and galaxies in the universe are moving apart from one another, like particles do in an explosion.

    • Photo: Karen Masters

      Karen Masters answered on 13 Mar 2012:

      “The Big Bang” was actually a scornful term used by a scientist to make fun of the idea of the expanding Universe. Edwin Hubble in the 1920s provided the first evidence that the universe must have been much smaller, and hotter in the past. He discovered that most of the galaxies were moving away from us – and that the further away they were the faster they moved. The only way to explain this if you don’t think the Earth is in a special place in the Universe (which we don’t) is that the whole universe is expanding. And if it has been expanding, you just have to imagine winding back the clock to find that a long time ago it must have been very very small……

      Then in the 1960s some scientists detected the leftover glow of the Big Bang (which we call the Cosmic Microwave Background) – and won the Nobel Prize for the discovery. That was really the start of “The Big Bang” as the accepted model for the Universe.

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