How Fast is the Universe Expanding? | Sci Guide with Tom Whyntie and Andrew Pontzen | Head Squeeze
669Discover the concept of 'dark energy', why it's making the universe expand and how even Tom and Andrew cannot explain the unexplainable - it is Space Week after all!
The universe is expanding at 0.007 per cent per million years. While we may take this knowledge for granted now, it was only ratified in the late 90s. Before that it was equally possible that the universe was in fact contracting.
The Big Bang theory may have sent all matter flying outwards into space, but once started things can be stopped via their gravitational pull to each other. Thus cosmologists proposed that gravity might win the day, pulling everything together in a catastrophic 'Big Crunch'.
The world of science was shaken to its foundations by the revelation that the universe was in fact expanding. By the mid 80s scientists had a good idea of how much energy there was in the universe, dark matter had even been discovered. However the total amount of energy that was supposed to be in the universe didn't correlate with the abounding theories and this is what lead scientists to investigate the idea of 'vacuum energy' - as a way to explain the universe's continuing rate of expansion.
Vacuum energy is a concept from quantum physics, it posits that even where there is no matter at all, there is some residual energy present. It has strange properties like negative pressure which would help to accelerate the universe's expansion.
Dark energy is the name now given to this matter. However truly understanding it as Tom and Andrew explain in this Sci Guide video is quite another matter. Hit us with your questions and we'll do our best to answer them, subscribe to the channel for more from our scientific duo and don't forget to share us with your friends.
Just because it's World Space Week, we want to know if you have seen the awesome Northern Lights this year. Head Squeezer Jheni Osman explains what they are: http://www.youtube.com/watch?v=vS0gssL7wJE&list=PLMrtJn-MOYme6klSjJXoZfWmNZ6ZthOSA&index=3
Going to a table quiz? Brush up on your Space Facts with our Awesome Space Fact Vid: http://www.youtube.com/watch?v=WHMIFAbkM5g
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