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Hello only 5% of our universe is composed of visible matter stars planets and people something called dark matter

It makes up about 25% and an enormous 70% of the universe is pervaded with the mysteriously named dark energy

It's a recent discovery and maybe only a conjecture, but it has been invoked to explain an abiding riddle of the cosmos

If the expansion of the universe is powered by the energy of the big bang then why isn't the expansion slowing down over time as the

Initial energy runs down and the attractive force of gravity asserts itself

Scientists have predicted a big crunch as the logical opposite of the big bang but far from

Retracting the expansion of the universe is actually accelerating. It's running away with itself

How do we know that the universe is behaving like this and what's causing it if dark energy is the cause then what is this elusive

There were apparently omnipresent entity with me to discuss dark energy is the astronomer royal

Professor Sir Martin Reese professor of astrophysics at Cambridge University

Parallel Crawford Ross Society research fellow at the Institute of Astronomy University of Cambridge and Sir Roger Penrose

Emeritus Rouse Ball professor of maths at Oxford

Margin Reese Einstein when he wrote his equations for relativity didn't think the universe was expanding

So what was the single most important observation made after him that

Showed us that it was still expanding and accelerating in the 1920s people realized that

Universe was far bigger than had been thought before they realized that our galaxy

The Milky Way which contains all the stars we see with an naked eye is just one

Island as it were in a universe which contains as we now realize zillions of other galaxies like ours and in the 1920s

Astronomers studied how these galaxies were moving and they found that the light from these distant galaxies was reddened

implying a sort of Doppler shift implying that

...