The mysterious dark energy that speeds the universe's rate of expansion

Phys.org, The Conversation ^ | Apr 23, 2015 | Robert Scherrer

[Patriot777]

The nature of dark energy is one of the most important unsolved problems in all of science. But what, exactly, is dark energy, and why do we even believe that it exists?

Step back a minute and consider a more familiar experience: what happens when you toss a ball straight up into the air? It gradually slows down as gravity tugs on it, finally stopping in mid-air and falling back to the ground. Of course, if you threw the ball hard enough (about 25,000 miles per hour) it would actually escape from the Earth entirely and shoot into space, never to return. But even in that case, gravity would continue to pull feebly on the ball, slowing its speed as it escaped the clutches of the Earth. But now imagine something completely different. Suppose that you tossed a ball into the air, and instead of being attracted back to the ground, the ball was repelled by the Earth and blasted faster and faster into the sky. This would be an astonishing event, but it's exactly what astronomers have observed happening to the entire universe! Scientists have known for almost a century that the universe is expanding, with all of the galaxies flying apart from each other. And until recently, scientists believed that there were only two possible options for the universe in the future. It could expand forever (like the ball that you tossed upward at 25,000 miles an hour), but with the expansion slowing down as gravity pulled all of the galaxies toward each other. Or gravity might win out in the end and bring the expansion of the universe to a halt, finally collapsing it back down in a "big crunch," just like your ball plunging back to the ground.

[Patriot777]

Isaiah 40:22" "He sits enthroned above the circle of the earth, and its people are like grasshoppers. He stretches out the heavens like a canopy, and spreads them out like a tent to live in."

[Vaquero]

What we DONT know fills this incredible expanding universe. Perhaps some day we will break the code.

Now for something completely different, Stephen Hawking sings python’s Galaxy Song

https://m.youtube.com/watch?v=XfcC6FYyL4U

[Ben Ficklin]

Invisible Universe Revealed

PBS Nova documentary on the history and accomplishments of the Hubble telescope aired 4/22/15

[I want the USA back]

To “fix” a theory that doesn’t work, they postulate something that can’t be observed.

[trenton1776]

I wrote a science fiction book series that offers a creative explanation for why the universe is flying apart. If any freepers would like a free ebook copy of book 1 in the series, freepmail me with the email address you’d like it sent to.

[Tenacious 1]

Why you gotta go down the man made climate change road? 😜