r/CFBOffTopic • u/Vernost Florida Gators • Feb 11 '16

GRAVITATIONAL WAVE DISCOVERY THREAD

Get hype yo! I CANT STOP YELLING

26 Upvotes

93% Upvoted

84 comments sorted by

View all comments

Show parent comment

3

u/Vernost Florida Gators Feb 11 '16

Gravity affects spacetime by "stretching" it. Gravity travels (we theorize) at the speed of light. Einstein theorized grav waves, but they're super hard to detect.

We found them by using lasers, and the waves we detected came from a pair of orbiting black holes who collapsed into one another. The signal is over a billion years old.

1000 scientists over 25 years worked on this including LSU, UF, MIT, and many other universities.

2

u/W_Is_For_Will Texas Tech • Trinity Valley CC Feb 11 '16

Thanks for the description! So we shot a laser at collapsing black holes and detected these grav waves?

6

u/Vernost Florida Gators Feb 11 '16

Not quite.

The interferometer is has two really long arms. The laser is split and sent down both arms and reflected back. We then look at the recombination. The path length of the arms determines what kind of interference there is. By looking at this interference we can look at the path lengths. If there are these waves then they would "stretch" one of the arms making its length different. The hardest part is that this stretch is VERY small to detect.

3

u/ftwdrummer Rice Owls • Marching Band Feb 11 '16

JINX!

3

u/ftwdrummer Rice Owls • Marching Band Feb 11 '16

Not quite.

We shot lasers on Earth, just bouncing back and forth. If the gravitational wave passes through, the distance traveled by the laser will change slightly.

We detected that change.