Way OT: Gravitational Waves discovered???

Submitted by superstringer on

For the uber-geeks out there, be sitting down:  Twitterverse (never known to be wrong) is abuzz with the suggestion that LIGO has detected gravitational waves.  To the non-geeks, this is a huge, major, really big scientific discovery.  It basically is a "check the box" of one of Einstein's major theories, which mostly had been assumed to be unprovable.

I can post a ton of links, or you can google it, but here's one link:  http://www.techinsider.io/gravity-waves-detected-rumor-2016-1

What's a gravitational wave?  The idea is, if a massive body (black hole, large star, etc.) undergoes a sudden movement -- like a cataclysmic explosion, or an impact with another equally-sized mass -- then a ripple will be created in its gravitational feels, for a brief moment.  Gravity travels across vast distances, so a gravitational wave, basically, can travel millions or billions of lightyears.

Only, gravity is so weak,* it was long assumed gravitational waves can't be detected.  Scientists, armed with big budgets, weren't to be deterred, and set out building huge experiments to detect them.  LIGO is the most famous.  IIRC, it's basically an L-shaped underground tunnel, many miles long, where a laser beam is split then travels down both legs and recombined.  If a gravitational wave were to pass through the Earth, it would affect the two legs different (being oriented differently), and the split laser beams when recombined would be out of phase.  You'd detect the wave -- if you could eliminate every other possible source of vibrations (e.g. trucks driving overhead).

* How weak is gravity?  It's (1 followed by 40 zeros) times weaker than electromagnetism. Put another way.  A single magnet the size of a pencil eraser can lift a paperclip off of a table; meaning, that tiny magnet exerts more force on the paperclip than does the gravity of our entire planet.

Should you care?  Discovering gravitational waves doesn't have immediate, practical implications, except that I'm sure HARBAUGH will use them to break down defensive fronts next season.  But this is a step towards confirming the basic building blocks of the universe.  There could be long-term research implications from this, and ultimately, if you wanted to build a signalling device to humans around other stars (or on long-duration interstellar missions), sending gravity waves is better than light signals b/c they travel so damn far.

Here we go again?  A year ago, there were rumors LIGO had discovered gravitational waves.  The idea was debunked by the scientists on the project, and the rumor died down.  It seems that TODAY, the rumors are exploding in the scientific community, and they aren't being debunked by the scientists involved -- just, you know, "still checking the data."

Still...pretty cool.  Even if this doesn't come to pass, it's a neat window for non-scientists into the cutting edge stuff that our technology, and budgets, is able to achieve.  It seems that these kind of "aha!" moments are coming more and more for us now.

bjk

January 11th, 2016 at 9:51 PM ^

If a gravitational wave were to pass through the Earth, it would affect the two legs different (being oriented differently), and the split laser beams when recombined would be out of phase.
Isn't this the Michelson-Morley experiment of 1887 all over again?

evenyoubrutus

January 11th, 2016 at 9:54 PM ^

This wasn't a rumor a year ago. They issued a press release and made an official announcement. It was later debunked for a rather simple explanation. There was even a 2 hour long National Geographic special about it.

bjk

January 11th, 2016 at 9:57 PM ^

if you wanted to build a signalling device to humans around other stars (or on long-duration interstellar missions), sending gravity waves is better than light signals b/c they travel so damn far.
Part of the problem with light is speed; it takes a year for light, tautologically enough, to travel a light-year. Is it too early to discuss how fast gravity waves travel? Is there a gravity particle to serve as a counterpart to the gravity wave?

might and main

January 11th, 2016 at 10:15 PM ^

I was really surprised to see gravity waves described as better than light for long distance communication.  Light goes a long damn ways too, no?  And isn't basically nothing faster than the speed of light?  Would it just take too much power to make a light source big enough for super long distance communication?  But if so, wouldn't you need to like blow up a planet to make gravity waves big enough to travel that same super long distance?  I dunno man, I'm confused, and curious.

Ecky Pting

January 12th, 2016 at 12:57 AM ^

If it is truly a wave phenomena, then it would have a corresponding frequency - or range of frequencies. The lower the frequency, the lower the capacity to carry information. My hunch is that the frequency would be low due to the size of the objects that generate them? Maybe someone could confirm this... Also, the waves would be subject to the same spreading loss as any other wave, which increases in proportion to the square of the distance. The only way to counter that is to increase the intensity of the emitted wave. Electromagnetic waves can be collimated using antennas. Gravity waves? Maybe with an array of Death Stars.

MichiganTeacher

January 11th, 2016 at 10:58 PM ^

Yeah, regardless of the particular phenomenon, you can't send a signal (or have a cause-effect relationship) faster than light. Gravitational waves are no exception. Entanglement can give you instantaneous 'spooky action at a distance,' but it can't be used to send information faster than the speed of light.

The particle is the graviton. Interestingly, complete mastery over gravitons similar to what we have over electrons would allow us to build an anti-gravity device. However, confirming gravity waves is a long, long, long way from finding, much less mastering, gravitons. 

Black Socks

January 11th, 2016 at 10:28 PM ^

Wake me up when we can teleport to France.  

Really though it's pretty cool.  There is so much that humans don't know.  We are nevertheless pretty arrogant.