Datahopa

Heavens Above => Astronomy & Near Earth Phenomena => Topic started by: Snowcrash on February 13, 2016, 09:52:24 AM

Title: Gravity Waves
Post by: Snowcrash on February 13, 2016, 09:52:24 AM
There's been loads of hyperbole in the news announcing the measurement of gravity waves.

Here's the science. BTW they are very, very, very small.

http://www.youtube.com/watch?v=azSHQT0HCA0 (http://www.youtube.com/watch?v=azSHQT0HCA0)
Title: Re: Gravity Waves
Post by: Carl2 on February 13, 2016, 11:54:13 AM
What I heard from the video is they are measuring the movement of space time.  That really doesn't have much meaning to me.
Carl2
Title: Re: Gravity Waves
Post by: DaveMorton on February 13, 2016, 17:12:40 PM
It doesn't have much meaning to most people, Carl. But for those of us who wear pocket protectors (real or imagined) it's "final proof" that Einstein was right, so it's really exciting... at least to us. :D

We talked about this in Astronomy class on Thursday, and the instructor (who only learned about the announcement about an hour before class) scrapped the day's original agenda in order to discuss it. He even scoured the Internet to find an activity that was relevant, in the form of "Signal to Noise" analysis, where we were to examine several signals with considerable noise in them, attempting to match them up with a large list of templates of potential matches. IT was a little tedious, but since this was a group activity, and I was teamed up with a couple of pretty ladies to work with, it was rather fun. Our instructor thinks (and I tend to agree with him) that Humans are just a bit better at this sort of thing than computers are, and that idea sparked a bit of a debate within the class. All in all, it was a rather good and fun class session. :)
Title: Re: Gravity Waves
Post by: Carl2 on February 13, 2016, 22:47:51 PM
  I remember the ink stains on the shirt pocket and the pocket protectors.  I always wondered about Einstein thinking about what he did while I thought about the girls.  Read quite a bit about him, got an A when quizzed about his studies.
  As far as S/N I built an audio filter for use with Dragon, it increased the S/N from 19 db to 32 db.  Reminds me of your experience of dragon and I'm wondering how you made out.
  I'd agree it would take a person with experience to decide what type of filtering is required.
Carl2
Title: Re: Gravity Waves
Post by: Snowcrash on February 15, 2016, 20:45:13 PM
Spacetime is quite a hard concept to get your head around but it stems from the fact that the speed of light (in a vacuum) is constant. Everything else is variable. If you are travelling at a fair proportion of the speed of light (0.25C say) and I was "stationary" compared to you, then my space would be a mixture of your space and time and vice versa. We would never agree on the timing of an explosion that happened between us but both of us would be right and the laws of physics would not be broken.

Did not check on the S/N ratio of gravity waves. I heard the mass of a truck driving past several miles away swamps the signal.
Title: Re: Gravity Waves
Post by: DaveMorton on February 15, 2016, 20:52:59 PM
I'm given to understand that they have devices (probably seismometers or accelerometers of some sort) that can be used to subtract such disturbances from the incoming signal, but having never been there (or read tech specs on the facilities) I'm not sure. Stands to reason that something like that would be in place, though. :)
Title: Re: Gravity Waves
Post by: Data on February 15, 2016, 21:14:37 PM
I heard on the news that with the next generation of detectors they should be able to gather some useful information from the gravity waves. Now they have detected them and proved they are there the next step will be to do some science with them.

What exact knowledge they can gain from the detected gravity waves I don't know, maybe someone else does  :)
Title: Re: Gravity Waves
Post by: DaveMorton on February 16, 2016, 03:37:28 AM
With only 2 LIGO facilities running now, all they can do is detect the presence of gravity waves, and a general "direction", but 2 more are in the works, and when those are put into service, they can more precisely determine the direction, plus they'll be able to accurately determine the distance of the source. Also, with 4 units, they'll be able to detect much smaller signals, so supernovas may well be within the range of sensitivity, and maybe even the gravity waves generated by the orbits of some of the stars around the black hole in the center of the Milky Way (though that might also require improvements in the tech before that's possible). In one of the articles I've read on the announcement, it was mentioned that gravity waves may actually be capable of FTL speeds (it's estimated that they may travel between 0.8 and 1.2C, though I suspect it's just at the speed of light). Once the other 2 facilities are online, it may be possible to gauge the exact speed of GW, and with that, we could learn if FTL is actually possible. :)
Title: Re: Gravity Waves
Post by: Carl2 on February 16, 2016, 12:27:41 PM
  I still remember one of the first ruby lasers, it was used to measure the band pass of infrared filters.  It actually used a ruby crystal and was the size of a large machine.  I took ages before the semiconductor version of a led was manufactured, it was a great device in the electronic labs but the only color was red.  Then the seven segment device to indicate numbers which could replace meters.  Special integrated circuits were made for use with these leds.  Seems it took 45 years to develop them to a point where I can use them for home lighting.
  I'm thinking the TV I use as a monitor is using leds also, mass production makes it cost less than the monitor.  It will be interesting to see what we learn about gravity.
Carl2
Title: Re: Gravity Waves
Post by: Data on February 16, 2016, 13:23:09 PM
Dave, thank you for your explanation  :thumbsup:

Faster than light speed, wouldn't that be something, after all we have been taught that nothing can travel faster than light. Time will tell or should that be space time will tell.  ;)

Agree with carl2, this next gen of detectors might take a long time to develop.
Title: Re: Gravity Waves
Post by: 8pla.net on February 16, 2016, 14:42:03 PM
I noticed a pattern to what Dave posted.

First they had 2^0 facility, Einstein.
Now they have  2^1 facilities.
They will have 2^2 facilities.

When they have an odd number of facilities,
that is not mentioned.

Title: Re: Gravity Waves
Post by: Freddy on February 16, 2016, 16:19:45 PM
I find the faster than light bit interesting - when I first saw this story, I thought hmm, does that mean FLT is something that happens - which is a thing with me as I could never see why speed should be limited.
Title: Re: Gravity Waves
Post by: DaveMorton on February 16, 2016, 22:35:00 PM
I doubt that I can explain it accurately in "layman's terms", but essentially, the faster you go, the more energy it takes to go faster. The way the equation (E=MC2) works is that, the closer you get to C (the speed of light), the more mass an object acts like it takes on, till when you reach C, you have an object with infinite mass, which is, of course, impossible, but.... Ok, I'm glazing over my own eyes here. Sorry. See? I can't explain it well, so never mind. :P
Title: Re: Gravity Waves
Post by: Data on February 16, 2016, 22:46:27 PM
Here's a thought that I might have picked up somewhere. 

Nothing can travel faster than light but it might be possible for something to travel further distance than light can for a given amount of time.

If the space between can be compressed somehow.

I think gravity waves might have something to do with that.

Ok now my brain hurts  ;D
Title: Re: Gravity Waves
Post by: Freddy on February 17, 2016, 00:18:45 AM
I'm pretty sure the answer was 42 guys.

:sign-go-team:
Title: Re: Gravity Waves
Post by: Carl2 on February 21, 2016, 18:12:49 PM
  I've been thinking about this for some time and just realized
"If the space between can be compressed somehow. "  we can't have that since compression places less atoms or what ever closer together so we have something like an atmosphere which slows down the light.  I don't think we have a perfect vacuum in space and the closer we approach it the faster light would travel.  It's interesting that sound waves travel faster the more dense the media.  Magnetics has strange properties, flux fields, only attracts certain things, it attracts and repels.
Motors and things moving, it seems they do the work for us.
Carl2
Title: Re: Gravity Waves
Post by: Data on February 21, 2016, 19:11:15 PM
You make an interesting point there Carl2,

Quotewe can't have that since compression places less atoms or what ever closer together

I couldn't possibly argue with that, sounds logical to me. 

After a quick google I came up with this:
http://www.gizmag.com/warp-drive-bubble-nasa-interstellar/24392/ (http://www.gizmag.com/warp-drive-bubble-nasa-interstellar/24392/)

Title: Re: Gravity Waves
Post by: Snowcrash on February 23, 2016, 19:22:09 PM
The answer is definitely 37 or greater. Maybe 42. The question is a little more tricky. Here goes. How many fields does it take to make a Universe?

Data, you are very close. It is possible for 2 objects in the Universe to be travelling away from each other faster then light. BUT, and it's a big one, no light or information can travel between them. The objects themselves are not travelling FTL, it's the space between them expanding FTL.
The Universe being 13.8 billion years old means that any observer can only see 45 billion light years in any direction (not sure of exact figure but it's about a 45 billion LY bubble due to time dilation). The Universe's expansion is accelerating so even though the visible bubble gets bigger, the visible amount of matter gets smaller each year.

My head hurts.  :-\
Title: Re: Gravity Waves
Post by: Data on February 23, 2016, 19:52:04 PM
Quote from: Snowcrash on February 23, 2016, 19:22:09 PM
Data, you are very close.

I'll take that  :thumbsup: but no cigar for me  ;D

Read your explanation a few times, the best I can come up with is 22  :LOL:

But seriously, nicely put Snowy.