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Gravitational waves detected

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Brian Blake
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http://www.bbc.co.uk/news/science-environment-35524440. Great discovery.

 
Posted : 11/02/2016 4:21 pm
Tej
 Tej
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Huge.

 

One of the lectures at Astrofest last weekend teased there will be a huge announcement later in the week, man, they werent kidding.

 

One of those lectures described new projects based on "if" gravitational waves are discovered (cheeky, looks like they knew already, lol).  The key thing I took away from that lecture was that gravitational waves is not just a new single tool to peering deeper into the secrets of the universe but a whole "SET" of tools equivalent to that of the electromagnetic spectrum.   So just a we uses different parts of the electromagnetic waves for different applications and detection, eg, radio waves, infra red, ultra violet, visible light for broadcast/entertainment/radio astronomy/medical practices etc.  Gravitational waves will be a similar splitting of different wavelengths for different observations.   And to me, that's what makes this discovery so huge.

 

Its also wonderful that Einstein still rules the day 🙂 ...though so do the LIGO team!

 

 

 
Posted : 11/02/2016 5:01 pm
Mike Meynell
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A quite incredible achievement. I have to admit that I was sceptical that gravitational waves (if indeed they existed) would ever be detected on Earth. The energy levels are so tiny - how they can distinguish a signal which is the equivalent of a fraction of a proton, with all the noise that must surround the equipment, is just extraordinary.

There is no doubt that they detected gravitational waves... the results are absolutely clear, with two detectors 3,000km apart giving the same signal simultaneously (or 7 milliseconds apart, to take account of the speed of light!):

This really does open up an entirely new field of science. For the first time, we can directly detect black holes without relying on circumstantial evidence.

Who knows where this will take our understanding of the universe? An amazing day in scientific history.

 
Posted : 12/02/2016 8:02 am
Andy Sawers
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The sensitivities - and hence margin of error - is just so extraordinary. I just hope the signal wasn't caused by a cosmonaut tripping over a toolbox on the ISS and bumping his head on a bulkhead as the space station was coming up over Rio.

 
Posted : 12/02/2016 9:10 am
Tej
 Tej
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Mike, how long does this ripple caused by the two black holes colliding last for from the perspective of our measurement observation?  So Ligo detected a ping which was the moment of collision, right?  Then comes the ripples.  Those ripples I imagine will subside just as the ripples of a pebble dropped into a pond does the same...or is it the same? are space time ripples (gravitational waves) endless?  Is that why we should be able to detect events further in towards the time of the big bang?  Because I am wondering how are we supposed to detect ancient large impact/explosive events such as the big bang if the ripples have subsided and certainly the moment of the event, we would have missed 13.8 billion years ago as we were in it at the time.

 

 

btw isnt the detection of two black holes colliding big news in and of itself?!  We should be able to get useful new secrets from that event, I imagine?  Or are black hole collisions a common thing?

 

I've enrolled on that FutureLearn Gravity course again that starts in May, I couldnt follow through with it last time (so much maths!).  Some of you might like to do the same or do the previous course (without tutor interaction).

 

https://www.futurelearn.com/courses/gravity

 

 
Posted : 12/02/2016 8:23 pm
Mike Meynell
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btw isnt the detection of two black holes colliding big news in and of itself?!  We should be able to get useful new secrets from that event, I imagine?  Or are black hole collisions a common thing?

Yes, it is big news. We didn't even know that two black holes orbiting each other even existed until now. They existed in theory, but we had no observational evidence for them.

We've no idea how common they are. Though I note that the LIGO team think they detected 4 events in the period from September to January.

I'm not sure about your other questions. Will go away and ponder!

 
Posted : 12/02/2016 8:41 pm
Tej
 Tej
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<div class="d4p-bbt-quote-title">Tej wrote:</div>
btw isnt the detection of two black holes colliding big news in and of itself?! We should be able to get useful new secrets from that event, I imagine? Or are black hole collisions a common thing?

Yes, it is big news. We didn’t even know that two black holes orbiting each other even existed until now. They existed in theory, but we had no observational evidence for them. We’ve no idea how common they are. Though I note that the LIGO team think they detected 4 events in the period from September to January. I’m not sure about your other questions. Will go away and ponder!

 

Its a quadruple whammy, isnt it?  We detected a black hole directly for the first time.  We detected two orbiting black holes for the first time.  We detected two black holes colliding for the first time. And finally we detected gravity waves for the first time.  All in one go!

 

Ponder away on those other questions, Mike!

 
Posted : 13/02/2016 2:10 pm
Tej
 Tej
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...and now that Blackheath stargazing is cancelled, i think you have everyone's approval to buy yourself a nice little 4km GW detector to answer those questions 🙂

 
Posted : 13/02/2016 2:45 pm
Andy Sawers
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Posts: 742
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Someone (you, Mike?) left a copy of December 2015's Sky & Telescope on the refreshments table last night, so I nabbed it.

The article on the search for gravitational waves is extraordinary. Amazing to think that just a few weeks later everything in the article would turn out to be true!

 
Posted : 05/04/2016 9:23 am
Brian Blake
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Posts: 597
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