Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: flr on 29/02/2016 22:38:07

Title: Gravitational waves: should we be sceptical about their practical importance?
Post by: flr on 29/02/2016 22:38:07
 The discovery of gravitational waves is indeed of great academic interest.

 However, I am skeptic that too much of practical importance can be expected from it. Am I wrong?
Title: Re: gravitational waves: sould we be skeptic about their practical importance?
Post by: quandry on 01/03/2016 09:11:10
The importance is not that gravitational waves exist. The importance is that they have been detected albeit as a unique coincidence of two black holes merging and the engineering science to build a detector being implemented exactly 1.3 billion years later.
In terms of gravitational waves the detector sensitivity is incredibly low, requiring an enormous event to trigger it.
I dare say that the most immediate benefit of this will be the technology improvements that will (need to) occur to enable the gravity waves resulting from the earth / moon barycentric rotation.
The next step will probably be being able to measure the wavelength of gravitational waves which may be able to be used to tell us a huge amount about what's happened ion the universe.
Title: Re: gravitational waves: sould we be skeptic about their practical importance?
Post by: evan_au on 01/03/2016 10:29:45
Quote from: flr
I am skeptic that too much of practical importance can be expected from it.
I agree that it is hard to see any practical applications on Earth at this point in time.

The current generation of gravitational wave detectors will give astronomers a much better look at the most violent events in the universe - black holes colliding, supernovas (which are the source of most elements up to iron & nickel), neutron stars colliding (which is thought to be the source of most heavy elements beyond gold), gamma-ray bursts and "Starquakes" on neutron stars.

It may resolve questions about why there only seems to be about a quarter of the supernovas that astronomers expect to find in our galaxy. It may resolve some more speculative theories around cosmic strings (http://en.wikipedia.org/wiki/Cosmic_string).

Future generations of detectors may allow astronomers to peer much more closely into the Big Bang - further than is possible with the CMBR. It may also allow astronomers to peer beyond dust in the center of our galaxy to observe the central black hole in our galaxy devouring stars.

It is hard to see future applications of a technology. By 1889 Hertz had confirmed Maxwell's 1865 prediction of electromagnetic waves. This was a 25 year gap between prediction and demonstration - and the demonstration required the resources of one person and a small workshop.

A 100 year gap between Einstein's prediction of gravitational waves and their reported detection is an indication of the greater difficulty in detecting this very subtle effect (maybe 4 times harder?). The fact that it took a $billion, and required the work of thousands of people in a multinational collaboration is another indication of the degree of difficulty (maybe thousands of times harder?). 

I am sure that Hertz could not have imagined a smartphone or understood why people get so addicted to WiFi hotspots - devices that required 125 years of development after his initial laboratory demonstration. Similarly, it is hard for us to imagine what might happen with gravitational waves in 500 years (if it is only 4 times harder).

A few wild speculations: Could it lead to ways to control gravity, and make space travel easier?
Could it allow us to detect rogue black holes, which are thought to be drifting through space, invisible to us?
Title: Re: gravitational waves: sould we be skeptic about their practical importance?
Post by: lightarrow on 01/03/2016 13:17:24
Could it allow us to detect rogue black holes, which are thought to be drifting through space, invisible to us?
Could it allow us to detect alien spaceships using curvature propulsion?  [:)] [:)] [:)]

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lightarrow
Title: Re: gravitational waves: sould we be skeptic about their practical importance?
Post by: lightarrow on 01/03/2016 13:24:27
The importance is that they have been detected albeit as a unique coincidence of two black holes merging and the engineering science to build a detector being implemented exactly 1.3 billion years later.
No, it's not such a coincidence: the detectors were built after precise calculations (made also from Kip Thorne, if I remember correctly) about the statistical number of such events in the radius of action of the detector itself, they found those devices would have a non zero probability to detect such kind of events in a year.

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lightarrow
Title: Re: gravitational waves: sould we be skeptic about their practical importance?
Post by: jeffreyH on 01/03/2016 13:26:16
To overcome gravity would require a medium that is opaque to or blocks the field. Like a Faraday cage for gravity.

If you could reflect the field back to the centre of mass then all gravity cancels. A suitably advanced society could cancel the tidal forces surrounding a black hole. Maybe even revealing the singularity.
 
Title: Re: gravitational waves: sould we be skeptic about their practical importance?
Post by: evan_au on 01/03/2016 15:48:57
More wild speculation: If Aliens are harnessing black holes as a combination powerstation and garbage disposal, a future generation of more sensitive and directional gravitational wave detectors might pick this up?

It might explain why SETI hasn't picked up anything at radio frequencies - ET is hunkered down in his cave, busy warming himself around his accretion disk fireplace, while he throws another Jupiter on the fire...
Title: Re: gravitational waves: sould we be skeptic about their practical importance?
Post by: jeffreyH on 01/03/2016 16:29:23
More wild speculation: If Aliens are harnessing black holes as a combination powerstation and garbage disposal, a future generation of more sensitive and directional gravitational wave detectors might pick this up?

It might explain why SETI hasn't picked up anything at radio frequencies - ET is hunkered down in his cave, busy warming himself around his accretion disk fireplace, while he throws another Jupiter on the fire...

I would advise against more coffee today.
Title: Re: Gravitational waves: should we be sceptical about their practical importance?
Post by: JoeBrown on 06/03/2016 19:30:25
I believe the scientific community is kinda breathing a sigh of relief.  Einstein predicted gravity waves traveling at the speed of light.  Until this discovery, everyone was kinda like...  Well he was right about a lot of stuff, so that's probably right too.

Now we have evidence that gravity is propagated at (about) the speed of light and has "wave" like properties.

I'm skeptical this line of research will produce more substantial findings, but who knows what the future holds, I think this is the main proof LIGO was hoping for.
Title: Re: Gravitational waves: should we be sceptical about their practical importance?
Post by: chiralSPO on 06/03/2016 21:43:22
Currently black holes are both very interesting, and very hard to study. They have implications on both cosmological and fundamental physics, so I think it is not unreasonable to think that there could be paradigm-shifting discoveries waiting to be uncovered. And since there are so few methods at our disposal for studying (let alone observing) black holes, I think any new tools should be viewed as potentially very useful.

We may also be able to find other phenomena that have yet to be theorized (as gratifying as it is to verify predictions made by currently held theories, I think the most dramatic advances in science have usually started out with someone seeing something that makes them think, "what the heck?!?")