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The Absurdity of Detecting Gravitational Waves (2017) [video]

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Re: The Absurdity of Detecting Gravitational Waves (2017) [video]

#31

Post by andrewflnr »

sleavey wrote: post #23
maxxxxx wrote: post #6

Earlier quoted context omitted.

What would be the advantage of using gravity waves?

One reason would be that gravitational wave amplitude decays only as 1/distance instead of electromagnetic radiation which decays as 1/(distance squared). ...But man-made gravitational waves are, without some scientific advance eclipsing the discovery of electricity, completely beyond any human capability of being produced at the levels required for extra terrestrial communication.

> gravitational wave amplitude decays only as 1/distance

Wait, what? How? The wavefront still spreads out over the quadratically increasing surface of a sphere, right, just like EM waves?

Re: The Absurdity of Detecting Gravitational Waves (2017) [video]

#32

Post by spuz »

ci5er wrote: post #16
sillysaurus3 wrote: post #13

Earlier quoted context omitted.

Another answer to the Fermi paradox is that a Kardashev Type 4 civilization is able to harness the power of an entire universe. We wouldn't be able to detect this by definition, since they exist outside of our perceived reality. At first glance, this seems to be a useless theory, since it's not refutable. But it lends itself to a belief system: by studying the universe, we gain an understanding of whatever created it…

> But why do humans find this idea so seductive? It's because of an underlying loneliness: we want to believe that we are connected with the universe in some fashion, that our existence has a point [...] No. It's simply that statistically, we can't believe we are the first, nor that we are unique. It would be (statistically) extremely odd if we were, and there is a bias against anthropo-centric theories. Heck, I'd be…

> No. It's simply that statistically, we can't believe we are the first, nor that we are unique. It would be (statistically) extremely odd if we were, and there is a bias against anthropo-centric theories.

Fermi's paradox does not ask about civilisations like ours. It asks about interstellar travelling or at least interstellar communicating species. We have not achieved this level yet so we are not the 'first' as you say. You might claim that our radio signals should be able to be detected, but they are so weak and have been travelling for such a short period of time that they may as well not exist to an outside observer. There may be millions of our type of civilisation out there presently and throughout history but they would all be undetectable to us and hence our civilisation doesn't play into the paradox.

Re: The Absurdity of Detecting Gravitational Waves (2017) [video]

#33

Post by ci5er »

spuz wrote: post #32
ci5er wrote: post #16

Earlier quoted context omitted.

> But why do humans find this idea so seductive? It's because of an underlying loneliness: we want to believe that we are connected with the universe in some fashion, that our existence has a point [...] No. It's simply that statistically, we can't believe we are the first, nor that we are unique. It would be (statistically) extremely odd if we were, and there is a bias against anthropo-centric theories. Heck, I'd be…

> No. It's simply that statistically, we can't believe we are the first, nor that we are unique. It would be (statistically) extremely odd if we were, and there is a bias against anthropo-centric theories. Fermi's paradox does not ask about civilisations like ours. It asks about interstellar travelling or at least interstellar communicating species. We have not achieved this level yet so we are not the 'first' as you…

Ok. Fair enough. My point was simply that: we might be curious, but most of us aren't lonely or looking for any higher purpose or meaning (well, many may be, but if we were - we wouldn't look to aliens to satifice them)

Re: The Absurdity of Detecting Gravitational Waves (2017) [video]

#34

Post by lovemenot »

tntn wrote: post #15
sillysaurus3 wrote: post #13

Earlier quoted context omitted.

Another answer to the Fermi paradox is that a Kardashev Type 4 civilization is able to harness the power of an entire universe. We wouldn't be able to detect this by definition, since they exist outside of our perceived reality. At first glance, this seems to be a useless theory, since it's not refutable. But it lends itself to a belief system: by studying the universe, we gain an understanding of whatever created it…

I don't understand how this is any different from believing in God.

No doubt that was your parent poster's intention. There have been many ontological arguments throughout history. This was one such.

Re: The Absurdity of Detecting Gravitational Waves (2017) [video]

#35

Post by stefanough »

phkahler wrote: post #2

This seems like a thing to build on the moon.

This is actually a plot point in Greg Egan's Diaspora. A moon-based laser interferometer is used to detect an impending neutron star merger that will have catastrophic results for biological life on Earth.

Re: The Absurdity of Detecting Gravitational Waves (2017) [video]

#36

Post by nonbel »

a1369209993 wrote: post #18
TomMckenny wrote: post #4

I wonder if gravity wave detection could be ever be precise enough for communication. I wonder this because it occurs to me that one possible answer to Fermi's paradox is that aliens don't use Radio or other EM to chat. And maybe they don't leak it because they move energy and information around more efficiently than we do.

Communication is a red herring; the actual Fermi paradox is why huge sections of the night sky aren't black[0] due to all the stars being enclosed by Dyson spheres. Or, for that matter, why the planet hasn't been eaten by von Neumann swarms yet. 0: technically a uniform dim infrared of waste heat

This is called Olbers paradox, and is much older: https://en.wikipedia.org/wiki/Olbers%27_paradox

Re: The Absurdity of Detecting Gravitational Waves (2017) [video]

#37

Post by basementcat »

elorant wrote: post #29
eternauta3k wrote: post #25

Earlier quoted context omitted.

> Gravitational waves last for an instant and then you've missed them. Could you go into more detail? How do they differ from EM waves?

I'm not a physicist so I can't elaborate much on the subject. From a few articles I've read at the time of the LIGO discovery they mentioned that the signals lasted for a very short period. Other than that I might be totally wrong so don't take for granted my assumption.

Much of the data from LIGO is publicly available. Most scientists have been looking for chirp-like signals indicative of events like colliding black holes. Maybe you can find some other interesting signals?

https://losc.ligo.org/s/events/GW170104/LOSC_Event_tutorial_...

Note that there's quite a bit of interference from the Earth. (trucks driving about, etc)

Re: The Absurdity of Detecting Gravitational Waves (2017) [video]

#38

Post by roywiggins »

meowface wrote: post #5
TomMckenny wrote: post #4

I wonder if gravity wave detection could be ever be precise enough for communication. I wonder this because it occurs to me that one possible answer to Fermi's paradox is that aliens don't use Radio or other EM to chat. And maybe they don't leak it because they move energy and information around more efficiently than we do.

Even if tons of intelligent civilizations happened to be radiating gravitational waves (or some other form of radiation which travels at or very close to the speed of light) encoded with information directly towards Earth right now, it's very likely we'd never receive them in the next million years due to the vastness of the universe.

What about all of the intelligent civilizations who were doing it a million years ago? With a million years for waves to fill space, you'd think we'd be able to hear something.

Re: The Absurdity of Detecting Gravitational Waves (2017) [video]

#39

Post by roywiggins »

sleavey wrote: post #23
maxxxxx wrote: post #6

Earlier quoted context omitted.

What would be the advantage of using gravity waves?

One reason would be that gravitational wave amplitude decays only as 1/distance instead of electromagnetic radiation which decays as 1/(distance squared). ...But man-made gravitational waves are, without some scientific advance eclipsing the discovery of electricity, completely beyond any human capability of being produced at the levels required for extra terrestrial communication.

Gravity follows the inverse-square law. Every conservative vector field does, actually, and gravity behaves like one.

https://en.wikipedia.org/wiki/Inverse-square_law#Gravitation

Re: The Absurdity of Detecting Gravitational Waves (2017) [video]

#40

Post by RachelF »

sillysaurus3 wrote: post #3

Happy to see Veritasium getting some attention on HN. You may have seen his previous video from 2014, Facebook Fraud: https://www.youtube.com/watch?v=oVfHeWTKjag One of my favorite videos is on his alternate channel, 2veritasum. Survivor Bias: https://www.youtube.com/watch?v=_Qd3erAPI9w

He's a great presenter, not the normal dumbed down documentaries that are fashionable these days. He actually tries to explain things, not just waffle and make the watcher feel good.

He recently made a full length movie:

https://www.vitamaniathemovie.com/

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