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The Absurdity of Detecting Gravitational Waves

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posted on Jan, 9 2017 @ 08:43 AM
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I saw this great video yesterday on the Veritasium channel on YouTube. The mind bending things they went through to figure out how to detect and measure gravitational waves is amazing.

Measuring variations just 1 / 10,000 the width of a proton. Its the equivalent of measuring the distance from here to Alpha Centari and variations just the width of a human hair.

It all started 1.3 billion years ago when two black holes merged, creating traveling distortions in the fabric of space time. In the last tenth of a second, the energy being released in these waves was 50X greater than energy being release by everything else in the observable universe COMBINED! These waves eventually reached earth, where we were able to detect them by measuring light distortions from a laser beam traveling in perpendicular tubes.




Sounds simple but what went behind building this rig and solving some of the problems is just amazing.

The laser uses 1 megawatt of energy. That's 1 MILLION watts. 1 MW hour can serve about 650 residential homes.




The smoothest mirrors in the world were created and they are hung from silicon threads to help eliminate outside vibrations.






There are so many things I left out, check out the video below to get the full picture. Like an answer to the question: If everything is stretching, how do you know anything is?


edit on 9-1-2017 by FauxMulder because: (no reason given)




posted on Jan, 9 2017 @ 09:07 AM
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Outstanding layman terms layout. Watching video....

Edit: If gravity travels in 'waves', can one assume that gravity is made of particles like waves of light, water and air? Does that mean they are looking for that 'graviton' (particle)?

Why are they waiting for these 'black hole events' to measure gravitons? Can't we get a close up of intense gravity measurement from our own sun?

Must be expensive to fire this mw laser, how do they know when the waves arrive from some billion year ago event, down to the 'tenth of a second?

Are they firing it continuously hoping they catch some distant merger of black holes, by accident?


edit on 9-1-2017 by intrptr because: Edit:



posted on Jan, 9 2017 @ 09:27 AM
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a reply to: intrptr

I suggest you check out their FAQ page Here

but here is an answer to a couple of your questions:


How often do gravitational waves that LIGO can detect pass by the Earth? Nobody really knows yet. Strong gravitational waves are believed to occur rarely enough that LIGO did not detect any in its first 3.5 years of operation between 2005 and 2010. However, after a major upgrade, where LIGO was outfitted with extra-special noise-cancelling headphones, higher-power lasers, and larger mirrors, the Advanced LIGO detectors made their VERY FIRST OBSERVATION of gravitational waves on September 14, 2015, within days of becoming fully operational! This means either LIGO got lucky, or these kinds of events are relatively common. Now that we know LIGO can detect gravitational waves, more detections will enable astronomers to answer this question more definitively. At present, aLIGO is still not at its 'design sensitivity', so it's mostly capable of "hearing" only the loudest gravitational wave-producing events in the Universe. This is precisely what we heard: two massive black holes colliding 1.3 billion light years away (that means it actually happened 1.3 billion years ago!) Multitudes of fainter gravitational waves are produced in the Universe all the time, but these still appear to lie below our current sensitivity. With further planned upgrades to improve LIGO's sensitivity over the next several years, we expect to detect fainter events with some frequency. But it will still be extremely challenging. To illustrate the point, imagine standing in the middle of a field a few acres in size. A handful of people are scattered across the field; none are very close to you. One or two are shouting, some are talking, and some are whispering. The sound waves from all of them along with all the other noises in the environment are passing by your ears, but will you be able to decifer all of the conversations? No -- you're likely to hear only the shouters, whose voices are much louder than the others and the surrounding environmental noise. That's what LIGO heard in its first gravitational wave detection--big, loud 'shouting' colliding black holes, over a billion light years away. We can't yet hear the closer whispers.

edit on 9-1-2017 by FauxMulder because: (no reason given)



posted on Jan, 9 2017 @ 09:44 AM
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originally posted by: intrptr
Outstanding layman terms layout. Watching video....

Edit: If gravity travels in 'waves', can one assume that gravity is made of particles like waves of light, water and air? Does that mean they are looking for that 'graviton' (particle)?


You don't need something to "wave" to have a wave. EM is composed of photons, but the "waves" are electric and magnetic fields. There are no particles "waving" like water and air waves.

A 'gravity wave' could be viewed as a wave of space-time distortion. Although I'm not sure how that propagates, it's not like EM.



Why are they waiting for these 'black hole events' to measure gravitons? Can't we get a close up of intense gravity measurement from our own sun?


They're looking for big changes. It's hard to see ANYTHING. The Sun puts out a big steady state field, but it doesn't change a lot. It's tough to see the Sun's mass turning into light. That's a small signal, because it's a tiny tiny percentage change.



Must be expensive to fire this mw laser, how do they know when the waves arrive from some billion year ago event, down to the 'tenth of a second?

Are they firing it continuously hoping they catch some distant merger of black holes, by accident?


Sure. Let 'er rip, look for signals. If gravity waves propagate at light speed, and there's no reason to think it doesn't, then you won't be able to see an event coming. You'll have to run them all the time.



posted on Jan, 9 2017 @ 09:48 AM
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a reply to: FauxMulder


Thank you Mulder...


after a major upgrade, where LIGO was outfitted with extra-special noise-cancelling headphones, higher-power lasers, and larger mirrors, the Advanced LIGO detectors made their VERY FIRST OBSERVATION of gravitational waves on September 14, 2015, within days of becoming fully operational! This means either LIGO got lucky, or these kinds of events are relatively common.


Ummm hmm, and I am going to strike lotto the first time I buy a ticket. See my point? Something fishy here. Converging back holes are not that common.

What other 'undisclosed' purpose does this contraption have? I bore in on this because to me its seems such a delicate passage of such distant gravity waves would be out shined[/]i by the close source of gravity, our own sun. No...?

It also seems continuous firing of a mw laser is expensive, in the hopes of catching such rare events.
edit on 9-1-2017 by intrptr because: bb code, spelling



posted on Jan, 9 2017 @ 09:51 AM
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a reply to: Bedlam


You don't need something to "wave" to have a wave. EM is composed of photons, but the "waves" are electric and magnetic fields. There are no particles "waving" like water and air waves.

Tilt.

So far, everything that makes waves is comprised of particles. In the case of light-- photons, water and sound-- molecules, sand dunes-- grains, clouds-- water drops.

Every spectrum detectable from both ends inclusive is detected as waves of particles...



posted on Jan, 9 2017 @ 09:53 AM
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a reply to: intrptr

Well it seems they can also detect it from other events and are estimating being able to detect up to 40 a year.


We predict that once LIGO reaches its most sensitive state we could detect about 40 per year, but that's just from merging neutron stars. There will be even more if we detect other sources like supernovae or more merging black holes (which is precisely what LIGO detected for the very first time on September 14, 2015). You might now ask, "how is this possible if such events are so rare in our galaxy?" If LIGO couldn't hear anything outside of our own galaxy (say beyond 80,000 light years), we would probably have to wait a very long time to detect a gravitational wave. But LIGO’s advanced detectors can hear thousands of times father away than this, listening for gravitational wave vibrations from galaxies hundreds of millions of light years away.


As far as why this is important, this is what they say they have to offer:


Gravitational waves probably won't be useful in helping us understand processes on the Earth, but they will help us understand processes that occur in outer space, such as the collisions of pairs of black holes. We've already learned a lot from our very first detection, such as (a) binary black holes actually exist, and (b) black holes with masses about 30 times that of the sun also exist Neither of these facts were known before LIGO's historic detection! The knowledge that astronomers gain from measuring gravitational waves could also improve our understanding of space, time, matter, energy, and the interactions between all of these things. In so doing, this field of study could revolutionize humanity’s knowledge and understanding of the nature of existence itself.

Also, LIGO's impact on science in general will reach far beyond just the fields of astronomy and astrophysics. To learn even more, visit Why Detect Them? in Learn More.

What kinds of information can gravitational waves provide?

Gravitational waves will provide a test of Einstein's theory of general relativity under extreme conditions of gravity where it has never before been tested. They will also give us more information about the unimaginably dense form of matter that makes up neutron stars. Neutron stars contain more matter than our sun packed into a sphere the size of a city--about 10 km (6 mi.) across. These objects are so dense that a person weighing 150 lb (68 kg) on Earth would weigh 21,000,000,000,000 pounds (9,545,000,000,000 kg) on a neutron star! Packed so closely and densely together, the matter that makes up a neutron star is called "degenerate matter", which is not well understood.

LIGO will help improve our understanding of degenerate matter. Gravitational waves will also tell us about how many objects like black holes and neutron stars exist in the Universe. They will give us insight into what happens during some of the Universe's most violent explosions such as supernovae and gamma ray bursts.

Someday, gravitational waves might even allow us to listen to what was happening in the earliest moments of the Universe, when it was so dense and hot that no light could move around. Any photons emitted during that time were long ago absorbed by a plasma of hot ions, but gravitational waves from that era could travel directly to us on Earth with little interference from the matter in the Universe. For a longer list of ways in which LIGO data will contribute to science, read the answer to the above question, "How does LIGO use the data that it collects?"

What discoveries does LIGO hope to make?

LIGO's historic 2015 detection of two colliding black holes will open up a new field of astrophysics. Whether gravitational waves are detected from colliding black holes, supernovae, remnant radiation from the Big Bang, or even just the tiniest imperfections on rapidly spinning ultra-dense neutron stars, the amount of potentially new fundamental knowledge of the extreme Universe (extreme because we’re studying extreme forces of gravity, extreme explosions, and extreme collisions) that we stand to gain is astounding. Even better, as with any science, the best rewards come from discovering things we never knew before nor could even have imagined. As with every other time we've looked up at the sky in a different way, be it through infrared, x-ray, or gamma-ray goggles, we will almost certainly be surprised and intrigued by what we didn’t expect to find once gravitational wave astronomy becomes its own genuine field of inquiry.



posted on Jan, 9 2017 @ 09:57 AM
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a reply to: FauxMulder

Thanks again...

We've already learned a lot from our very first detection, such as (a) binary black holes actually exist, and (b) black holes with masses about 30 times that of the sun also exist Neither of these facts were known before LIGO's historic detection! The knowledge that astronomers gain from measuring gravitational waves could also improve our understanding of space, time...


Maybe theres a lot more of the missing matter (called Dark matter) wrapped up in many more invisible black holes than we first thought?



posted on Jan, 9 2017 @ 09:58 AM
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a reply to: intrptr

I'm still trying to get around how such a far away source is 'louder' than our own close up sun?



posted on Jan, 9 2017 @ 09:58 AM
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originally posted by: intrptr
a reply to: Bedlam


You don't need something to "wave" to have a wave. EM is composed of photons, but the "waves" are electric and magnetic fields. There are no particles "waving" like water and air waves.

Tilt.

So far, everything that makes waves is comprised of particles. In the case of light-- photons, water and sound-- molecules, sand dunes-- grains, clouds-- water drops.

Every spectrum detectable from both ends inclusive is detected as waves of particles...



I think this is another reason why it is so important. It isn't particles. Its a wave in space-time itself! If you think about it they are only detecting it because of the effect it has on other things.



posted on Jan, 9 2017 @ 10:00 AM
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originally posted by: intrptr
a reply to: intrptr

I'm still trying to get around how such a far away source is 'louder' than our own close up sun?


Because remember that collision put out 50X the amount of energy then everything else in the observable universe COMBINED! The sun doesn't even come close to that.



posted on Jan, 9 2017 @ 10:02 AM
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a reply to: FauxMulder


I think this is another reason why it is so important. It isn't particles. Its a wave in space-time itself! If you think about it they are only detecting it because of the effect it has on other things.

The old wave vs particle argument...

too bad. The world around us is comprised of energy striking us as waves... of particles.

In case of conundrum go outside on a windy day, (wind is invisible) or go surfing. Or stand in front of a MW laser, an X-ray machine, the core of a reactor...
edit on 9-1-2017 by intrptr because: spelling



posted on Jan, 9 2017 @ 10:04 AM
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a reply to: FauxMulder


Because remember that collision put out 50X the amount of energy then everything else in the observable universe COMBINED! The sun doesn't even come close to that.


But the sun is way closer, its gravity bends the orbit of our planet, these remote 'gravity waves' are so 'quiet' they need all that delicate detection apparatus just to detect them. If they are so powerful they should knock earth out its orbit...



posted on Jan, 9 2017 @ 10:08 AM
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originally posted by: intrptr
a reply to: FauxMulder


I think this is another reason why it is so important. It isn't particles. Its a wave in space-time itself! If you think about it they are only detecting it because of the effect it has on other things.

The old wave vs particle argument...

too bad. The world around us is comprised of energy striking us as waves... of particles.

In case of conundrum go outside on a windy day, (wind is invisible) or go surfing. Or stand in front of a MW laser, an X-ray machine, the core of a reactor...


Well I wasn't entirely sure so I Googled it:

"Your questions struck right at the center of one of the hottest and most challenging research topics in physics. So far, physicists don't know the full answers to all your questions. Although gravity is well understood at the macroscopic (every-day-life) scale, scientists are far from understanding it well at the microscopic scale (quantum level).

Gravity is a force. For all other forces that we are aware of (electromagnetic force, weak decay force, strong nuclear force) we have identified particles that transmit the forces at a quantum level. In quantum theory, each particle acts both as a particle AND a wave. This is called duality. So if there is a graviton, we expect it to behave both as particle and as a wave as well.

The electromagnetic force, for example, is transmitted by photons, and light is nothing but a large number of photons. Photons/light show wave and particle properties."



posted on Jan, 9 2017 @ 10:16 AM
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a reply to: FauxMulder


The electromagnetic force, for example, is transmitted by photons, and light is nothing but a large number of photons. Photons/light show wave and particle properties."

Because of the 'double slit' experiment, interference patterns of individual photons and all that.

I also understand their single photon gun isn't as singly productive as they might think.

Depending on who you listen to.

Nature
edit on 9-1-2017 by intrptr because: link



posted on Jan, 9 2017 @ 10:24 AM
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originally posted by: intrptr
a reply to: intrptr

I'm still trying to get around how such a far away source is 'louder' than our own close up sun?


I believe the answer to this is that the gravitational waves the sun puts out are way too small for us to detect. They can detect neutron stars which contain more matter than our sun packed into a sphere the size of a city about 6 miles across. These objects are so dense that a person weighing 150 lb on Earth would weigh 21,000,000,000,000 pounds on a neutron star.

All very interesting topics that no one truly knows all of the answers to yet. It seems that with every new discovery, there are way more questions than answers.



posted on Jan, 9 2017 @ 10:32 AM
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a reply to: intrptr

Water, air waves etc are qualitatively different from EM. EM radiation is not 'waves of photons' like water is a wave of water or sound is a compression wave of air.



posted on Jan, 9 2017 @ 10:36 AM
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a reply to: intrptr

The sun doesn't emit gravity waves very much.

A static mass sensor measures gravity. A gravity wave sensor measures CHANGES in space-time curvature. So the Sun isn't emitting a lot of what they're looking for.

Gravity != gravity wave.



posted on Jan, 9 2017 @ 10:37 AM
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a reply to: FauxMulder


I believe the answer to this is that the gravitational waves the sun puts out are way too small for us to detect.

But hold our earth in orbit. How powerful is that influence of gravity compared to these 1 billion light year removed waves?

I know they say they are cancelling 'noise'. Like filtering a radio signal, or making light 'coherent'. But still if gravity has a single 'wavelength' then any gravity from a plethora of sources, even stronger ones (like the center of galaxies), should bury the noise of two billion light year distant black holes colliding?

Galactic black holes hold billions of suns in their sphere of influence.

As well, this device (thanks for the wonderful simple descriptives and pics) isn't a 'focused' apparatus like a telescope that magnifies, zooms in on one source. It is a 'trap' designed to capture random passing waves, without the ability to do time exposures of a single magnified source (like two black holes colliding), for instance.

If gravity waves that far away are so intense as to outshine our suns gravity so much, they should have some impact on our orbit, ya think? Can't they tune this super sensitive device to read our own suns gravity 'waves'?




edit on 9-1-2017 by intrptr because: bb code



posted on Jan, 9 2017 @ 10:43 AM
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a reply to: Bedlam


The sun doesn't emit gravity waves very much.

No? Even the earth does. See how high you can jump. The sun bends the mass and momentum of our planet round its gravity.

Thats some powerful "stuff".




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