Gravitational waves claimed to be detected by aLigo

[steph]

Supposing they manage to get these things even more sensitive than they've been so far, would it be possible to do something akin to seismic radar using this? Map the movements of the Earth's core and magma simply by monitoring the gravitational radiation that the plumes give off?

 

[Urwumpe]

Supposing they manage to get these things even more sensitive than they've been so far, would it be possible to do something akin to seismic radar using this? Map the movements of the Earth's core and magma simply by monitoring the gravitational radiation that the plumes give off?

That kind of thing is already possible, but a different technology, more based in Newtonian physics. We use this already for discovering ore deposits.

http://science.nasa.gov/science-news/science-at-nasa/2001/ast30oct_1/

 

[steph]

Dated from 2001. I know we're lagging behind on manned spaceflight and what not, but in some other fields....the impossible already happened a long time ago . Must do some more reading on the subject, it seems I haven't been keeping up with the news lately :lol:

 

[Urwumpe]

Dated from 2001. I know we're lagging behind on manned spaceflight and what not, but in some other fields....the impossible already happened a long time ago . Must do some more reading on the subject, it seems I haven't been keeping up with the news lately :lol:

Its pretty special science, I would say, so hardly surprising that its not that famous in public.

I learned a lot after the Deepwater Horizon accident about oil wells, drilling and applied geology, that I did not even think about before. Before, working for the oil industry was like working for banks. Well-paid, but evil and boring. Now it is a pretty challenging industry with high-demands, that is very closely following recent scientific research and not that much different to spaceflight in terms of engineering at the extreme edge of what is possible. If a way is found to drill 12000 meter deep, a few years later, all will be using this technology and drill that deep. And especially in Germany, economic constraints are important and make the job much more "fun", even as computer scientist.

Sadly, it is an industry with designed obsolescence.

 

[fred18]

I have a doubt on what is being said around about gravitational waves:
I agree and understand that this is an exceptional achievement, because it's a new confirmation of relativity and because how hard it was to achieve it.

But everybody keeps saying that this is an opening to a whole new era of studying. Why? isn't it just the confirmation that Einstein was right also about this? Actually I think there were already a lot of clues that relativity was right, so how this is going to change universe observation? and could it take again 30 years to detect some other gravitational wave?

 

[Urwumpe]

But everybody keeps saying that this is an opening to a whole new era of studying. Why? isn't it just the confirmation that Einstein was right also about this? Actually I think there were already a lot of clues that relativity was right, so how this is going to change universe observation? and could it take again 30 years to detect some other gravitational wave?

No, the time to discovery was a matter of scientific improvements needed for the sensors. It was in a way inevitable that, if Einstein was right about the gravity waves and wrong about it being impossible to detect them, one day it would be possible to build sensors sensitive enough to detect them. After all, what was discovered was a wobble on the magnitude of a fraction of a proton diameter. And it was measured with some accuracy to be sure it existed and not, like previous assumptions on gravity waves, lost in the SNR.

With the current technology, it is estimated that we could detect 10 black hole mergers per year. That much energy is needed for creating the distortions in space that we can detect now.

In the future, with better sensors, we might detect more events, like rapidly orbiting Neutron stars. maybe even a signature of a star collapse. And the better the detectors will become, the more information of a event could be measured - so more science is possible. It is really revolutionary because it literally gave astronomers a new sense for seeing the universe.

 

[fred18]

I see, so basically it is the technology improvement which is the big leap, not the fact that there actually are gravitational waves, since this was highly probable already.

The conquer is: hey, finally we can build a sensor as sensitive as needed, so from now on we will start to study the result of this new sensor and it will be like having a new type of telescope, that will of course improve in time.

Clear, thanks!

 

[Andy44]

I see, so basically it is the technology improvement which is the big leap, not the fact that there actually are gravitational waves, since this was highly probable already.

The conquer is: hey, finally we can build a sensor as sensitive as needed, so from now on we will start to study the result of this new sensor and it will be like having a new type of telescope, that will of course improve in time.

Clear, thanks!

Not just the technological leap, this is also the first direct confirmation of gravity waves. That's a big achievement in science.

 

[Thunder Chicken]

Wait, shouldn't there be some residual gravitational wave oscillation from the Big Bang? I'd assume the amplitudes would be small and wavelengths very long. If we could see these waves, we could potentially investigate to much earlier times just after the Big Bang. I believe the CMB was "first light" after stable hydrogen formed, but that was thousands of years after the BB. Maybe we could potentially investigate very close in time to the Big Bang, as I'd suppose the wave generation would be greatest closest to the event itself.

Whoa.

 

[Linguofreak]

I see, so basically it is the technology improvement which is the big leap, not the fact that there actually are gravitational waves, since this was highly probable already.

Gravitational waves were already known to exist from indirect evidence. The significance of having detected them directly is several-fold:

1) From how sensitive of a detector we needed, we know something about the distribution of gravitational wave sources in the universe (if there were many sources of mass X within distance Y, we'd have made a detection already).

2) We are now able to investigate how closely general relativity corresponds to reality. Especially significant in the case of this merger is that we now are able to see how general relativity holds up in strong gravitational fields (with escape velocity approaching the sowed of light), whereas all previous data we had was for relatively weak fields.

3) For situations where we use iterative simulations to determine the behavior of general relativity because we don't have exact solutions, we can investigate how closely or simulations correspond to general relativity (assuming it models reality well).

4) If we ever are able to correlate a gravitational wave event with electromagnetic or neutrino observations, we will have another source of data on the event.

 

[Unstung]

Why are gravitational wave detectors best at listening to very specific frequencies?

I can see how finding the deformation caused by gravitational waves would be harder at low frequencies, where it would be challenging to distinguish a long period gravitational wave from noise, but what's with the upper limits? Can't rapid deformation just be observed in higher temporal resolution, like using a high speed camera?

My guess why eLISA is theoretically better at recording lower frequencies is that it's in a (near) frictionless environment, space. It doesn't encounter all the noise sources from being on the surface of Earth. But it should be better than LIGO at recording higher frequencies too.

 

[Col_Klonk]

Why are gravitational wave detectors best at listening to very specific frequencies?

The resonant frequency of the sensor comes into play.

Every physical (and non-physical I'd imagine) device has it's own characteristic frequency (fr) determined by it's dimensions... any vibrations around this fr and the device goes 'bananas'.. or gets 'excited'. If the excitation is too much it can destroy the device (ie.. Rocket engines.. 'wobbly' rocket structures..)

You can still pickup a wide range well outside the resonant frequency with Signal Processing... Naturally the further away the signal is from fr in the spectrum, the more difficult it is.

 

[Artlav]

So, now the real question is:
When are we getting gravity wave communication in our smartphones?

No more cell towers, just talk through the planet!

We need to miniaturize the receiver. I heard of some new type of quantum clock which is tiny, but precise enough to distinguish time dilation from being moved one meter of altitude. Good starting point.

Then, CERN should listen to the conspiracy theorists, and start producing the black holes.
Run an electron gun into one, and you got a charged hole that is easy to contain and vibrate.

Then it's just a matter of putting a black hole into every cellphone.

Place your bets.
I bet it would be within 100 years.

 

[jedidia]

Sounds like an awfull lot of effort just for more convieniently watching pr0n on the go, but I'm sure we'll get there...

 

[Urwumpe]

Sounds like an awfull lot of effort just for more convieniently watching pr0n on the go, but I'm sure we'll get there...

Gravitational wave pr0n... doesn't already exist? Those must be the ones where they are hardly moving at all and just wait for space to contract and expand for doing the work...

 

[Col_Klonk]

So, now the real question is:
When are we getting gravity wave communication in our smartphones?

I've been looking at this feasibility for about 2 years.. and have already worked out a possible means of communication structures.. etc.
..and funny enough it's very simple.. even more so than current cell phone technologies.

Just a matter of putting it together, but have another more important (that is .. not so cracked) project to finish by the end of this year.

If I'm not mistaken, with 'gravity cell phones', it is possible that communication would be nearly instantaneous (ie: faster than light) and ranges well beyond what we have today - I'm sort of hoping it'll be moon distances and beyond. (Scott me up Beamie!!)

I have no means as yet to test this range idea, but can test the comms concept by just making the device.. later though, it's not going to happen in a hurry - maybe it might, or I might now that it's been exposed

---------- Post added at 04:23 PM ---------- Previous post was at 04:09 PM ----------

Gravitational wave pr0n... doesn't already exist?

Well it does.. have you ever been to a 'gentleman's club' ?
:rofl::rofl:

 

[Urwumpe]

Well it does.. have you ever been to a 'gentleman's club' ?
:rofl::rofl:

No. :lol:

I was only responsible for knowing where such clubs are, for making sure that when a stranger is seen crawling towards the base, none of our own officers gets shot.

 

[jedidia]

If I'm not mistaken, with 'gravity cell phones', it is possible that communication would be nearly instantaneous (ie: faster than light)

So that's why my mother called me last week and didn't know about it until yesterday... :shifty:

 

[boogabooga]

If I'm not mistaken, with 'gravity cell phones', it is possible that communication would be nearly instantaneous (ie: faster than light) and ranges well beyond what we have today - I'm sort of hoping it'll be moon distances and beyond. (Scott me up Beamie!!)

How are you getting that? There is every indication that gravity waves travel at (about) the speed of light, but not faster.

Same as radio waves, which already travel at the speed of light.

 

[Unstung]

After reading some of this thread, I have a bit to add.

It is really revolutionary because it literally gave astronomers a new sense for seeing the universe.

Gravitational wave detectors can be used with other telescopes, it's like finding a new part of the spectrum to observe events in different light. Obviously composites can't be made by overlaying gravitational wave data onto Hubble images, but GW observations will help understand astronomical events in new ways. They may discover things that simply cannot be observed by other types of observatories.

Wait, shouldn't there be some residual gravitational wave oscillation from the Big Bang? I'd assume the amplitudes would be small and wavelengths very long. If we could see these waves, we could potentially investigate to much earlier times just after the Big Bang. I believe the CMB was "first light" after stable hydrogen formed, but that was thousands of years after the BB. Maybe we could potentially investigate very close in time to the Big Bang, as I'd suppose the wave generation would be greatest closest to the event itself.

Whoa.

Measuring the polarization of the CMB reveals something about inflation, which happened 380,000 years before recombination. Any details are way over my head.

BICEP may have already made measurements of conditions before recombination, but so could gravitational wave observatories.