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Astrophysicists Use Apollo Seismic Array To Hunt For Gravitational Waves

Posted by Soulskill on from the where-in-the-moon-is-carmen-sandiego dept.

KentuckyFC writes: Back in the 1970s, the astronauts from Apollos 12, 14, 15, and 16 set up an array of seismometers on the lunar surface to listen for moonquakes. This array sent back data until 1977, when NASA switched it off. Now astrophysicists are using this lunar seismic data in the hunt for gravitational waves. The idea is that gravitational waves must squeeze and stretch the Moon as they pass by and that at certain resonant frequencies, this could trigger the kind of seismic groans that the array ought to have picked up. However, the data shows no evidence of activity at the relevant frequencies.

That's important because it has allowed astronomers to put the strongest limits yet on the strength of gravitational waves in this part of the universe. Earlier this year, the same team used a similar approach with terrestrial seismic data to strengthen the existing limits by 9 orders of magnitude. The lunar data betters this by yet another order of magnitude because there is no noise from sources such as oceans, the atmosphere and plate tectonics. The work shows that good science on gravitational waves can be done without spending the hundreds of millions of dollars for bespoke gravitational wave detectors, such as LIGO, which have yet to find any evidence of the waves either.

25 comments

  1. Gravity Waves of Unusual Size? by Mr+Z · · Score: 4, Funny

    I doubt they exist.

    --
    Program Intellivision!
    1. Re:Gravity Waves of Unusual Size? by Anonymous Coward · · Score: 0

      You haven't met my mother-in-law.

    2. Re:Gravity Waves of Unusual Size? by Steve1952 · · Score: 2

      You mean the G. W. O. U. S's? You keep using that word. I do not think it means what you think it means.

    3. Re:Gravity Waves of Unusual Size? by Em+Adespoton · · Score: 1

      You mean the G. W. O. U. S's? You keep using that word. I do not think it means what you think it means.

      Inconceivable.

    4. Re:Gravity Waves of Unusual Size? by K.+S.+Kyosuke · · Score: 2

      How I Gravimetrically Deduced The Existence of Your Mother-in-law...? As far as names for TV shows go, one could do even worse.

      --
      Ezekiel 23:20
    5. Re:Gravity Waves of Unusual Size? by wonkey_monkey · · Score: 1

      Mostly dead.

      And so on.

      --
      systemd is Roko's Basilisk.
  2. Gratuitous LIGO Slam by PvtVoid · · Score: 5, Insightful

    The work shows that good science on gravitational waves can be done without spending the hundreds of millions of dollars for bespoke gravitational wave detectors, such as LIGO, which have yet to find any evidence of the waves either.

    Do you mean aside from the cost of putting seismometers on the moon in the first place?

    The experiment referenced is a fabulously clever re-use of existing data, but it has nothing whatsoever to say about the funding case for LIGO. LIGO, like many cutting-edge experiments, requires very long-term technology development before it can produce a positive result. Some science requires long-term thinking, not just until the next quarter or the next election cycle.

    1. Re:Gratuitous LIGO Slam by Idarubicin · · Score: 2

      The experiment referenced is a fabulously clever re-use of existing data, but it has nothing whatsoever to say about the funding case for LIGO. LIGO, like many cutting-edge experiments, requires very long-term technology development before it can produce a positive result. Some science requires long-term thinking, not just until the next quarter or the next election cycle.

      Indeed. One wonders what remarkable scientific discoveries and conclusions will result from creative analysis of today's data, forty years hence.

      ...At least, as long as we actually do continue to fund new instruments and research, and don't insist that all data collection is now 'done', and that all the work that remains is winnowing smaller and smaller pieces of useful information from the last century's scientific output.

      --
      ~Idarubicin
    2. Re:Gratuitous LIGO Slam by amorsen · · Score: 1

      One of the challenges is that there is just so much data from modern experiments. E.g. the LHC throws a lot of irrelevant data away before it even hits the hard drives. To a layman like me it seems likely that some potentially useful data gets thrown away in this process.

      You cannot fault the LHC designers for doing this; the data handling and storage there is awe-inducing. Transporting and storing orders of magnitude of (probably useless) more data is just not feasible.

      --
      Finally! A year of moderation! Ready for 2019?
    3. Re:Gratuitous LIGO Slam by Anonymous Coward · · Score: 1

      To a layman like me it seems likely that some potentially useful data gets thrown away in this process.

      They keep a fraction of data randomly, with no filtering, in case their filtering algorithm has a bias or mistake that they missed. While ideally it would let them figure that out in the short run and change the filtering algorithm, in the long run the data is still there. Statistics won't be as great as if they kept all data, but it would still be something.

    4. Re:Gratuitous LIGO Slam by Anonymous Coward · · Score: 0, Troll

      Wouldn't you like as a PhD student to dream up some idea that sounds plausible and have job security the rest of your life to hunt it down especially in this time of so many layoffs? That is what is wrong with science.

      Yes, I am posting anonymous, because I know this will get modded to -10 by all the people here that have read something out of a school book that was originally printed more than 100 years ago. And not a one of them modding me down has done any study on gravity.

      Gravity is not a wave. There are no gravity waves. Gravity is not a particle either. Gravitons are something someone drempt up in order to do a thesis and pretend he knew something.

      I would love to get paid the rest of my life to hunt down and do experiments to find gravity waves too. It's not going to happen.

    5. Re:Gratuitous LIGO Slam by Anonymous Coward · · Score: 1

      have job security the rest of your life to hunt it down especially in this time of so many layoffs? That is what is wrong with science.

      Which is why only one in ten of my classmates in physics grad school managed to keep a job in academia. Many left because they couldn't get a new job after their contract ran out, others quit when their project got canceled mid-stream (i.e. laid off). Yet more left when they stared a family, because they wanted more stability of income by going into industry work.

      all the people here that have read something out of a school book that was originally printed more than 100 years ago

      If you know of a textbook that covers general relativity from more than 100 years ago today, do tell considering it was mainly published about 99 years ago, with a lot of important results to come later.

      And not a one of them modding me down has done any study on gravity.

      If not studying gravity doesn't stop you from posting about it, it shouldn't stop others from modding it. I guess technically I only studied it in grad-school and wrote a couple papers on the topic before changing tracks to a more engineering heavy position in a another subfield of physics, but that doesn't actually seem applicable considering the lack of any actual argument or content about gravity in your post.

    6. Re:Gratuitous LIGO Slam by RockDoctor · · Score: 2

      Do you mean aside from the cost of putting seismometers on the moon in the first place?

      The seismographs were a piggy-back on what was essentially a political project.

      Getting unexpected results like this out of data such as a seismograph simply means that any piece of hardware that lands on another planet, moon or comet will have what seismographic equipment put on board that the weight (and/ or data transmission) budget can support without busting anything else. Data links and relays would be additional hardware to put on such jettisoned hardware.

      --
      Birds are not dinosaur descendants;birds are dinosaurs, for all useful meanings of "birds", "are" and "dinosaurs"
    7. Re:Gratuitous LIGO Slam by stoatwblr · · Score: 3, Interesting

      "One wonders what remarkable scientific discoveries and conclusions will result from creative analysis of today's data, forty years hence."

      None whatsoever if the data isn't curated.

      One of my constant battles is to get resources to retain data from old space missions. They're flagwaving missions first and scientific expeditions second, which means there's very little interest in keeping record around for prolonged periods.

      That's DESPITE pointing out that if the raw data for NOAA satellites hadn't been kept, it would have been impossible to use them to confirm the existance and development of the ozone hole, simply because the processing system discarded low data values as "equipment error" - which added 20 years to the discovery of the thing in the first place.

  3. Lunar resonance can be quite sensitive. by queazocotal · · Score: 4, Insightful

    But only at specific resonant frequencies.
    LIGO is in principle sensitive to very different frequencies of gravity waves.

  4. Good science, me too! by Lije+Baley · · Score: 2

    My experiments with a laser pointer and a moldy old potato have clearly established that gravitational waves are not strong enough to affect it.

    --
    Strange things are afoot at the Circle-K.
    1. Re:Good science, me too! by bytesex · · Score: 1

      Yes but have you tried the resonant frequencies?

      --
      Religion is what happens when nature strikes and groupthink goes wrong.
  5. This was attempted in the 1970s by rotenberry · · Score: 4, Informative

    The idea of using Lunar Seismic activilty to measure gravitational radiation dates back to the 1970s.

    http://en.wikipedia.org/wiki/A...

    In particular, consider the purpose of the Lunar Surface Gravimeter (LSG).

  6. Re:Danger To Our Biosphere by itzly · · Score: 1

    It's fun ?

  7. Yeah? by Anonymous Coward · · Score: 0

    Well YOUR MOM makes gravity waves of unusual size!

    Bazinga!

  8. Re:Danger To Our Biosphere by Anonymous Coward · · Score: 0

    "Look at me still talking when there's science to do.
    When I look out there it makes me GLaD I'm not you.
    I've experiments to run there is research to be done
    On the people who are still alive"

    --Still alive, by Jonathan Coulton.

  9. Had to read the whole damn article to find out by JasonGoatcher · · Score: 0

    The range that gravity waves could still exist in is 0.1Hz to 1Hz. (It's at the very end of the first link in the summary)