7 ms·

Astronomers make history in a split second with localization of fast radio burst

132 points by Hooke 7y ago

mrybczyn 7y ago
cached: https://webcache.googleusercontent.com/search?q=cache:89RLX_fqiIMJ:https://news.ucsc.edu/2019/06/fast-radio-burst.html+&cd=1&hl=en&ct=clnk&gl=ca https://webcache.googleusercontent.com/search?q=cache:89RLX_...
nisten 7y ago
Galaxy: Honey I'm 3.6 Billion light-years away. Scientist: I'm getting mixed signals I don't know what to do anymore.
SiempreViernes 7y ago
A more interesting account by two of the members of the project that did the novel bit: https://theconversation.com/how-we-closed-in-on-the-location-of-a-fast-radio-burst-in-a-galaxy-far-far-away-119177 https://theconversation.com/how-we-closed-in-on-the-location... Also, the full science paper, might be decent too: https://science.sciencemag.org/content/early/2019/06/26/science.aaw5903 https://science.sciencemag.org/content/early/2019/06/26/scie...
segmondy 7y ago
Amazing engineering
alanning 7y ago
"Since ASKAP is an array of 36 dish antennas and the burst had to travel a slightly different distance to each dish, it reached each one at a slightly different time." “From these tiny time differences—just a fraction of a billionth of a second—we identified the burst’s home galaxy and even its exact starting point..." Simply amazing that they can get such precise measurements from so small a differential in distance.
- BurningFrog 7y ago
  I guess it's like any old heist movie: The key is to synchronize your clocks beforehand!
  - deepsun 7y ago
    Poincare has proven that it's impossible to synchronize clocks exactly
    - fit2rule 7y ago
      By the time you count your clocks, they've gone askew.
- umvi 7y ago
  > Simply amazing that they can get such precise measurements from so small a differential in distance. How do they know the billionths of a second differences aren't due to the radio waves travelling through pockets of air that have slightly different densities/temperatures/moisture/refraction properties? That just seems like incredible error tolerance
  - sixplusone 7y ago
    With 36 antennas it would average out to some extent, but since propagation in air is very near that of vacuum already, I don't think a °C or two makes much of a difference.
  - kawfey 7y ago
    There is a system in place to account for atmospheric effects on radio signals. Here's one example at the Very Large Array, which uses the GPS to measure (via interferometry) and correct for disturbances in the ionosphere: https://www.aanda.org/articles/aa/pdf/2001/06/aa10277.pdf https://www.aanda.org/articles/aa/pdf/2001/06/aa10277.pdf
  - ajford 7y ago
    A lot of the atmospheric affects are on longer timescales than the sampling times, which means they can be calibrated out. Most observations of this nature (interferometric observations) will point at a nearby calibrator source (usually a well characterized quasar or other "point source" star/object), and an atmospheric noise model will then be constructed based on this calibrator to apply to each dish to minimize/account for the atmospheric influence. This is often repeated periodically to account for changing weather over time. And on top of that, a benefit of the location chosen for ASKAP was relatively dry air (being in the western desert climate of Australia).
titzer 7y ago
Amazing they can measure timing differences less than nanoseconds and use them to localize phenomena millions or billions of light years away. And I can't reliably measure whether I made my program 1% faster or not :(
- Cthulhu_ 7y ago
  I bet you could, but you need more measurements and statistical analysis. Keep in mind that a lot of these astrological measurements - and a more notable recent example is the black hole visualization - are not based on direct measurements, but statistical analysis on huge datasets.
  - SiempreViernes 7y ago
    It is spelled > astronomical < measurements, you squidface!
    - gmfawcett 7y ago
      Well, it still stands as written, as long as you're one of those big-data astrology people.
  - T-A 7y ago
    Yep, astrological measurements require data going back all the way to the Sumerians... If you're interested in astronomy, on the other hand, and dealing with a radio burst lasting a millisecond or less, relying on the wisdom of the ancients is not an option. Fortunately enough though, you can go out and by off-the-shelf electronics capable of measuring distances at sub-cm level using the time of flight of photons. If you've ever used a (newer) Kinect, or a RealSense camera, you've already seen it in action: https://www.pocket-lint.com/phones/news/147024-what-is-a-time-of-flight-camera-and-which-phones-have-it https://www.pocket-lint.com/phones/news/147024-what-is-a-tim... https://www.dronezon.com/learn-about-drones-quadcopters/best-uses-for-time-of-flight-tof-camera-depth-sensor-technology-in-drones-or-ground-based/ https://www.dronezon.com/learn-about-drones-quadcopters/best...
danschumann 7y ago
My confirmation bias says it's aliens. Who moved my car keys? Aliens.
- zeofig 7y ago
  Add it to the list. Alienses are here.
- NotTheFBI 7y ago
  I find that to be highly doubtful.
- jimmcslim 7y ago
  If an Albecurrie Drive is feasible, could an FRB be a sign of operation?
  - dylan604 7y ago
    Only if someone was around to hear it
elorant 7y ago
One thing I don't understand from the article is whether they took into consideration galaxy movements. Given that this is a 3.6bn years old signal wouldn't it be safe to assume that the place we can pinpoint now as the originator might not be the same it was back then?
- gilbetron 7y ago
  The radio signal is just as old as the light (both being EM), so they align (more or less).
- sp332 7y ago
  Sure it's moved, but the light from the galaxy arriving now is the same age as the radio burst (they travel at practically the same speed).
perlgeek 7y ago
They made history in a split second, presumably after spending decades on building the infrastructure and gathering all the prerequisite knowledge. The first observed binary black hole merge signal was probably also quite short (I'd wager less than a minute, possibly even less than a second), and many of us have read about how much effort that one took.
joncp 7y ago
This as well as the recent imaging of the M87 black hole are both phenomenal feats of signal processing. Is this the new normal for astronomy?
- petschge 7y ago
  Radio astronomy has always been pushing the frontier of signal processing. Gamma ray telescopes also need large amounts of data crunching. Until recently optical telescope where much more about instrumentation than data processing. But even that is changing, e.g. with small and mid-sized robotic telescopes that automatically search for transients and schedule their own follow-up observations.
imroot 7y ago
This has been happening since 1999 by the NAAPO (the same group who ran the "Big Ear"). They had a cluster of helix antennas being fed into a VA Linux Systems Hardware Cluster doing analysis on radio astronomy events: http://www.naapo.org/Argus/docs/docsmenu.htm http://www.naapo.org/Argus/docs/docsmenu.htm I volunteered there from 2004-2008. I believe that the cluster is still active today.
YeGoblynQueenne 7y ago
That's great news- but I'm confused by the following analogy: >> "It's like looking at the Earth from the Moon and not only knowing what house a person lived in, but what chair they were sitting in at the dining room table," Bannister said. What are chairs and dining room tables by analogy to galaxies and in the context of fast radio bursts? Could someone please clarify?
- Zoo3y 7y ago
  Further in the article they mentioned telescopes have to be placed certain distances apart to calculate differences in radio wave arrival by billionths of a second. These differences gives them granular placement within the galaxy (I'm assuming the analogy is referring to arms, stars, planets, etc.)

132 points by Hooke 7y ago

cached: https://webcache.googleusercontent.com/search?q=cache:89RLX_fqiIMJ:https://news.ucsc.edu/2019/06/fast-radio-burst.html+&cd=1&hl=en&ct=clnk&gl=ca https://webcache.googleusercontent.com/search?q=cache:89RLX_...

nisten 7y ago

Galaxy: Honey I'm 3.6 Billion light-years away. Scientist: I'm getting mixed signals I don't know what to do anymore.

SiempreViernes 7y ago

A more interesting account by two of the members of the project that did the novel bit: https://theconversation.com/how-we-closed-in-on-the-location-of-a-fast-radio-burst-in-a-galaxy-far-far-away-119177 https://theconversation.com/how-we-closed-in-on-the-location... Also, the full science paper, might be decent too: https://science.sciencemag.org/content/early/2019/06/26/science.aaw5903 https://science.sciencemag.org/content/early/2019/06/26/scie...

segmondy 7y ago

Amazing engineering

alanning 7y ago

"Since ASKAP is an array of 36 dish antennas and the burst had to travel a slightly different distance to each dish, it reached each one at a slightly different time." “From these tiny time differences—just a fraction of a billionth of a second—we identified the burst’s home galaxy and even its exact starting point..." Simply amazing that they can get such precise measurements from so small a differential in distance.

BurningFrog 7y ago
I guess it's like any old heist movie: The key is to synchronize your clocks beforehand!
- deepsun 7y ago
  Poincare has proven that it's impossible to synchronize clocks exactly
  - fit2rule 7y ago
    By the time you count your clocks, they've gone askew.
umvi 7y ago
> Simply amazing that they can get such precise measurements from so small a differential in distance. How do they know the billionths of a second differences aren't due to the radio waves travelling through pockets of air that have slightly different densities/temperatures/moisture/refraction properties? That just seems like incredible error tolerance
- sixplusone 7y ago
  With 36 antennas it would average out to some extent, but since propagation in air is very near that of vacuum already, I don't think a °C or two makes much of a difference.
- kawfey 7y ago
  There is a system in place to account for atmospheric effects on radio signals. Here's one example at the Very Large Array, which uses the GPS to measure (via interferometry) and correct for disturbances in the ionosphere: https://www.aanda.org/articles/aa/pdf/2001/06/aa10277.pdf https://www.aanda.org/articles/aa/pdf/2001/06/aa10277.pdf
- ajford 7y ago
  A lot of the atmospheric affects are on longer timescales than the sampling times, which means they can be calibrated out. Most observations of this nature (interferometric observations) will point at a nearby calibrator source (usually a well characterized quasar or other "point source" star/object), and an atmospheric noise model will then be constructed based on this calibrator to apply to each dish to minimize/account for the atmospheric influence. This is often repeated periodically to account for changing weather over time. And on top of that, a benefit of the location chosen for ASKAP was relatively dry air (being in the western desert climate of Australia).

titzer 7y ago

Amazing they can measure timing differences less than nanoseconds and use them to localize phenomena millions or billions of light years away. And I can't reliably measure whether I made my program 1% faster or not :(

Cthulhu_ 7y ago
I bet you could, but you need more measurements and statistical analysis. Keep in mind that a lot of these astrological measurements - and a more notable recent example is the black hole visualization - are not based on direct measurements, but statistical analysis on huge datasets.
- SiempreViernes 7y ago
  It is spelled > astronomical < measurements, you squidface!
  - gmfawcett 7y ago
    Well, it still stands as written, as long as you're one of those big-data astrology people.
- T-A 7y ago
  Yep, astrological measurements require data going back all the way to the Sumerians... If you're interested in astronomy, on the other hand, and dealing with a radio burst lasting a millisecond or less, relying on the wisdom of the ancients is not an option. Fortunately enough though, you can go out and by off-the-shelf electronics capable of measuring distances at sub-cm level using the time of flight of photons. If you've ever used a (newer) Kinect, or a RealSense camera, you've already seen it in action: https://www.pocket-lint.com/phones/news/147024-what-is-a-time-of-flight-camera-and-which-phones-have-it https://www.pocket-lint.com/phones/news/147024-what-is-a-tim... https://www.dronezon.com/learn-about-drones-quadcopters/best-uses-for-time-of-flight-tof-camera-depth-sensor-technology-in-drones-or-ground-based/ https://www.dronezon.com/learn-about-drones-quadcopters/best...

danschumann 7y ago

My confirmation bias says it's aliens. Who moved my car keys? Aliens.

zeofig 7y ago
Add it to the list. Alienses are here.
NotTheFBI 7y ago
I find that to be highly doubtful.
jimmcslim 7y ago
If an Albecurrie Drive is feasible, could an FRB be a sign of operation?
- dylan604 7y ago
  Only if someone was around to hear it

elorant 7y ago

One thing I don't understand from the article is whether they took into consideration galaxy movements. Given that this is a 3.6bn years old signal wouldn't it be safe to assume that the place we can pinpoint now as the originator might not be the same it was back then?

gilbetron 7y ago
The radio signal is just as old as the light (both being EM), so they align (more or less).
sp332 7y ago
Sure it's moved, but the light from the galaxy arriving now is the same age as the radio burst (they travel at practically the same speed).

perlgeek 7y ago

They made history in a split second, presumably after spending decades on building the infrastructure and gathering all the prerequisite knowledge. The first observed binary black hole merge signal was probably also quite short (I'd wager less than a minute, possibly even less than a second), and many of us have read about how much effort that one took.

joncp 7y ago

This as well as the recent imaging of the M87 black hole are both phenomenal feats of signal processing. Is this the new normal for astronomy?

petschge 7y ago
Radio astronomy has always been pushing the frontier of signal processing. Gamma ray telescopes also need large amounts of data crunching. Until recently optical telescope where much more about instrumentation than data processing. But even that is changing, e.g. with small and mid-sized robotic telescopes that automatically search for transients and schedule their own follow-up observations.

imroot 7y ago

This has been happening since 1999 by the NAAPO (the same group who ran the "Big Ear"). They had a cluster of helix antennas being fed into a VA Linux Systems Hardware Cluster doing analysis on radio astronomy events: http://www.naapo.org/Argus/docs/docsmenu.htm http://www.naapo.org/Argus/docs/docsmenu.htm I volunteered there from 2004-2008. I believe that the cluster is still active today.

YeGoblynQueenne 7y ago

That's great news- but I'm confused by the following analogy: >> "It's like looking at the Earth from the Moon and not only knowing what house a person lived in, but what chair they were sitting in at the dining room table," Bannister said. What are chairs and dining room tables by analogy to galaxies and in the context of fast radio bursts? Could someone please clarify?

Zoo3y 7y ago
Further in the article they mentioned telescopes have to be placed certain distances apart to calculate differences in radio wave arrival by billionths of a second. These differences gives them granular placement within the galaxy (I'm assuming the analogy is referring to arms, stars, planets, etc.)