5 ms·

This is just mind-blowing - what a time to be alive!

by danparsonson 3y ago

SoKamil 3y ago
I read it with the voice of Károly Zsolnai-Fehér
- not_your_mentat 3y ago
  Hold onto your papers!
- 29athrowaway 3y ago
  That man needs a voice coach.
BiteCode_dev 3y ago
Can you ELI5 why the fact we have evidence of Hellings and Downs correlations is mind-blowing?
- danparsonson 3y ago
  I was referring more to the measurement of slight variations in pulsar frequencies across decades used to detect background gravitation waves - I'm afraid I have no context besides this article to ELY5 the science they're trying to prove.
- nonameiguess 3y ago
  I would agree with the other comment that the fact we can measure gravitational waves at all using pulsar timing with data collected over decades is what is mind-blowing, more than the actual waves being detected. However, depending on their nature, there is a possibility that this is still a pretty significant event. When we observed the cosmic microwave background, because this is light emanating from everywhere at the very first time photons decoupled from ionized matter and the mean free path exceeded the particle horizon (the universe "became transparent" as they say), this is the furthest back you ever see using light. A much earlier event can possibly be observed via the cosmic neutrino background. The universe would have been transparent to neutrinos much earlier, when the electroweak force first decayed into the weak and electromagnetic forces. This is a big difference, fractional seconds after the Big Bang compared to I think 379,000 years or so for light. However, the very earliest event that could ever be observed by any means at all would be the cosmic gravitational background expected to exist when gravity first decoupled from strong and electroweak forces. If that's what this is, we're not seeing the literal beginning, but it's the closest we can ever get by any sensor we currently have the ability to conceive of.
  - dredmorbius 3y ago
    One lesson from the history of science is that new developments in detection and sensing capabilities often herald tremendous increases in knowledge. Lenses, and the telescope and microscope, both advanced astronomy and biology tremendously. Interferometry grows out of optics, spectroscopy, and the ability to detect interference at scales. Chemical tests, electromagnetic principles, radiation, and the ability to detect electromagnetic radiation outside the visible spectrum (infrared, radio, ultraviolet, x-ray, gamma ray) had similarly large influences. Another area of progress is increased precision in measuring both space and time, which this discovery addresses. I've also done some fairly casual eyeball-assessments of trends in Nobel-awarded research in physics and chemistry since roughly 1960, which is a convenient demarcation between the period of profound discovery through the earlier part of the 20th century, with fundamental laws and particles making frequent mention, to the past 60 or so years in which it's often been measurement or emission capabilities (think LIGO and blue LEDs) which have been the subject of awards. In one sense, these seem less significant than the earlier work, and that's been my own tendency in ascribing heft. But if this does in fact represent a gestation period in which new observational tools and techniques are being cultivated, there might well be more impact than appears initially. We're in what may well be the early stages of gravitational wave measurement and detection, and we're figuring out how to "build" galactic-- and intergalactic-scale measurement "devices" which are necessary to detect this pervasive but very low-energy effect. It is exciting, and I'm thinking over the past record of sensing technologies to think how these might inform us. My initial read is that gravitational waves are very low frequency, which is to say, low resolution, but because they have extraordinarily high upper bounds on magnitude (unlike, say, magnetic or electromagnetic events associated with stars, galaxies, and even black-hole and neutron-star interactions, though the latter play a strong role in gravitational wave phenomena), what I suspect we'll find is a general sensing capability which can "see through" cosmic structures that are otherwise opaque to us (gravity isn't bothered by dust and other matter), and also provides a mechanism for directly observing dark matter, which is defined by the fact that it does interact gravitationally but does not with the electromagnetic spectrum. That's a lay view, no specific expertise, but informed by a model of technologies and capabilities afforded, one element of which is information, itself comprised of sensing, processing, storage and recall, and transmission.
  - 3y ago

This is just mind-blowing - what a time to be alive!

SoKamil 3y ago

I read it with the voice of Károly Zsolnai-Fehér

not_your_mentat 3y ago
Hold onto your papers!
29athrowaway 3y ago
That man needs a voice coach.

BiteCode_dev 3y ago

Can you ELI5 why the fact we have evidence of Hellings and Downs correlations is mind-blowing?

danparsonson 3y ago
I was referring more to the measurement of slight variations in pulsar frequencies across decades used to detect background gravitation waves - I'm afraid I have no context besides this article to ELY5 the science they're trying to prove.
nonameiguess 3y ago
I would agree with the other comment that the fact we can measure gravitational waves at all using pulsar timing with data collected over decades is what is mind-blowing, more than the actual waves being detected. However, depending on their nature, there is a possibility that this is still a pretty significant event. When we observed the cosmic microwave background, because this is light emanating from everywhere at the very first time photons decoupled from ionized matter and the mean free path exceeded the particle horizon (the universe "became transparent" as they say), this is the furthest back you ever see using light. A much earlier event can possibly be observed via the cosmic neutrino background. The universe would have been transparent to neutrinos much earlier, when the electroweak force first decayed into the weak and electromagnetic forces. This is a big difference, fractional seconds after the Big Bang compared to I think 379,000 years or so for light. However, the very earliest event that could ever be observed by any means at all would be the cosmic gravitational background expected to exist when gravity first decoupled from strong and electroweak forces. If that's what this is, we're not seeing the literal beginning, but it's the closest we can ever get by any sensor we currently have the ability to conceive of.
- dredmorbius 3y ago
  One lesson from the history of science is that new developments in detection and sensing capabilities often herald tremendous increases in knowledge. Lenses, and the telescope and microscope, both advanced astronomy and biology tremendously. Interferometry grows out of optics, spectroscopy, and the ability to detect interference at scales. Chemical tests, electromagnetic principles, radiation, and the ability to detect electromagnetic radiation outside the visible spectrum (infrared, radio, ultraviolet, x-ray, gamma ray) had similarly large influences. Another area of progress is increased precision in measuring both space and time, which this discovery addresses. I've also done some fairly casual eyeball-assessments of trends in Nobel-awarded research in physics and chemistry since roughly 1960, which is a convenient demarcation between the period of profound discovery through the earlier part of the 20th century, with fundamental laws and particles making frequent mention, to the past 60 or so years in which it's often been measurement or emission capabilities (think LIGO and blue LEDs) which have been the subject of awards. In one sense, these seem less significant than the earlier work, and that's been my own tendency in ascribing heft. But if this does in fact represent a gestation period in which new observational tools and techniques are being cultivated, there might well be more impact than appears initially. We're in what may well be the early stages of gravitational wave measurement and detection, and we're figuring out how to "build" galactic-- and intergalactic-scale measurement "devices" which are necessary to detect this pervasive but very low-energy effect. It is exciting, and I'm thinking over the past record of sensing technologies to think how these might inform us. My initial read is that gravitational waves are very low frequency, which is to say, low resolution, but because they have extraordinarily high upper bounds on magnitude (unlike, say, magnetic or electromagnetic events associated with stars, galaxies, and even black-hole and neutron-star interactions, though the latter play a strong role in gravitational wave phenomena), what I suspect we'll find is a general sensing capability which can "see through" cosmic structures that are otherwise opaque to us (gravity isn't bothered by dust and other matter), and also provides a mechanism for directly observing dark matter, which is defined by the fact that it does interact gravitationally but does not with the electromagnetic spectrum. That's a lay view, no specific expertise, but informed by a model of technologies and capabilities afforded, one element of which is information, itself comprised of sensing, processing, storage and recall, and transmission.
- 3y ago