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It's pretty incredible to think that we're at a point in human history where we can map 450 million galaxies and probe the origins of the universe

Tepix 2y ago
The Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Survey has recorded more than one billion galaxies. But there are many more galaxies in the observable universe … somewhere between 2 and 20 trillion
- jajko 2y ago
  > But there are many more galaxies in the observable universe … somewhere between 2 and 20 trillion A bit less officially, need to remove one zero [1] [1] https://en.wikipedia.org/wiki/Galaxy#:~:text=It%20is%20estimated%20that%20there,galaxies%20in%20the%20observable%20universe. https://en.wikipedia.org/wiki/Galaxy#:~:text=It%20is%20estim...
  - Tepix 2y ago
    There are more recent estimates going from 6-20 trillion now: https://bigthink.com/starts-with-a-bang/galaxies-in-universe/ https://bigthink.com/starts-with-a-bang/galaxies-in-universe...
    - hnuser123456 2y ago
      That article is going beyond the observable universe, other comments were talking about within it.
      - Tepix 2y ago
        What makes you think that? I quote: > "Instead, based on what we see around nearby Milky Way analogues, there ought to be at least 6 trillion galaxies contained within the observable Universe, and it’s plausible that a number that’s more like ~20 trillion"
- eleveriven 2y ago
  Yeah, the scale of it is absolutely mind-blowing
jimkleiber 2y ago
I feel infinitesimally small.
- igleria 2y ago
  me too, but big things have small beginnings!
- eleveriven 2y ago
  Yeah, same here. It's a humbling feeling... realizing how tiny we are in the grand scheme of things. But also kind of amazing that, despite our smallness, we've figured out how to explore and understand the universe at this scale
JKCalhoun 2y ago
And to think I assumed Astronomy was a stagnant field some decades ago. I have no idea why I thought that. Maybe that optical resolution from ground-based telescopes was not going to advance orders of magnitudes? Maybe I didn't think the sciences would continue to get money for space telescopes?
- DiogenesKynikos 2y ago
  Astronomy has been in a golden age for the last 35 years, based on: 1. Digital cameras, and the computers to analyze images. 2. Space telescopes (Hubble Space Telescope, the first large space telescope, only launched in 1990). 3. The building of massive ground-based telescopes. Before 1990, the largest telescope had a mirror diameter of 6 meters. Now, multiple 30-meter telescopes are under construction. Collecting power goes with the square of the diameter, so this is an increase of 25 times in collecting power! 4. Very recently, the development of gravitational-wave interferometers, which allow astronomers to observe a totally new type of radiation.
  - nuccy 2y ago
    To add to the list (the order is arbitrary): 5. Advances in the multi-messenger observations, where apart of photons and gravitational waves, astronomers can detects also neutrinos with specialized neutrino detectors, e.g.: IceCube [a], though there are many more of those [b]. 6. Advances in very-long-baseline interferometry [c] using a globe-sized array of radio-telescopes, like Event Horizon Telescope [d] [a] https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory [b] https://en.wikipedia.org/wiki/Neutrino_detector https://en.wikipedia.org/wiki/Neutrino_detector or here https://en.wikipedia.org/wiki/List_of_neutrino_experiments https://en.wikipedia.org/wiki/List_of_neutrino_experiments [c] https://en.wikipedia.org/wiki/Very-long-baseline_interferometry https://en.wikipedia.org/wiki/Very-long-baseline_interferome... [d] https://en.wikipedia.org/wiki/Event_Horizon_Telescope https://en.wikipedia.org/wiki/Event_Horizon_Telescope
    - hnuser123456 2y ago

Tepix 2y ago

The Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Survey has recorded more than one billion galaxies. But there are many more galaxies in the observable universe … somewhere between 2 and 20 trillion

jajko 2y ago
> But there are many more galaxies in the observable universe … somewhere between 2 and 20 trillion A bit less officially, need to remove one zero [1] [1] https://en.wikipedia.org/wiki/Galaxy#:~:text=It%20is%20estimated%20that%20there,galaxies%20in%20the%20observable%20universe. https://en.wikipedia.org/wiki/Galaxy#:~:text=It%20is%20estim...
- Tepix 2y ago
  There are more recent estimates going from 6-20 trillion now: https://bigthink.com/starts-with-a-bang/galaxies-in-universe/ https://bigthink.com/starts-with-a-bang/galaxies-in-universe...
  - hnuser123456 2y ago
    That article is going beyond the observable universe, other comments were talking about within it.
    - Tepix 2y ago
      What makes you think that? I quote: > "Instead, based on what we see around nearby Milky Way analogues, there ought to be at least 6 trillion galaxies contained within the observable Universe, and it’s plausible that a number that’s more like ~20 trillion"
eleveriven 2y ago
Yeah, the scale of it is absolutely mind-blowing

jimkleiber 2y ago

I feel infinitesimally small.

igleria 2y ago
me too, but big things have small beginnings!
eleveriven 2y ago
Yeah, same here. It's a humbling feeling... realizing how tiny we are in the grand scheme of things. But also kind of amazing that, despite our smallness, we've figured out how to explore and understand the universe at this scale

JKCalhoun 2y ago

And to think I assumed Astronomy was a stagnant field some decades ago. I have no idea why I thought that. Maybe that optical resolution from ground-based telescopes was not going to advance orders of magnitudes? Maybe I didn't think the sciences would continue to get money for space telescopes?

DiogenesKynikos 2y ago
Astronomy has been in a golden age for the last 35 years, based on: 1. Digital cameras, and the computers to analyze images. 2. Space telescopes (Hubble Space Telescope, the first large space telescope, only launched in 1990). 3. The building of massive ground-based telescopes. Before 1990, the largest telescope had a mirror diameter of 6 meters. Now, multiple 30-meter telescopes are under construction. Collecting power goes with the square of the diameter, so this is an increase of 25 times in collecting power! 4. Very recently, the development of gravitational-wave interferometers, which allow astronomers to observe a totally new type of radiation.
- nuccy 2y ago
  To add to the list (the order is arbitrary): 5. Advances in the multi-messenger observations, where apart of photons and gravitational waves, astronomers can detects also neutrinos with specialized neutrino detectors, e.g.: IceCube [a], though there are many more of those [b]. 6. Advances in very-long-baseline interferometry [c] using a globe-sized array of radio-telescopes, like Event Horizon Telescope [d] [a] https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory [b] https://en.wikipedia.org/wiki/Neutrino_detector https://en.wikipedia.org/wiki/Neutrino_detector or here https://en.wikipedia.org/wiki/List_of_neutrino_experiments https://en.wikipedia.org/wiki/List_of_neutrino_experiments [c] https://en.wikipedia.org/wiki/Very-long-baseline_interferometry https://en.wikipedia.org/wiki/Very-long-baseline_interferome... [d] https://en.wikipedia.org/wiki/Event_Horizon_Telescope https://en.wikipedia.org/wiki/Event_Horizon_Telescope
  - hnuser123456 2y ago