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> The one billion to be catalogued by Gaia is still only 1% of the Milky Way's total I mean, wow. We are so tiny. > The called-for specification was to get to

> The one billion to be catalogued by Gaia is still only 1% of the Milky Way's total I mean, wow. We are so tiny. > The called-for specification was to get to know the brightest objects' coordinates down to an error of just seven micro-arcseconds. This angle is equivalent to the size of a euro coin on the Moon as seen from Earth. This is quite an impressive feat of engineering!

overcast 10y ago
It's amazing, and completely depressing at the same time. 1% of the stars in 0.00000000001% of all galaxies. Totally out there thought of the day. I'm hoping some day my atoms are reformed into another human in the much distant future, where we are technologically advanced to get something meaningful out of all of it.
- acqq 10y ago
  Why don't you see that it's meaningful now? We didn't know about the galaxies only some 100 years ago. Now we know a lot even about how the universe started, read as an example, we will never see most of the first 500 million years, except on some places where the reionization process ended sooner: https://medium.com/starts-with-a-bang/why-hubble-will-never-see-the-first-stars-69bbe535a755 https://medium.com/starts-with-a-bang/why-hubble-will-never-... But we already see in the past all the billions of years: the further the object from us, the older is what we see. And we see the glow of the Big Bang. In the distant future, much less will be observable. https://medium.com/starts-with-a-bang/throw-forward-thursday-where-will-we-be-in-100-billion-years-39b3f3078379 https://medium.com/starts-with-a-bang/throw-forward-thursday... "Instead of clusters and superclusters of galaxies, there will be… nothing. Dark energy will take care of that, driving all the other galaxies in the Universe, everything that isn’t bound to our local group, our beyond our visible horizon. Even the closest galaxies to us beyond the local group, like the Virgo Cluster, the Leo triplet, and even the extremely nearby M81 group will have redded out, and will leave no measurable signature behind." "Even the leftover glow from the Big Bang would be undetectable! What appears now as a 2.725 Kelvin afterglow, with a relatively dense 411 photons-per-cubic centimeter, will look nothing like that 100 billion years from now."
  - overcast 10y ago
    Unfortunately the distance to even the nearest stars, makes travel to them unrealistic in any of our lifetimes. Sure we're getting new observational knowledge, but it's still depressing to think about the scale of the universe.
    - Razengan 10y ago
      It would be a lot more depressing if we had already found all there was to find and knew there wasn't anything more...
      - overcast 10y ago
        Considering the Universe is debatably infinite. I don't think we have to worry about that scenario.
      - acqq 10y ago
        There are known limits, "the Limits Of How Far Humanity Can Go In The Universe" no matter which technologies it possesses: https://medium.com/starts-with-a-bang/the-limits-of-how-far-humanity-can-go-in-the-universe-b5717808737e https://medium.com/starts-with-a-bang/the-limits-of-how-far-... https://www.youtube.com/watch?v=ZL4yYHdDSWs https://www.youtube.com/watch?v=ZL4yYHdDSWs "Appreciate the view we have today; it’s the greatest one any living creature will ever have of our Universe, exactly as it is."
  - astazangasta 10y ago
    This isn't new, either. In the early Iron Age we knew a lot about how the universe started, "B'reshit bara elohim..."
pmoriarty 10y ago
And there are more galaxies in the known universe then there are stars in our galaxy.
- okket 10y ago
  Yes, there may be more galaxies than stars in our milky way. But almost all of them are extremely far away and we will never have a chance to interact, or even visit them. Worse, the rate they are moving away from our galaxy/local cluster is accelerating. We have a bit time to study those galaxies before they fade into the eternal redshift, but the real interesting stuff, what at least has a decent chance to matter beyond pure curiosity is what Gaia observes.
  - jobigoud 10y ago
    > We have a bit time to study those galaxies before they fade into the eternal redshift Just want to point that we do receive light from galaxies that are receding from us faster than the speed of light and always have been.
    - okket 10y ago
      Until they are so far redshifted that they fade into background noise. And the expansion of the universe is accelerating. We have a bit time to watch this spectacle, but the fate seems it is just our local cluster that will matter, for most of the time while stars generate heat. That is why I am not so keen on emphasising the billions and billions of galaxies. It's only a nice good-bye firework. Edit: I still think there are much more galaxies in our universe than stars in our milky way: The universe must be bigger than our observable part and there is no reason to believe that it is much different there (read less or no galaxies) than where we happen to be. So the "eternal redshift" already happened for many galaxies (from mutual perspective).
- dalke 10y ago
  The number of stars in the Milky Way galaxy is about as the same as the number of galaxies - 1e11 to 1e12: http://www.esa.int/Our_Activities/Space_Science/Herschel/How_many_stars_are_there_in_the_Universe http://www.esa.int/Our_Activities/Space_Science/Herschel/How... . Double-checking: https://en.wikipedia.org/wiki/Milky_Way https://en.wikipedia.org/wiki/Milky_Way says 2.5e11 ±1.5e11 stars in the Milky Way. https://en.wikipedia.org/wiki/Galaxy https://en.wikipedia.org/wiki/Galaxy says about 1.25e11 galaxies in the observable universe. That's nearly a mole of stars in total.

overcast 10y ago

It's amazing, and completely depressing at the same time. 1% of the stars in 0.00000000001% of all galaxies. Totally out there thought of the day. I'm hoping some day my atoms are reformed into another human in the much distant future, where we are technologically advanced to get something meaningful out of all of it.

acqq 10y ago
Why don't you see that it's meaningful now? We didn't know about the galaxies only some 100 years ago. Now we know a lot even about how the universe started, read as an example, we will never see most of the first 500 million years, except on some places where the reionization process ended sooner: https://medium.com/starts-with-a-bang/why-hubble-will-never-see-the-first-stars-69bbe535a755 https://medium.com/starts-with-a-bang/why-hubble-will-never-... But we already see in the past all the billions of years: the further the object from us, the older is what we see. And we see the glow of the Big Bang. In the distant future, much less will be observable. https://medium.com/starts-with-a-bang/throw-forward-thursday-where-will-we-be-in-100-billion-years-39b3f3078379 https://medium.com/starts-with-a-bang/throw-forward-thursday... "Instead of clusters and superclusters of galaxies, there will be… nothing. Dark energy will take care of that, driving all the other galaxies in the Universe, everything that isn’t bound to our local group, our beyond our visible horizon. Even the closest galaxies to us beyond the local group, like the Virgo Cluster, the Leo triplet, and even the extremely nearby M81 group will have redded out, and will leave no measurable signature behind." "Even the leftover glow from the Big Bang would be undetectable! What appears now as a 2.725 Kelvin afterglow, with a relatively dense 411 photons-per-cubic centimeter, will look nothing like that 100 billion years from now."
- overcast 10y ago
  Unfortunately the distance to even the nearest stars, makes travel to them unrealistic in any of our lifetimes. Sure we're getting new observational knowledge, but it's still depressing to think about the scale of the universe.
  - Razengan 10y ago
    It would be a lot more depressing if we had already found all there was to find and knew there wasn't anything more...
    - overcast 10y ago
      Considering the Universe is debatably infinite. I don't think we have to worry about that scenario.
    - acqq 10y ago
      There are known limits, "the Limits Of How Far Humanity Can Go In The Universe" no matter which technologies it possesses: https://medium.com/starts-with-a-bang/the-limits-of-how-far-humanity-can-go-in-the-universe-b5717808737e https://medium.com/starts-with-a-bang/the-limits-of-how-far-... https://www.youtube.com/watch?v=ZL4yYHdDSWs https://www.youtube.com/watch?v=ZL4yYHdDSWs "Appreciate the view we have today; it’s the greatest one any living creature will ever have of our Universe, exactly as it is."
- astazangasta 10y ago
  This isn't new, either. In the early Iron Age we knew a lot about how the universe started, "B'reshit bara elohim..."

pmoriarty 10y ago

And there are more galaxies in the known universe then there are stars in our galaxy.

okket 10y ago
Yes, there may be more galaxies than stars in our milky way. But almost all of them are extremely far away and we will never have a chance to interact, or even visit them. Worse, the rate they are moving away from our galaxy/local cluster is accelerating. We have a bit time to study those galaxies before they fade into the eternal redshift, but the real interesting stuff, what at least has a decent chance to matter beyond pure curiosity is what Gaia observes.
- jobigoud 10y ago
  > We have a bit time to study those galaxies before they fade into the eternal redshift Just want to point that we do receive light from galaxies that are receding from us faster than the speed of light and always have been.
  - okket 10y ago
    Until they are so far redshifted that they fade into background noise. And the expansion of the universe is accelerating. We have a bit time to watch this spectacle, but the fate seems it is just our local cluster that will matter, for most of the time while stars generate heat. That is why I am not so keen on emphasising the billions and billions of galaxies. It's only a nice good-bye firework. Edit: I still think there are much more galaxies in our universe than stars in our milky way: The universe must be bigger than our observable part and there is no reason to believe that it is much different there (read less or no galaxies) than where we happen to be. So the "eternal redshift" already happened for many galaxies (from mutual perspective).
dalke 10y ago
The number of stars in the Milky Way galaxy is about as the same as the number of galaxies - 1e11 to 1e12: http://www.esa.int/Our_Activities/Space_Science/Herschel/How_many_stars_are_there_in_the_Universe http://www.esa.int/Our_Activities/Space_Science/Herschel/How... . Double-checking: https://en.wikipedia.org/wiki/Milky_Way https://en.wikipedia.org/wiki/Milky_Way says 2.5e11 ±1.5e11 stars in the Milky Way. https://en.wikipedia.org/wiki/Galaxy https://en.wikipedia.org/wiki/Galaxy says about 1.25e11 galaxies in the observable universe. That's nearly a mole of stars in total.