To add on to your “with telescope” numbers, the number you can see with the naked eye is surprisingly small. If you are out on a clear night, you can pretty much only see stars within the milky way, and even then you’re talking the ballpark of 5000. If you’re naming them and counting them on all sides of the earth (not just those visible from your one location) you can double that if you have great eyes.
DomeGuy@lemmy.world 1 week ago
The whole universe? Absolutely. Even the smallwst infinity is larger than any countable sum.
The visible universe, meaning those close enough that a photon could have passed from there to here since the “big bang” faded enough to allow such transmissal? I don’t know offhand.
A simple web search suggest that our galaxy has less than 10^11^ stars – 400,000,000,000 or so. ( en.wikipedia.org/wiki/Milky_Way )
Finding our other figure is a bit harder, since trusty Wikipedia doesn’t include a direct figure and the first few articles I could find was from the BBC and used number names instead of scientific notation, which is ambiguous at this scale. ( in the long scale we only have milliardaires, and Elon Musk’s brief paper fortune was a billion rather than trillion.)
Thankfully a NASA articke linked to what appears to be the underlying research paper, and gives us a helpful number of 2x10^12^. (2,000,000,000,000)
…nasa.gov/…/STScI-01EVSR313NHNAC17DF62MP9QV9.pdf
So, if the paper is right then, yes, there are more galaxies in the observable universe than stars in the Milky Way. But, the paper was an indirect measurement that increased the galaxy count by a whole order of magnitude, so there may be only 2x10^11^ galaxies. Except, of course, that the estimate of stars in the miky way was an estimate and could be as little as 1/4 of the number I cited above…
And if the paper is wrong and the truth of the estimate is in the middle, both of our numbers could be 2x10^11^, with approximately one star in our galaxy for every galaxy in the observable universe.
Dave@lemmy.nz 1 week ago
AwesomeLowlander@sh.itjust.works 1 week ago
The whole universe? Absolutely. Even the smallwst infinity is larger than any countable sum.
Sorry, I don’t understand. Surely the number of galaxies is not infinite?
rockerface@lemmy.cafe 1 week ago
For us, it might as well be. Infinity, zero, any other value. We can’t measure what’s outside of the observable universe, by definition, so we can’t confirm any theories with an experiment.
DomeGuy@lemmy.world 1 week ago
Our models do not specify a shape for the universe, because we have not seen any evidence for a spatial (as opposed to temporal) limit to how big the universe is.
In fact, we infer that since what we can see becomes homogenous on a surprisingly small scale, the whole infinite universe is similarly filled with galactic clusters, and thus there is an (unreachable) infinite number of galaxies.
This quickly gets into the weeds of “can we even say trees fall in the forests of planets no humans will ever observe”, possibly followed by an argument over if infinites are equal or comparable.
ash@piefed.ca 1 week ago
Just a small addition if you don’t mind—we don’t know whether the universe is finite or infinite. Intuitively, I prefer a finite universe because I can’t wrap my head around actual infinities.
Locally flat or curved regions are possible in both cases.