You and I are in the above photos from today’s Astronomy Picture of the Day which shows Earth from a distance that provides perspective. In the photos I think I see you smiling.
https://apod.nasa.gov/apod/astropix.html
Ptolemy’s concept of the universe with our planet at the center was believed by the best and brightest for 1500 years until Copernicus in 1543.
I have written a poem about that with which you are not doubt familiar, but which will do no harm to print here again.
As I have written here before, until a little over a hundred years ago scientists thought that our galaxy comprised the entire universe. Now we are told that there are about two trillion galaxies in the universe. The universe has grown a lot in a hundred years. It is almost enough to cause one to wonder if we are really that important.
From Liu Tsung-yuan 773-819.
From Percy Bysshe Shelly 1792-1822.
And a poem which I had never read before which I find interesting and troubling because of its title.
3 comments:
I have enjoyed your writing here and in book form for many years - Thank you.
I believe that the correct text is The moon arose (not mood). “mood” is written in some online sources.
That is a good observation, Eric. I simply screen shot the page in the MOUNTAIN HOME anthology and did not catch that. I strongly agree that you are correct and it should be ‘moon’ not ‘mood’. Thank you for commenting and the kind words about my writing.
I touched the wrong line about a comment and deleted it when I meant to post it. That happens with my vision. So I have copied it and publish it here. I expect it comes from someone who is not a regular reader of my words, but one who goggled something about the size of the galaxy and chanced upon me. If not, please correct me. Also someone who has more math and science than I, but whose numbers only reinforce my observations about the size of the universe and our relavtive importance.
The post came from: Chewbacca & Sasquatch Yeti.
“And if we don’t simply rely on what either our direct observations (from the Hubble eXtreme Deep Field, for instance) or a simulation tells us, but rather use what we observe about nearby galaxies and their small, faint, low-mass satellites to inform our conclusions, we find that “billions and billions” or even two trillion galaxies is simply too low of a number.
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 — with approximately 100 small, satellite galaxies for every Milky Way-like galaxy out there, throughout cosmic time — might be an even better estimate.
If there are somewhere between 6 and 20 trillion galaxies in the Universe, you might wonder what that means for the total number of stars in the Universe.
The answer, remarkably, appears to be “no.” In a big, Milky Way-sized galaxy, there are hundreds of billions of stars today, and even back in the early stages of the Universe, their predecessors still possessed hundreds of millions to billions of stars. The galaxies we’re presently missing, particularly on the lowest-mass end, all have no more than a few ten-thousand stars each, with the smallest ones of all having only a few thousand or maybe even only a few hundred stars inside. All told, there are still about 2 sextillion (2 × 1021) stars in the Universe; the additional galaxies only add about 0.01% to the total number of stars present. It’s true that there are hundreds of billions of stars within the Milky Way, which is just one galaxy among trillions — likely between 6 and 20 trillion — in this enormous, expanding Universe. But even though we’re seeing just the tip of the cosmic iceberg with even today’s greatest, most powerful observatories, we really are capturing most of the stellar activity that’s present throughout our cosmos. With the advent of the James Webb Space Telescope, we’re finally getting the observational confirmation of these faint, distant, early-type galaxies that we know must be out there. The Universe, no matter how we conceive or misconceive of it, cannot hide its truths when faced with superior data.” — https://bigthink.com/starts-with-a-bang/galaxies-in-universe/
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