{"id":11368,"date":"2021-02-17T17:15:36","date_gmt":"2021-02-18T01:15:36","guid":{"rendered":"https:\/\/www.markrkelly.com\/Blog\/?p=11368"},"modified":"2021-02-17T18:44:10","modified_gmt":"2021-02-18T02:44:10","slug":"links-and-comments-astronomical-photos-from-apod","status":"publish","type":"post","link":"https:\/\/www.markrkelly.com\/Blog\/2021\/02\/17\/links-and-comments-astronomical-photos-from-apod\/","title":{"rendered":"Links and Comments: Astronomical Photos from APOD"},"content":{"rendered":"

After seeing links to the site Astronomy Picture of the Day<\/a> (APOD) occasionally on my Facebook friends’ posts over the past few months, I added it to my morning regimen of sites to check every day.<\/p>\n

Here’s today’s. Click for the site itself with a larger photo and an explanation (and click their photo for a really big photo).<\/p>\n

<\/a><\/p>\n

<\/p>\n

This is a sun pillar, a rare sight that even more rarely fans out at the top. They “are known to be caused by sunlight reflecting from wobbling, hexagon-shaped ice-disks falling through Earth’s atmosphere.” And so on.<\/p>\n

As I commented to one of my Facebook friend’s (Moshe Feder’s) post about this:<\/p>\n

Throughout most of human history, and for most people alive today, this would be taken as a supernatural event, confirming whatever gods or angels they had been taught to believe in as children.<\/p>\n

And of course, until a couple centuries ago, everyone thought that about rainbows.<\/p>\n

\\\\<\/p>\n

Here’s another one, with a different implication.<\/p>\n

<\/a><\/p>\n

This is a mosaic of photos taken over many years, of a relatively large patch of the sky. The photo covers enough of the sky to include the entire constellation of Cygnus. Deneb is at left; faint lines connect the other stars in the so-called Northern Cross.<\/p>\n

This illustrates something I never realized before, even after having been an astronomy fan and student since the 6th grade. I’ve always had the impression that the impressive photos we see of far-away galaxies and nebulae were photos of tiny patches of sky, magnified to see what was too small to see with the naked eye. No: these nebulae (and even galaxies like Andromeda), are relatively *enormous* in a view of the night sky, if only we had the eyes to see them. (The photo here includes the entire North America Nebula<\/a>, in lower left, for example.)<\/p>\n

If we had more sensitive eyes — which we don’t because our eyes, though sensitive over a wide range of brightness, have been evolutionarily adapted to our place here on Earth — we would see magnificent views like this.<\/p>\n

It’s another lesson in how human perception of reality is limited. We can expand our perception of reality through our science and technology, our instruments to perceive what we cannot.<\/p>\n

Here’s one more, of the Andromeda Galaxy, the famous M31, just visible with the naked eye on a dark night, but larger than you would think from that naked eye, or binocular, or telescope view.<\/p>\n

<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

After seeing links to the site Astronomy Picture of the Day (APOD) occasionally on my Facebook friends’ posts over the past few months, I added it to my morning regimen of sites to check every day. Here’s today’s. Click for … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[31,2],"tags":[],"class_list":["post-11368","post","type-post","status-publish","format-standard","hentry","category-astronomy","category-science"],"_links":{"self":[{"href":"https:\/\/www.markrkelly.com\/Blog\/wp-json\/wp\/v2\/posts\/11368","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.markrkelly.com\/Blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.markrkelly.com\/Blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.markrkelly.com\/Blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.markrkelly.com\/Blog\/wp-json\/wp\/v2\/comments?post=11368"}],"version-history":[{"count":30,"href":"https:\/\/www.markrkelly.com\/Blog\/wp-json\/wp\/v2\/posts\/11368\/revisions"}],"predecessor-version":[{"id":11398,"href":"https:\/\/www.markrkelly.com\/Blog\/wp-json\/wp\/v2\/posts\/11368\/revisions\/11398"}],"wp:attachment":[{"href":"https:\/\/www.markrkelly.com\/Blog\/wp-json\/wp\/v2\/media?parent=11368"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.markrkelly.com\/Blog\/wp-json\/wp\/v2\/categories?post=11368"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.markrkelly.com\/Blog\/wp-json\/wp\/v2\/tags?post=11368"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}