Myer explores 10 iconic images from Hubble and explains why they are important and the science behind the pictures. Druing this course one will learn about exo-planets, black holes, the big bang and curved space among other concepts. This course lends itself to the video format. I streamed this course through The Great Course Amazon channel.
This is a Great Courses DVD. Meyer’s presentation is top-of-the-line. He stays focused on the big picture and out of the weeds.
A puzzling point of his presentation is that his treatment of galactic structure is descriptive, not explanatory, even speculatively. So, by default, he relies on the Messier and Hubble classification scheme: mainly, spirals, ellipticals, and irregulars. The puzzling part is that, for such a significant part of the cosmos, these shapes have to tell a story. Elsewhere, Meyer talks about gravitational lensing - the curvature of light in the presence of galactic clusters - and Einstein’s rings (arcs of light created by gravitational lensing) as examples of Einstein’s curvature of space (time) by a large gravitational presence (collections of galaxies). Might not galactic structure also be real-time manifestations of Einstein’s theory of general relativity - the curvature of space in the presence of large, massive structures? Might it be possible that there’s an evolutionary sequence here where (1) gas and dust (and light) begin to pull together into globular clusters; (2) loosely wound spirals begin to form, with a small bulge; (3) tightly wound spirals follow, with a larger bulge as more matter is pulled toward the center; followed by (4) elliptical galaxies when most of the gas and dust has flowed into the galactic center?
Meyer also mentions barred spirals, cigar shaped structures running horizontally across the bulge. Might this might be the remnant of a collapsing disk? Irregulars mess up the shape of two galaxies because each pulls from the other, or one pulls more than the other toward the more massive gravitational center. Here, though, Meyer says that such collisions form ellipticals that ignite star creation. But he also says that ellipticals are gas poor because they have largely contracted into clusters of stars, which are older. There seems to be a contradiction here between ellipticals as star creators versus ellipticals as collections of older starts.
Meyer also used gravitational lensing and galactic rotation speeds to illustrate the necessity of dark matter in the sense that (1) the pull of light in lensing is ten times greater than the masses of the studied galaxies and (2) that the speed on the outer edge of spiral systems is much faster than the mass of such galaxies should allow. For example, this means that dark matter must explain the missing mass. He likens the spiral rotation speed to the orbits around stars by planets. Yet, galaxies and galactic structures are open-ended. They are pulling mass-energy toward the galactic center, increasing their velocity and density (per inverse square law) as they do so. This is quite different from a balanced and relatively closed star-planetary system. Inertial movement continues one way, with the spiral shape being created by the increased “pull” toward the gravitational center, at increasing velocity. Light seen in gravitational lensing would also be subject to the same curvature effect, but less so because of light’s mass being manifested as speed, not matter, so the pulling effect on its highly-diffused energy (the rings, the arcs, of light) is less?
The professor discusses 10 images taken from the hubble space telescope and explains their significance and the science behind them. Overall pretty interesting, but at the same time easy to understand.
Although Hubble is outdated now, it wasn’t when I used these lectures to learn more about the universe. For young me, the images taken by Hubble were some of the most beautiful pictures ever. I am glad I got introduced to them through this course. It made space look really cool.
Очевидно, читающий лекцию профессор многого достиг и многое сделал. И очень любопытно было посмотреть, с комментариями, с какими реально снимками работают сейчас астрономы.
Но досмотреть лекцию до конца я не смог. Очень нудно. Профессор пытается читать живо и энергично но он с большим напором выделяет очень странные фразы и это скорее мешает воспринимать смысл. Кроме того, он очень бытовыми словами описывает явно непростые вещи, так что в итоге у меня возникает просто море вопросов на которые мне неизвестны ответы - я же и стал смотреть эту лекцию, чтобы мне дали какую-то астрономию 101. Отчасти еще необычно что уважаемого профессора, в отличие от других лекций The Great Courses усадили, это говорящая голова - учитывая обилие фотоматериалов даже непонятно зачем ее так много на экране, лучше бы больше дали времени на фотографии и визуальные пояснения на них.
Итого, тема шикарная и в общем смотреть можно хотя бы несколько лекций. Но полный курс - бессмысленно, тут надо было бы дать больше знаний, а не однообразно рассматривать фото за фото.
В общем-то что-то профессор объясняет и рассказывает, но для меня все это было очень не систематично и нудно.