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Showing results for tags 'Cosmology'.
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These BBC videos are a bit "for the masses," but they do their job: Feb 6, 2019 - "Why Almost All the Universe Is Utterly Invisible" on bbc.com Just to throw something out there, since black holes are causing everything in each galaxy to swirl around them, why can't they be repelling everything that's outside of their galaxy? Doesn't it seem like galaxies are all pushing themselves away from each other, sort of like (for a visual example) two magnets whose negative poles are facing each other? If black holes have a such a strong attractive force, then why can't they have an equally impressive repulsive force? There. I just solved all the mysteries of the cosmos in two minutes. Only I could have done this. Sincerely, Donald
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These are two really well-written articles: Apr 9 - "A Brief History of Black Holes As We Await the Big Reveal from the Event Horizon Telescope" by Sarah Kaplan and Joel Achenbach on washingtonpost.com Apr 10 - "See a Black Hole for the First Time in a Historic Image from the Event Horizon Telescope" by Sarah Kaplan and Joel Achenbach on washingtonpost.com And here it is, an actual Black Hole - this is one of the most important pictures ever taken:
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1492 - everyone knows that year. The universe is 14 billion years old. The universe is 92 billion light-years large (diameter). Give or take a few. --- You can stop here, or go on for some theory. Assuming the Big Bang took place at the centroid, that means that the radius is 46 billion light-years (half of 92 billion), and that in a duration of 14 billion years, mass was able to travel 46 billion light years. Given that no object can travel faster than the speed of light, how is that possible? To travel 46 billion light-years in 14 billion years, objects would seemingly have to travel at over 3 times faster than the speed of light. I'll let you sit on that one for awhile.
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I read Stephen Hawking's (R.I.P.) "A Brief History of Time" not long after it was published in 1988, and even though everyone is saying how simple it is, I'm pretty much in the Charles Krauthammer camp: I found it almost 'incomprehensible' at the time. Granted, I'm much, much more educated now than I was then, so maybe it would be a walk in the park for me now, but it was not easy reading for me at age 28-ish. (I should add that Richard Feynman's book, "Six Easy Pieces," put me in the same boat: They were *not* easy. And then, I was foolish enough to tackle "Six Not-so-Easy Pieces," which I read more as a personal challenge than anything else - I remember nothing about it.) I think the problem might be that, while these are two scientific geniuses, they aren't great authors. Honestly, I question the myriad of five-star reviews, and all the comments saying they were reading "Six Easy Pieces" to their grade-school children. I don't believe it! There are two kinds of people who say they enjoy these books: those with a degree in physics, and those who are trying to impress people - I am neither. Grade-school children, my eye.
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It's a sobering thought, realizing that 15+ billion years went by without you being alive, and who-knows-how-many billions of years will pass after you're no longer alive. Talk about a blip in time! Being non-existent doesn't bother me; dying to me don't sound like all that much fun, Don Cougar PS - If you want to die early, fixate on visualizing the beginning of time, or the end of space. Like a cat trying to understand calculus. Moral of the story: Treat yo'self.
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Awhile back I found an amusing cartoon on BBC that explained why nothing can go faster than the speed of light. Now, I've found a similar thing that explains why we can only see 5% of the known universe. It's not going to answer the mysteries of the cosmos for you, but it will explain things as best as they can currently be explained, in a way that you'll understand. "Why Almost All of the Universe Is Utterly Invisible" on bbc.com
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"Observation of Gravitational Waves from a Binary Black Hole Merger" by B.P. Abbott et al on journals.aps.org Yesterday, two separate detectors (in Hanford, WA and Livingston, LA) simultaneously observed a transient gravitational wave signal. I know this is "out there" stuff for a "restaurant website," but these waves are thought to be curvatures of spacetime which propagate outward from the source. For Einstein's two Theories of Relativity to be true, these needed to exist (i.e., Einstein predicted their existence), and Sep 14, 2015 was the first confirmation (heavily peer-reviewed, and the news released just yesterday), so this is a big deal. "Gravitational Waves, Einstein's Ripples in Spacetime, Spotted for First Time" by Adrian Cho on sciencemag.org "Einstein's Gravitational Waves Found at Last" by Davide Castelvecchi and Alexandra Witze on nature.com "Gravitational Waves Detected, Verifying Part of Albert Einstein's Theory of General Relativity" by Robert Lee Hotz on wsj.com
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"How Small Is Planet Earth!" by Renaud Margry on facebook.com (Speakers down; the music gets to be a bit much - but *well* worth seeing.) Watch the video first, then investigate VY Canis Majoris. Are we really any more significant than ants? We have been cursed with self-awareness.
