Space | Evolution | Physics | Social Sciences | Natural Sciences | DNA | Psychology | Biotech | Medicine | Anthropology | Astronomy

Neil deGrasse Tyson: Decoding the Universe

More from this series:

Commonwealth Club of California

More videos from this partner:

69
Likes
0
Dislikes
RATE
146,118 Views

  • Info
  • Bio
  • Chapters
  • Preview
  • Download
  • Zoom In
Advertisement
There are 18 comments on this program

Please or register to post a comment.
Previous FORAtv comments:
moistearth Avatar
moistearth
Posted: 01.28.12, 01:47 AM
10:45 Being English, I remember the visible spectrum like this: Richard Of York Gave Battle In Vain. If we didn't have Indigo, we'd need a different mnemonic aid Another one, for mixing the three primary colours (RGB): Right Colour Gets Me BY.
Periergeia Avatar
Periergeia
Posted: 05.28.10, 06:49 PM
"Questions : How did the ‘single point ‘ create if the matter can escape from any strong gravitational force?" Answer: The cosmological solutions of Einstein's equations are different from the Black Hole solution. A black hole is a static solution which does not change in time. In a non-feeding black hole spacetime has come to "rest". The black hole metric decays (pretty much) exponentially to the static solution and is then (classically, at least) the same until disturbed. In contrast, the cosmological solution is dynamic. It either expands forever or first expands for a finite amount of time and then collapses back to the infinite density (again, only classically) that it came from. If you want a classical analogy, the black hole is like a stone at rest on the ground. Once at rest, without external force, it will never move. In comparison, the cosmological solution is like a cannonball. It, too, was once on the ground, but then it was given a finite amount of kinetic energy by the exploding black powder in the cannon and is now following a parabolic (or, as in case of our cosmos) hyperbolic ballistic trajectory. So the only real question is where did the cosmos acquire its initial energy that makes the cosmological solution qualitatively different from the black hole solution? The answer can not be found in Einstein's theory. It has to be looked for in quantum mechanics, which says that space and time can not be restricted to the infinitely small because that restriction alone causes the energy to diverge. Therefor, an initially small cosmos must have had some finite self-energy, which sets the rest of the machinery in motion. I believe the observed energy in the universe points to an initial size that is on the order few tenth's of an inch or so (that's speculative, anyway, because we need to understand quantum gravity before we can attempt to actually calculate a realistic, meaningful number). Now, if you want to speculate in religious terms about it, I would suggest something like this: "In the beginning God held the universe between his thumb and index finger. And the universe was very small and very hot and very dense. And God saw that it was good. And God smiled (Why wouldn't he? Isn't crating a universe a happy occasion?). And he let the universe go. And the universe inflated greatly. And God saw that it was almost homogeneous, with faint ripples that echoed his fingerprints. And God saw matter forming from the brightness that illuminated the universe and for a moment it went opaque. And then the hot matter condensed and became translucent again. Where his fingerprints had created ripples in the radiation, the now cooling matter began to form wispy strings of primordial galaxies and the stars lit up the universe, once more. This time the light would last for a trillion years and illuminate the days of countless inhabitants of his new creation. And God kept smiling."
Matthew Smith Avatar
Matthew Smith
Posted: 02.04.10, 01:35 PM
Calling them dwarves does give obvious names for the next 7 KBOs. That is something to do with Disney
Courage the Cowardly Dog Avatar
Courage the Cowardly Dog
Posted: 01.24.10, 01:08 PM
He should be a teacher, he is really happy to tell we will all die.
socratus Avatar
socratus
Posted: 12.23.09, 09:24 PM
Black hole and Big bang. ============== .... 1. A black hole is a theoretical region of space in which the gravitational field is so powerful that nothing can escape. 2. Hawking Radiation theorizes that black holes do not, in fact, absorb all matter absolutely; they give off some return matter. 3. Once upon a time, 20 billions of years ago, all matter (all elementary particles and all quarks and their girlfriends- antiparticles and antiquarks, all kinds of waves: electromagnetic, gravitational, muons… gluons field ….. etc.) – was assembled in a ‘single point ‘ The reason of this unity is gravitational force. 4. Questions : How did the ‘single point ‘ create if the matter can escape from any strong gravitational force? ==== . Best wishes. Israel Sadovnik. Socratus.
ajstavely711 Avatar
ajstavely711
Posted: 11.22.09, 04:52 AM
@laurele I have never heard the gravity that allows large bodies to clear their orbits somehow changes the further out from the sun you go in the solar system.
RicoPenguin Avatar
RicoPenguin
Posted: 09.15.09, 08:26 PM
@laurele A Dwarf Planet is not a Planet much like an Ant Lion is not a Lion. If people are going to use erroneous examples could they make them harder to dismember?
Johnny Daryanani Avatar
Johnny Daryanani
Posted: 09.02.09, 12:59 PM
@ JEAN D: We better not label Ceres as the 5th planet. That would piss Jupiter off... and I do not think we should upset it. After all, see what it did to poor Europa (as a side note, life on Europa being called Europeans... ha ha ha, funny! Europeans always seemed a little 'otherworldly' to me) Johnny D.
Jean D Avatar
Jean D
Posted: 08.22.09, 01:56 PM
@laurele: So I guess you are also willing to lobby for declaring Ceres the 5th planet in our solar system. Fits all of your criterias. Jean
joeguitargod Avatar
joeguitargod
Posted: 02.06.09, 09:14 AM
I think what makes Neil deGrasse Tyson so entertaining to watch is not just his ability to explain technical topics in layman's terms, but also in his animated and rather comedic style in which presents them. If he wasn't an astro-physicist, he would probably do well as a comedian or comedic actor. An informative and quite entertaining video clip worth watching!
Advertisement

Advertisement
FORA.tv ticker
Watch Now
Watch Now
Watch Now