Smath74 All American 93278 Posts user info edit post |
^^exactly. (3) 2/9/2011 2:36:34 PM |
mrfrog ☯ 15145 Posts user info edit post |
Quote : | "Unless the current models change significantly there is nothing that can go near a black hole and survive the tidal forces." |
Completely and totally wrong. One of the great myths of popularized physics.
What you've been told about spagetification only applies for black holes below a certain mass. Granted, this is a huge mass, but black holes of a mass similar to many galaxies are not uncommon in our universe. Supermassive black holes can actually be quite quiet. The 'density', defined by the mass divided by the volume in the event horizon can be less than that of water for such large sizes, and tidal forces for such black holes are infinitesimal.
Entering a supermassive black hole, if it's not devouring stars at the moment, would be incredibly smooth sailing into eternity. Well, it would be as far as observers outside observe. You would likely still be squished and squashed when approaching the singularity, but that's unknown physics so we can't say technically. Maybe you'd cruise into a new universe, spaceship and all intact, greeted by natives in hula skirts... until of course, you meet your double :-O
Quote : | "also, I heard that there is one thing faster than electromagnetic radiations and that is the speed at which the universe is expanding. That's why earth is at the center of the known universe and we will never be able to see beyond the light horizon. This makes me sad if true " |
Yes, but... with provisos.
Many conceptual things can move faster than the speed of light - like shadows. There are also points... somewhere... that are be theoretically said to be presently moving away from us faster than the speed of light. BUT, that is not the reason for our universal event horizon. General relativity predicts the full casual disconnection between 2 points given a constant ACCELERATION between them. By other accounts, no point even beyond the event horizon even moves faster than the speed of light away from us, they just have above a certain critical acceleration due to the fact that God (or the devil) is constantly inserting new space inbetween us and that point. But we really can't say much of anything about stuff beyond any event horizon, so it's kind of semantics, say it's going faster than the speed of light if you want to.
If you have a spaceship that constantly accelerates in one direction for the rest of time you may outrun a beam of light. This is only possible by a limit analysis - for you never exceed the speed of light and thus the light is always going faster than you. But it still never catches you and certain photons will never even get closer than a given distance because of the math.
Quote : | "Due to the relativistic travel, he was able to go from superstar status to biggest mistake in history in his own lifetime." |
Oh, but this only happened because he allowed it and actively wrote about the horrors of the Xenocide because he was repenting for killing them. Probably one of the most over relied upon protagonists in sci fi right up there with Luke in the expanded universe.
[Edited on February 9, 2011 at 8:58 PM. Reason : ]2/9/2011 8:50:22 PM |
Smath74 All American 93278 Posts user info edit post |
Quote : | "Completely and totally wrong. One of the great myths of popularized physics.
What you've been told about spagetification only applies for black holes below a certain mass. Granted, this is a huge mass, but black holes of a mass similar to many galaxies are not uncommon in our universe. Supermassive black holes can actually be quite quiet. The 'density', defined by the mass divided by the volume in the event horizon can be less than that of water for such large sizes, and tidal forces for such black holes are infinitesimal." |
true, with a supermassive black hole you might make it across the event horizon, but as you approach the singularity (inside or outside of the event horizon) you will be spaghetti-ed.2/9/2011 10:30:22 PM |
disco_stu All American 7436 Posts user info edit post |
And we were talking about theoretically creating black holes. Surely we weren't talking about theoretically creating black holes the mass of galaxies. When we have the power to do something like that, wormholes will be unneeded. 2/10/2011 9:15:16 AM |
mrfrog ☯ 15145 Posts user info edit post |
^^ granted
^ they already exist, and you're wrong about wormholes. Stable wormholes can only be created with massive quantities of "exotic" matter, that is, stuff that creates negative energy that we haven't yet proven, much less created, much less created in stable form.
Supermassive black holes, in addition to already existing, would not be difficult to make bigger. Trajectories of stars would be hard to tinker to a civilization of our scale, but if you consider a Kardashev scale 1-2 civilization (goes up to 3 and beyond), it wouldn't be out of the question, and it would be doable because over long time frames the motion of the stars transitions into chaos. Small pushes now can completely change the face of the galaxy in a million years. Because of this, both the acts of 'cleaning' the area around a supermassive black hole and throwing more matter into a black hole would be feasible by a very ordinary appearing space faring civilization. 2/10/2011 10:53:25 AM |
Wraith All American 27257 Posts user info edit post |
http://www.youtube.com/watch?v=j2oXFWKpJiA
Some inspirational words from Carl Sagan, one of the greatest astronomers of our time. 2/10/2011 11:56:33 AM |
mrfrog ☯ 15145 Posts user info edit post |
^ that was a really good one. It's fun to hear him talk about the philosophy of the empty universe. The discovery of Earth-like planets in terms of orbital and mass characteristics is certainly a first step in the direction of actually reaching out into the new world that other civilizations might inhabit.
It really is interesting that we seem to live in an "empty" universe, meaning that there is no other life outside out own brethren as far as we can see. Everyone else might have killed themselves, and we might do so too. What is really up with all those exoplanets we're finding? 2/10/2011 12:21:22 PM |
Smath74 All American 93278 Posts user info edit post |
AFRICAN AMERICAN TREES
http://www.space.com/11424-alien-planets-suns-black-trees.html 4/20/2011 1:24:51 PM |
GREEN JAY All American 14180 Posts user info edit post |
that would be more interesting if we didn't have black plants here. 4/20/2011 4:48:22 PM |