Astronomy and Cosmology

Also organic molecules in comet http://www.newscientistspace.com/article.ns?id=dn7961 http://astrobiology.arc.nasa.gov/news/expandnews.cfm?id=597 So I'm starting to wonder from all the places we looked for (if I'm correct) then it was only the moon that didn't have organic molecules (and that is probably because we didn't look good enough.) Aren't we getting in a situation that we will assume that there are organic molecules everywhere. (almost hard to find a place without some) Maybe in a few decates we will find out that there are all kind of small lifeforms everywhere.

There is something i dont quite understand. Maybe this is just a newb question so flame away but, here goes. How do black holes "suck in" light, if it has no mass? Or does it have mass? I googled this but didnt really find anything, so if anyone could explain this in a easy-to-understand way ( thats right, imagine your talking to an idiot =P ) id be grateful.

Unless I am mistaken, a new method of interstellar propulsion has been invented here at SFN, and blike may wish to apply for a patent so that everyone can share in the royalties the method is based on the fact that http://www.scienceforums.net/forums/showthread.php?p=208256#post208256 our galaxy is full of neutron stars whizzing around at speeds up to 1000 kilometers a second. Here is a map that shows over 200 of them with arrows to show the speed and direction----look at Figure 1 on page 2 of: http://arxiv.org/abs/astro-ph/0504584 so the method is TO HOOK A RIDE by means of GRAVITY SLINGSHOT. It takes neglible propulsion compared with what you get, b…

We are looking at stars at night ? We all know the velocity of light and stars are very far away from us. So whether stars are in that point when we are looking at that instant at the same point?

Whats the best summery of all basic info that could be found at a liberary.

Is every part of the universe equally old? The universe is estimated to be several billion years old. If I had a really accurate clock that measured the time from the big bang would it show the same time as anyone elses similar clock?

who believes in the big bang theory and whats your opinion on it?

How would you power a future fusion engine? What's it's fuel? In one article it said helium-3. But are there other kinds of possible fuel? It seems so from the wiki article but I sadly don't understand much of that article. Where would you get helium-3? I know of Luna and Uranus, how about Jupiter, Saturn and Neptune? I also read that with only the helium-3 on Uranus you could send a fusion-driven ship to every star in the galaxy, is this true?

The idea of dark energy I believe was to explain why the observable universe's expansion is accellarating. This seems like such a radical conclusion, surely something else more simple could explain this? Here is my idea: Perhaps the universe has a similar topology to a sphere, meaning that if I travel in any given direction for long enough I will end up at my starting point from the opposite direction. If that were so then perhaps all of the farthest parts of the universe are accellarating away because it is actually being pulled by matter in the opposite direction, with all of the matter actually converging upon a point rather than dispersing. Does this make sens…

http://abc.net.au/science/news/stories/s1460730.htm Could these make up the missing dark matter? I doubt it but still.. Some recalculations might need to be made.

It has always been a heated topic for debate whether we have been "visited" or not. But when will we reach outside our own solar system to prove or disprove life in other areas of space. You see scifi shows and books about interstellar travel all of the time, yet how far is humankind from making a breakthrough and finally starting up the interstellar space race? How far are we from such technology? I hoping sometime in my lifetime.

Several theories claim that the universe is expanding, or that at some point it was. My question is (assuming the universe isn't infinite), what could be at the edge of the universe? If I somehow ended up at the boundary of the universe, I presume there would be a sort of barrier where the universe ends, but if the universe is expanding, there must be something outside the barrier for the empty space to even be created? And on that note, what actually defines space itself? Could it be possible there are an infinite number of universes all within one huge multiverse one one plane (dimension), and while one increases in size, another decreases (Big Bang, Big crunch), like …

what is the minimum thickness for a dyson sphere(with a radius of 1AU) such that it won't fall apart?

Does anyone have a good guide to what it would take to terraform Mars? I'm thinking of writing something about it. I've already looked into http://www.ibiblio.org/astrobiology/index.php?page=mars04, and am thinking of looking into the Red/Green/Blue Mars novels, I hear the science in them is very plausible. Can you also just give me your thoughts on what terraforming Mars would take? Thanks

Hello all! I am in the midst of writing a young reader's Sci-Fi book and am having difficulties with some of the hard and theoretical science aspects! Is anyone here willing to help me out? The sub story is based around terraforming Ganymede and part of the problem I'm having is in finding general terraforming theories. I've found tons of specific stuff for Mars, the moon, and Venus, but most of that doesn't help me! So, the main points I'm stuck on currently are: Increasing Ganymede's gravity without altering its orbit or destroying it Creating an atmosphere (I've got a good idea for this, and will go into details if asked) And, creating a permanent he…

Could it be possible that the universe is older then what we presume, and that the empty space in between galaxies is actually burned out dead galaxies containing super massive black holes, and that these invisible dead galaxies could account for the large amount of matter that is undetectable? How feasable is that hypothesis?

Last night I told my dad I wanted a Celestron telescope to replace my little meade. When I mentioned $2000 he choked. He wants me to get something cheaper, so here I am. What can I get that is descent but cheaper? Bettina

http://www.newscientistspace.com/article.ns?id=dn7754 I thought it was interesting to think life could have begun so long ago. I wonder how advanced a alien lifeform that started forming that long ago would be by now?

On Tuesday morning around 4:30AM August 30, I witnessed a "shooting star" off my balcony. This was by far the widest tail of white-blue light I have ever seen. It appeared from my left and was headed right. (like a rainbow shape only consisting of white and deep blue colors) Right over the city of D.C. (or at least it looked that close). I never before followed a meteorite like this one. I noticed that after it crashed into the atmoshere (maybe final layer) it turned into a red firey ball and bounced back into space like a pin ball untill steadily rising up like a heluim balloon. Amazing! to say the least.

RedNova News - Space - Black Hole Blows Bubble Between the Stars http://www.rednova.com/news/space/203045/black_hole_blows_bubble_between_the_stars/

Stars are created when a cloud of particles/dust/whatever collapses under its own gravity. I've read this in several places, but none of them tells me exactly how dense a cloud of particles must be in order to collapse. What are the numbers here? If a cloud were close to the right density, could humans (in theory) jump-start the process?

my idea is that it expanded like a sphere due to the fact that there was equal pressure outside the universe as it was expanding-or-it waz expanding soo fast that it didnt react to the pressure. but if im wrong then how DID the universe expand?

http://news.bbc.co.uk/2/hi/science/nature/4727847.stm it looks to be a round patch of ice about 10-15 kilometer in diameter in the middle of a larger crater. the crater is in Vastitas Borealis yeah there is a lot of water ice at the poles of Mars, and maybe this is not especially surprising news, but I was glad to see the picture, so passing it along in case anyone else is interested

I'd appreciate any opinion or clarification about this For starters there's this popularization in CERN COURIER http://www.cerncourier.com/main/article/44/10/4 And then there are a couple of technical papers, one of which just came out this month. http://www.arxiv.org/abs/astro-ph/0403353 Is the low-l microwave background cosmic? Dominik J. Schwarz (CERN), Glenn D. Starkman (CERN, Case Western Reserve University), Dragan Huterer (CWRU), Craig J. Copi (CWRU) 4 pages, 3 figures; more figures available at: http://www.phys.cwru.edu/projects/mpvectors/ Phys.Rev.Lett. 93 (2004) 221301 The large-angle (low-l) correlations of the Cosmic Microwave Background …

Is the expansion (Hubble Flow) in agreement with the conservation of energy? I'm not sure how the accounting for the energy balance would work with distant volumes of space approaching/surpassing lightspeed wrt each other. So is the expansion considered to be in agreement or is this question considered not relevant or just unknown? I realize energy is not invariant wrt frames of reference. Also how would entropy increase relate to the above?