Astronomy and Cosmology

How can something achieve 60c? Is this referring to swanson's "aggregate stretching"? Just making sure. If the radius of the known universe is 45 billion LY across and it is expanding at a speed of at least c, then why is the universe only 13.7 billion years old, when mathematically it corresponds to at least 45 billion years old, not counting superfast inflation? Ok, so if the universe was expanding at a speed greater than c, this would explain the discrepancy in measurements. Now, if the universe is expanding at 60c now, that would mean that for most of its life, it was expanding at speeds substantially less than c, in order for the radius to only be 3.5 time…

In this article, they are claiming that antimatter is produced when black holes gobble up stars. What I have trouble with is when they say that matter is formed by waves. http://news.yahoo.com/s/space/20080111/sc_space/sourceofmysteriousantimatterfound

Why is it emphasized that the gravity of a black hole is centered in one specific point, rather than as a whole. Gravity usually pulls things towards the surface. As far as I can tell a black hole still must have all of the similar functions of a star, only much greater, which would incinerate ANYTHING that gets too close. It seems to me that a singularity is really just a token point of reference to the center, but that the overwhelming gravity is produced by the mass of the black hole, in its entirety.

http://www.spitzer.caltech.edu/Media/releases/ssc2008-01/release.shtml

Just found this, very interesting. A number of simulations have been run by the COSMA super computer at Durham Uni, the results will aid in the design of the satellite for the future 'SPACE' mission, which aims to understand dark energy. Please see the full article below... From the article... The tiny ripples are called BAO's or Baryonic Acoustic Oscillations, which similar to the background radiation (CMB) are the sound equivalent... emphasis mine http://www.dur.ac.uk/news/newsitem/?itemno=6038 Below is an overview of the 'SPACE' mission, from arxiv... http://arxiv.org/PS_cache/arxiv/pdf/0710/0710.3970v1.pdf

link. 1 in 75 chance mars gets a heavenly slap on the 30th of january. should be interesting. maybe expose some underground ice?

We all agree solstice, like December 22, is the point of maximal polar axis pointing away from the sun, and so it is the longest night and shortest day. Yet those of you who have been holding your breath for dawn to come earlier are dead. You are not illuded to see that mornings have come even later. I think I can see this as a sidereal shift at the sinusoidal minimum in which, for 2-3 weeks either side of the solstice, the pole angle hardly changes. Look at the numbers, given that the pole goes +/- 23 degrees or so in 13 weeks. The 'top of the roller coaster' is a bit broad. THE FACTS ARE THAT AFTERNOONS REACHED THEIR DARKEST ABOUT 2 WEEKS BEFORE SOLSTICE, AND MORN…

We had a poll on this question: How many planetary systems in the galaxy have evolved any recognizable life at all, or to be definite, some kind of carbon and water based life analogous to Earth's that we would clearly see as comparable to what we have here, even if still very primitive. and the responses averaged out to 100 Let's try the next question. ASSUME that in all the Milkyway there are 100 planets where some recognizable water+carbon life has evolved, even if it is just single celled. Of that 100, perhaps some evolved multicell, central nervous system etc etc, and on up. Perhaps. Of those 100, HOW MANY do you estimate have evolved life sophisticated…

Aigbusted posed this question People had various ideas about the likely abundance of habitable planets. Let's see what we think about this collectively----how many say 1, how many say 10, or 100, and so on. For definiteness, let's say IN OUR GALAXY. Milkyway is about 100,000 LY diameter and 1000 LY thick. It might have as many as 400 billion stars (most however smaller than the Sun.) I guess there are at least two questions. 1. How many planetary systems in Milkyway galaxy have evolved life sophisticated and curious enough to build radio telescopes and LISTEN for artificial signals. 2. How many planetary systems in the galaxy have evolved any recognizab…

Check out Spitzer's latest find: See the rest: http://www.spitzer.caltech.edu/Media/releases/ssc2007-18/release.shtml

Hey guys, today I found a great thought experiment to prove that time can't exist without mass and motion. It can be found by proving photon's rest mass = 0. I don't know the actual derivation. So, I have made my own derivation (this is the one I made to prove photon's m = 0 to my friend). Let's start: E=mc^2 (Rest energy equation) E/c^2=m=0 (To prove) We know that c^2 is a constant so if we want to prove m=0, we will have to prove E=0. Let's take another formula: E=hv So, we can prove it by this equation. As we are taking the photon to be at rest, there is no frequency at rest. …

More Spitzer news! See the rest: http://www.spitzer.caltech.edu/Media/releases/ssc2007-19/release.shtml

What propels all of the heat and activity in a star if the rate of fusion is very slow? My guess is that the energy released by fusion is quite substantial in proportion to the quantity of components that go into it. So exactly what kind of energy is produced that keeps the rest of the star "alive"? Evidently, the matter within most of the star is in various plasma states, but I have a hard time seeing what exactly drives all of the heat and energy, or rather, what the energy consists of. "The fusion of two nuclei lighter than iron or nickel generally releases energy while the fusion of nuclei heavier than iron or nickel absorbs energy; vice-versa for the reverse p…

Any ideas on what causes/allows the matter to be expelled, in light of all of the gravity that is supposed to keep it there? Why not just keep growing? http://news.yahoo.com/s/ap/20071217/ap_on_sc/death_star

Hey, I love looking at space photos, I can do that all day, and ever since galaxyzoo.com opens, I'm having a hard time disconnecting from it. Really. Space is amazing. But I was thinking. Most of the known photos of Nebulas in particular (but a lot of other stellar phenomena) are colored artificially. From my understanding, some of the artificial colors are from the medium (like, X-ray filters or ultra-violet filters, etc) and some are just dyed by astrophysics computer programs. So.. I was wondering.. if I was to take a space shuttle next to a Nebula -- what will I see from the view port? Will it even have color? Can that dust *truly* reflect light? (I r…

Article found here. Is he right about the science?

I found the airbrush tool on photoshop, so I thought I would have a bit of a play around with it and see what it could do. The first two pics are about 1/2 hour each of work. The Third is 1 hour. THe last I did tonight took me 3 hours. This thing it HEAPS of fun!!! Found something to do with my cloudy nights!! Baz.

Greetings earthlings! A.S.I.G.N. Observatory is proud to present the latest layman's guide to astrophotography. http://www.asignobservatory.com/AstrophotographyGuide.aspx As the Canon 400D and it's ilk are the most commonly used these days for the average budget, I thought it pertinent to be a little more specific in this area. I hope you enjoy the tutorial, share it with new and old astrophotographers, and add it to your links so everyone can gain from it! Happy space travels! Baz.

here is an article i wrote about the solar system let me know what you think . The History of the Solar System. The cloud of gas surrounding the dull yellow star cooled. From the remains everything in our solar system was born, the last skin of the dead star made our blood, all of the material that makes our skin and faces, our hearts and brains were all first made together in a colourful ball of light in the sky. The exploded debris circled the left over star like water circling a drain, and eventually the lumpiness of the matter meant that it fell together again making different balls at different distances, some so heavy that the matter near them be…

Just read this article from sciencedaily, thought some of you may be interested... http://www.sciencedaily.com/releases/2007/11/071127142128.htm Just incase anybody is a little confused by the article, a small excerpt from wiki explaining how the CC will agree with this data, and not a static model for the universe... http://en.wikipedia.org/wiki/Cosmological_constant

having looked at this thread: http://www.scienceforums.net/forum/showthread.php?t=29651 an Idea occurred to me, assuming the Impossible for a second, If we went into the "Void" at the very edge where our universe hasn`t expanded into yet. Would we be able to see the Big Bang as it happened (albeit from a great distance away) ? my Idea is that the Big Bang is still happening at this junction, although only as Images, a bit like rolling back to the beginning of a film, so that the Light and stuff that hasn`t reached into this void yet would be what happened at the very beginning of "time". it makes sense to me as a Logical extrapolation, but are there any other…

Planetary science is awakening to the realization that our solar system contains many more planets than any 20th century textbook ever envisioned. It's not your father's solar system. by S. Alan Stern Principal Investigator - New Horizons Boulder CO (SPX) Sep 11, 2006 A real revolution is afoot in planetary science. The first shot was fired in 1930, with the discovery of Pluto, but almost no one realized its import. The second and third shots came in the late 1970s, with the discovery of distant objects called Chiron and Charon, but again, few recognized what they would portend. Rapid-fire volleys began in the 1990s, as myriad discoveries of icy bodies 100s to well …

Hello all, If anyone is interested in building their own observatory from scratch, learning about astrophotography, or trying their hand at a few astronomy related DIY projects, please say hello and have a bit of a look through my website. It is all free and there are no gimmicks. Put your credit card away, I don't want to see it! LOL Big cheers, Baz. _________________ A.S.I.G.N. Observatory Canberra, Australia http://www.asignobservatory.com

I'm interested in this as a potential Extinction Level Event. I understand that life would end due to the destruction of the ozone layer, causing cancers and the collapse of the food chain. How long would this take from, say, the catastrophic effects on the ozone layer to the first cancers and then to the extinction of life on Earth? Would anything survive? If a man could survive that initial trauma, what kind of precautions would he need to take in order to go outside? Sorry for the melodrama... I'm a writer interested in what if...

So who's following any recent stuff about condensed matter and radio astronomy these days? All the white dwarf and AGN surveys?