Astronomy and Cosmology

I remember reading a theory (but unfortunately I forget where) that the Big Bang could have been kick-started needing only about a kilogram of matter, and all the resulting matter and energy in the Universe is the result of an equation between matter and energy and zero-point energy not actually being zero. Is anyone familiar with this idea? I'll have to try and find which book I found it in to explain it a little better, but can anyone expand (heh, pun) on this concept?

Does anyone know where I can find the info to this: How many degrees of arc does a star move in an hour? Also, does it matter how far north or south the star is.

Not really sure if this is the right place for this question but im sure you guys can answer it. For the question im going to use a hypothetical situation: say you have two small objects, like two apples, out it the middle of space very close to each other, and very far from any other object. because the closest objects are so far from these two apples, there would not be much other force (like gravity) effecting these two apples (right?). So my first question is would the gravitational pull from these two apples pull the apples together, or perhaps cause them to start orbiting or something? Or would Inertia prevent these two apples from pulling together? i Asked…

That's what it says here. This is kind of old news, 2004. Interestingly, they don't mention anything about superfast inflation, just the aggregate growth exceeding light speed. Then again, this is 2004. I checked out the WMAP website, and while it did not confirm this conclusion, it did offer another good resource for explaining everything related to expansion. http://www.space.com/scienceastronomy/mystery_monday_040524.html http://map.gsfc.nasa.gov/

Is it correct to say that" if we reduce the normal forces acted upon us nd other bodies to zero,than the whole universe will reduce to small lump?

I just can't understand why the rings of Saturn are stable... My knowledge of the theory of gravity, which may be limited, is that there is only an attraction force (when we look at macroscopic things like rocks and planets). These rings seem to defy everything I know of gravity. Why don't the rings form a few moons, or at least larger lumps of rock? Any disturbance in the homogeneity of the rings should irreversibly cause the formation of lumps of rock. There are plenty of disturbances (even from outside, in the form of asteroids and comets), but also moons, and a size distribution in the rocks (they are not all equally big). Can anyone explain to me how the popu…

I have recently come across in my book about how people are able to hold plasma in a magnetic field, in which the north and south pole reach and equilibrium. Anyway, I was wondering, would the same be true for anti-matter within a vacuum?

It is said that dark matter is needed to hold the galaxy together, otherwise stars would just fly off out of the galaxy at the speeds they travel. Our sun moves at about 175 mps, almost stationary by galactic standards. The ancients thought the Earth was flat. If you look at any circle close enough, a small enough piece of it will look straight. An arc second is just 102 feet at the equator. The Sun/Earth take 200,000,000 years to travel once around the galaxy, some 188,400 light years. An arc second of that is over 847 billion miles and it takes the Sun/Earth over 153 years to travel that distance, for the equivalent curvature over a distance of 102 feet on Earth. …

Okay, I know there is observational evidence for spinning black holes, so therefore I must be confused about something, and I want you to tell me what. If you have a star that is spinning, therefore it has orbital angular momentum (mass revolving around a point), then as it is collapsing in a black hole, it shoots out particles that probably take some of that with it, but not all, and because angular momentum is conserved the black hole will spin. However, it is my understanding that the actually 'massy' part of the black hole is a simple point structure with a large mass and density with (almost?) infinite curvature. But if it is a point, there is no mass to r…

Bojowald's What happened before the Big Bang? article in the August 2007 issue of NATURE PHYSICS is now available to non-subscribers http://npg.nature.com/nphys/journal/v3/n8/index.html During August it was accessible only if you paid, but they just made it free. The link gives the TOC for the August issue. Scroll halfway down the page to where it says LETTERS and click on the PDF for the Bojo piece. Or get the article directly in HTML http://npg.nature.com/nphys/journal/v3/n8/full/nphys654.html In this piece Bojowald derives (in the context of his quantum cosmology model) some definite limitations on what can be known about the universe prior to the begin…

Have you guys heard of this site here: http://www.atlasoftheuniverse.com/universe.html Basically, it is an attempt to map the entire visible universe. Each little speck represents clusters of galaxies. Damn, that's pretty big. The map also allows you to zoom in on our part of the universe, and gives some interesting facts about the number of stars within a given patch of space. There's alot more in it too, like the big bang data, and so on.

How common is planetary “wobbling”. The earth has the chandler wobble: http://en.wikipedia.org/wiki/Chandler_wobble http://hpiers.obspm.fr/ As well as various other types of wobbles: http://www.agu.org/sci_soc/prrl/prrl0622.html So, how common is wobbling? Is everything wiggling and wobbling out there?

I was interested to hear some thoughts from someone who understands the technical details of the idea proposed by the British astrophysicist, Dr Hongsheng Zhao. Please see the sciencedaily and arxiv articles below...at face value it seems like chalk and cheese to me, but as a lowly undergrad, I'd like to hear an expert opinion on the idea... http://www.sciencedaily.com/releases/2008/01/080131094056.htm http://arxiv.org/abs/0710.3616

I have this great confusion. I am not able to distinguish between sky and space. I feel that sky is the space but space is black but sky is blue(generally) I am a kid in this field. So can anyone please take the pain of explaining in a easy and liberal manner. Thank you

Is human thought "data"?

So I need to clarify some details about this flat universe ideology. Is the universe supposed to be 2 dimensional? Is it supposed to be, say, one galaxy thick, on average, give or take a galaxy? Or is it supposed to be, say, one nanometer thick? Of course, I just found out that there are other competing philosophies, but I was wondering why this is even considered. Even the hyperbolic philosophy makes no sense. I envision a spiky ball of fuzz.

In space there is neither friction nor gravity.Then how is it possible to stop a missile or a spacecraft in the space. We need friction to stop a moving vehicle. Is there a special mechanism behind it.

What is the temperature of space just beyond the earths atmosphere?

Hey guys, In a lunar eclipse the moon dissappears as it goes through the umbra, but when it is completely inside, it turns red. I am not sure why... Lunar eclipse happens when the earth is between the moon and the sun. Technically, shouldn't the moon completely "disappear" (be blackenned out)? Why is it red...? Thanks in advance ~moo

NASA article dated 24 January about GRB, includes some animation http://science.nasa.gov/headlines/y2008/24jan_glast.htm?list45222 GammarayBurst astronomy is featured in the agency's news because the satellite instrument GLAST is scheduled for launch the first half of this year. Currently the launchdate is set for 16 May. Here's a GLAST webpage http://glast.gsfc.nasa.gov/ As the animation in that 24 January article shows a gammarayburst can take only 5-10 seconds, with the main peak coming in a spike that lasts only one or two seconds. Nobody knows the mechanism---some kind of star explosion that differs from supernova. On the other hand GRB oftentime…

It certainly looks like the larger the universe gets, the more space you get between galaxies. Which is why I have trouble picturing why we would collide with Andromeda.

we all hear about talk of the space tourism industry getting off the ground in the next decade or so - what interests me more though, is that given NASA's snail pace progress in solar system exploration, as well as bureaucratic processes that bog it down, can we expect private companies to explore the solar system with robotic probes? Would it depend solely on potential profit? If so, would there be a demand realistically, for purchasing the data gathered, to make it commercially viable, if no private company wants to do so for the sake of discovery alone?

Do you know what a blue moon days? The average period of lunar revolution is nearly 27.6 days. certain months of certain calendar has nearly 32 days. If a full moon day appears during the first or the second day of the month, another full moon day appears during the end of the month. This day is known as blue moon day

To inform you if you have a clear night and live Europe or America a nice lunar eclipse will happen ! Lunar eclipse animation More details

Hi everybody. Can any one say what's beyond or outside the universe.If it's going on expanding,where is the free space for it's expansion? what is there????