Astronomy and Cosmology

Doe's dark have speed? can darkness be measued? or is it Zero I wonder coz light travels (186,000 miles per second) yet darkness is faster coz it's here but if they both have speeds what's dividing them or in between? or am I quoting sheer nonsense? I don't know but I've never heard anyone question whether darkness has a speed; everyone seems to take for granted, it doesen't!...I don't...us.2u

I presume all manned spacecraft when in space break the sound barrier; so can anyone enlighten me, that when the astronauts are traveling faster than sound, how & why is it possible for radio communications with that craft in space to us here on Earth? because if they've broken the sound barrier it dosen't seem feasible we could hear them us.2u

If the Earth did not rotate on it's axis, but it did still orbit the sun, then one day and one year would be the same. See what I am saying here? So, the question is, in a 365 day year, how many times does the Earth rotate on it's axis? 364? or 366.

Hey guys, I was wondering if there's a good book on the topic of String Theory. Thanks in advance!

I was recently reading an article about the problems with space travel and muscle atrophy. It disscussed how when astronuats go into space they loose muscle an bone mass due to the lack of gravity. It also went on to discuss ways of preventing this muscle loss, such as spring and cables to simulate weight that is driven by the forces of gravity, and i started thinking up ways of my own. What if a space ship were created with a strong magnetic field in it that could pull the astronuats to the ground, or repel them from the cieling? im sure an elctro magnetic field could be produced to simulate 9.81 m/s^2 if the astronuats were to waer a light metal suit. What are your …

To have a blakhole we need enought mass in a small volume. A neutron star with more than 3 solar mass will do. The gravity is strong enought to overcome the repulsion of neutron http://hyperphysics.phy-astr.gsu.edu/hbase/astro/blkhol.html But something is bugging me. Relativity tells us that the more intense the gravity the slower time is going. From our point of view we would see the collapse of the neutron star going slower and slower until the Schwarzchild radius is attained. At this radius from our point of view time will almost be stopped: it will take an infinite amount of time for the collapse to finish. If the universe have existed a finite time how can…

this paper came out 10 january 2005 http://arxiv.org/astro-ph/0501171 it makes it seem more likely (than say a year ago) that the universe is finite To keep in touch with current developments in cosmology it can be helpful to check Ned Wright's "News of the Universe" at his website. Ned is one of the top halfdozen cosmologists in the world and teaches at UCLA and is one of the directors of WMAP (satellite now mapping the cosmic microw. backgrd) http://www.astro.ucla.edu/~wright/intro.html Ned gives the reference to this paper (48 authors, Sloan Survey) and then he comments. His comment may be easier to understand than the paper Ned Wright featured this …

IMHO I truly believe going back to the KT boundary; that the meteorite that crashed in Mexico at that time can be the one & only true castrophic event that wiped the poor Dinos' out I really can't see any other plausible explanation. I think something like that would've caused global flooding, global volcanos not to mention evidence of Iridium; are most of you with me on this one? or does anyone have different plausible explanations?....I've heard other stories but I feel most of these would've wiped out life completely being unable to give our planet any rebirth of life it will be so interesting for all your views on this one.....us.2u

the Solar system in specific. I`de like to know whether the planets orbit on a plane of concentric circles as depicted in books. OR, do some go over and under? we have the sun in the center and a planet going around it, that can be shown in 2D. but might another planet be moving up and over the inner one and the sun, requiring a 3d representation. I realise this cant be shown on the page of a book very easily, but I find it hard to imagine a reason Why all the planets would be on the same plane in concentric orbitals. I`ve scoured the net for an accurate illustration of what our orbits are REALLY like, and come away empty handed. any one know for sure …

Can this phenomena be taken seriously? or just dreamt up in the sci-fi world? if this could be true would one defy the speed of light? I believe light is not the fastest thing we know of, because I believe I read that a certain black hole was swallowing in matter at speeds superceeding light; & the measure was almost equal (if craft could travel at that speed) from Earth... to Earths moon in 10 seconds; Wow! I thought, Please check this claim out I believe it to be true; so would time travel be eventually possible? what doe's everone think?...us.2u

I was doing a little reading and looked and some pictures about planet orbits and other things. One thing they talked about is how they're all within one plane pretty much. I was wondering why this is, since gravity is holding it in, why wouldn't it be more spherical. If you look at dust clouds surrounding a star, they're planar, why isn't it a big sphere encompassing the planet?

Hi, i've been asked to do something on rocket science. I was particularly interested in the mathematics behind rocket separation. I am in the third year of a maths degree and I was wondering if anyone knew of any books which may help me out? Thanks

Doe's anyone believe we will ever find ETI's out-there or will we be alone for-ever? I thought by now at least we would've had some communication of some type; or maybe the distance is just too far? Is SETI still in operation?......

What do think, is there yet any possibilities to discover big unknown celestial bodies in our solar system INSIDE the orbit of Pluto. What if for example there was a planet same size as Pluto, but nearer the Sun, whose orbit plane was 90 degrees from other planets plane. I don't know how this kind of planet could have been born, but could it be not yet discovered.

I am writing a research paper about NASA and our funding. It is an arguementative research paper, so I would like to hear both sides. What benifits does NASA give to the non scientists of the world? NASA's Budget for 2004 was $15.47 Billion, which is proposed to relatively stay the same and gradually increase to about $17 billion by 2009. currently it represents 0.7% of the yearly budget. You can read the 2005 budget presentation, in connection with the new vision of NASA here: (it is highlighted administrator O'Keefes budget presentation) http://www.nasa.gov/about/budget/index.html Is this a reasonable amount for the designated tasks? What kind of benif…

http://www.universetoday.com/am/publish/upper_limit_star_size.html?422005 The maximum mass that a star can possess is around 120-200 solar masses

Check out this image from the Keck telescope of Saturn. Its multiple infared exposures. The article says its the sharpes images ever taken of Saturn from the ground. http://story.news.yahoo.com/news?tmpl=story2&u=/050204/480/ny11302040632&e=6&ncid=1756

Ive been thinking of getting a telescope. I saw a telescope review in Astronomy Magazine. I think it was a 10" Orion. It said you could see Jupiter up close and you could see the shadow of the moon on the misty clouds of Jupiter. My question is, if i get a big 10" scope like this, what will it be like for observing things like the Plaides and the Moon. Can you switch the eyepieces or whatever to get a whole view of the moon with a big scope like that.

Ok, my friend wants the "specs" on the Hubble teliscope. We found soem stuff over gnutella, but no go. Google wasn't much help either.

Hello all, I am wondering if anyone would explain some basics about telescopes to me. I have done searches of previous posts and could not see anything that answered my question. I am wondering if anyone can explain the following relationships too me? I have the fact that the following equations: focal length = focal ratio * aperture for a Newtonian reflecting telescope. Is focal length the ration between the light reflecting off the primmary mirror and the secoundary mirror? How does the focal length of the eyepiece of the eye piece differ to that described above? I realise the shape of the secoundary mirror must be a eclipse as its the cross section…

Isn't it possible to view everything in the universe as relative to the earth? Like the sun going around the earth? I'm pretty sure there is a fatal flaw to my idea, but I just can't find it... I guess it does make more sense the way it is, but i wonder...

Someone said that we're all looking back in time because light takes billions of years to get to us from far away places. Were they right? What would those places look like if we could see them close up?

There is a theory that a Mars sized object collided with Earth, sending up an enormous amount of debris which orbited the Earth and eventually came together to form our moon. I recently saw on the science channel a picture of Mars where it looked like it had a big scar on the side. I was thinking maybe it was actually Mars itself which rubbed up against the Earth taking a chunk out of the Earth and leaving a scar on Mars. Its not as good a picture as i saw, but here is the "scar" i was thinking of. Its the wide canyon-looking feature that is in the lower center area that spreads out horizontally. In the other pictures i saw on tv, it is much deeper than it appears in …

Current observable evidence seems to be indicating that the universe is not only continuing to expand, its expansion is accelerating. (see http://www.er.doe.gov/Sub/Accomplishments/Decades_Discovery/43.html ) My basic philosophical paradigm (see my signature) is much easier to see if the universe were oscillating between expanding and contracting phases. Thus I found that the current evidence that this might not be the case to be somewhat disconcerting. After considerable thought and research, I have developed a cosmological model that takes this and other current observational evidence into account while still being consistent with my basic view of the nature of the…

Hi At the Big Bang period all the mass of the universe was contained in a very small volume. I think that the density and mass is enought to consider the universe at that time has a black hole and from a blackhole nothing can go out. Then how is it possible that the Bigbang happened ? Do we live in a blackhole ?