Astronomy and Cosmology

I am trying to understand exactly how the earth moves around the sun. Specifically, I need to be aware of any anomalies in the earth's orbit over the past 6000 years or so. I want to get an intuitive feel for just how much the positions of the other planets actually influence earths orbit. Copernicus supposedly went against Ptolemy's teachings in the 1500s by speculating that the earth, and other planets went around the sun. I don't really trust history, but at least you get a general feel for things. Copernicus` book was umm, On the revolutions of the celestial spheres... I think, and Ptolemy's book was Amalgest. But, and someone please correct me…

Does anyone know why the antarctic circle and the arctic circle are at 66.5S and 66.5 N respectively? Thank you

My dad turned around and said that mars was the first of the external planets. i though it was the last of the internal but i'm not sure.

I'm asking: does life exist on other planet/s?. My thought is that life exist on other planet/s, and intelligent, the Universe is too great to have us as unique living beings

I am interested in learning how to read star charts, and in familiarizing myself with at least some of the various constellations. Does anyone here know how I can use the internet properly, in order to accomplish this? Thank you

Suppose that you are located at 29 degrees 58 minues 24 seconds North latitude, and 31 degrees 7 minutes 45 seconds East longitude And you have a compass in your hand, and its pointing north. If you look directly at the North star from that position, at 8:00 PM in the evening, what angle will you have to tilt your head back to see it?

The Hubble observatory may be on its last legs, according to space.com.

I have heard many times that there are more Stars than there are grains of sand on every beach on the Earth. Can we take that further and say there are more Stars than there are Atoms that create the Earth?

What is the universal velocity of the solar system? Do we have exact values for galactic velocity and galactic spin at the position of the solar system, and from this what would be the mean velocity for the solar system? Signed SpaceTime

help again. It dosn't seem to clear to me. Thankx

There seems to be a lot of threads discussing dark energy and dark matter, but non about how, in what way, space is expanding. (Or have I missed someone ?) When space expands, is it known if the space is streatching or new space is inserted ?

i had to write a senior exit project for school...this is my paper (and its the first draft still, i should have the 2nd draft due in about a week)...could anyone give me any feedback or ideas on the paper? Thanx to anyone who can help Part of Something Bigger: The Universe Within In the history of the collective as in the history of the individual, everything depends on the development of consciousness. --Carl Jung The whole of life lies in the verb seeing. --Teilhard de Chardin There are many strange theories about our universe. One is that one single string holds the universe and all other universes together. Another is that we are noth…

I'm pretty sure that photons mediate the gravitational force now. Does anyone disagree? He was wondering about how it is that the universe can expand, and take the matter along with it... inquiring into the method through which space couples to matter. But a true vacuum can not ever couple to matter. So, he made me think about what really is responsible for the gravitational force. I know it's not action at a distance. Or I should say,"It isn't instantaneous action at a distance." If the sun suddenly stopped existing, we here simultaneous to that, would still follow an elliptical path around the place in the solar system, which is the center of in…

Thought this was interesting. Anyone for input? http://news.yahoo.com/news?tmpl=story&u=/ap/20050419/ap_on_sc/liquid_surprise_4

In the cyclical cosmology hypothesized within the framework of M-theory time is still highly asymmetrical. I was wondering if time reversal symmetry had truly shown to be broken experimentally or if there could exist reflection points around which time itself is symmetrical, creating a cyclical cosmology with perfect symmetry in all dimensions.

Yesterday I read a book, in my language, called "COSMOS a short history" with the original title "A brief history of time" by Stephen W. Hawking 1988. The book is mostly a history of the progress of science, with parts of self-biography and some cosmological ideas of him for the general puplic. I got stuck already on page 17 where Hawking implies there is a center of mass of the Universe. (At least in a infinite Newtonian Steady State Universe.) I don't intend to discuss if the Universe has a center of mass or not, just what Hawking implies or not. What I want to know if this prof, (math ?), exists or if Hawking is just over-simplifying in a way such it fa…

What is the degree variation between Map North and True North and how can one tell if a map is accurate? If this is not a good place for this question, where should I post it instead?

In 2007 NASA will launch a spacecraft named Kepler which will search for extra- solar planets it's telescope can scan 100,000 stars every 15 minutes if a planet passes in front of the star it's brightness will dip & kepler will detect it. Scores of extra-solar planets have been found already,but are gas giants like Jupiter.Kepler will be able to detect small Earth like planets....

I am curios how and when light defuses or stops, By this i mean is the light from the sun continue to go untill the edge of the universe (using this as an example not wanting to discuss the edge of the universe). Pleese explain in some detail.

i am going to build a telescope,as i live very close to the sea the telescope would mostly be used for water viewing,even though a spotting scope would be all i would need i am very keen to build a refractor out of brass tube being a retired plumber i have all the tools and knowlege to work with brass. having never built a telescope the only ideas i have come from the web .i was thinking under the lines of a 83mm achromatic objective lense with a 900mm focus with a 1.25" *40 kellner eyepiece does this sound like a good idea ??? any advice from you people who would know would be more than welcome. thanks in advance sol

I was just wondering if anyone had any ideas on how one could create a telescope may it be radio or optical??

And does it only work if their orbital plane is almost exactly edge-on as seen from Earth?

I have a theory on pertaining to Dark Matter and that might have some merit. The document is available online at http://www.dynarama.com/Whirlpool Space-Time Distortion.doc Here is the text of it: April 11, 2005 Whirlpool Space-Time Distortion: Another facet of General Relativity Offering insight into the motions of massive spinning systems The greater the mass and spin-speed of a system, the less its centripetal forces are oriented with respect to the universe as a whole. The fabric of space-time becomes more tightly coupled to a spinning body as the mass of the body increases, causing a whirlpool in the fabric of space-time. As space-time begins to…

i was recently reading a book called 'The Universe In A Nutshell' by: Steven Hawking. He said that the universe DOES end somewhere. He knows this because if the universe was infinit then that means everywhere we look there would be a star, and the night sky would be as bright as the sun. so in other words if the universe went on forever then there would be a star EVERYWHERE we look. But there isnt. So the universe must end at some point

I was thinking; if the lochness monster does exist could she or her family be survivors from the KT boundary? & maybe there could be other water reptiles still living from that period; but what I do find hard to accept there has never been an attack on man or it's craft in dear old Lochness.. 'presuming all these creatures' I would have thought to be predatory, the reason I put this post here if by some means the story is true & other survival of creatures from that period have survived... wouldn't it be amazing if that huge metorite didn't wipe all the Dinos out afterall?....us.2u