Astronomy and Cosmology

the astronomical distance scale is established step by step in a kind of ladder the lowest rung is parallax and each lower rung is used to calibrate the rung above it Wikipedia does not have an entry for "astronomical distance scale" yet. Wiki has a STUB. Someone should write them an article. the distance scale is very important and a lot of different kinds of physics and astronomy went into establishing and checking the various steps on the way up the ladder. Many people know about the H-R diagram (Herzsprung-Russell) gauge of distance and the Hubble-law redshift gauge of distance, and the Type IA supernova standard candle gauge of distance. but the thin…

If two bodies of roughly equal mass coalesce into a condensed form (neutron star or black hole) would we experience dipole waves? If the masses are different are there then quadrupole components?

http://www.cnn.com/2006/TECH/space/04/05/supernova.blast.ap/index.html This in perticular was always my personal speculation: "It shows that planet formation is really ubiquitous in the universe. It's a very robust process and can happen in all sorts of unexpected environments," said lead researcher Deepto Chakrabarty, an astrophysicist at the Massachusetts Institute of Technology."

http://www.cnn.com/2006/TECH/space/03/14/stardust.results/index.html Im a little confused here... what does this all mean? Were the comets part of cataclysmic collisions between planets and they broke off, thus creating the "fire" part to them, and then floated around collecting cooled off pieces of debree creating the "ice" part? Im so lost...

Here is an apparent paradox They say that everything was created by the big bang whıch was a single point event. So both big bang background radiation and we the viewers of this radiation were created by the big bang. The radiation is travelling at the speed of light Then surely we must have travelled faster than the speed of light in order to get in front of it to be in a position to view it. sorry about the lack of punctuation. Im in a turkish internet cafe with funny characters ığüçö

Very Cool. Check out this article on Fox News.

Gravitational Redshift *************************** Could it be that the gravitational redshift is an obvious fact and can in no ways be used to prove GR. If we only use the following facts we can derive the gravitational redshift ; 1.The conservation of energy-matter. 2.The potential energy on earth PE=m*g*h (or that of a star G*M/r ) 3.The energy of a photon E=h*f. 4.E=mc^2. There are no other theories or facts that we need to prove the gravitational redshift. To show this we make a thought experiment with Alice and Bob. Alice and Bill have decided to do something unhonest. They wa…

In a recent article in the magazine New Scientist (on 25 March 2006) they taked about these gravitational "Tubes" that allow easy travel through the solar system. These tubes lie along the gravitational contours of the solar system. What I was wondering is could these "Tubes" exist between stars? and could they give a means to easily send a spaceship to another star (of course it would still take time to get there, but would these allow a ship to get there faster and with less fule needed)?

Here is the question - How/why/when has Universe appeared? The only thing i can think about is that It has appeared from The Nothing You will say that was all about the singularity but from what, then, the singularity appeared? If our Universe appeared from nothing (and without a purpose/reason), then I can say that there are infinite number of "Universes" (in our perspective) appear every "moment" with totally different laws of nature, logic, constants etc which we are never gonna understand, because we weren't born there and having different brain. Very probably that all the universes aren't interconnected so technically we can say they all don't exist (in our perspect…

There is a website http://www.worldjumpday.org It says that if 600000000 people jump at the same time, our planet's orbit will be a little bit further from the Sun. I wanna hear a scientific opinion about that? Can it really be true?

If you know any rare astronomy events, post them here. Make sure you include dates, specific times, locations, where to look, what to look for, and links. Mine: Catch Mercury While You Can http://space.com/spacewatch/060217_night_sky.html Location: Northern Hemisphere When: The best time to see it is February 24, 2006. But it is visible until March 3rd. Time: About 45 minutes after sunset. Where to look: Just south of due west. What to look for: A very bright "star" with a trace of a yellow-orange tinge. Start posting some events!

the March 2006 issue of the DUTCH version of the Scientific American has an interview with physicist Renate Loll called "The Bubblebath of the Universe" http://www.phys.uu.nl/~loll/Web/press/RLoll_in_Sciam.pdf is there anybody here at SFN who can read Dutch and would take a look to see where the good parts are? the interview is 4 pages, if we could focus down onto a few paragraphs that have the main message then we could use the Babelfish translator and see what they say.

Now that we also sending more digital TV around. I was wondering would it be easier, or more difficult for an other intelligent lifeform to reconstruct an image from it.

Padren posted this picture on the news forum yesterday of a double helical nebula - orignally published in nature last week. does anyone know what its chirality is?

I think I have an idea that would make the Big Bang theory impossible. First, I think the Big Bang theory says that all the matter in the universe was once compressed into a small sphere. Now, can you imagine how much mass that small sphere must have had? If a sphere with that much mass really did exist, I don’t understand how it could possibly expand into the universe. A black hole would contain much less mass than the small sphere in the Big Bang theory. Yet, a black hole has so much gravity that light itself cannot escape. If matter cannot exceed the speed of light, wouldn’t that also mean that matter couldn’t escape from a black hole? If matter isn’t able to…

It's a thought I had earlier today and I've done no research on it at all, so if it's wrong, be sure to tell me. But I was reviewing the String Theory and the way many physicists view the way our solar system as sitting on a large bedsheet, the planets are weights in the bedsheet causing pull on other objects. Well I had a thought and recalled some information. There seems to be no real corellation between planet size and gravitational pull. Saturn has the same mass as 95.162 Earths but has a gravitational pull of 8.96 m/s^2 or .914 g's. The thought was that the all these factors came into play to determine the amount of gravity. Size, mass, and age all play a…

starting Thursday I will be checking these websites http://lambda.gsfc.nasa.gov/ http://lambda.gsfc.nasa.gov/product/map/current/ right now the "current" site only has "first year data"---it should soon be updated to show "third year data" the WMAP is the satellite at Earth-Sun L2 which gives us an accurate map of the Cosmic Microwave Background (CMB). The three-year data from WMAP are due to be released this week, around Thursday 16 March. Most of what we can say about cosmology---overall outlines of the universe---depends on measurements of the CMB. So it is a big deal. People have been waiting for 3 years for this data. I have heard a lot of impa…

I'm reading that photons get absorbed by electrons which then emit new photons. (electrons in cosmic gasses or other mediums) So the photons that reach us are not the photons that started out the journey. Is this true?

First of all I am not claiming that I have a new theory or something.What I am just saying is that I have another viewpoint of looking at the things which will follow.Before that,I request you all that if you read the post please leave a reply,may be a comment,a flaw that you find,some criticism,if you want you can put that I am a jerk but please discuss and guide.So here goes. When I first learnt that G relativity puts gravity as space-time geometry then my response was that other forces must also be space-time geometry as nature can't be biased to one force.That was just an intuition.No other reason for believing that.Then I came to know about kaluza-klain theory an…

How do you think things would be affected in space, like lets say fish considering they swim or birds being that they fly? Or what about coldblooded animalsl?

Check this out: http://www.nytimes.com/2006/02/28/science/28prof.html I just have to say, "!" Does anyone have any more info on this? I, personally, had always assumed that black holes were inherently unvisualizable, seeing as how no light would actually reach the eyes (not only that, but the "tearing" of space wouldn't fit into our 3D mental frameworks). Was I mistaken, or am I missing something?

Why are the planets traveling in an elliptical orbit. According to GR the sun bends space time so the planets orbit. I'm assuming the pull of other planets would not cause it. Would it be the angle it orginally came at and began being pulled by the sun and then it just continues an imperfect orbit? Also, does this orbit slowly become circular, just taking many billions of years? I was just wondering about this.

Pardon my ignorance but how on Earth, er… well… in the universe do supernovae reform into new stars? We know that our sun was formed from a supernova because we have heavier elements. Without a supernova, there can not be heavy elements. It is my understanding that we have heavier elements on Earth (and throughout the solar system) because a previously existing star in the vicinity of our solar system went nova. I am also to understand that a star goes nova when it runs out of Hydrogen, then helium, carbon, nitrogen, oxygen, etc until it reaches iron and cannot fuse any more. Then the force of gravity causes the core to collapse and the star explodes. And the lif…

I've just been learning solar radiation distribution and it's effects on our environment (as infrared transfers) however it stated the solar luminosity is 70% 4600 Ma ago to what it is now. I guess that a lot of energy is being absorbed due to the strong gravititational field of the Sun, but why doesn't it just keep gaining energy. Is it due to the half-life of the Sun's core...I'm really not up on nuclear reactions et.c so that might be nonsense, but what kick's starts the energy depletion to warrant the demise of our Sun into a white dwarf...why is it that it's gaining energy to sustain itself, and then the reverse happens ? Sorry if this seems a daft question…

http://www.cnn.com/2006/TECH/space/03/09/cassini.enceladus/ NASA press release http://science.nasa.gov/headlines/y2006/09mar_enceladus.htm?list45222 liquid water squirts out in geysers--------tap for energy? more: http://www.nasa.gov/mission_pages/cassini/media/cassini-20060309.html