Astronomy and Cosmology

How did I miss this news about my favorite Astro mission? "....So granting Kepler at least four more years gives it a chance to look for planets in more distant orbits, allowing the telescope to survey the habitable zones of warmer stars. (It could take a hypothetical alien version of Kepler up to three years, after all, to see Earth transit the sun three times.) Seeing more transits will also increase the signal-to-noise ratio for closer-in planets, allowing more of them to be detected, researchers have said. The review committee's report did not explicitly lay out funding for Kepler's extended operations, but Kepler team members have said that it costs about $…

I consider myself to be fairly up-to-date when it comes to astronomy and cosmology, given that I've never taken an official class on either subjects. I read the popular science books, and I have a few text books about it. So the basic concepts of how the universe works are things that I decently understand. I was having a conversation with a person the other day about the center of the universe. I tried to explain how the universe is isotropic and homogeneous, and how we observe space expanding, and how this suggests that there is no center or middle of the universe. However, he insisted that the expansion of the universe and how the things inside it have nothing to d…

Is a "-pause" a boundary or a boundary layer? For example, is the magetopause the boundary between where the Earth's magnetic field dominates and where the solar influence dominates, or is it the boundary layer between the two? Similarly, is the heliopause a boundary or a boundary layer (i.e. does it have thickness)? =Uncool-

How long does one normally see a comet in the nightsky for? From some news articles on astrobiology websites, it seems possible to view parts of a comet and its orbit for around a week, though most seem to use telescopes...

In the Hebrew version of Wikipedia it is stated that there is no need for dark matter at the elliptical galaxy due to the low velocity: "כאשר נערכו תצפיות דומות בגלקסיות אליפטיות,היה נראה שהחומר האפל אינו נחוץ שם, וניתן להסביר את התנועה בתוך הגלקסיה בהסתמך עלהחומר הנראה בלבד" In English: "When similar observations were made in elliptical galaxies, dark matter would seem there is not needed, and can be explained by the movement within the galaxy, based only on visible matter " בגלקסיות אליפטיות קיימת תנועה מן המרכז והחוצה, שאינה מתגלה בקלות עלידי אפקט דופלר על-פי גישה זו, מהירותם של הכוכבים בגלקסיות אליפטיות גבוהה מזו שנדמית לנו, ולכן גם בהן מתחייב ק…

Are there any empty vacuum space through which light can not travel in the Universe? Do we have any information about it? Are there any Dark Matter which has such property?

I'm posting this here because the material I'm reading deals with cosmology and the origin of the universe. If the topic belongs in a more appropriate location, please advise me, and I'll ask the mods to move it. I've been reading The Origin of the Universe by John Barrow and I'm starting this thread to discuss an idea he puts forward that I have to disagree with. I'll quote the salient passage here and then put forth my counter-argument. The last line is the part that I take issue with. From my understanding, what Professor Barrow seems to be saying is that we cannot define time unless we append some concrete units to it - pendulum swings, seconds, vibrat…

I read that dark matter accounts for 23% of the mass-energy content of the observable universe, while the ordinary matter accounts for only 4.6%. My question is which category do black holes fall into? Do you count them as ordinary matter? If a massive star collapses, we get a black hole. What if a huge collection of dark matter collapses? Will we get a black hole again? I guess yes. Can we distinguish such two black holes? Can we count the latter black hole as part of dark matter?

And what would happen in a universe without time or space as the case may be. Well I am just a curious 15 year old so please don't make fun of me if I am asking silly questions.

Hi all, new to the forum but not to science! As all of you probably know, the transit of venus event is coming up on June 5th and 6th and what better way to witness this historical event by building a sun funnel! The sun funnel will allow a large group of people to view this event by using rear-projection screen material. You can check out Rick Fienberg's guide to building a sun funnel for step-by-step instructions!! The key element to safely viewing the sun and to building the sun funnel is the Da-Lite High Contrast Da-Tex rear-projection material. The material is also linked in Rick's guide to building the sun funnel. They have free shipping and a great price and there …

Hi all, sorry if this question has been asked before, but are there habitable planets and/or moons in our solar system? If so, how is that possible?

Hello all. New user, novice thinker. I searched the forums but didn't see any relevant response - apologies if this is redundant. Everyone knows that the universe is expanding. But, to where is it expanding? Doesn't the mere fact that it's expanding indicate that there is something on the other side of the expansion? I'm thinking of it like an expanding balloon, pushing the air away as it expands. Also, using the balloon analogy (maybe that's where I'm mistaken), a balloon expands because it fills with air. So if the universe is expanding, with what is it expanding? Thanks for your input.

The Milky Way was formedrelatively soon after the Big Bang – about 13.5 billion years ago. In contrast, the solar system was formed just about 4.5 billion years ago. So, where the solar system was formed? Suppose that it was formed at thesame location as it is today. In this situation, we would expect to see anactive star formation at various locations throughout the galaxy. But this isnot the case. A star forming activity had been found only near the galactic nucleus. Wikipedia - "The region where the Scutum–Centaurus Arm connectsto the bar of the galaxy is rich in star-forming regions". "The current hypothes is isthat the bar structure acts as a type of …

I've never seen a worm hole, and I can't think of anyone who has, but there are still a few theories about worm holes. You guys told me that worm holes are more theoretical, but does that make black holes theoretical as well? Maybe worm holes are a type of black hole. Then there's the idea that worm holes are randomly everywhere in the universe. Could they really do that? If so, how could anybody find them before they close? And if worm holes close, how long do they stay open before then? If there are worm holes, maybe they could be utilized as an aid in transportation in space.

thoughts?

does anyone know how I can place images on this forum of models I have to show? I have tried the insert image icon but it seems not to be working, also these images I just want to load from my desktop up onto here, they have no url address, thanks!

Based on Wikipedia: 1. Star birth at the center of the galaxy: "The region where the Scutum–Centaurus Arm arm connects tothe bar of the galaxy is rich in star-forming regions" "The current hypothesisis that the bar structure acts as a type of stellar nursery,fueling star birthat their centers". 2. Older stars as move outwards from the center: "The metallicity of anastronomical object may provide an indication of its age… older stars havelower metallicities than younger stars such as our Sun". "Across the MilkyWay, metallicity is higher in the galactic centre anddecreases as one moves outwards". "Population I or metal-rich stars are thoseyoung stars wh…

. What do you guys think of this news: "Is the Universe Spinning?" What is the universe spinning with respect to? Has there been any further developments regarding the discovery? .

Does anyone have any recommendations for books or articles on black holes? I'd really love some ideas, thanx guys

Is there a chance of new planets still forming far away in space, even at this very time?

There are two options here: either the universe is FAR FAR FAR older than 6,000 years, or God is a liar. Since God isn't a liar (by definition of the traditional YHWH as being morally perfect), that leaves us with only one option. It's a simple Disjunctive Syllogism: OvL ~L O But how can we set up that initial disjunction? Well, it involves knowing a couple of things about physics, astronomy, and the Bible. The speed of light is both constant and invariant. This follows directly from the Maxwell equations that describe how electric and magnetic fields behave and is the basis for one of the most well tested theories ever. If the speed of light weren't c…

Okay, so I tried to google what would eventually happen to a neutron star and nothing showed up, so i'm gathering either no one knows or we think that it will remain a neutron star, I thought that they may become pulsars but I don't know what happens to the others, some people say they become invisible but does anyone know why this is?

It's said that there are only 6 categories of different string theories and around over 600 known different models, what's yours?

According to my understanding, a black hole is defined as an object whose mass is hidden behind an event horizon. According to its definition, an event horizon represents a boundary from which it takes an infinite time for light to reach a distant observer. Thus, in the observer's frame of reference, event horizons are at an infinite distance in time. Now, current doctrine teaches us that there are black holes in the Universe while it also teaches us that the Universe has existed for only a finite time. To me, it is obvious that these teachings contradict each other, yet I have seen them repeated over and over again also in the most prestigious publications. How c…

Saw interesting article on testing dark energy and general relativity versus the idea that there is a fifth force affecting gravity out there. Seems like Einstein wins, at least so far: http://spaceandearthsciencearticles.blogspot.com/2012/05/is-there-fifth-force-that-alters.html?spref=tw Comments?