Astronomy and Cosmology

http://sciencenetlinks.com/science-news/science-updates/solar-power-from-moon/ The science behind it shows it can be done and meet global demands, but could it be done? The moon is smaller than earth so it's not like putting panels around the equator but it's still a huge surface to cover, there would be countless trips to space, huge wastes of money and decades of planning Putting panels around the equator could be a simpler task There is water frozen under the moons surface which it is believed could be used to launch space crafts from the moon using hydrogen, it still takes a lot of fuel to get there in the first place though, even so by the time this cou…

I've heard neutron stars can rotate 500 times per second, I don't know if it's true, it sounds so incredible that it could be one of those space facts that is made up just for the sake of it but I can also apply this question to hypervelocity stars there is a neutron star named RX J0822-4300 which is moving through the milky way, this star travels at 3 million miles per hour, As the faster you travel -the more you weigh would this neutron stars mass get multiplied travelling at this rate? Another question to add to the previous would be whether in space, the speed of travel affect the weight of an object and perhaps friction is needed but there are still atoms i…

In September 2011 the star SDSS J102915+172927 has been observed in the Constellation of Leo. It has been found to be 20,000 times poorer in metals than the Sun which would suggest it is incredibly old (13bn years). Yet its mass is only 0.8 times that of the sun while the stars that formed at that time are thought to have had masses millions of times greater. Also the Lithium fraction is 50 times lower and it lacks the metals concentrations thought to be necessary for it to have formed. While other metals poor stars have been observed, this seems the most extreme example. So I thought, half jokingly, whether it could be... mmmhh... how can I put it... "artificial". I mean…

So the current knowledge is that our universe is expanding at an accelerating rate; the farther the detected universe, the faster its velocity away from a center. My question is, when we look at distant galaxies, we are also looking into the past. So the greater doppler shift to red, or the faster movement away from a center of the galaxy, the farther into the past we also look, because of the fact that a greater doppler shift to red also means that the galaxy is farther away from us. So can't the reason for the greater velocity at greater the distance be due to the fact that galaxies in the past moved at a greater speed due to the momentum given to them during th…

What created Big Bang? What created the thing that created Big Bang? And why is there something rather than nothing?

I recently thought of something. I've heard several times that if a person were to fall into a supermassive black hole, that they would survive quite comfortably for a while even after they've crossed the event horizon due to the lack of significant tidal forces. But there's one thing I don't understand. From what I've read about black holes, the event horizon is the absolute point of no return; it's the point at which outward movement becomes impossible. In other words, once you cross the event horizon, the only possible direction you can move is inward towards the singularity. Now this got me thinking though; if that is true, and past the event horizon nothing can m…

If you were given no knowledge of modern theories what would you guess black holes would be like from observations? -They seem to emit no light. -Massive amounts of material seem to be being shot out from areas in the vicinity of black holes- Do spiral bars come from there? Is that all we know?If so,what would be a best guess for the nature of black holes and how much does it agree with theory? What other observations agree with the conventional wisdom that they are singularities? (Sorry,another speculative BH topic)

Ive heard different theories and statements that when the asteroid that hit the earth during the time of the dinosaurs that it wiped out all life. Even micro-organisms and bacteria, then also that it didnt wipe out all life, or that when it did destroy all life there was a burst of life later that no one can really explain. So if it did wipe out all life, where did the burst of life come from afterwards, when not even bacteria and micro-organsims lived? how did life begin again after the asteroid that hit earth at terminal velocity?

What if our universe is the inside of an atom? Could it be possible?

Hi, i was wondering if the photons of today are the same as those of the easy universe. In terms of the understood gravitational wave which occurred during inflation through space-time. Could/did this wave change the spin of the photons, while not changing there bosonic form, but changing their intrinsic properties by jolting them 'so to speak' in such a way that their property of spin changed. similarly like a planet being hit by a meteorite etc and having its centre of gravity changed while still being a planet... ? Thanks.

The typical answers for the shape of the universe are positive curvature, flat, and negative curvature. Is it possible that the curvature could be such that the entire universe is one closed timelike curve? One such that the Big Bang is caused by the Big Crunch? I'm not talking about a cylical model, but one where the end event and the beginning event are in fact the same event. What would we need to look for to falsify this idea?

I wonder if an asteroid could possibly be soft landed on Earth. I mean, if it could be brought down to the surface without causing havoc with its impact and dust clouds. I've seen news about parts of satellites and rockets falling down rather intact without burning up in the atmosphere. What does it take to put something into a gentle fall like that from space? Is there a size limit? It's the speed which makes asteroid impacts dangerous, so my thought is to drop them down at minimum speed. I imagine that some asteroids might not be so very difficult to move into near Earth orbit using gravity slings, collisions, reflected solar light, rockets et cetera. And if they co…

In the many movies the arrival of extraterrestrial beings or machines takes place in the form of a major ship retrofiring its main propulsion as it approaches the solar system. In my view, a much more reasonable expectation, would be for robotic probes to evasively (out basic prudence, if for no other reason) enter our system using the sun and the more massive planets to manouver and lose speed before approaching our planet to deploy and activate on orbits closer to Earth and eventually on it. It is even plausible that the entire event would never involve any major vessel coming in our vicinity; it may not even involve any contact (manifest presence) at all. This i…

I have created a hypothesis about the formation of supermassive black holes affecting the formation of galaxies. Feel free to critique but don't steal my idea, please. Black holes have an affect on galactic formation by bringing in planets and asteroids. The larger gravitational pull of of the black hole, asteroids and planets would then have a larger gravitational pull. This would cause more materials to be attracted towards the black hole. (The black hole would gain more mass when it sucks in matter, so the gravitational pull would still increase.) This would keep snowballing until it turns into a very large black hole classified as a Supermassive black hole. More …

Hi, Not sure if this is a particle physics, Cosmology or physical science question - maybe all ! If light travels as a wave, why do the waves not interact with each other (like water waves do) on the way to our eyes. We should surely end up seeing just a mess of light. The question also relates to light sources in the universe where the light has been travelling with/alongside and interacting with other light sources for billions of years. So, how can we see individial (e.g. stars, galaxy's etc) light sources ? Stupid question - obvious answer ? George

I would appreciate any information in respect of the force responsible in galaxy formation.

A new look at dark matter and dark energy is uniquely presented in an interesting demo program available at link: http://dl.dropbox.com/u/26262175/SagitariusBRprogramDescription.pdf I am interesting if anyone knows other educational programs on dark matter or dark energy which are available on the Internet?

I am trying to understand the theory behind "slingshotting" around planets or suns. I can see the benefit of aiming towards Jupiter and missing it to reach Saturn. Let the gravitational pull of Jupiter add to your acceleration and detract a bit once you are past it so you wind up with a net profit in avg. velocity. Is there a circumstance where it will actually give you a net increase in end velocity. Just aman

If an asteroid or a comet Were on a collision course with earth, of diameter ~300m, and we fired a hydrogen bomb at it, would it be destroyed? And is rock harder to destroy than ice? ( I guess it is)

If a star, or a sun, 'burns/converts' matter into energy, chances are the homogeneity of its matter among its active surface is not, as flares appear in an area and later on another, as a non uniform surface 'burning' Is our sun propelled (transported, pushed) randomly in space by the energy flares it emits as to move towards opposite the random significant flares ?

Forgive me if this is an obvious, or simplistic question but I am completely new to the field. Thank you. CONFUSED: When we see images of deep space, or something like therecent "Ultra Deep Space Field," I believe it's called, we are seeingan area of space not as it is now, but as it was millions of years ago,correct? We are essentially, seeingBACK IN TIME. But if that is the case then, what we are seeing has been altered by millionsof years of expansion, so that the objects we do see are, AT PRESENT, muchfarther away. Is that correct? Now, when we are given the numbersdescribing the distances of these objects, do those number reflect the distancesas …

i have a quistion. when does the universe end? it cant stop, because there has to be something there. space is nothing but yet is something. its a paradox. we cannot feel space, yet we cannot see it or touch it. there is no gases in space. yet we know about it, and there is somehitng there. so if the universe goes on forever, there would be infinite items.s there would also be infinite space. one day, im gonna get in a spacship and keep going until i find out for myself. its bugging me, and my head hurts. someone help me and answer this hmm.. no posts yet. im starting to get tired, bt i cant sleep with this on my head going to sleep notify me if u post. *beep* g…

Does universe expand for ever or will it have a big crunch?

Is it possible for planets to orbit each other over an extended period of time, i am thinking billions of years, as described by Robert L Forward in his book Roche world? http://en.wikipedia.org/wiki/Rocheworld

Let's say that a space probe orbiting the Sun in an elliptical orbit would emit heat towards the motion direction., and hence causing resistance against motion. Let's say it would happen exactly half of its orbit, - and that the motion resistanceis 1E-9 m/s. The other half of the orbit the heat escape would be turned to acceleration instead, also 1E-9 m/s. I believe this would cause the space prove to get its own perihelion precession anomaly. I know I must use Lagrange's planetary equations, but this is above my head. How can such be calculated? (Thisis not homework)