Astronomy and Cosmology

Is it an impossibility to "create a new universe" at some point in the present universe? Obviously assuming some far off technical ability is it theoretically possible to create a new "universe" that would have its own independent laws and also be unaffected by and not subject to the laws of the universe wherein it had been created? Is that an entirely impossible concept? Would there have to be some kind a a barrier between the two universes? Would the barrier have to obey the laws of both universes? If such an attempt were ever to be made would someone just pipe up "it is the same universe ,just a subset"?

The Universe has been expanding since the Big Bang ye? so we can see the 'red shift' in galaxies moving away. Does this mean literally that galaxies are getting further away from us in miles? or does 'stretching space' mean something else? I'm not a scientist so I need some assistance on this one

Hi Why You Can't See Stars on the Moon ? the answer is on the video Link deleted i hope that you will like it guys

Ok, so if gravity propagates in waves at c, I have few questions. 1. Does the cosmic horizon also apply to gravity? 2. Is gravity 'red shifted' by expansion of space? 3. Is this taken into account in current models of expanding universe? 4. Would this explain dark matter/energy to some degree?

Could gravity just be electromagnetic fields? Things we observe on a smaller level (static cling, polarity in magnets, etc) seem to show that the flat shape of our solar system is shaped more by the electromagnetic field of the sun while the sensation of gravity just seems to be one object static clinging to a much larger one (an apple falling towards a planet). Just a thought though.

I was watching the documentary about this project based on La Palma with the "magic" telescopes last night. Am I right in believing that the gamma rays being monitored are of 2 different energy levels and if so could someone explain (as simply as possible) how the 2 states come to be - and define the differences in practical terms if possible. or perhaps correct me if I have misconstrued something? thanks

I'm just curious about the project to send a 1 gram solar sail accelerated to a significant percentage of light speed in order to "image" a planet? The project reminds me of a scene in the UK TV series "UFO" where they sent a camera out and were amazed at the results ... until that is they realised they had no measure of perspective or distance or size. What they were looking at could have been anything. Is this 1 gram spacecraft going to have this issue or has that been worked out somehow? I'm also curious about what material could withstand the space dust and other particles out there at those velocities. Is this project really useful or is it a gimmick…

Dear Everyone. I expect I'll be back but basically this is the question I've joined to ask. I've seen loads of NASA pics. of The Earth from Space - but you'd expect to see loadsa stars in the background, many more than you usually see on light-polluted Earth (on the whole!) But there's never any, Space is always jet black in NASA shots without a star in sight. Evidence: http://earthobservatory.nasa.gov/blogs/elegantfigures/2013/04/22/earth-day-and-night/comment-page-1/ Like - where's the rest of the universe gone!?! (Google 'NASA Pictures of Earth from Space' and you'll find every one is galaxy-free! And the same with the Moon, Jupiter even.) I'm so…

Why is the 4-dimensional entity of the universe not argued to be the beginning of the universe but instead t=0? Arguably, the 4-dimensional entity is our best understanding of what the universe is, if but our beginning understanding of it. Otherwise, I suggest that is has been argued that the universe is a three-dimensional object that exists along time.

I've read that, because of the curvature of the universe, light going in a "straight line" would, given enough time, end up where it started. Now, I know this is impossible to do, but imagine if we had a wire making machine that could, for the sake of this thought experiment, make wire really, really fast. Ignoring the length of time it would take - would it also end up where it started so that the front end could connect to the back end, resulting in an actual loop of wire in some sense. Is there some abstract mathematical perspective from which it would be "seen" curving back on itself? I'm afraid - and I'm probably not the only one - I keep imagining it going in a …

I'm currently writing a book and need help working out a possible solution to a problem I'm having. The world is almost completely automated and, therefore, a solar flare large enough to knock all the world's electronics would definitely spell the end of everything. In this world all of the world's resources can be directed towards individual tasks at once if need be so thinking big is not a problem here, the planet is totally unified. The best I can think of is either to install circuit breakers in all electronics and some mechanism that would restart everything after a few hours or install some sort of huge magnetic installation that uses immense amounts of power to …

Greetings, Idealism is a minority position in physics but has significant supporters. I have created a ppt entitled "How the Universe Works" that uses Dr. Radins recent double-slit experiment with meditators to support the position that the universe is idealism, please view the video link in the ppt. Idealism can explain theodicy - the ruthless, amoral, violent universe we live in. In addition, I propose a modernized Neoplatonic Cosmological Proof, not for "God," but for "dynamis" the quantum field of infinite potential as the non-personal basis of being. Many of the slides have significant notes, to see the notes and slide animations view as a ppt on your local …

Could the expansion of space affect the star rotations in the outer regions of galaxies? Since lamda has negligent effect on solar system scales, newton prevails. With the outer stars of galaxies being gravitationally bound to the core, and with their orbital distances resisting the increase, could not lamda be converted into a small forward thrust?

A new planet was discovered recently orbiting Proxima Centauri, Earth like in both size and habitable zone orbit it has of course fueled considerable speculation. The planet is thought to be so close, orbital period or year is 11.5 Earth days, that it is tidally locked with it's star keeping one side facing the primary much like the moon does the earth. In our own Planetary system The Planet Mercury was once thought to be tidally locked due to it's close proximity to the Sun but it is now known Mercury rotates on its axis exactly three times for every two revolutions it makes around the Sun. Could this new planet also be orbiting in this manner due to the sam…

There is a conondrum in cosmology related to the 13.7 billion year estimate for the age of the universe. It is as follows: Quasars are estimated at distances approaching the age of the universe, and began emitting radiation (light) to our position close to 13 billion years ago. But according to big bang cosmology the universe had a beginning 13.7 billion years ago, space expanded along with the material from which Quasars were formed, and the universe was near its beginning compressed to a more confined, restricted dimension of space. The conundrum: How did Quasars escape from this earlier confined region of space to assume those position in space that the evidence (…

I keep hearing gravity waves described as ripples in space time. Does this suggest that space time is a substance like the discredited notion of the aether? It seems to me that if space time can be said to ripple then a preferred reference frame is suggested by this "ripple" I know I must be off base here but how am I mistaken?

Anyone know if the first manned missions to Mars will have artificial gravity during the long voyage to and from Mars? It seems simple to have a spacecraft designed to rotate and create one g. At least while they are sleeping or their free time they can relax in a one g environment. Is that possible? Anyone know if a centrifuge can be built on the surface of Mars or the Moon where the crew can sleep, or even recreate, in a one g environment?

For the last time I never said that it would be entirely different but think of this , in another solar system where the mass of the star would be lower or greater than earth but the radiations and the gravity of that star would also influence the space around its system thus due to that factor the planets revolving around it would also get influenced by it and their revolution and rotation would differ from the planets in our solar system. Thus the behavior of the entire system would not be as ours, hence there would be different laws for the matters to interact.

According to relativity, gravitational fields cause time dilation effects, lets say for instance i have a 'magic' device that can generate gravitational fields Is it possible that this can be used to slow down one's time so as to make the journey seem much shorter

Could the observed missing mass of the universe/galaxies be a result of unobserved black holes or other dense but faint objects

could there be whole other galaxies and solar systems and being made of dark matter

At first I thought it was fake but then I went to the Nasa site and saw this animation of the Moon passing in front of the Earth. http://www.nasa.gov/feature/goddard/from-a-million-miles-away-nasa-camera-shows-moon-crossing-face-of-earth And then i thought, if the satellite is always facing the daylight on Earth, it means the sun is behind. And if the sun is behind, doesn't that mean that this is actually a solar eclipse going on?

If the expansion of the universe is uniform throughout and is less than c, how is it that beyond the Hubble Limit (HL) a photon will never reach the observer? I can understand, at great distances, that it gives a certain measured or apparent expansion rate that may exceed c, causing a photon to redshift, but locally, around the photon, the expansion rate still matches, objectively, the expansion rate at the locality of the observer. As it stands atm, in my current - wrong, no doubt - understanding, it seems that, beyond the HL, the expansion actually increases incrementally faster than c locally, resulting in the photon never reaching the observer i.e. it doesn’t just se…

I came upon this statement about gravity lensing the other day. It reads: "The ratio of a planet's radius squared to its mass lets us calculate the distance a spacecraft must reach to take advantage of gravity lensing." It's the first part of this statement that I can't understand - "The ratio of a planet's radius" especially. While I know the meaning of each individual word, I simply cannot string them together in any meaningful sense. Neither can Google apparently. Any suggestions?

Hello, it's my first post here I wanna discuss an idea that has come to my mind, when I was thinking about how an advanced civilization (> type 2 in Kardashev scale), could develop. So if an civilization, wants to win competition in advancement of technology with other civilizations, then one way would be to use time dilation effect for advantage. There are at least 2-3 ways to use this effect. Method 1 - use time dilation to make your civilization time run faster, compared to other civilizations, to increase speed of advancement in technology compared to other civilizations. There are few ways to make time run faster (if I'm not wrong). First would be to slow down…