Astronomy and Cosmology

Here are some 1st reports from the Herschel space observatory: http://herschel.cf.ac.uk/news/herschel-reveals-stellar-surprises-and-galaxies-galore Merged post follows: Consecutive posts mergedAt another forum, a member of the ESA told me that they were terribly disappointed with this press release. It contains a lot of erroneous info and should probably just be ignored.

According to theory, the universe has been ever expanding since the Big Bang. Is the force from that initial event the only cause of the expansion of our universe? Also, if that happens to be true. Would the force of gravity slow the universe's expansion to a point where it stops all-together? since gravity affects matter in an infinite distance in all directions, would it not be true that the universe would begin to contract? Lastly, because gravity would be the only force affecting all the galaxies, would they over time condense into an infintesimally small and dense black hole, recreating the initial conditions for the Big Bang?

Is it possible to build a shelter for people on Mars that rotates in such a way to create one G gravity on the surface of Mars? I was thinking of the slowly rotating "bicyle-wheel" space station that can create one G gravity anywhere in outer space. If that concept was slightly modified to rotate at an angle, the humans inside the Mars, or Moon, station would experience one G gravity. I was thinking of a cone shaped structure. The crew compartments would be at an angle of about 20 degrees from horizontal. Except for that, I think it would be very bad for people to spend such a long time in one nineth G gravity that exists on Mars. Human missions to Mars would tak…

A star exploded 2 millions years ago. This star is at a distance of 1 million Light Years from us. Can we see the explosion?

The goal of the Planck Telescope is primarily the analysis of the Cosmic Microwave Background, however some recent images from Planck show the huge amounts of interstellar gas that exist. We typically see interstellar space as pretty empty, with occasional nebulae and stars, but as we see from these images of the Orion Constellation, that's pretty far from the truth Just as interestingly, the light that we see there is actually stuff that has to be discarded in order for Planck to do it's prime job, though of course there will still be researchers who are very interested in these images as a part of their work. http://news.bbc.co.uk/2/hi/science/nature/86…

I often wondered whether the sub-particle data generated within particle accelerator/colliders accurately simulates the conditions of the creation of the universe. These products of particle colliders, seems to generate data that is a better simulation for a collapsing star or universe, but not an expansion. Let me explain this with a little common sense logic. If we took X number of protons and only accelerated them in a particle accelerator, to very high energy, we still have protons. This is the expansion scenario. For experiment two, we will divide the protons into two halves (1/2X) and accelerate them in the opposite direction, so the total system energy is…

Alright, here's what I understand. After it flies by Pluto, it just goes off and sooner or later leaves the solar system, I assume I'm correct on that. After that, can is still transmit radio waves to us? Can is still send us pictures?

This is sort of related to the "can the speed of light slow down"thread.Will it really slow down? I think so because the sound gets softer the farther away it is.Why not slow down and get softer?

considering that a gravity field in fluctation will produce a gravity wave, will a gravity wave contribute to the formation of a stellar mass collapsing to a neutron star? how?

What happened to mars there is a theory that there was life on mars is it true. I think so mars has valleys and ice. So was there liquid water or not if not why were there valleys.:confused:

What is the momentum of a single photon? Is there a way to demonstrate the momentum? Say using a cylinder with a diameter of "D" filled with a gas of known mass/density with a height of say H=D/6. If photons from some source, that can be measured, are directed into the cylinder with the outside of the beam of light at the tangent of the inside edge in several places along the perimeter of the cylinder will it, over time, move the gas into circulation around the cylinder?

Keeping it short and simple, If light is traveling (at the speed of light of course) in the exact opposite direction to the pull of a black hole, will it not HAVE to slow down? Light is effected by the gravitational pull of black holes, and usually spirals into them, but if a photon is traveling in -exactly- the opposite direction to the pull of the black hole, then it will have only one way to accelerate: backwards. It seems to me that physicists are always saying light can't slow down in a constant medium...but if light didn't slow down here what would happen? I can't see another possible solution. Please reply with your thoughts, I have tried talking with person …

Preface of my understanding: While galaxies may be moving, they are primary enacted upon by the expansion space. while a galaxies standard motion accounts for some redshift, most redshift derives from the expansion of space. Primary questions: 1. I am not entirely sure how space itself expanding impacts the frequeency of light, does it smear out light of the expanded area? 2. As space expands there is now more space TO expand therefore causing the acceleration we see. So can we observe the redshift of the most distant galaxies getting more and more red the further they get... if indeed the further they are the faster they go?(i.e. measure redshift today, co…

this scenario describes the final collapse of a star to a black hole, and also will ask some questions that i hope you can help me with. heres the short version: gravity wave triggers spatial contraction to singularity, a 2-dimensional object

this page will deal with the formation of black holes. your comments are welcome on the following points. perhaps youve seen pictures of black holes with swirling clouds orbiting around them? this would seem to indicte that during collapse (preferably during spatial contraction and because of it) only a certain amount of mass/energy is required for its formation, and no more. the saturation point is reached or satisfied, composed exclusively of packed in, scrunched-up light? remember the gravity-well illustration for black holes? previously it was considered as an inward-spiral to the center. now, however, it may be that it should be viewed as concentric rings, ea…

gravitational waves, as predicted by Einstein, are an integral component and an "inescapable conclusion"of the mass to energy transformation equation, E=mc^2 As defined, gravitational waves are pertubations in a gravitational field. when an object changes its configuration, its gravitational field changes. the strongest waves come from massive objects changing configuration at high velocity. so, when mass is converted to energy a gravitational wave is produced. this would certainly apply to the collapse of a massive star to a singularity. (if a gravitational wave is not used in calculating this event, then it c…

are the following steps in the formation of a blackhole generaly accepted? 1. the final chaotic stellar collapse intitiates the event. 2. the accelerated mass is imploded and converts to energy. 3. spatial contraction is the final step in making a blackhole.

I was reading about solar flares in one of my "Space" books, and I came across a section on solar wind. I read regular info that I mostly knew; it causes the aurorae borealis, its caused by solar flares, ect. What I thought to myself, though, is that if we have solar winds containing electrons and protons with energies between 10-100 eV, and with large amounts of internal and kenetic energy touching close to our ionosphere, why havent we sent something up in our atmosphere to harvest what could be an endless and abundant energy source? Dont we have the technology to do such a thing?

I don't portent to really know what i am talking about, and I expect the answer to be obvious like there's not enough matter to distort the image enough so that the image on the scale that we are looking at could be that inaccurate. but that is my question, so how can we know that the differences in temperature in the W map image are not just the by-product of gravitational distortion rather than actual differences in temperature. I know the physics back up the finding of the Wmap image but its just a question, and i know a lot of people a lot smarter than my self have already discarded that as a possibility probably for the reason i stated at the top. thank t…

It seems to be said, fairly often, that "gravitationally bound objects experience no expansion of spacetime". For example, the incessant "stretching" of Spacetime does not "rip apart" our Solar System, nor our Galaxy, nor our Local Group. So, once a "glob" of matter becomes "gravity bound", the Spacetime it occupies (apparently) stops "stretching", and "freezes out" of the background Hubble Expansion. It is my understanding, that current computer simulations assume, for simplicity, a uniform "background" expansion rate, which uniformity they then "force" upon, & across, the whole simulation volume. It is under such simulated conditions, that "Dark Matter" is ne…

Asteroid pushing practice! We would look to the world like the good guys if we convinced the world nukes are an efficient means for saving the world from doomsday. We embark on robotic missions to NEOs and see what kind of effect nuclear explosions in close proximity will do to alter the path of asteroids and comets of various sizes and compositions.

Planets are much dimmer than stars. Perhaps, then, you could do a "Hubble Deep Field" type, Long Duration image, of targeted star systems ? Blocking the light, from the central star, by standard means ("artificial eclipses"), such a "Planet-Finder Deep Field" might image many dim planets, perhaps as "arc-like" smears across the image, from the light accumulated over many days, weeks, or even months. Moreover, imagine training an "phalanx" of telescopes, each observing a different EM spectrum, at the same star system. Then, you could create, in composite, an "all spectrum telescope", which would image the target star system in everything from Radio to X-Ray (say). …

i was reading in my astronomy magazine that scientists have discovered a new type of supernova that was thought only theoretically possible but a 2002 supernova didn't fit the stereotype (white dwarf exploding or the collapse of a highly massive star) but this supernova is relatively faint, quick and doesn't have the scattering of elements that other supernovas produce. and there is other info but it doesn't relate to my question, would it be possible that some of these supernovas that're weaker that regular ones have happened further than 13.7B light years away but produced a light dim enough to not reach the reaches of our sattellites? thus leaving our belief that our u…

The redshift of light might not be related to scale factor like 1+ z = a(1)/a(2) as traditionally thought but as 1+z = [a(1)/a(2)]^2 ........................(1) This leads to a luminosity distance of c/H*(1+z)(sqrt(1+z) -1)..........(2) , with H half the traditional value, and gives a very good match to supernovae data without dark energy (for small z, d=c/2H*z so matches observations). The WMAP value for omeg(matter) of 0.25 comes about because omega = rho/rho(crit) and rho(crit) = 3H^2/8*pi*G and the value used for H is twice the real one. ---------------------------------------------------- The reason for (1) is not known for the purposes of this post…

Can anyone tell me how close to reality this bit of information is: --- The distance between the Earth and Moon is 108 times the diameter of the Moon The distance between the Earth and Sun is 108 times the diameter of the Sun The diameter of the Sun is 108 times the diameter of the Earth --- Appreciate your help...