Astronomy and Cosmology

Questions Concerning The Planck Epoch I must begin this thread with an apology. I am NOT a physicist nor astronomer; in fact, my degree is in biology. However, for decades I have had a deep interest in what is commonly referred to as Big Bang Cosmology and have an “educated layman’s” knowledge and appreciation for this field. My eventual goal is to establish a “best-guess” or “theoretically-acceptable” step-by-step chronology of the Big Bang. I have found WikiPedia’s Chronology of the Universe to be an extremely useful starting point. However, a number of areas in their Chronology are in need of clarification for my humble intellect. In addition, in cross re…

The spectral lines in the light we receive from distant galaxies are shifted towards the red. There is a “cosmic redshift”. The waves arrive stretched. We observe expanded waves in a static space. The idea that space itself could expand or contract is not very common, but it is diffused by some cosmologists and their followers. These claim that space is expanding and that this is the cause of the cosmic redshift. But this is unintelligible to me. What do they mean? An expanded wave in an unexpanded space is equivalent to an unexpanded wave in a contracted space – not in an expanded one.

Me again, with another problem in my story concept. I've been considering the fact that if planets were too close to each other's orbit that it would drastically affect what happens on them. I don't know exactly how close that would be though. What would happen if two planets were only 500,000 km apart? Would it depend on the physical traits of each planet?

Part 1: This piece of writing is a revised edition of an earlier work, and it was inspired by watching Hawking, a BBC television film1 about Stephen Hawking's early years as a PhD student at Cambridge University. The film got me thinking about both physics and my own life and this piece of writing was the result. Hawking is now an English theoretical physicist, cosmologist, author and Director of Research at the Centre for Theoretical Cosmology within the University of Cambridge. This film-drama follows Hawking's academic search at the age of 21 in the field of physics for an understanding of the Universe; the film is aslo about his struggle against motor neuron d…

Have there even been two non-spiral galaxies collided with each other?

Would it be possible for one or more cases of successive gravitational lensing to direct light back towards its source?

Spoiler alert. If you have not seen this movie yet, you will probably not want to read this. It may give away the ending. Has anyone else seen this movie? I saw it yesterday. It seemed to be very well done, but the scientific details were too vague for me. I'm not sure exactly what happened. How can planets be habitable that are orbiting a black hole? Seems unrealistic to me. Can anyone explain what happened at the end? Cooper entered the black hole and survived because time slowed down so much that he had plenty of time to send the important info that combined relativity with quantum mechanics, so that he could save the human race and also be rescue…

What is the cause of Saros cycles ? http://www.orbitsimulator.com/gravity/saros.GIF?

With regards to the future merging of the Andromeda Galaxy with our own Milky Way, would this event create a quasar? If so, would this in turn eradicate all existing life in both galaxies? (assuming, of course, that Earth isn't the only repository of life in our part of the universe). Many thanks.

Lunar Inclination anomaly - Is it true? If not what is the explanation? http://galacticconnection.com/moons-orbit-shifted-34-degrees-twelve-days

When a planet is transiting across a sun we can calculate the radius of the planet by the change in photon flux. However, I've read that limb darkening (reduced photon flux at the edges of the sun) can affect the calculation of the planet's radius. How can this be? Surely this wouldn't as you would measure the flux before the planet obscures any part of the sun then measure the flux when the planet is mid transit thus negating any effect limb darkening has on the readings. Am I missing something?

Represents superclusters as 'stationary' and the distance between them as what is increasing with time. IMO other illustrations are much more representative of reality, but my hope is that this might provide an alternative illustration as an aid to comprehension.

How much is the Energy emitted by Sun ? Where does it go and what form it transforms itself - Matter or Energy Storage ? As of this moment Virginia US has around -2 Deg C while New Delhi has around 9 Deg C and Kashmir around - 9 Deg C and Bangalore has 20 Deg C ! We all know how much Energy it takes to Air Condition a Small area and Imagine what an amount of Variation in Energy and Temperature is involved in lifting the Temperatures or lowering it over such vast areas. No MAN is an ISLAND and similarly no Particle, Atom , Molecule , Body , City, Planet , Star System , Galaxy or Universe is so, in such a way that its Properties are not determined by the Re…

why most of space videos are CGI? i never saw how Mar's Curiosity lands, maximum all space images & videos in google & youtube are CGI. why so? why NASA hiding real videos? see most of space images are artistic.

We know that time goes slower in areas of massive gravity. Is there a formula to describe the relationship between time and mass? It is an inverse relationship, I suppose, since the greater the mass the slower time goes. Tx

Ok, I am a language student so admittedly don’t know anything about physics and I explain everything with colorful metaphors, etc., but over a few too many espressos this week, I starting reading up on mathematics… seems to me that numbers are simply ideas, and math is the grammar that ties them together. So it is akin to a language to describe the relation between things, and thus a man-made construct. That drew me into looking at physics; physics is something else. It is an instrument: the opposite of dogma, it is like a chisel in the hands of a great sculptor, chipping away to reveal a deeper truth. Rodin once said he did not create, but that the form was already ther…

So I was fascinated by this simulator of the solar system on this site. It shows evidently the result of the fact that the orbital speed of the outer planets is less than the speed of the inner ones. The Average Orbital Speed of the Planets In the simulator I increased the speed to 2000 days/sec, put the viewer in zero projection (down right between the arrows), made a zoom out, and I was patiently waiting for all the planets to align. After a few minutes (only) my patience exhausted and I took the following screenshot where I draw roughly the alignment I expected to see: Then I went on drawing the displacement of each planet following Keppler's law: the outer pla…

I always thought the uniformity in the temperature of the CMB was supposed to be expected, since it's a much more probable initial condition for the universe, what I mean in much better words: The only "counter-argument" I could find for that, ironically enough, comes from Jason Lisle (link): But if that "random nature of the initial conditions" is of the same order of magnitude as quantum fluctuations, wouldn't that apply to the early instants of inflation too? If so, how would thermal equilibrium be even possible under such quantum fluctuations during inflation?

Ok, now, before anyone blurts out the answer some of you are certainly thinking ... yes, I know that the reason it's blue as opposed to pink (like on Mars) is because of our oceans. That's not what baffles me. I'm wondering why a clear, daytime sky has ANY color at all, other than black. When it's night, we see the stars as just a bunch of white dots scattered across an otherwise black void. The night sky is black ... because that's the color of nothingness. The stars are, absolutely, shining light in all directions. The only problem is ... there's nothing in the deep void of space for those stars' lights to bounce off of (at least, nothing large enough, and c…

I'm reading Gaggero's Cosmic Ray Diffusion in the Galaxy and Diffuse Gamma Emission and he makes the claim, The existence of neutrinos stems from relativistic protons colliding with ambient protons. Neutral pions are the primary decay mode for [latex]pp[/latex] collisions, but charged pions can also be made alongside the neutrinos. My question is then would the non-detection of neutrinos be a statistic issue or would it suggest Supernova Remnants do not accelerate protons?

I came across the two articles below and wonder if anybody knows of any developments with regards to revised galaxy rotation curves and/or the total amount of dark matter? 'Lost in Space: Half of All Stars Are Rogues Between Galaxies' http://www.space.com/27682-rogue-stars-between-galaxies.html 'Milky Way has half the amount of dark matter as previously thought, new measurements reveal' http://www.sciencedaily.com/releases/2014/10/141009091600.htm

This is a question: Suppose that I am looking in my telescope to a distant star 1 million light years away. Around this star is a planet. On this planet I see an alien observatory and an alien scientist looking in my direction. Can he see me?

So I've been looking up the holographic principle for a while and I'm having trouble understanding somthing that I feel is obvious that I'm missing. I understand that a volume of space will have the same information as it's surface area, but is it the same information? What I mean is if I drop Alice into a black hole, from her view inside the black hole she will see everything 3-dimensionally. Bob, who is outside of the black hole, will see Alice's information 2-dimensionally on the event horizon. The part I'm having trouble with is are they looking at the same Alice? Is the Alice on the inside a clone of the one on the surface, or is she in a sense in both places…

Here is the question At the Big Bang, the universe were created and started expanding. The universe includes us, the Earth, the Milky way galaxy, and also the CMB. So the question is: how is it possible for us to observe a radiation that was emitted at the time we were born? It looks like the archer running faster and being killed by its own arrow.

I posted this as a sort of answer to another thread about where does space stop, but the thread was quite old and so I thought I might create a new thread just to see what you all might think, hope that's ok. Hi Everyone, this is my first time on here, but I love the subject and so would like to share my thoughts, although I'm not sure it's going to answer the question, "Where does space stop". It depends on whether you believe in the multiverse theory or not. Personally I do. I think it's more than likely that the big bang happened many many times before and after the one that created our own universe and is still happening over and over again like bubble…