Astronomy and Cosmology

A while ago I came across a Q+A list compiled by Sten Odenwald for the "GP-B: Testing Einstein's Universe" site. The Q+A was as follows..... https://einstein.stanford.edu/content/relativity/a11332.html The highlighted part I found confusing to say the least and so I E-Mailed Sten Odenwald. He replied soon after by apologising and saying it should be "do not" without the "can and". OK, since we now have that cleared up, I will comment on the answer. Simply put, it seems to make a lot of sense to me, particularly with the generally accepted notion that our first fundamentals originated after the Superforce started to decouple a short time after the BB as p…

So I downloaded that game called "Universe Sandbox 2" and i have had a lot of fun with it. There are some things missing but the developers are updating it regularly. Anyway, I was looking at Mercury and it looked like this The colour seemed off because I saw a picture of Mercury that was taken by "MESSENGER" back in 2008 and it looked like this (second image). But then I decided to look at NASA's pictures of mercury aaaand... Sorry if the pictures are too big. I know that Universe Sandbox is not very accurate simulation but i have also heard that NASA uses CGI most of the time. So how d…

The old forum software never could accept the latex structure of the cosmo calculator in my signature. So I was never able to introduce its sheer usefulness. Here is a 100 step history of Cosmology. [latex]{\small\begin{array}{|c|c|c|c|c|c|}\hline T_{Ho} (Gy) & T_{H\infty} (Gy) & S_{eq} & H_{0} & \Omega_\Lambda & \Omega_m\\ \hline 14.4&17.3&3400&67.9&0.693&0.307\\ \hline \end{array}}[/latex] [latex]{\small\begin{array}{|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|} \hline a=1/S&S&z&T (Gy)&R (Gly)&D_{now} (Gly)&D_{then}(Gly)&D_{hor}(Gly)&D_{par}(Gly)&V_{gen}/c&V_{now}/c&V_{then}/c&H/Ho \\…

My Question was that if Black Holes encountered Something Bigger than the black hole in terms of mass and area, What would Happpen? Of course the object is a solid. Will the object break down to smaller rocks and then get sucked into the black hole or will it just plug the black hole?

I found the above quote on Quora, but I'm not registered there and I don't know how the damn thing works and it was an old post, so I'll ask here, what does the guy mean by the Big Bang not being something from nothing?

A member (now banned) recently posted the following dishonest statement as a way of defending his religious beliefs: In case anyone is misled or confused by his lies, I just wanted to point out that this result does not throw any doubt by on either the cosmic background radiation or the big bang model. As the article says, the polarisation of the CMB had been interpreted as possible evidence for inflation (a hypothetical phase of very rapid expansion). But it (the polarisation) is now understood to be caused by dust. So we can conclude that the CMB is there and supports the big bang model, but it doesn't provide any evidence for inflation (which is not …

This is just some fun calculations I'd like to share but what if we made a body in space out of ourselves? so let's do some calculations and you can tell me about any mistakes or add in your own 5 cents right: currently there are ~ 7.57 billion humans on our planet, The average human weighs about 62kg (according to google) and the density of a human(flesh) is similar to water therefore 1kg of us = 1 litre = 0.001m^3. So if we calculate the mass of our planet we'll get 469.34 billion kg or 4.6934E11 kg. The volume of the planet will be 4.6934E11 * 0.001 = 4.6934E8 m^3 or 469.34 million metres cubed. So now we can work out the radius of our planet as V= 4/3(pi)r^3 theref…

This question came to me reading about "Worth of the sun?". It is possible that we could discover an asteroid nearby that is very rich in valuable metals. It could be so valuable that a mission might be sent to the asteroid to attach rockets to it to move it closer to Earth. Then it could be mined in Earth orbit for decades or hundreds of years. Suppose it is worth quadrillions of US dollars worth of rare earth metals, gold, silver, uranium, you name it. According to supply and demand, the value of such precious metals will plummet to a lower value. But it could still be worth Trillions of dollars after deducting the costs of moving the asteroid and mining opera…

So I was reading my Hubble feed this morning over some eggs and sausage when I stumbled across an article about a possible failed supernova in NGC 6946, where the star brightened considerably, but not enough to be classified as a supernova, and after this event it's infared output lessened considerably as well so it could not have simply remained a star hidden behind the dust cloud it created. This star specifically is N6946-BH1, and I find it rather interesting that it may be a black hole even though the star did not go supernova, and I think this could redefine a large section of research on the nature of black holes. I for one think that a new type of celestial body wa…

I was recently reading about Terra-forming Mars and possible colonization. I saw that a big problem with this is that Mars does not have a magnetic field which makes dangerous radiation reach the surface. Why do some planets have a magnetic field and some don't? I found this theory as a reference but there are smaller planets than Mars that do have a magnetic field so it does not hold up. http://www.astronomynotes.com/solarsys/s7.htm

So we believe that gravity absolutely bends light? Could there not be another explaination? Below are some classic examples of gravitational lensing that we acknowledge as validating relativity. Further below is an example of a circular interference pattern. Is the light "bending" or could it be that the direct line of sight to the light is being blocked? Which one is less speculative? Looking through a magnifying "lens" the images never resemble the "lensing" effect in the photos.

So I've been on a astrophysics bender the last week. Found out about Shoemaker levy, the asteroid that collided into Jupiter's atmosphere and exploded. My question/thought is: Can asteroids also explode on impact with our atmopshere, if they're going fast enough. SML was traveling at 35mi/sec, so when it hit, it was completely obliterated. Is there a flatline of where an asteroid travels too fast that simply disintergrates on impact with our atmopshere? ~ee

The monetary value of the sun preferably in pounds (£) also not counting the value lost in all of these materials if we had such high amounts of them. I have done a bit of this myself, see if you can improve or expand on anything or point out some mistakes. Let's get it as accurate as we can offsite link removed

I keep hearing that the "Big Bang" happened everywhere and was not an explosion but an inflation or expansion. Well ,it is not claimed that the Big Bang Theory accounts for the 10^43 second prior to its applicability . If the "Big Bang" happened "everywhere" does this not imply that at 10^43 seconds "everything" was in the same place? Does this not also imply that the "volume" of everything at that time had zero extent? (no top or bottom or left or right) If there was "extent" then would not some areas of the observable Universe differ from other areas in that they originated from different areas of the Big Bang ? O…

is it possible to produce sound in space? if so, how?

Hey guys! I was wondering what you guys think about this. So, I was researching the chemical composition of Europa and I had an interesting thought. We clearly see reddish-brown staining on and around the cracks in Europa’s surface. This indicates that the staining must be endogenous as it isn't found anywhere else on the surface. There is so far no consensus as to what the staining may be. The chemical composition of the stained ice seems to be water ice bound to some other material. Salts like magnesium sulfate match spectral analysis (sulfuric acid hydrate has also been suggested), but these are either white are colorless, so some other material must b…

If it is correct that the expansion of the universe is accelerating, it seems that this would imply that the universe is not as old as previously thought? This would lead to the conclusion that the most distant galaxies are not as far away as we previously thought, obviously they can not be older than the universe itself? Do they have a model for the rate of expansion as a function of time post the above discovery, i.e. has it been accelerating ever since inflation?

Do you believe there will be fifteen days of darkness in November? If so, what do you think about it? It seems like it'll be a wonderful experience! (^-^)

So I have an idea that I have been thinking about. I am doing independent research to work things out so that I can first disprove it before I really stick with it. Now the philosophy behind this idea are that it CAN happen, but it's not definite. With how astrophysics is currently, there is so much that aren't being explained, nor being asked (as far as I can see, but I could be wrong). Now the thing about this idea is that it is currently conceptual, so don't take this as definite or anything. Now enough of my rambling... My idea is regarding the composition of the universe. We are always fascinated by the idea that the universe is existing right now, but one …

I know I don't have to explain this to any of you here, but just in case you find it hard to explain to your friends why the shadow goes from west to east, despite the fact we see it moving from east to west in the sky, with just a piece of paper and some crayons (there is a vid like that too ahah Show them this, and save yourself some time https://youtu.be/WK-ykoAsLHo

There is an ongoing issue with the density of exoplanets. My proposition is that exoplanets are being discovered that have one eighth of the expected density and I have produced a video that sheds some light on why that might be the case. Recent press releases from the Kepler mission state "Like 19 earlier finds by other groups, four of the exoplanets are unexpectedly lightweight for their size. Although they are about 40% larger than Jupiter, all four are far less dense, ranging from 0.166 grams per cubic centimeter to 0.894 g/cm³. (Jupiter, with its rocky core, has a density of 1.326 g/cm³.) " If we multiply the density by eight for a comparison we get a fig…

I came across this paper and would appreciate a basic rundown on essentially what it is suggesting or proposing. From my limited understanding, it seems to be illustrating how through various effects, cosmologists are able to deduce or eliminate alternative gravitational hypotheticals, and further enhance, [or otherwise] GR. Anyway, I would appreciate a professional outline........ https://arxiv.org/pdf/1111.5661.pdf Stochastic backgrounds in alternative theories of gravity: overlap reduction functions for pulsar timing arrays: In the next decade gravitational waves might be detected using a pulsar timing array. In an effort to develop …

In the coming months NASA will celebrate 40 years since the two Voyager probes were sent aloft. Now 40 years on, they have left the confines of our Solar System: The first man made probes ever to do this. Each of these probes carried a "golden record" with a collection of the sights and sounds of our fragile Earth, and as a message to any potential Intelligence out there, that should happen to recover these probes. In my opinion, I doubt that any man made endeavour has ever gained such a huge amount of knowledge of our solar system and the planets and moons it contains, and inspired mankind to continue the exploration of the vastness of space, and the con…

I just cam across this interesting article....... https://phys.org/news/2017-07-tetrahedron.html extracts: "Thanks to an innovative ring laser design, geophysicists at LMU can now measure and monitor Earth's rotation with unprecedented accuracy. The new instrument in Fürstenfeldbruck will be formally inaugurated this week. Moreover, quantifying the minimal variations in the many different components of the Earth's motions is not solely a matter of academic interest. For example, all GPS-based navigational systems must be periodically recalibrated in order to take account of these variations, which would otherwise give rise to significant errors in determining one's po…

Today I was watching the sky and thinking if i was about the circle a black hole then time pass slow for me and time pass faster for someone on earth but what would happen if there is no gravity but anti-gravity?