Astronomy and Cosmology

Was there a heat death of our universe before the big bang occurred? If so would there be another big bang after the heat death of our universe? I have heard a theory that our universe is in a cycle of creation and destruction, but is the heat death the end all be all? Keep in mind, I'm 15. Sorry for the bad question, read up on the cyclic model, its the big crunch not the heat death.

Would it be correct to say that cosmological expansion is an emergent property? I think so because it appears only on scales of hundreds of megaparsecs where the space becomes homogeneous and isotropic on average.

Can anyone recommend a telescope for astronomy for under about £200/ $US250? Is there one, or do I need to go higher? Thanks GIAN x

Some pretty creative reporting by MSN on this, but it's an interesting snippet about what the Mars explorer cameras are finding : Scientists are claiming an alien spaceship crashed straight into Mars (msn.com) These bizarre spiky Mars rocks likely formed by erosion and ancient fractures | Space I'm thinking that the second picture looks like gas from below, or water from above, created holes which got silted up and hardened, and later exposed by the wind erosion. ( just me speculating ) You wouldn't see it on Earth because the air is denser and gravity is higher, which would erode it more, and cause it to collapse.

ATC 20210525.docx

I've heard of a goldilocks zone for solar systems--a region around the solar system's sun that's not too close and not too far away from the sun for life to thrive--but is there a similar concept for galaxies? For example, could a solar system capable of sustaining life exist deep within the central bulge of a galaxy? Or would that region be too hot? Similarly, could a solar system exist far outside a galaxy and still be capable of sustaining life? It might be significantly colder in the empty space between galaxies but the solar system's sun could provide all the heat life needed, couldn't it?

Whats the ground speed of moon on the surface of earth ? i mean the speed of the point that the moon is exactly above it ? Is it the speed of earth rotating around its self minus the ground speed of moon orbiting earth ? As both revolutions are towards east ? Thanx To calculate that do we have to subtract the angular speed of moon rotating earth from the angular speed of earth rotating its self then project that angular speed on to earth radius ?

iv heard the theory that the binary system of the moon and earth is a result of an ancient collision with some rogue planet or some large object, which seems to have split the moon from the earth and set us in this rotating motion but that would mean the object itself was somehow absorbed into earth and became part of it so, im just wondering, would it not make more sense that the moon itself might actually be that object? or the remains of it?

I recently watched a science video about the classes of stars and how they generate energy and it listed brown dwarfs as fusing deuterium, saying that deuterium was easier to fuse than straight up hydrogen and that deuterium fusion was how they got their meger energy... It also mentioned that some of them fused lithium because it was easier to fuse than hydrogen and deuterium. Is this true? If so why is lithium not used as fuel in fusion reactors if it is easier to fuse?

There was a recent episode of "How the Universe Works" about this giant merger. Did anyone see that? In the episode they only dance around the incredible amount of energy that is required to accelerate a mass of 3 billion solar to a speed of 1300 miles per second. "The two galaxies' central black holes circled closer and closer to each other during the collision. As this happened, the black holes emitted gravitational waves. This gravitational-wave emission occurred preferentially in one direction. When the two central black holes finally merged, this emission stopped, and the newly created leviathan rocketed off in the opposite direction." Gravitational Wave…

Hi my name is Nick. I have absolutely zero scientific background. But I run things through my head every once in awhile, the latest thing that I was running through my head was gravitational pulsation waves. I searched it up on the internet which sadly is my main source of information. But the only thing I could find on it was tsunami sized events when I'm more interested in is the normal pulsation / waves that are created by the abnormalities of gravitational generators. If anybody knows of anything I can read to get an understanding I would greatly appreciate it.

Hi again, I've found interesting video. Roller homopolar motor : Roller Motor Do you think the motor from 1:08 min Will self rotate in Vacuum/Space (No other forces : Gravitational or Other type.) Thank you in advance.

Just seen a post on the Fedivese from NASA that it is black hole week, so they have linked to their black hole basics page. https://universe.nasa.gov/black-holes/basics/?linkId=212543809 Happy #BlackHoleWeek

This is from Universetoday.com. So where is the LMC in relation to the Milky Way and Andromeda, I am guessing somewhere between the two or even closer. So this will collide with us first then the andromda galaxy, which is predicted in a few billion years, I think by that time the earth may be gone due to our sun expanding, however if the LMC gets here first and life still exists here, could there be implications for life on earth.? It does seem that if Andromeda is going to collide then our own galaxy is having some sort of influence already. Tue 2 Feb 2021 https://www.stsci.edu/contents/events/pls/2021/the-milky-way-…

It was said that the observable universe was larger than the entire universe. It was said at https:www.youtube.com/watch?v=tYh8GZDH8E4 3:17 to 3:26 It cannot be right because the observable universe is part of the entire universe?

Are they ?? And if yes why ? Decrease in rotational speed ? Or increase in orbital radius ?? Thanx.........

Michio Kaku says that certain bodies that look like galaxies are black holes. How can this be?

Hi all! It has been quite a while since I last posted here. Again. I'm currently interested in supernovae and the exotic stellar remnants that are left behind from such events. I'm interested in the physics and science surrounding this subject, it's something that I currently have an interest in and want to learn more about. I'm considering doing a degree in astrophysics as I've found myself with quite a bit more free time recently. I'm brushing up on my physics (it's been a while since I used it). I have no problem with them being technical and in-depth and would prefer the details as opposed to the popular science expla…

The Big Bang model is an attempt to explain a host of observations that tell us how the universe evolved from its first fraction of a second onwards. However, it does not explain clearly what dark energy or matter is, and how the universe was created at the very start. So is the Big Bang theory a complete model of the universe?

Has a supernova ever been recorded? I mean with a telescope? I'm used to seeing images from Hubble or JWST but I've never seen videos. Are these telescopes capable of generating videos? If they're not, would it be possible to connect an earth-bound telescope to a video generating device and record what it sees? If so, could it be directed to a star expected to go supernova very soon and just record until it happens? What would it look like?

Is it possible to fly on an astroid? Is it profitable to fly on an astroid? I have heard such theories many times. Were there real projects? In the game Oxygen Not Included and also in the well-known Warhammer 40,000 universe, orcs flew on them. Maybe there are other works about this?

This equation is true for a rocket: where, m is mass, v is velocity, g is 9.81, k is constant, u is the velocity at which mass is being ejected and gamma is the rate at which mass is being ejected. I have drawn up two methods, the Euler's method and perturbation theory. I need a third method and can't seem to think of any. All suggests would be great.

Disclaimer: I am, not a physicist nor do I possess any knowledge or understanding of the math involved behind the answers to these questions, but I still want to learn On Earth, we’re fairly close to the Sun, at a distance of some 150 million km (93 million miles). Earth's orbit around the Sun takes 940 million km and 365.24 days, or what we call one year. Over this time, Earth notches up a speed of 108,000km/h (67,000 mph) on its journey round the Sun. <-- Thats impressive! Let's talk about Gravity for a sec, or at least a simple form of it, outside of GR, and its effect on us. Gravity is not the only source of g-forces. A living being L…

Do planets from Jupiter & beyond receive any heat from the Sun ...? Or are they too far to get any heat from it ? How about Mars ?

Suppose we find a region in space without (or practically without) fields and we introduce a system of quantum objects which subsequently fly apart due to their mutual repulsion ( would protons behave like that?) Would the space between the objects that made up the system be "new space" and would there be a new gravitational field extending throughout it?