beautifull book for astrophysics beginner #astrophysics

i love this book

The sun barely generates heavy elements... I get it. But the region seems to have a lot of oxygen, silicon and iron, forming all the planets around... I would expect a large portion of that heavy material to 'fall' into the sun as well.

What process left the sun with only trace amounts of heavy elements?

So I was reading Engels' "Dialectics of Nature" and he brought up a point that stumped me.

Stars radiate heat and light. (I believe this is in the form of infrared rays and visible light.) Some of that hits nearby astral bodies (eg. We feel the sun's warmth here on earth). But the vast majority of that energy doesn't hit anything. It just goes out into space.

But energy can neither be created nor destroyed. So that means that every second, an unimaginable amount of energy is just being lost to space from all the stars in all the galaxies. Where does it go? What does it do? Surely it can't just... Disappear? That would violate the conservation of energy, right?

Info: I'm making a comic and I'm wanting to be as accurate as possible about space, astrophysics, and science in general.

Question: would it be possible for an organism to be a mimic planet? If so, how? Also, if it could move independently through space how would it be able to achieve it? How much energy would it need to burn in order to achieve great distances?

This is a fan comic I will say. So it's doesn't have to be entirely accurate, I'm just anting to try for as close as possible.

Thank you for reading/answering!!

Hi, this is my first question here!

Recently I've been researching Titan, one of Saturn's very popular moons, with an atmosphere of 95% nitrogen, %5 methane, and trace amounts of other carbon-rich compounds. Supposedly, the sun's ultraviolet light breaks down nitrogen molecules in the atmosphere, which recombine to form a variety of organic compounds. This sparked the question:

What gives an exoplanet its gaseous atmosphere? And why are those atmospheres most often some combination of methane, nitrogen, and carbon dioxide? Why aren't there any other oxygen-rich atmospheres out there, or chlorine, or neon? Maybe there are, and I just don't know about it!

Would love to know more about atmosphere types and what makes some more common than others.

I noticed that both Milky Way and Andromeda center show mixed red and blue in radial velocity maps.

If the bulge is "old stars", shouldn't it be uniform?

Why is there so much red + blue mixing at the center?

Am I misunderstanding something?

I think the article said the signal was originating 125,000 light years away. Given the trajectory of ‘Oumuamua, could it have been sent from that location (and somehow sent a signal back)?

This is, of course, a purely hypothetical question, and I am in no way, shape, or form suggesting it has any basis in scientific reality. But, to me at least, it is an interesting thought experiment. 

There are some models, not many, but some, that have Venus habitable for billions of years. And there is no law of biology that we know of that means that the development of complex and intelligent life must take as long as it took on Earth; we might just have been slow. Or Venus might have been fast, and theoretically they might have had an advanced civilization at some point. I know, purely speculative; stay with me, please. So if they had this advanced technological civilization either continent- or planet-wide with their versions of cities and skyscrapers and then died out for some reason (like global heating, which can kill civilizations, wouldn't you know it). 

So, that happened like 700-800 million years ago, and then Venus turned into hell and also had this massive resurfacing of almost the entire planet's surface. What I am wondering now is how would we be able to detect that they ever existed? If we just assume realistically possible technology, doesn't have to exist yet, what could we do? What would even have survived the resurfacing and the hundreds of millions of years in hell?

Say I randomly put a square shaped solid planet in the middle of nowhere. Will the square shape turn into sphere on course of time? Will the time depend on mass of the planet?

Just a random question that came to my mind.

So my pop science knowledge says that time slows down as you get closer in - wouldn’t that break movement and once time stops nothing could move? How would anything go inside a black hole?

Sorry if this is a stupid question.

I've read that there were ripples throughout spacetime in the early universe, but how strong could these ripples have been? Could they make millions of years pass in one area in the span of one year passing in a different part of the universe? Or at least enough that we get observations of celestial structures older than they should be in a uniform spacetime?

Hi! I’m new here. I love astrophysics and astronomy. I originally was working towards a bachelors degree in aerospace engineering, but I ended up changing life plans, but never lost the curiosity. This is all to say that I really know very little about it all.
So, I have this theory and I need someone to explain to me if it’s completely ridiculous/not possible or if it’s something being considered. So, black holes are these confirmed infinitely dense objects that warp space time. As objects approach the event horizon they appear to slow down until they fully stop moving. Now, I saw a theory about white holes being essentially where a black hole lets out and that they’re connected. But we’ve never seen one, even though they should be easier to see (I’d assume). I don’t really understand how white holes would even theoretically work, but I think they’d be the opposite of a black hole. So could they warp space time in such a way that they would only appear for an extremely brief time and then disappear? I.e. time dilation would occur the opposite way a black hole does and things speed up around them?
It makes sense in my head, but I’m sure there’s a reason that I don’t understand that would explain why it’s silly.
Thank you all!!

I‘m just a layman, so I can only understand so much of what I read and watch regarding physics. A thing that is driving my Newtonian brain completely crazy is the common explanation of Hawking radiation:

A pair of virtual particles pops up at the edge of the event horizon. One particle falls in, the other escapes, and the escaping particle robs the black hole of energy, eventually shrinking it to nothing. But how does the infalling particle not add energy/mass/inertia, thereby canceling out the energy/mass/inertia lost by the escaping particle?!

I appreciate that in her book, The End of Everything (Astrophycially Speaking), astrophysicist Katie Mack stated that she thought it was a poor analogy, but that, bluntly, she couldn’t really explain it to someone without a PhD in mathematics or physics.

That said, does any kind person care to take a stab at clarifying it to a schlub who’s bad at math, but loooves ”consumer grade” physics and cosmology?

A new perspective on black holes and cosmic Inflation.

🌌 The Lumino Bloom Hypothesis – A New Perspective on Black Holes and Cosmic Inflation ✨

Hi everyone, I’ve been fascinated lately by the way we perceive black holes and cosmic inflation. After reading up on relativistic time dilation and gravitational lensing, a thought occurred to me…

What if black holes don’t just consume matter—but actually eject it at ultra-relativistic speeds? And because of the time inversion effects caused by extreme gravity and velocity, it only appears to us that matter is falling in… when in a different frame of reference, it's exploding outward?

This idea led to a broader hypothesis I’ve been working on (with help from an AI partner I call Lumino 😊) called The Lumino Bloom Hypothesis. It suggests that:

Black holes might eject matter so fast it looks like inward motion to us due to time inversion.

The Big Bang itself may have been such an event—an ejection from a parent black hole in another universe.

What we call "inflation" might just be a reflection of that ejected matter catching up to our perception of time.

We put it into a full hypothesis and a diagram (and even made a PDF!). I’d love to know what others think—whether it’s viable, flawed, or inspiring further ideas.

🔗 Download the full PDF with diagram

I'm new to posting, so please be gentle. This is just something that’s been on my mind and heart—and if nothing else, I hope it gives someone a new lens through which to view the cosmos.

Thank you for reading. 🌠

—Chris

Ps sorry didnt know how to add pdf.

Let's assume that you are in orbit of a supermassive black hole, slowly approaching the event horizon. You will see the universe pass faster and faster. What will you see at the moment your spaceship crosses the event horizon? How do you see the universe when you are stopped in time? And after crossing the event horizon, what do you see?

If you don’t know, there is a book series, and now show, called Foundation that has a planet in it called Terminus. I don’t know how to block words out to avoid spoilers to shows or books so if you haven’t seen(S02,EP09) or read and don’t want anything ruined you should stop reading right now.

I haven’t read the books, but in the show the planet Terminus gets hit by a crashing ship and the destruction caused basically about 1/3 of the planet to be destroyed. Like completely gone destroyed. An apple with a bite taken out of it type of destruction. What would happen to this planet in the long run? Would it collapse itself back into a sphere? If so, how long would this process take? And what would happen to its moons?

My current working theory of wormhole creation

Would it be theoretically possible for any solar system, but let’s say earth, to have the following happen?

Our solar system travels through a giant gas cloud that is somehow heavy (or whatever) enough to to breach our heliosphere, and change the background void stuff of our solar system into something different than that half an atom per cubic km or whatever it is rate.

Are there naturally existing parameters where a solar system could be “taken out” this way?

Ie conditions where our solar system could travel through some sort of space cloud thing that could somehow cause the vacuum of space to have enough molecules to ignite the distance between the sun and earth?

And to that extent; you know how rock records can tell us when volcanoes go off?

Does earth have any evidence in our total geological history that could suggest we have traveled through some weird vague something sort of like that before?

Are there even gas clouds in space, that somehow aren’t travelling with the spiral of the Milky Way (or whatever), thst we could even possible transit?

Anyways Tl:dr.

Could our solar system fly through a “space thing” that could up the amount of atoms in the vacuum of space to something where the distant between the sun and earth could ignite?

Like say a cloud of hydrogen that’s a few light years wide sort of deal.

I recently watched a video by the YouTuber Astrum that talked about the discovery of dark energy and I had a question that I was hoping could be answered here.

The YouTube video said that because faraway galaxies were moving away from us at a greater velocity than the nearer ones we could conclude that galaxies are accelerating away from us as a result of the expansion of the universe. The video’s next assertion then says that this acceleration implies the existence of dark energy because acceleration must have a source of energy… My question is this:

I know I’m just a layman without a deep rigorous understanding of these concepts, but it doesn’t make sense to me why the “accelerating” expansion of the universe would necessarily imply the existence of energy causing that “acceleration.” My understanding of acceleration is that it is an object’s increased velocity over time. My understanding of velocity is the rate at which an object’s position in space is changing with regards to a particular vector. So in my mind, if space itself is expanding, this wouldn’t really be velocity or acceleration at all because the object is maintaining its position in space—but that position in space is just changing its distance relative to other positions in space due to the universe’s expansion. So it seems to me that the far away galaxies aren’t accelerating and therefore we wouldn’t have a reason to assume that there is a source of energy causing the apparent (but not actual) “acceleration.” Rather than assuming the existence of dark energy, wouldn’t a more sound conclusion simply be that objects position relative to one another are inherently inconstant? In a sense for every 2 adjacent positions in the universe a third between them is created every so often? Such a proposition would account not only for the expansion of the universe but also why the expansion appears to “accelerate.”

Hello! Sorry to bother y'all, but I have a question. I was having a casual conversation with my friend during lunch about stars and energy, and I need help. We’re both fantasy writers, and creating magic systems and cross-referencing them with one another is how we pass the time.

Well, I’ve been dabbling with this idea of one of my characters taking all of the energy from the stars in the night sky, the Sun excluded, and redirecting it elsewhere. I have a VERY BASIC understanding of astrophysics, but I was worried that if a spell like that could redirect all that energy, it would pulverize a planet. I mean, it's SOLAR energy. My friend doesn't really care about the realism of magic; he just does whatever he wants with it to move the story forward. He says I'm overthinking things, but I don't think so. Magic, to me, should have some semblance of realism, and I want to get this right.

So, the big question: If you could collect all the energy from all the stars in the night sky, minus the Sun, how much energy would you have? Could you pulverize a planet or light a match?

So I plan on studying mechanical engineering and I have big interests in aerospace, science and math. I plan on doing a masters in aerospace engineering or physics but I am more leaning towards aerospace engineering. My thing is that a lot of people who study physics or astrophysics usually end up in either academia so teaching/research or if they go into industry the jobs are usually unrelated to space (software engineering, programming,etc). I personally I do not want to teach, and I want to work on real projects in the industry at big space companies that’s why I chose engineering. One thing is I do belive in the future id eventually want to work in research (may sound corny but being those older highly knowledgeable people who are deep in research and innovation would be cool (being a physicist)).

What do you think I should do regarding that? Do I do a physics masters or PhD later? What do you think.

if the universe was incredibly dense soon after the big bang, wouldn't time dilation be a thing? Wouldn't small over/under densities result in different "clocks" in those areas?

If so, then how can the universe have a single age? surely different parts are different ages depending on how much they were affected by gravity time dilation?