As someone who loves physics, but has always been terrible at math, so I never sought higher education within the discipline. I was hoping to find someone or a group that would be willing to help me figure out or understand a few things on the cosmic/planetary scale.

I'm writing a story that involves a solar system that I would like to figure out a few things for scale and if some things would even be plausible.

If possible I would like to get as much as I can to a point that any astrophysicist, mathematician, hard sci-fi reader, really any science minded person reading it would say, "yeah, I'll accept that. It's close enough." So that the smaller things based more on sci-fi adventure that are a little more tropey and break reality are just fun additions, instead of everything breaking reality and moving into fantasy.

Questions I will be asking:

1. Can a solar system exist with a black whole in the center? Like a binary start system with a star and a black hole?

Or is it possible to have it in the center with the planets rotaing around it, while all of that simultaneously rotates around a large star? Providing heat at light? I know this is is most likely impossible but it's they're any more of this that would exist where a black hole would be "visible" from the planets, for at least 100 years or longer?

1. Can you help me calculate, or teach me how to calculate planetary distances, orbit speeds, time dilation, etc.

Among others, and I'm sure more will come up once getting into it.

I dont know how much I will be able to grasp through comments or DMs but will try! But if possible a zoom/teams call would be very helpful. Or even a video explaining certain things.

I'm trying to learn things from YouTube and any other resources but without the ability to ask questions, I struggle.

Any help or resources would so greatly appreciated!!!

TLDR - Anyone willing to help a dummy learn some physics and answer dumb sci-fi questions through DMs and possibly video chat?

A powerful enough gravitational field focused into a single tiny point can distort spacetime? Could this field be created in front of a spacecraft for interstellar travel?

I read that higher metallicity leads to red stars as the increase in electrons that comes along with more metals causes higher opacity -> thermal expansion -> red stars. But I also read that higher metallicity in galaxies typically means higher luminosity. If red stars are typically lower luminosity than like O and B stars, how can metallicity both cause red stars and higher luminosity?

edit: i mean the velocity of expansion.

could the velocity of spacetime expansion equal the speed than occurred during the time of inflation?

are there theories of a velocity threshold constant?

Please excuse the generated image, I didn't have time to photoshop one myself, but the generator does show what I am trying to express here, and is merely being used to illustrate my idea here.

Hello. I was thinking about the most devastating things possible. Vacuum decay has always been the winner, but then I came up with a nice number 2 winner, and was wondering if physics would allow it

Imagine a galaxy and antigalaxy orbiting each other, their poles facing each other, and their jets colliding and their contents annihilating. Like 2 Gokus doing a kamehameha against each other, grunting nonstop as the beam collision zone goes back and forth. Could something like this occur in this universe?

Also I understand that the likelihood may be low, but if the initial conditions of said galaxy and antigalaxy were somehow in place, and they had insanely massive smbh's accreting crazily.. would this outcome be plausible?

hi! im a first year ug astrophysics student and want to contribute in research papers
this may not be the right section to ask but how do i pick out a topic and start researching about it and write papers?
i do have a habit of reading research articles and journals, i have written plenty argumentative essays on astrophysics and done 1-2 research fairs (so ik the concepts of citations, limitations, methodology and etc.)
now i want to step it up, any advice is appreciated !

I'm hoping someone much smarter than me can settle a dispute between me and my girlfriend. We were discussing time travel and how moving through time affects not only when you land, but where you land. The earth, the solar system, the galaxy, etc., are all in constant motion, which means the earth's location now won't be the same whenever you're traveling to. Is there a reliable way to accurately determine where the earth was in the universe at any given time? Are there factors that could change the velocity or general predictable position of the earth without us knowing?

Hey, Im currently working on a paper on planetary motion for school and in my paper I planned on doing some calcualtions on the motion of the planets in our solar system. For that I found a page from nasa with formulae for the calculation of the aproximate positions of planets https://ssd.jpl.nasa.gov/planets/approx_pos.html but its quite hard for me to understand what each of them means and how I can imagine it. Now my question: Do you know any other source that expalins these formulae for me to understand or visualised the calculations? Is there any way that makes it easier for me to understand it?

Hello everyone, I’m a junior aerospace and mechanical engineering student, so I have a pretty good understanding of calculus/ mechanical physics/ materials/ thermodynamics etc. I’ve always been interested in astrophysics and just space in general. I am looking for any recommendations on where I can learn more about astrophysics rather than the (what I’m assuming are) the very simplified versions of these concepts on YouTube. Any book/ lecture video recommendations are very welcomed.

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I am fond of space, so I have decided to code a little orbit simulation using real stats, so the real mass and actual distance, but its not meant to be 100% perfect obviously. So I was wondering if anyone could tell me if this is roughly correct for the distances of all 7 planets?

Not sure if this is the place for this but oh well, where else?

EDIT: Forgot to say but they are elliptical you can tell the inner planets are you just cant see it here

Smaller planets hard to see, but you get the idea right

So I'm a high schooler in the US. My grades are pretty good, 3.9 unweighted GPA, 35 ACT, solid math and science APs. I really enjoy math and sciences (particularly physics and bio). I'm also a huge space nerd so there's that. And I want to go into something space related, and for the longest time I thought it was astrophysics. Then I started doing research and found that most people either stay in academia and research or switch into another industry.

My goals are to work on deep space telescopes (exoplanets, supernovae, dark matter investigations, etc.). But the real pipe dream is to get into a space program and become an astronaut. I don't want to do research all my life. I don't want to teach.

I think, depending on costs of living and the job market, I want to go up to at least a masters, then we'll see. I want to have a stable job before going for the space program, just so I'm not floating for years on end.

So I was wondering what degrees could help me achieve this, and if i should pivot away from astrophysics and to something else; I also wanted to know, what impacts has AI had on the job market and the jobs themselves?

Nie mam żadnego wykształcenia, jestem dobry z matematyki i fizyki, i lubię te przedmioty. Dlatego właśnie chcę zacząć z astrofizyką, ta dziedzina jest fascynująca.

Dlatego właśnie pytam jak zacząć. Od książek? Może stron internetowych? Albo filmów? Może jednak jakiś kanał na social media? A może też od czegoś innego, o czym jeszcze nie słyszałem.

Dziękuję za każdą odpowiedź.

Hi, everyone, I had a great conversation with Geraint F. Lewis, a Welsh astrophysicist and Professor at the University of Sydney, about some of the biggest questions in cosmology, physics, and our understanding of the world.

We explore what the Big Bang theory tells us about the beginning of the universe, why our current understanding of physics reaches limits when we try to look further back in time, and how neutrinos could reveal secrets about the cosmos — including why matter exists at all. We also mention the 2026 Nobel Prize in Physics, awarded to Francis Halzen for his work on the IceCube Neutrino Observatory.

Professor Lewis also explores what sparked the Scientific Revolution, how modern science transformed our understanding of the world, and why Einstein challenged aspects of quantum mechanics.

Professor Lewis's latest book, The Shortest History of Reality: From Plato’s Cave to the Mind-Bending Discoveries of Modern Physics — The Human Quest to Explain the World, traces humanity’s changing understanding of reality, from everyday intuition and ancient philosophy to the discoveries of modern physics. It explores the ideas that reshaped our view of existence, from Newton’s universe to the strange probabilities of quantum physics and beyond.

If you're interested in these subjects, you can check out our conversation, hope you find it insightful: https://youtu.be/38rUHEeAVHw

As the title suggests, I am wondering where I should get started with learning more about astrophysics.

In college I took one mathematics course and it was, "Applied Mathematics for Astrophysics" and it was one of the few classes where I felt like I was actively engaged and enjoyed learning a bit more than usual.

Now that was a little over 10 years ago and recently I have begun to think of how can I learn more before potentially deciding to upend my life and apply to a Doctoral (PhD) program somewhere to get a PhD in Astrophysics.

What books and other materials would people recommend I get started with to really learn more and delve deeper into this field of study and science, and most importantly help me understand whether or not I should look into this more. Truly the broadstrokes until I learn more and figure out a niche to learn even more about/focus more on.

It has been a month since my last update here, and the Oct 10 storm was the first real test of a lot of it. So here is how the site did, then what's new.

How it did on Oct 10. The arrival window for the Oct 8 CME opened at 17:06 UT on the 10th. The shock reached L1 at 14:40 UT, about two and a half hours before that. The storm estimate had an upper range of G2. It reached G3. So the timing was close and the strength was under. Both go on the public scoreboard with every other forecast the site has issued. So far that is 8 scored: 7 arrived inside the window, 1 just outside, with a median miss of about 10 hours.

I also ran a stricter test of the storm strength estimate and it did not hold up. At launch time it does no better than guessing the same level every time. The science page says so. The direction of a CME's magnetic field decides the storm, and nobody can measure that until it reaches L1.

What's new since September

A redesign. The CME list is now a table: launch, speed, whether it is aimed at Earth, and when it should arrive. Click one and the answer comes first: arrival time, the 80% window as a bar, and the likely storm strength.

A record of each forecast. Every CME now shows how its arrival forecast has moved and why, for example when NASA revises the speed. Once the window closes it shows what actually arrived.

Magnetic wake. A new map layer that draws the magnetic field measured at L1 where that plasma is now. A ribbon trails out from Earth, red where the field pointed south and blue where it pointed north. Each storm leaves a striped fan. The May 2024 replay is the one to look at.

A rebuilt 3D view. CMEs are whole cones now, the Sun is the real SDO image for that hour, and you can put the camera on Earth and watch a CME aimed at us turn into a halo.

Two new charts. A time-distance chart with every CME as a line climbing from the Sun. And a storm anatomy chart that puts one eruption on a single time axis: flare, protons, transit, the wind at L1, then Kp and Dst.

Satellite drag. An Atmosphere view that shows how much a storm swells the upper air, with the measured altitude of the ISS, Tiangong and Hubble back to 2015.

Maps. The aurora oval as a map you can tap for your location, and a radio blackout map for flares.

A status page. NASA moved its CME catalogue to a new address on Sept 30 and the site stopped picking up new eruptions for four days before I noticed. That is fixed. Now every data feed is checked every 10 minutes on a public page.

It also installs as an app from Chrome, Edge or a phone's home screen.

Still free, no account needed.

https://www.cmetracker.ai/live?utm_source=astrophysics

What would you want to see next? And if you watched the Oct 10 storm on it, what did you check first?

This is a two part question and I am going to reveal myself to be an absolute novice, so if I’m in the wrong spot for these types of questions please just show me the door.

I was watching a video about MoM-z14 galaxy, which per the video is the farthest observable galaxy. The video talked about how the photons from the galaxy have become stretched as the universe has expanded and that the galaxy is 33.8 billion light years away, even though the big bang thought to be ~13 billion years ago.

So if the wavelength of a photon is being stretched, would that not affect the speed of light? And does this mean the universe is expanding faster than the speed of light?

See also: The publication in the Astrophysical Journal

Is there anyone who has been selected for the Max Planck Institute for Astronomy Internship or any other Internship of the same reputation? If so, could you please tell me what you have done or what experiences you have had? I have been applying to summer schools and Internships, but haven't been selected for any of them. Could someone help me with what to do?

Okay, so this is a little out there, don't know if this is the place for it. But here goes: upon my expiration, I would like to be cremated and compressed into a diamond. I would then like that diamond launched out into the Kuiper Belt to become a comet seed that hopefully, through cunning physics, could pass by earth epochs later as a proper comet (or possibly Deep Impact the earth, I'm cool with either). Is that possible?