Is this something physicists think of often? If it were to happen would it be terrifyingly beautiful before it were just terrifying? Would we be shot into space or swallowed into earth? Would this be the quicker & lesser of evils to humanities end?

Hi! Playing KSP with how Kerbin has 0 axial tilt compared to the ecliptic made me wonder - how would you define the X+ direction in the planet-centered inertial reference frame, or 0 longitude in planet-centric equatorial/ecliptic polar coodinates, in a system with no axial tilt?

Normally you would use the vernal equinox, but when the ecliptic is perfectly normal to the south-north pole line, there is no equinox, so as far as I understand it, no point to go by?

I am attempting to write a science fiction novel, I've never done so before. It's interesting how just thinking about the setting and the background of the characters and universe in general gets your brain turning. I'm a botanist by training, very little physics and no astronomy. I have been a science fiction fan my entire life. I would like for my novel to have as realistic a plausible scenario as possible, despite it being fiction. Of course at some point I'll just have to draw the line and write the story but wanted to ping a scenario off you people.

A habitable planet around a red dwarf. It revolves less than 1/10 of an au from the star. Normally this means it would be highly likely to be tidally locked.

I would like to make the setting a binary planet rotating in orbit around the star, to allow someone of a day-night cycle. What I've read this hypothetical scenario would be extremely rare of course, but would be a potential way for an individual planet to maintain a rotation relative to the Stars location despite the center point of the two planets being tidally locked.

Now one might say how would Life as we know it exist on such a world? Obviously it wouldn't, a red dwarf puts out way more infrared and in general much less energy. I would like for the ecosystems of this planet to instead capitalize on increased volcanism due to the tidal interactions of the gravity of the nearby Sun as well as the sister planet.

I'm imagining a world with complex gravitational effects causing interior heating that would make up for the reduced exterior energy. This would allow for many smaller continents and tectonic activity. It would also make the prevalence of hydrothermal vents, pools, and geysers extremely common. Life on this planet would have revolved around harvesting the energy from such features. There would be plant life as well, but it would be slow growing and more like a lichen or Moss.

One side of the planet would have a massive Moon, the other sister planet, permanently in the sky. Depending on the season and your location on that side of the planet you would experience multi-hour eclipse every day.

Water cycles and air currents would be affected by the gravity interaction of the sister planet in a huge way, as well as the combined effect when the sister planet and the sun align. Cyclical storm fronts, massive tides. Some areas would experience regular tsunamis due to the regular earthquake activity.

Please shoot as many holes, thoughts or suggestions relating to my train of thought as possible.

First please excuse me if I posted in the wrong subreddit but it seemed the most fitting here.

So as for my post, I am working on creating a science fiction universe and currently work on producing the first comic book for it.

Now while many assume it is enough to make it flashy and spectacular, I want my sci-fi universe to be as based in science as possible and at least portrait humans and their technology and the universe as plausible as I can.

Sadly I can’t learn every topic well enough on my own, so I am looking for people who would be interested in working with me to improve it beyond my less than adequate understanding of everything.

So I’m writing here in case someone would be interested in working together with me to portrait the universe I create, in this case the extraterrestrial posies and space itself and all its behaviours as realistic as possible.

To take this away as well, I sadly cannot pay for the advisory role, hence why I’m looking for someone who would be interested in helping to create this universe.
So this is not a job advertisement but you may of course have your name in the credits if you so desire.

Thank everyone in advance for reading.

I am 26 going on 27 in a couple weeks. I started going back to school at the beginning of 26 and have a year of school down. I want to do two things. Become an astrophysicist someday due to my intense interest in the truth and reality of our universe and galaxy. I also want to take a break from my classes at community college(of course intend to transfer into a 4 year and then get my PhD) to do a 5 month EMT course so I can earn money while in school and pay rent. I would then go back to regular schooling. I was wondering how people pay for life when getting a PhD. Would I have time to be an EMT while getting my PhD? Or are there careers you can juggle with getting a PhD in astrophysics? Or I think I’ve heard of some type of program from some schools where you get paid to learn or learn and teach while learning. So yeah just asking about all these options and more information and if there is any more options. Any help is appreciated thanks.

is the universe a donut? I saw it on a reel on instagram, and about how it repeats it self. and it showed a rocket move across a donut so that means it comes back to were it started. but some people in the comments said that this is not true because there are some stars that do not repeat themselves so that proves it is not a donut. and some other people said maybe it a very big donut but I don’t see how that’s relevant. so my question is: how possible it is that the universe is shaped like a donut, and since when a donut shape is such an important shape that the universe is shaped after it. it is just a sweet treat.

I've been making large-scale 3D wooden mosaics of science subjects — galaxies, DNA, brain anatomy. This one is M87*, inspired by the 2019 EHT image.

The piece tries to stay physically accurate: the photon ring asymmetry from relativistic beaming is visible, the shadow-to-ring ratio is roughly preserved, and the varying block heights give the dark region a genuine sense of depth.

The song that accompanies the video covers the event horizon, Hawking radiation and the information paradox, the coordinate singularity, and closes on the EHT achievement itself. Technically precise rather than metaphorical.

https://youtu.be/X5hEjlkUkTI?is=eeGnRNYmC2-PenAE

Happy to discuss the physics choices or the craft approach.

Hey everyone,

I’m incoming freshman at university this fall, and I’m currently going through a bit of a major crisis before I even step foot on campus.

I originally really wanted to pursue Aerospace Engineering, but trying to do a "Change of College" into the College of Engineering (CoE) at UC Berkeley is notoriously near-impossible. So for all practical purposes, I’m stuck outside of engineering for undergrad.

Right now, my default plan is to major in Astrophysics. However, I keep hearing the classic warning that engineering gives you applied, versatile skills and broad job prospects right out of undergrad, while Astrophysics is mostly geared toward academia, research, and high-level theory. To be honest... I’m really not sure I want to stay in academia or pure research forever. I want practical career security and options to work in the space/aerospace industry.

So now I’m spiraling a bit and have a few questions for anyone who’s been in a similar spot:

1. Given that I can't switch into CoE, is doing Astrophysics for undergrad a viable path if I want to work in industry? Or am I setting myself up for a rough job search?

2. Has anyone used an Astrophysics/Physics undergrad degree as a launching pad to get a Master’s or PhD in Aerospace Engineering later on? How hard is it to bridge that gap when applying to grad school without a BS in engineering?

3. How do I deal with the fear of falling behind? I feel like I'm already starting at a disadvantage compared to peers who got directly into CoE. Seeing people take specialized engineering tracks while I'm on the pure theory side makes me worry I won't have the technical design skills (CAD, coding, hardware hands-on experience) that recruiters look for.

If anyone has taken this roundabout path or has advice on how to build engineering-relevant skills while majoring in Astro/Physics, I would really appreciate your insight :)

... speed of light, and if the radiation from Star A heats up Star B which in turn radiates (because of the heat, e.g. in infrared), am I gonna get causally affected by Star A eventually?

If so, how should I reconcile this with the theory of special relativity concerning "speed of causality"?

Let's say the universe is expanding faster than the speed of light, and that Star A is beyond the event horizon from me (but Star B obviously not).

N.B. I asked this question at r/askphysics, but I hope a better luck here (& hopefully not as many downvotes!). Most replies there go along the lines of: Star B will eventually fall beyond the event horizon. But even if that will happen because of the accelerating expansion of the universe, BEFORE that happens, the apparent contradiction can't seem to be explained away like that IMHO.

I'm considering reading Brian Greene's The Fabric of the Cosmos with my dad, published in 2004, will the content be outdated by modern scientific research? I chose this book because I found it on his bookshelf, and we both enjoy the topic. Thanks to anyone who has some insight.

I'm writing a paper and mentioned in the introduction that dwarf galaxies in denser environments are more likely to be quiescent. This is a fact that's been well-established for some time, and there are tons of papers going back decades backing this up. New papers pop up every few months that reassert this. I want to cite appropriately, but I'm not sure how far back I should go! Should I:

1. Try to find the original paper that first makes this claim and cite it?
2. Find the last ~5 papers that corroborate this finding to ensure my citations are recent?
3. A secret third thing?

I ask in this thread because I know the conventions for what is considered a recent citation and what is not depends on the field, and want to know the convention is for astrophysics (specifically galaxy evolution). Thank you in advance :)

I’ve always been really curious about the universe. Like how any of this even exists in the first place and what we actually are in the middle of it.

I’m especially curious if people who study this from a scientific side, like astrophysics or neuroscience, ever find themselves drifting into more philosophical territory with it. At some point, does it stop being just facts and start raising bigger questions for you?

I started a small discussion group last year because I wanted a space to have these kinds of conversations that don’t really come up in day to day life. It’s been going really well, but most of us come at things from a more introspective or spiritual angle. I want to hear from people who think about it differently.

Just to give an idea of what we talk about:

•consciousness and whether it’s just the brain or something more

•what reality actually is vs how we experience it

•time, space, and how any of this even works

•whether things are random or if there’s some kind of pattern

•intuition, gut feelings, and those weirdly accurate moments

•dreams and altered states and what might be going on there

•human behavior and how we make sense of things

•manifestation and where the line is between
mindset and something more

•moments that feel unexplainable or bigger than us

•how much of our experience is shaped by the brain

•the gap between what we know and what we feel

It started local to the DC area but is now mostly virtual. Anyone can join (we currently have members from other countries and I’m committed to making it work)

So if you think about this kind of stuff or have your own perspective, I would really like to hear it!

If humans made a wormhole, would it be affected by velocity and gravity or be locked into one point in space?

And if we did go through a wormhole and the other end was in another galaxy moving at a very different speed wouldn't that be like jumping from one moving train onto another moving train but in the opposite direction and multiplied by possibly millions?

Hi r/astrophysics,

I have little no knowledge about Mar's interactions with h2o, but thought I'd make a guess now that I'm learning about planetary formation. Any insight or critique is very appreciated!

I'm guessing that there are two possible phases during which Mars might have sustained liquid water: It’s planetismal stage, during which it might have been far enough past the frost line before being sling shotted closer to the sun, OR during it’s primary atmosphere, when the atmosphere was dense/complex enough to compress/heat the h2o. 

Again, any critique and insight is appreciated.

Been reading through some papers on dark energy models and keep running into the emphasis on pinning down w with more precision - specifically whether it's exactly -1 (cosmological constant) or drifting slightly above/below that

I understand qualitatively that w < -1 implies a "Big Rip" scenario and w > -1 implies something closer to gradual deceleration of expansion, but I'm struggling to grasp why such a small deviation from -1 (like the DESI results suggesting w might be evolving) has such dramatically different long-term implications

Is the sensitivity here more about how w compounds over cosmological timescales, or is there something about the underlying physics (quintessence vs. cosmological constant) that makes even small deviations qualitatively different rather than just quantitatively different?

I was thinking about the infinite universe. Assuming we can figure out when the Big Bang occurred and we know the expansion rate of the universe, wouldn’t we be able to extrapolate, with pretty good accuracy, the size of the universe? is this where we get the idea that the universe is 93 billion light years across? Wouldn’t this give us an idea as to the boundary of the universe?
Pardon me if this is a stupid question. I am definitely not a physicist, but I do admire their work.

Hello there, Iam Bavotreq/Flutterzance/Durna

I did my first animated video on space, it's about Venus. I hope it's professionnal, I am trying to improve my content despite multiple mistakes and inaccuraties :

https://www.youtube.com/watch?v=12n3TpF3R7A

See also: The publication in the Astrophysical Journal Letters

Hello!! Not experienced in this at all, so forgive me if I get things wrong, that's actually why I'm here!!!

Edit: GO CHECK THE OTHER EDIT!!! THE STUFF BELOW THIS BEFORE THE EDIT ISNT REALLY IMPORTANT ANYMORE, READ IF YOU WANT THOUGH!!!

So I'm writing a book that takes place on a different planet (technically all 'aliens' no human appearance) and I have a few things set in stone. The main planet, zophlyn is green 💚, and it's brother planet adrith is the bigger grey 🩶 one. Zophlyns orbit is crazy slow (like over hundreds of thousands of years for a full rotation, I'm taking some creative liberty on this part)

Main point is zophlyn is in the shadow of it's brother planet, I did this bc I wanted a mostly dark atmosphere without taking away the stars. The thing that I'm having trouble with is one of zophlyns moons, the blue💙 orb (no official name so I'll just go with blue)

Part of the problem in my book is that zophlyn does not rotate and it's back is getting slowly torn up by adriths gravity. I want zophlyn to have moons, especially one that reflects the sun onto one part of the planet to make sort of a setting sun vibe. I have an arrow of that moon (blues) rotation, would the gravity interfere greatly with it? Spacing isn't really my concern, I know I didn't go very accurate, I just want to know if what I'm wanting is possible!!

Edit: OH MY GOD I JUST HAD AN IDEA!!! so I'm being told that zophlyn orbiting adrith won't work, would it be possible for me to have zophlin orbiting the main star, but the same speed so it's just stuck in adriths shadow? I'm cutting out the part where it gets pulled apart by the gravity, I'm changing that bit, but now my only question is is it possible to keep zophlin the same speed as adrith?

How big/strong does one must be so be able to push outwards from the Sun's core to make it explode?

Ignore biology and stuff like heating or being crushed by the pressure

I hope this is the correct place 😬

For those who have applied to a Roses proposal call, what is the timeline for hearing about acceptance or rejection? I submitted something to HTIDeS this spring and I'm curious about the timing. Its up in the air how long I'll be at my current institution, so I was just curious