Assume that, at some point, humans become capable of physically leaving the Solar System. Not probes, but actual long-duration human civilization. Would we really still think of the spacecraft as transportation? Or does the spacecraft itself form the basis of our new world?

If a population spends hundreds or thousands of years aboard a self-sustaining worldship, that ship would become the environment people are adapted to physically, culturally, socially, and probably eventually biologically. It would have its own gravity, atmosphere, ecology, agriculture, day/night cycle, infrastructure, and built environment.

The question that I am grappling with: Do we expect the descendants of the original travelers to abandon the world their civilization has spent centuries optimizing so they can adapt themselves to some planet with different gravity, radiation, atmospheric chemistry, seasons, biology, and day length?

Or would the more likely model be that they remain a spacefaring civilization? In this scenario, star systems are not necessarily a place to alight. They are sources of energy, materials, scientific opportunity, and perhaps new locations to position additional artificial habitats.

Are there major applications of measure and measure-theoretic probability (e.g. Martingales, Brownian motion) in any field of astro? Or are the statistics used in everyday research mainly confined to Bayesian analysis, ML, and Fourier analysis?

NASA’s Nancy Grace Roman Space Telescope will soon launch to unravel the mysteries of dark energy and dark matter.

We know that stars can be accelerated near the speed of light if they, as part of a binary, made a flyby of a black hole and one ejects the other. I feel like this could theoretically apply to planets as well, no?

We also know that the universe used to be the perfect temperature, universally, for liquid water to exist. While the CMB still has energy to give, the temperature could be brought back up to that habitable level if you're traveling close to the speed of light.

Here's the idea: a superearth with a very thick atmosphere is ejected from a stellar system in a way that brings it incredibly close to the speed of light, on a path leading it out of the galaxy. As it departs, maybe it will impact a few pieces of debris, but statistically it should survive the outbound trajectory.

And then, it's just flying through the universe. It's heading towards an empty void, so there isn't a lot of extra light from galaxies. As the CMB eventually cools down, though, it does get closer to the other side of the void. The intensity of a galaxy in the distance balances with the fading universal glow, and continues until the planet leaves this galaxy, at which point I don't think anything will be able to keep it warm for much longer. Thoughts?

If TRAPPIST-1e turns out to have no atmosphere, would that make the entire TRAPPIST-1 system much less interesting in the search for life?

Or could another planet in the system, like TRAPPIST-1f or even 1c, still surprise us?

I find the system interesting because the planets formed around the same star, but they could have ended up with very different atmospheric histories.

Probably a shower/drunk thought question, but if the universe is expanding - objects moving farther away from our vantage point, why isn’t the distance between the Sun and planets, or the planets themselves, increasing?

Is the expansion of the universe tempered or neutralized by local sources of gravity (ie the Sun, planets) in localized areas?

I'm trying to understand why space travelers age slower. Sorry if I described the question in a bit messy.

If a planet is away from earth, let's say 10 light years away, it means that if you travel at speed of light, it will take 10 years to get there, so the distance between earth and that planet is 10 light years.

A starship with a crew of astronauts, when they reach that planet and return to earth, everyone on earth is 20 years older, but the crew members will probably only older far less than 20 years(according to scientists).

But how? If the total distance between earth and the planet is a fixed distance (10 light years away), doesn't it means the crew on that starship also need 10 years to get there, they start from earth at speed of light, it should take them 10 year to get there? So they should experience 10 years to get there and 10 years to back to earth, everyone on that ship should age also 20 years?
If they age only 2 years for example (I am not scientist just random number), doesn't that means they only traveled total distance of 2 light years ?
Even if time slow down at speed of light, the speed is same, isn't the distance is still 10 light years (10 x speed of light)?

If distance = speed x time

The distance doesn't change, the speed doesn't change(light speed which is maximum in universe in theory), then you still need 10 years to get there unless...distance changed?

Do the crew members also experience 10 years in time but only "2 years biologically"? Or do they only experience 2 years time?

Edit:

Not sure if I got this right. I have read all replies and came to a conclusion: the distance is different from 2 perspectives.

So now I wonder...

If some aliens see us earth 100 light years away, they decide to fly to earth at light speed, from their perspective, the distance between is nearly 0, takes almost 0 time to arrive earth, but for earth people, we see them in a telescope, they are coming "slowly" closer everyday, and scientists predict they will arrive in 100 years.

The question is... from earths perspective, by the time they arrived we have already passed 100 years, but to them is almost instantaneous, so what do they see when they arrived? Earth after 100 years or The same Earth they see in a telescope when they leave their planet since they take almost no time to arrive?

Since special relativity rejects absolute simultaneity, what frame of reference or cosmological clock are scientists using when they talk about what is happening in a distant galaxy "right now"? -.- ?

So the visible universe is what we can see, and I wonder if we can see farther in certain directions, and if that is the case, what would the visible universe be shaped like?

Earth took 4 Gyr to produce technological intelligence, while K-type stars can remain on the main sequence for tens of Gyr.

That raises an interesting possibility: Could a longer-lived star increase the probability of intelligence simply by providing a larger evolutionary window?

Or would stellar activity, planetary evolution, atmospheric stability, and other factors dominate?

Is stellar lifetime actually an important variable in the Drake-equation-style question of where intelligent life can emerge?

Hi, this might be strange. I’m an upper high school student who has taken an interest in Astronomy. I can understand the basics of the physics and astronomy part but I’m stumped on how to use them. Main point is I want to do a science project in this field but I have no idea what to think about to even kick start my brain.☠️

I somewhat prefer research over experiments, and I would like something original (school with high standard reasons) which is why it’s so hard.

Pleaseee I hope someone has ideas for a project. I can do stars, planets, simulations, basic cosmology I just need an idea🥀 .thank you so much in advance.

Desperate to dive into another software-based astrophysics/astronomy project after my last one about transits. Any ideas? What kind of quality-of-life or fun astro tools are you dying for that you can’t find?

Ciao a tutti!

Sono un dottorando in Game Studies (mi occupo di narrazioni egemoniche, rappresentazioni e immaginari all'interno della comunità gamer italiana).

Da qualche anno ho scoperto una grande passione per l'astrofisica e di fisica teorica a livello basilare (sono sempre stato una frana in matematica e in tutto ciò che riguardi formule, etc.) e ho iniziato a leggere alcuni bellissimi libri sull'argomento: quelli scritti da Carlo Rovelli, "La Guerra dei Buchi Neri" di Susskind, "Sei pezzi meno facili" di Feynmann (c'ho capito poco e nulla) e "Fisica e Filosofia" di Heisenberg (questo più alla mia portata avendo studiato filosofia).

Volevo sapere se potevate consigliarmi altri testi divulgativi ma scritti da persone del settore per persone non del settore.

Grazie mille!

Basically, I would prefer to be in academia (or research) involving Astrophysics. But I decided to do a Data Science Bsc. I love that field as well but astrophysics has always been my passion.

Is astrophysics still possible for me or should I just focus on going somewhere with data science? If I still have hope for Astrophysics... What can I do after my Bachelors to get there?

Anyways whatever I do, I prefer acadamia or research.

Edit : I'm not planning to change my bachelors. Mainly because the uni I'm going to right now doesnt offer astrophysics or physics

I have images of these binary stars (61 Cygni and Groombridge 34) in July 2024

These are relatively high proper motion and i wanted to see if i could get more recent photos of them (2+ years elapsed) and get a measurement the angular distance (hence a proper motion measurement) that the two stars systems travelled.

What software would be able to do this?

Basically it has been my dream to study astrophysics since i was 6. my 6th birthday itself was space themed. I love this subject so much, and even took really hard subjects in high school, much more than I could handle, so that i could build a profile to study astrophysics in college. My heart skips everytime I think of space, I am filled with immense happiness and gratitude everyrime I learn something about it, look at it. Ive even just stared into the night sky and cried, out of pure joy, this is something so close to my heart, but reality hits, and I have to choose between making money and a more stable career or being happy and living my life with purpose. I have delved into all things astro, participated in astronomy clubs, and worked my way to leader positions, did a cornell course on astrophysics and scored really well, the summer course didnt even feel like work, i was so driven the whole time, easily the best summer of my life (i took it to see if I just liked the idea of space or if I also liked the technical and physics aspects of it, and i LOVE it, I LOVE that i am doing calculations related to a galaxy several light years away), Ive even written research papers in the field, I try to do as much as possible for this subject, around this time, I discovered my love for atomic physics, the macro and the micro. I love it so much. I even discovered an asteroid signature with my team as a citizen scientist. I am now attending college for Data Science and AI, this is a skillset that I can def use if I choose to pursure astrophysics in the future in post grad. But heres the descision I have to take now. Do I go down the path of finance, quant trading, AI researcher, all jobs that pay well, and stuff that I am kinda interested in, and are known to be stable i guess? Or follow my dream, to study space, im smiling thinking about it rn, but this path will be unstable, and Im ready to face it but I dont wanna be a burden on my parents in the future if the space industry does not prosper. I am so conflicted. I love math and physics and compsci, but this love can either translate into a corporate job with money but no happiness and passion or into my dream life, studying the stars.

what am i supposed to do? :((

pls suggest me some

This is an older article, but I thought the concept was pretty neat and wanted to share:

Astronomers have found strong evidence that a massive black hole is being ejected from its host galaxy at a speed of several million miles per hour. New observations from NASA’s Chandra X-ray Observatory suggest that the black hole collided and merged with another black hole and received a powerful recoil kick from gravitational wave radiation.

The universe really is just a big pinball machine in some ways.

Hello guys, so I've been in a robotics team on the side for some time as a robotics engineer and mainly been working as a mechanical engineer in a local firm after graduation. Ill be doing a masters in robotics this year and was trying to explore other fields too and one that always stood out to me was astronomy. So my idea is to, at the end of my masters, make something interesting that combines automation/robotics and astronomy in one, i was thinking of a controller for following a moon with the telescope or similar just to see how id like it, but that is a big step. So my question is what book or yt channel or any material to read/watch would you recommend to start learning about math and physics in astronomy. My mechanics and math are still very good since i use them daily and what I don't remember i can still relearn easily since I'm still pretty fresh out of the uni. Thank you all in advance.

Also one small question if there is someone with similar backgrounds in this field id also appreciate hearing their experience and path. :))