Part of my effort to be able to learn astrophysics, cosmology, and its concepts better as it is my area of study. This thread is here to serve as a way for those within this community to ask questions about the great unknown, hopefully get a quick answer, and to be able to go to your friends next time you see them as say "did you know x about the universe?"

Some of my backstory:
- Undergraduate University student studying Space Systems Engineering, specializing in Astrophysics, Computer Science, and Math.
- Even from an early age I have always looked up and wondered about the great blackness that is all encompassing. It has brought me to tears over some of the facts and has even brought me comfort knowing the indifference it has over us. Some of the greatest pieces of advice and pieces of thought are from those who have studied the stars and universe.

Some other stuffs:
- I am an undergraduate so there may be questions I don't understand; however, if I don't then I will use that reply as a thought experiment
- I will not solve your homework (unless I have the exact same problem for mine).
- Philosophy under the guise of astronomy, cosmology, and astrophysics will be permitted but I will not talk about religious concepts. The osu! forums are not a place for that and I will not entertain them.
- Be respectful. All persons come from a different understanding of the universe and a different way of life. There are no dumb questions only a different starting point of knowledge.

Without any more jargon, lets learn together!

What is the most facinating thing about the universe that you can think of?

- Marco - wrote:

What is the most facinating thing about the universe that you can think of?

Something that tends to blow peoples' minds is the fact that while the universe is expanding, it is not expanding into something but into nothing. There is no outside of the universe and there never is... anything. It is nothing. The universe is expanding into an infinite nothing creating something.

What is most likely to cause the eradication of humanity? A supernova explosion? A black hole that will wipe us out?

Anaxii wrote:

What is most likely to cause the eradication of humanity? A supernova explosion? A black hole that will wipe us out?

Theres been some weird anomalies that happen in space. 1 of them being that NASA and other space agencies have a really hard time finding objects in space that are under 1km in size. This means that an asteroid 1km in size can come barreling down and into Earth's orbit before the space agencies can detect/deal with it (if we can). The most truthful one being in about 5billion years the sun will stop hydrogen burning and will move onto helium burning - this means that once that phase starts the sun's surface will expand to about orbit of Mars. This means that the Earth, and if there are any humans on it, will be killed and destroyed with that expansion.

The most probable of any is that humans will eventually extinguish themself through climate change, nuclear warfare, or just living out our days.

There are some other ways though. A supernova that is relatively close to our solar system may knock other stuff out of orbit or as it traveled through the cosmos it knocked other debris and material into the path of Earth and can collide or cause other chain reactions to cause us to become extinct.

It is very unlikely that we will witness a blackhole within our solar system or even within our Oort Cloud.

How dangerous would it be to open a bag of ruffled potatoes in space? Like in a spaceship.

eblf2013 wrote:

How dangerous would it be to open a bag of ruffled potatoes in space? Like in a spaceship.

Hmmmm opening up a bag of chips in a pressurized spaceship would be the same result as opening it down on Earth, especially since the... pressure.. is the same.

1 caveat is that you might want to make sure that they are whole chips and have not broken or what not as the crumbs and other food particles can become lodged inside air filters, air resupplies, and other ventilation systems. So it could be potentially dangerous, buttttttt not explosion dangerous.

If you were to open them in the vacuum of space, I would believe that the pressure inside would be enough and the airtight seal would also be enough for the chips to be relatively safe from exploding.

You think we will be able to colonize other planets?

Reyalp51 wrote:

You think we will be able to colonize other planets?

Planets would be pretty difficult imo, terraforming an entire planet to fit the atmosphere of Earth or even building enclosures in which we can imitate Earth's atmosphere will be tough.

The main issue comes from needing a place to land that is somewhat livable for the astronauts to land on the surface of the planet. Pretty much every planet in our solar system is either a Gas Giant or the planet itself is inhabitable for even robots (Venus).

Our real choices are Moons of planets. They are terrestrial and they can potentially be safe enough to where can land and start building a structure to house our astronauts.

Some other considerations to this is that while we have reclaimers and recyclers, we cannot get back 100% of the air, water, and other valuable resources. So, there are a few moons that have the ability to provide those resources with a little bit of effort. 1. Europa 2. Enceladus 3. Titan. These three moons have the potential to harvest water naturally (it may take a bit of effort and a lot of heating tools for 1 and 2. However, they are more than likely the places we would try to terraform or at least colonize before moving onto a place with no water and no atmosphere.

tl;dr: Planets, no. Moons, however, yes.

oooooo some interesting threads

what makes human sure that there are other life forms in the universe? if that is false, how do we know that we are the only lifeforms in such a vast emptiness?/

ClevelandsMyBro wrote:

oooooo some interesting threads

what makes human sure that there are other life forms in the universe? if that is false, how do we know that we are the only lifeforms in such a vast emptiness?/

tl:dr Q1: There are trillions UPON TRILLIONS of stars. It would be a statistical improbability for there to not be another planet in the goldilocks zone with the right amount of time as us to develop sentience, in whichever form it may take. It has to be true. The universe is not choosey and is not has deliberate to make us the only lifeforms.

tl;dr Q2: we may to early or be too late. Could be too far away. Could also be that they dont know we are intelligent enough to understand.

Theres been some good theories about why we haven't found intelligent life out there. I think the universe is too vast and there are literally trillions of stars, each one with their own solar system with possibly many many more Earth Like planets.

I think that we are in a period that may be too early for life to start thriving in other systems, or we are too late to the party and other civilizations have died out from their own doings or other things. Remember the universe is around 14 billion years old. Earth is only about 4 billion years old. Its hard to say why exactly we havent received anything if they have been out there, but the consensus seems to be that the exact distance of space is too vast so we just havent received anything yet or they are still traveling.

You gotta think that if they are not within like a million light years of us they are going to be seeing prehistoric and unevolved lifeforms, not humans. So they might not want to contact us because we'd have no way to contact back (from their view). They could be using a frequency or wavelength that we havent been able to discover or detect, so how would we know?

Somewhat the closest thing I can think of is that there is a star that is dimming and becoming brighter without the usual reasons of something passing by it or gas clouds/dark matter, so they are somewhat thinking it is a dyson sphere or some type of solar construct, but that is so far away that its hard to say for certain.

Is it possible that there are other universes similar to or different from ours? Like an infinite number of universes in our world

Anaxii wrote:

Is it possible that there are other universes similar to or different from ours? Like an infinite number of universes in our world

Yeah, while we wont be able to interact with them and theres no definitive evidence or proof that they do exist, I do believe that there have been a many universes and there are other universes in existence rn.

trying to perceive something outside of our universe would require an intermediary void/space that an object can exist into and through. Would also imply we are expanding into something and just becoming the something, so its a bit circular on how we describe multiverses and our own.

But to answer the question. It is definitely possible, its just near impossible to detect or figure out.

have you heard about the theory that we live inside a black hole?

luvissour wrote:

have you heard about the theory that we live inside a black hole?

I have not exactly heard of this theory, but it would somewhat explain the isolated system we are in and how energy is not either destroyed or created just transformed. Would also explain not being able to go faster than light, as that would mean we can escape the blackhole's gravity, and thus our universe (which isnt possible)

Let's say, hypothetically, we encountered aliens and they have a different understanding of mathematics to the point that their axioms and postulates are vastly different from ours. Since our understanding of the universe is based on Physics (and therefore Maths), what would the implications be (or is my hypothesis possible in the first place)?

Explain the heat death of universe a bit more and how it will gradually happen, so like what temperature would everything be, could we prevent/slow it down from happening and so on

What would happen to the planet if an asteroid crashed to earth? Like a big space rock the size of a city thhqt crashes into us

Anaxii wrote:

What would happen to the planet if an asteroid crashed to earth? Like a big space rock the size of a city thhqt crashes into us

Depends on the size of the asteroid. If the asteroid is a city size... and it was that size on impact and not when it hits the atmosphere it would probably end all civilization. I mean most cities are kilometers if not 10s of miles wide.

It would not be a good day for humans and other organic life.

Dementedjet wrote:

Explain the heat death of universe a bit more and how it will gradually happen, so like what temperature would everything be, could we prevent/slow it down from happening and so on

Heat death of the universe simply just means the average temperature of the universe stabilizes and the free work is all used up. It doesnt necessarily mean that it becomes blazingly hot. It just means that there is no energy that can be used from thermodynamic processes/temperature differentials.

Preventing such a... universal scale event would mean we would have to be able to create free energy to put back into the system (our universe).

Jangsoodlor wrote:

Let's say, hypothetically, we encountered aliens and they have a different understanding of mathematics to the point that their axioms and postulates are vastly different from ours. Since our understanding of the universe is based on Physics (and therefore Maths), what would the implications be (or is my hypothesis possible in the first place)?

There's a decent book that explains this idea, it's called "Project: Hail Mary" by Andy Weir.

The possible understanding that there is a civilization that is more advanced and they dont understand our mathematics and our physics because of a language barrier/fundamental understanding of the universe is really possible.

I'd say that we can probably come to terms and congregate about our mathematics and physics and come to an understanding to where we can get a level where they understand ours and we theirs, with the stipulation that we can only understand what we have already figured out. They would have to then explain their advances in the science fields in our terms... and that is possibly not able to be done in our human languages.

Do you still answer to questions?

Because I have a few

Anaxii wrote:

Do you still answer to questions?

Because I have a few

Ask away!

Blushing wrote:

Anaxii wrote:

Do you still answer to questions?

Because I have a few

Ask away!

1. Is it physically possible that white holes exist in our universe? I say this because there are black holes and we don't really know much about them; it's just a hole that sucks you in, turning you into spaghetti and burning you at the same time... but where do all the light and space objects sucked into the black hole go?

2. If stars can cause supernovas, then why aren't we all dead by now? Is it an extremely rare event?

3. How does the 4th dimension work in space? I heard that it was a thing there but I don't really understand that...

Anaxii wrote:

Blushing wrote:

Anaxii wrote:

Do you still answer to questions?

Because I have a few

Ask away!

1. Is it physically possible that white holes exist in our universe? I say this because there are black holes and we don't really know much about them; it's just a hole that sucks you in, turning you into spaghetti and burning you at the same time... but where do all the light and space objects sucked into the black hole go?

2. If stars can cause supernovas, then why aren't we all dead by now? Is it an extremely rare event?

3. How does the 4th dimension work in space? I heard that it was a thing there but I don't really understand that...

is the earth round? (proving every flat earther)

[-Omni-] wrote:

is the earth round? (proving every flat earther)

Or maybe... what if the earth wasn't round, what would it be?

Donut Shaped Earth

Kitte wrote:

Donut Shaped Earth

There's no way

Anaxii wrote:

Kitte wrote:

Donut Shaped Earth

There's no way

including the hole in the middle

[-Omni-] wrote:

Anaxii wrote:

Kitte wrote:

Donut Shaped Earth

There's no way

including the hole in the middle

Why a hole? OOF

this might not be related, but i just want your opinion, are galaxies pretty to you? i love anything galaxy related myself, and want to know if others feel the same (i like the purple toned ones the most :3)

Anaxii wrote:

[-Omni-] wrote:

Anaxii wrote:

Kitte wrote:

Donut Shaped Earth

There's no way

including the hole in the middle

Why a hole? OOF

the hole in the middle of the donut? since earth donut shape, add the hole for it to rlly be donut shape )

[-Omni-] wrote:

Anaxii wrote:

[-Omni-] wrote:

Anaxii wrote:

Kitte wrote:

Donut Shaped Earth

There's no way

including the hole in the middle

Why a hole? OOF

the hole in the middle of the donut? since earth donut shape, add the hole for it to rlly be donut shape )

No but why this form instead of an oval for example?

Anaxii wrote:

[-Omni-] wrote:

Anaxii wrote:

[-Omni-] wrote:

Anaxii wrote:

Kitte wrote:

Donut Shaped Earth

There's no way

including the hole in the middle

Why a hole? OOF

the hole in the middle of the donut? since earth donut shape, add the hole for it to rlly be donut shape )

No but why this form instead of an oval for example?

because thats the shape of the donut

[-Omni-] wrote:

Anaxii wrote:

[-Omni-] wrote:

Anaxii wrote:

[-Omni-] wrote:

Anaxii wrote:

Kitte wrote:

Donut Shaped Earth

There's no way

including the hole in the middle

Why a hole? OOF

the hole in the middle of the donut? since earth donut shape, add the hole for it to rlly be donut shape )

No but why this form instead of an oval for example?

because thats the shape of the donut

Imo an oval would be more logical than a donut

Oval and torus (donut shape) cannot happen under the gravity that a planet needs or has.

And yes, galaxies are really pretty when the filters are put on them. One of the biggest things I like looking at when scouring my text book and the interwebs.

Blushing wrote:

And yes, galaxies are really pretty when the filters are put on them. One of the biggest things I like looking at when scouring my text book and the interwebs.

i have a galaxy bg as my google chrome wallpaper :>
lemme give a screenshot

i love galaxy backgrounds, they're so pretty <3 (and yes i have a green day song (jesus of suburbia) and an avril lavigne song (keep holding on) open in my tabs)

Blushing wrote:

Oval and torus (donut shape) cannot happen under the gravity that a planet needs or has.

So why does Saturn has a ring then? Is it because of the gravity?