Hello everyone. This is my first time posting on this board, but I figured the answer that I've been looking for would have a greater chance of being answered here, rather than the other boards I usually browse. Before I explain further, I feel like it's worth mentioning that I'm not particularly religious, and I'm not trying to disprove/challenge any claims that have been generally accepted by the scientific community. Also, I have tried to research the answer on my own, but I have always come up short.
Anyway, I have some questions regarding the size of our universe. It is generally accepted that our universe is constantly expanding and has been expanding ever since the Big Bang occurred. The Big Bang is generally accepted to have taken place ~13.8 billion years ago, when a point of mass, infinitely dense and infinitely hot, began expanding, eventually creating the universe as we know it.
With the exception of the question, "where did that original singularity originate from? (I'm not particularly concerned with that question though)", that's a scientifically sound explanation. However, I have made one observation that casts a shadow of doubt (for me, at least) on the whole "Big Bang Theory". According to the Theory of Special Relativity, nothing is capable of traveling faster than the speed of light. However, our universe, provided it's formed in the shape of a sphere, is estimated to be approximately 93 billion light years across in diameter; and here's where the problem lies (for me at least). If the universe is, in fact, 93 billion LY in diameter, then, even if you half that distance (marking its radius), and you assume that the universe expanded into a sphere-like form, equally, without interference or hindrance of any kind, and in all directions from the Big Bang's original singularity, then you still have a universe that has expanded much faster than the SoL. Anyone want to try to explain this?
The Size of the Universe
The OBSERVABLE universe is 93 billion LY in diameter
The universe is 93 billion x 10^23
>nothing can travel faster than light
Wrong. Matter can't. Space can. Space is expanding faster than the speed of light.
We observe that all the galaxies are getting away from us at certain speed. And the more far away the galaxy is, the faster it gets away from us. The galaxies beyond the 93 billion LY diameter are no longer visible because they getting away from us faster than light.
There are two options here:
A) We are the center of the universe and matter travels faster than light
B) Space is expanding, and from any point in the universe it feels like you are the center of the universe, even though you aren't.
Imagine it like having several dots on a balloon. If you inflate the balloons, all the dots get away from each other.
Ok, that's cool to know, but that only makes me doubt the BBT even more so. That implies that the universe has expanded even more rapidly than I previously thought.
>Before I explain further, I feel like it's worth mentioning that I'm not particularly religious, and I'm not trying to disprove/challenge any claims that have been generally accepted by the scientific community.
lel
there was no reason to include that
He probably thinks Veeky Forums is actually full of smart and educated people
Thank you, user. Couple questions though, if you don't mind. Please feel free to tell me to bugger off if you don't feel like putting forth the effort to answer these. I know how broad and complicated these questions can become.
If what you said is true, then our estimation of the universe's size is only able to be calculated using what light has had time to reach us on Earth. We really have no idea how large the universe is in actuality, and there are parts of it expanding so rapidly that we, no matter how technologically advanced we become, will never be able to observe, correct? Or am I just misinterpreting this? Secondly, can you explain how space is able to reach these speeds? Tertiarily, is space expansion subject to the same Laws of Relativity that mass is? I.e. Does time on/in the expanding space become distorted in relation to other objects, like it does with an object that has mass? Also, I know this is probably a fairly broad question, and may take quite a bit of labor to answer, but would you mind explaining why space itself is somehow unaffected by the Theory of Special Relativity? I've just skimmed a few articles on the subject, but they seemed to be written for people who just wanted a cursory explanation. There was no depth to them at all.
Just trying to dodge the fedoras, bro.
Nah, I just figured that there was probably a slightly greater concentration of intelligent people here compared to other boards. That doesn't mean that I assume that most people here (including myself) are intelligent of any notable mention.
>We really have no idea how large the universe is in actuality
We can estimate with with the age of the universe, assuming the rate at which space expansion is accelerating is constant, etc.
>parts of it expanding so rapidly that we, no matter how technologically advanced we become, will never be able to observe, correct? Or am I just misinterpreting this?
The universe is expanding at the same rate everywhere. But by the nature of the expansion, what is far away, gets way from us faster. Think of inflating a balloon with painted dots.
A civilization born a trillion years into the future will find that their galaxy is the only galaxy in their observable universe, and the rest is empty space as far as the eye can see. This could mislead them in principle.
>Does time in the expanding space become distorted in relation to other objects, like it does with an object that has mass?
Relativity doesn't take into account the expansion of the universe.
>why space itself is somehow unaffected by the Theory of Special Relativity?
Because space is primordial, while relativity only concerns the things inside space.
>universe is expanding at the same rate everywhere
but the rate is also accelerating
>we can estimate
>a civilization formed a trillion years from now won't be able to see anything
Well with this in mind, it seems possible that we have also been deceived (visually, at least). This also seems to imply that, without some sort of wormhole or teleportation device, humans will never be able to reach any destination outside a certain distance limit. Or maybe I'm just being dense as shit.
Also, would it be possible for that given civilization (GC) to eventually get a glimpse of some light producing/reflecting celestial body, provided that they were around long enough for the light of that celestial body to reach them? Or would GC always perceive space to be a black void due to the rapid expansion of space in our universe? Would they never see anything beyond what was immediately observable to them within a certain distance? And would they ever be capable of reaching other significant locations in the universe using just SoL travel and without the use of teleportation/wormholes? That may be a dumb set of questions (or I may just be asking questions way over he heads of anyone on this board) but I'm not particularly gifted at mathematics, and theoretical physics, while fascinating, always seems to leave me with more questions than answers.
>a civilization formed a trillion years from now won't be able to see anything
I said "mislead in principle". They can eventually figure out ways around it. But we have it easier, clearly, being so close to the Big Bang.
>without some sort of wormhole or teleportation device, humans will never be able to reach any destination outside a certain distance limit
Correct. Not only "reach", we won't even see it. We know it exists because we know the age of the universe, and the rate at which the expansion accelerates, and assuming the geometry of the universe, you can estimate it.
So in theory if you had some kind of FTL drive and were to fly away from our galaxy new galaxies would appear while others disappear behind like a range limit on a game?
yes, because what you see is light (photons - basically massless elementary particles)
the fact they are massless, by the way, is one of the reasons we know nothing can be faster than that
What if there were a particle with negative mass?
Also:
en.wikipedia.org
en.wikipedia.org
All hypothetical, never observed
Wait, I'm not physicist (not yet) but how did you come up with the expansion of the universe going faster than the SoL?
Observable universe: 93 billion light years diameter
Age of the universe: 13.8 billion years
Magic? No! Universe expansion.
Nvm guys I'm a dumbass, I didn't know that this was a thing.
Also, you challenging scientific claims is good but you probably won't be able to disprove something like the BBT if you aren't a physicist. It's like a creationist that claims he researched evolution and thus denies it: it makes no fucking sense.
Wait for some reason I was reading it as 93 million light years in diameter
appeal to authority like a motherfucker
I'm not really challenging it per se. I was just wondering if anyone had an answer to the contradiction I saw. I figured someone out there had already thought of this, and the answer was probably already in existence, but I was simply unable to find it using Google and what not.
Thank you, kind user.
Well there is a bunch of weird shit in physics like quantum entanglement... it's technically fast than sol but it's not necessarily an object like flying through space but rather information being transmitted via some form of quantum mechanics
Space doesn't exist. The earth is flat and domed and al the stars and comets and sun and moon are within it.
What's outside the dome
>universe that has expanded much faster than the SoL. Anyone want to try to explain this
With enough distance, you always end up with speeds that exceed c
The Hubble constant, when translated to easier units, is about [math] \displaystyle \frac{2 \frac{cm}{ly}}{s} [/math]
Each light-year stretches 2cm/s --> stuff 15 bn ly is receding at the speed of light.
The stars at the edge of the observable universe, 45 bn ly away, are rushing away from us at 3c.
not even OP here, but thanks. that helped me, too
Interestingly it isn't faster than light because the fastest the information can travel is the speed of light so technically it doesn't break causality. Neat to think about honestly
Deep water