Another Universe question

Another Universe question

Author
Discussion

N8CYL

Original Poster:

460 posts

150 months

Monday 9th March 2015
quotequote all
To help a simpleton like me get a handle on the size of the universe, if the sun was the size of a grain of sand, how big would the known universe be?

Capt Bravz

344 posts

160 months

Tuesday 10th March 2015
quotequote all
Mmmm, someone far more learned than me will be along I'm sure but I don't think it works like that. The Universe is so vast, so mind bogglingly massive that our brains can't comprehend it.
We know that we are quite small, mountains are big, countries bigger still, the Earth even bigger and then once we start to get beyond that even in to the relative 'smallness' of our solar system compared to the universe it all goes out the window a bit.
Same with time. We're programmed to comprehend what we experience in that again, we know a minute is quite short, an hour a bit longer, a year takes a while and a decade much, much longer. Getting our heads round thousands, let alone millions of years is again a struggle.

The question in the OP is interesting though but I don't think you'll get an answer that you can go 'oh, yeah right, to.'
If the Sun was a grain of sand you can't just say the edge of the known universe would be just outside Birmingham. Or Australia. Or the edge of the Galaxy.
A grain of sand is probably many, many billions of times smaller than the Sun (don't know the exact figures, too late to look up) but even applying that same scale reduction to the rest of the Universe it still wouldn't quantitate it into something you could rationalise.

Look at some of the videos on Youtube about it and prepare to feel incredibly awestruck!

Edit; In fact here's one to start you off. https://www.youtube.com/watch?v=AC7yFDb1zOA

Edited by Capt Bravz on Tuesday 10th March 00:10

Capt Bravz

344 posts

160 months

RobDickinson

31,343 posts

254 months

Tuesday 10th March 2015
quotequote all
Aparently 1.4 x 10^6 km in diameter.

http://www.reddit.com/r/askscience/comments/2jq4v1...

Edit - sorry that is just the galaxy not the universe.


Edited by RobDickinson on Tuesday 10th March 00:35

rich83

14,221 posts

138 months

Tuesday 10th March 2015
quotequote all
RobDickinson said:
Aparently 1.4 x 10^6 km in diameter.

http://www.reddit.com/r/askscience/comments/2jq4v1...
Mind blown

scorp

8,783 posts

229 months

Tuesday 10th March 2015
quotequote all
RobDickinson said:
Aparently 1.4 x 10^6 km in diameter.

http://www.reddit.com/r/askscience/comments/2jq4v1...

Edit - sorry that is just the galaxy not the universe.
1,400,000 km isn't that big at all, you mean light years ?

RobDickinson

31,343 posts

254 months

Tuesday 10th March 2015
quotequote all
scorp said:
1,400,000 km isn't that big at all, you mean light years ?
Nope. If you scale the sun to a 1mm grain of sand the milky way would be 1,400,000km diameter.

The universe is somewhat larger.

people find it hard to grasp the size of even our solar system and sun let alone the galaxy/universe.

If you had a space ship that went the speed of light you would still die a long time before seeing more than a handful of other stars. Crossing our galaxy alone would take 100,000 years. Ignoring silly time compression relativity issues...

Einion Yrth

19,575 posts

244 months

Tuesday 10th March 2015
quotequote all
RobDickinson said:
Nope. If you scale the sun to a 1mm grain of sand the milky way would be 1,400,000km diameter.

The universe is somewhat larger.

people find it hard to grasp the size of even our solar system and sun let alone the galaxy/universe.

If you had a space ship that went the speed of light you would still die a long time before seeing more than a handful of other stars. Crossing our galaxy alone would take 100,000 years. Ignoring silly time compression relativity issues...
Ignoring reality you mean? Hard to make any definitive statements then...

jmorgan

36,010 posts

284 months

Tuesday 10th March 2015
quotequote all
Holds arms apart "this big"

No one knows.

scorp

8,783 posts

229 months

Tuesday 10th March 2015
quotequote all
RobDickinson said:
Nope. If you scale the sun to a 1mm grain of sand the milky way would be 1,400,000km diameter.
Ahh, Sorry I thought you were talking about normal scales.

RobDickinson said:
If you had a space ship that went the speed of light you would still die a long time before seeing more than a handful of other stars. Crossing our galaxy alone would take 100,000 years. Ignoring silly time compression relativity issues...
The 'you' on the ship would experience a much faster journey though.

RobDickinson

31,343 posts

254 months

Tuesday 10th March 2015
quotequote all
scorp said:
The 'you' on the ship would experience a much faster journey though.
Yes, thats why I said ignore that lol

If you could travel close to the speed of light you could lap the milky way in subjectively little time (15 years or something) though dont expect your mates to welcome you back.

Derek Smith

45,613 posts

248 months

Tuesday 10th March 2015
quotequote all
I used to instruct in home defence. One of my roles was to get over what the explosive effects of a megaton of TNT were. The idea was farcical. One of the suggestions was to say that in comparison with the Nagasaki bomb . . . etc. (This at a time when there was argument about how many kilotons it was.)

There is, it would appear, no way to appreciate the size of big things beyond a certain size.

It's big, really big. You might think it's a long way . . .

RobDickinson

31,343 posts

254 months

Tuesday 10th March 2015
quotequote all

N8CYL

Original Poster:

460 posts

150 months

Tuesday 10th March 2015
quotequote all
RobDickinson said:
scorp said:
1,400,000 km isn't that big at all, you mean light years ?
Nope. If you scale the sun to a 1mm grain of sand the milky way would be 1,400,000km diameter.

The universe is somewhat larger.

people find it hard to grasp the size of even our solar system and sun let alone the galaxy/universe.

If you had a space ship that went the speed of light you would still die a long time before seeing more than a handful of other stars. Crossing our galaxy alone would take 100,000 years. Ignoring silly time compression relativity issues...
Crikey, and there are billions of galaxies, billions of light years apart, there's me thinking the size of the moons orbit would be about right.

TwigtheWonderkid

43,327 posts

150 months

Tuesday 10th March 2015
quotequote all
It would be the size of a squirrel, but don't ask what colour squirrel.

jmorgan

36,010 posts

284 months

Tuesday 10th March 2015
quotequote all
Bbc two now. Horizon.

Edit. Scrub that ,not what I thought it was.

Edited by jmorgan on Tuesday 10th March 22:02

Capt Bravz

344 posts

160 months

Tuesday 10th March 2015
quotequote all
So I've played with some numbers today as I was intrigued as to how 'fathomable' the distances of space could be. Could I get my and the OP a sense of scale to the universe. All calculations are completely hypothetical but I had fun doing them. No flaming for any glaring errors though please.

So. We all know what 70 mph in a car feels like. Reasonably quick. By the time we are doing 140mph, where conditions allow, we feel this to be very quick or at least I do. Some of us will be fortunate to own or have experienced a top end super car doing over 200mph+. I think we can all agree that this is extremely quick for a road going car.
So lets say that we are going to drive to our nearest celestial body, the Moon. I know, I know, you can't drive a car to the moon blah blah but remember it's all hypothetical. And cos it's hypothetical I'm going to take my imaginary and space proof Aventador for a spin. To get to the Moon I need to cover approx. 238,000 miles. Wow! That sounds a lot already, how can I get my head round that?
Well, cruising at a steady 200mph in my Lambo (cos you know, it's nice to relax on a long journey) it's going to take around 50 days to get there. 50 days!!
And that's driving none stop, day and night, no meal breaks, no toilet stops, no Costa coffee if you feel a wee bit fatigued.
With a sensible amount of 'driving', say 8 hours a day, that equates to 150 days, 5 months solid, of 200mph driving, just to get to the moon. Jeez this end of the Universe road trip could take a while!

Still, baby steps. So we've covered the Moon. What about the next planet out? Mars.
Well, it's a bit further. Around 34 million miles away from us on Earth. See, there's another number I can't get my head around. 34,000,000 miles!
But never mind, I'm hopping in the Lambo again, this time with a crate of red bull. Not only for energy but you never know when you might have to hurl a can at a passing space ship.
Cruise control at 200 mph once more and oh, ffs, it's going to take me 19 years to get there!!! 19 years doing the double ton. And again that's non stop 24 hours a day driving. Go back to 8 hour stints and we're looking at the best part of 60 years to drive (very fast) to Mars. So once you've passed your test you can hope to arrive just before you die. Balls.

But never mind, lets go one step further. The edge of our solar system. Not the edge of our galaxy, just to the edge of the 9, or is it 8 now, planets that orbit our Sun. How far is that? It's approx 9 billion miles away. 9,000,000,000 miles. Nope, can't comprehend that either. To the Lambo and, ah crap, it's gonna take over 5000 years (non stop) to get there. 15,000 taking it steady.
I need a faster form of transport. How about a passenger jumbo jet? They're quick. Say 500 mph cruising roughly. Certainly I don't know how 500 mph feels like as I'm cocooned in a big metal tube at the time but I do know that it gets me many 000's of miles away to exotic holiday destinations in only a few hours. So yeah, lets take a 747 to the edge of the solar system. No need for stops and 8 hour stints like the Lambo cos I'm flying 1st class and I have a selection of very lovely stewardesses to attend to my (every) need.
How long will it take? A little over 2000 years. bks.
Even if I were loaded onto the plane as I was born and I lived (happily looked after by stewardesses remember)to the ripe old age of 85 years I would only have got half way to Saturn.

Clearly I need some thing much, much faster than any domestic form of transport. So I'll try out my new fangled, hyper doper space shuttle thingy that I pulled the trigger on just last week. It's very fast!! Tops out at escape velocity for Earths gravity at roughly 25,000 mph. And it's a hybrid so exempt from congestion charge.
In this at 25,000mph ( and again, this is an amount of speed I can't comprehend) I'll be at the edge of the solar system in a mere 41 years. Awesome!

But that's just the solar system, not the Milky way. And not to our closest neighbourhood galaxy, Andromeda. And certainly not any where near the limits of what we have defined as the visible Universe so far.
Will I (we, you, humans) ever fully grasp the enormity of what we exist in? Doubtful, but at least I enjoyed pondering on it for a while.

Evolved

3,562 posts

187 months

Tuesday 10th March 2015
quotequote all
Top post!

Capt Bravz said:
So I've played with some numbers today as I was intrigued as to how 'fathomable' the distances of space could be. Could I get my and the OP a sense of scale to the universe. All calculations are completely hypothetical but I had fun doing them. No flaming for any glaring errors though please.

So. We all know what 70 mph in a car feels like. Reasonably quick. By the time we are doing 140mph, where conditions allow, we feel this to be very quick or at least I do. Some of us will be fortunate to own or have experienced a top end super car doing over 200mph+. I think we can all agree that this is extremely quick for a road going car.
So lets say that we are going to drive to our nearest celestial body, the Moon. I know, I know, you can't drive a car to the moon blah blah but remember it's all hypothetical. And cos it's hypothetical I'm going to take my imaginary and space proof Aventador for a spin. To get to the Moon I need to cover approx. 238,000 miles. Wow! That sounds a lot already, how can I get my head round that?
Well, cruising at a steady 200mph in my Lambo (cos you know, it's nice to relax on a long journey) it's going to take around 50 days to get there. 50 days!!
And that's driving none stop, day and night, no meal breaks, no toilet stops, no Costa coffee if you feel a wee bit fatigued.
With a sensible amount of 'driving', say 8 hours a day, that equates to 150 days, 5 months solid, of 200mph driving, just to get to the moon. Jeez this end of the Universe road trip could take a while!

Still, baby steps. So we've covered the Moon. What about the next planet out? Mars.
Well, it's a bit further. Around 34 million miles away from us on Earth. See, there's another number I can't get my head around. 34,000,000 miles!
But never mind, I'm hopping in the Lambo again, this time with a crate of red bull. Not only for energy but you never know when you might have to hurl a can at a passing space ship.
Cruise control at 200 mph once more and oh, ffs, it's going to take me 19 years to get there!!! 19 years doing the double ton. And again that's non stop 24 hours a day driving. Go back to 8 hour stints and we're looking at the best part of 60 years to drive (very fast) to Mars. So once you've passed your test you can hope to arrive just before you die. Balls.

But never mind, lets go one step further. The edge of our solar system. Not the edge of our galaxy, just to the edge of the 9, or is it 8 now, planets that orbit our Sun. How far is that? It's approx 9 billion miles away. 9,000,000,000 miles. Nope, can't comprehend that either. To the Lambo and, ah crap, it's gonna take over 5000 years (non stop) to get there. 15,000 taking it steady.
I need a faster form of transport. How about a passenger jumbo jet? They're quick. Say 500 mph cruising roughly. Certainly I don't know how 500 mph feels like as I'm cocooned in a big metal tube at the time but I do know that it gets me many 000's of miles away to exotic holiday destinations in only a few hours. So yeah, lets take a 747 to the edge of the solar system. No need for stops and 8 hour stints like the Lambo cos I'm flying 1st class and I have a selection of very lovely stewardesses to attend to my (every) need.
How long will it take? A little over 2000 years. bks.
Even if I were loaded onto the plane as I was born and I lived (happily looked after by stewardesses remember)to the ripe old age of 85 years I would only have got half way to Saturn.

Clearly I need some thing much, much faster than any domestic form of transport. So I'll try out my new fangled, hyper doper space shuttle thingy that I pulled the trigger on just last week. It's very fast!! Tops out at escape velocity for Earths gravity at roughly 25,000 mph. And it's a hybrid so exempt from congestion charge.
In this at 25,000mph ( and again, this is an amount of speed I can't comprehend) I'll be at the edge of the solar system in a mere 41 years. Awesome!

But that's just the solar system, not the Milky way. And not to our closest neighbourhood galaxy, Andromeda. And certainly not any where near the limits of what we have defined as the visible Universe so far.
Will I (we, you, humans) ever fully grasp the enormity of what we exist in? Doubtful, but at least I enjoyed pondering on it for a while.

TwigtheWonderkid

43,327 posts

150 months

Wednesday 11th March 2015
quotequote all
Capt Bravz said:
So I've played with some numbers today as I was intrigued as to how 'fathomable' the distances of space could be. Could I get my and the OP a sense of scale to the universe. All calculations are completely hypothetical but I had fun doing them. No flaming for any glaring errors though please.

So. We all know what 70 mph in a car feels like. Reasonably quick. By the time we are doing 140mph, where conditions allow, we feel this to be very quick or at least I do. Some of us will be fortunate to own or have experienced a top end super car doing over 200mph+. I think we can all agree that this is extremely quick for a road going car.
So lets say that we are going to drive to our nearest celestial body, the Moon. I know, I know, you can't drive a car to the moon blah blah but remember it's all hypothetical. And cos it's hypothetical I'm going to take my imaginary and space proof Aventador for a spin. To get to the Moon I need to cover approx. 238,000 miles. Wow! That sounds a lot already, how can I get my head round that?
Well, cruising at a steady 200mph in my Lambo (cos you know, it's nice to relax on a long journey) it's going to take around 50 days to get there. 50 days!!
And that's driving none stop, day and night, no meal breaks, no toilet stops, no Costa coffee if you feel a wee bit fatigued.
With a sensible amount of 'driving', say 8 hours a day, that equates to 150 days, 5 months solid, of 200mph driving, just to get to the moon. Jeez this end of the Universe road trip could take a while!

Still, baby steps. So we've covered the Moon. What about the next planet out? Mars.
Well, it's a bit further. Around 34 million miles away from us on Earth. See, there's another number I can't get my head around. 34,000,000 miles!
But never mind, I'm hopping in the Lambo again, this time with a crate of red bull. Not only for energy but you never know when you might have to hurl a can at a passing space ship.
Cruise control at 200 mph once more and oh, ffs, it's going to take me 19 years to get there!!! 19 years doing the double ton. And again that's non stop 24 hours a day driving. Go back to 8 hour stints and we're looking at the best part of 60 years to drive (very fast) to Mars. So once you've passed your test you can hope to arrive just before you die. Balls.

But never mind, lets go one step further. The edge of our solar system. Not the edge of our galaxy, just to the edge of the 9, or is it 8 now, planets that orbit our Sun. How far is that? It's approx 9 billion miles away. 9,000,000,000 miles. Nope, can't comprehend that either. To the Lambo and, ah crap, it's gonna take over 5000 years (non stop) to get there. 15,000 taking it steady.
I need a faster form of transport. How about a passenger jumbo jet? They're quick. Say 500 mph cruising roughly. Certainly I don't know how 500 mph feels like as I'm cocooned in a big metal tube at the time but I do know that it gets me many 000's of miles away to exotic holiday destinations in only a few hours. So yeah, lets take a 747 to the edge of the solar system. No need for stops and 8 hour stints like the Lambo cos I'm flying 1st class and I have a selection of very lovely stewardesses to attend to my (every) need.
How long will it take? A little over 2000 years. bks.
Even if I were loaded onto the plane as I was born and I lived (happily looked after by stewardesses remember)to the ripe old age of 85 years I would only have got half way to Saturn.

Clearly I need some thing much, much faster than any domestic form of transport. So I'll try out my new fangled, hyper doper space shuttle thingy that I pulled the trigger on just last week. It's very fast!! Tops out at escape velocity for Earths gravity at roughly 25,000 mph. And it's a hybrid so exempt from congestion charge.
In this at 25,000mph ( and again, this is an amount of speed I can't comprehend) I'll be at the edge of the solar system in a mere 41 years. Awesome!

But that's just the solar system, not the Milky way. And not to our closest neighbourhood galaxy, Andromeda. And certainly not any where near the limits of what we have defined as the visible Universe so far.
Will I (we, you, humans) ever fully grasp the enormity of what we exist in? Doubtful, but at least I enjoyed pondering on it for a while.
Should have taken the Bugatti Veyron, and saved some time.

RobDickinson

31,343 posts

254 months

Wednesday 11th March 2015
quotequote all
Voyager 1 is doing 62,136 km/h and still took 36 years to leave the solar system!