What's outside space ....

[cyberknight]

All calculations are based on the distance to the edge of the observable universe from earth , if we are going to start moving around in space at close to light speed we get into the whole time distortion effects which i think the OP did not want to get into so i didn't raise that issue.

 

[Svendo]

I suspect the underlying answer is that the question is inherently contradictory. There's no 'outside' space as then there would need to be a space for space to be within. All the stuff about the observable universe is a bit of a red herring, as the question presupposes a classical conception of something that is inherently relativistic when considered as a whole.

Consider that everywhere was at the moment of the Big Bang at the same place (a singularity), and ever since everything else (not gravitationally bound) has been zooming away. That means that everywhere is still the 'subjective' centre of the universe and has a spherical boundary of visibilty ~13.5 billion light years away.

But of course your five year old will probably already know that he is the centre of the universe!

The size of the universe is subject to varied estimates although this article gives some useful info: http://www.popsci.com/science/artic...s-are-least-250-times-larger-visible-universe

The shape of the universe, is flat as far as the WMAP data goes, but beyond that is a very open question: http://en.wikipedia.org/wiki/Shape_of_the_Universe

 

[marinyork]

I suspect the underlying answer is that the question is inherently contradictory. There's no 'outside' space as then there would need to be a space for space to be within. All the stuff about the observable universe is a bit of a red herring, as the question presupposes a classical conception of something that is inherently relativistic when considered as a whole.

Depends what you mean by outside space. If we are children of the bubble there may well be plenty of multiverses out there that are in a sense part of our universe but so far away that they are classified as being not in the universe in any meaningful sense. That's the significance of 'observable universe'.

The shape of the universe, is flat as far as the WMAP data goes, but beyond that is a very open question: http://en.wikipedia....of_the_Universe

Most important bit

In general, local to global theorems in Riemannian Geometry relate the local geometry to the global geometry. If the local geometry has constant curvature, the global geometry is very constrained, as described in Thurston geometries.

 

[Zoiders]

Do what all scientists do when asked the question of what is the universe is actualy expanding into.

Distract him by saying "ooh look is that a squirrel!"

Then run away.

 

[GentleBenn]

Hmmm.....

Let's do a mind experiment:

Imagine there to be hypothetical traveller in space, 14 billion light years away, with yourself on earth. Both yourself and the traveller are eqipped with a stopwatch (at the moment set to zero).

I situate myself at the halfway point, 7 billion light years away.

I emit a signal, say a light pulse, which travels at a velocity of constant magnitude c in all directions, and therefore reaches both yourself and the traveller at the same instant (t=0).

On receipt of my signal (t=0), you start your stopwatch, whilst the traveller starts his stopwatch and simultaneously accelerates instantly from rest to the speed of light travelling in the direction of earth.

On arriving on earth, the traveller's velocity instantaneously changes from c to zero, and simultaneously both the traveller and yourself stop your stopwatches.


What does your stopwatch measure ?

What does the traveller's stopwatch measure ?

Do you still think that if the light has taken 14 billion years (as measured by who ?) to travel the distance, that the light you see is 14 billion years old.

This is quite interesting

I think at light speed time is relative to the traveller, a person travelling in a spaceship experiences time differently to a person on earth or at a point static to the ship because time slows the closer you get to the speed of light.

Light speed is a measurement of distance light travels in a year not time.


The traveller and I would be waiting 7 billion years for that signal surely ?

The person on earths stopwatch would read 4.41504[sup]14[/sup] seconds, the travellers stopwatch,roughly 75154 seconds !
( I've got an old calculator!)

But then I could be totally wrong because I only got a d in maths!

 

[JamesAC]

[QUOTE 1312727"]
When I read this thread title, I thought you were going to launch into a rant about how is parents keep him in the house I had the idea that he didn't know what outside space was, and he stayed in his bedroom playing video games!

I am glad to hear that he is pondering the endlessness that is our Universe, and you aren't worried because he doesn't play football
[/quote]

He does play football! And he's a pretty good rock-climber, too.
I'm really quite chuffed.

 

[Bman]

PLEASE! Can we leave Quantum Physics out of this? It makes my head hurt.

Lets just assume light travels at a constant speed and that Time is not affected by speed