What lies at the edge of the Universe? A
brick wall?
To answer this question, we must consider
the shape of space... Space is four-dimensional,
not three. First a few words about this mysterious
forth dimension. We are immersed in the fourth
dimension as surely as we are the other three.
It is all around you. We perceive the fourth
dimension as time, but it is a spatial dimension
also. It exists at right-angles to our familiar
three spatial dimensions, much like the essence
of a sphere is at right-angles to a small circle
drawn on it's surface. Just as we perceive that
time "passes" at a constant "speed"
(to horribly twist an analogy) the forth dimension
is relatively flat. This means it doesn't affect
our familiar dimensions noticeably, much as
a tiny circle drawn on the surface of a colossal
sphere is not noticeably affected by the curvature
of the sphere. To be obviously affected by the
curvature of the sphere, the circle's width
must be significant compared to the diameter
of the sphere.
We are between 1 and 2 meters tall. The observable
Universe is roughly a million, million, million
times taller than us. Look up. Its high up there!
Our fourth dimension dominates on Universe-sized
distance scales. But the fourth dimension evades
our senses, we are like the tiny circle on the
vast sphere: a bacterium on the giant's arse.
Lets hope he doesn't fart... Back to the
big
question: what lies at the edge of the Universe?
It turns out that space is finite and continuous,
like the surface of a bubble. The surface of
a bubble has no edge, no
brick wall
boundary. Likewise with space. In fact the Universe
is a three-dimensional curved "surface" of an
expanding four-dimensional ball. (Note that
an
infinite Universe
can expand, I give an explanation for this in
the feedback forum below).
Smoking gun
evidence of this fourth dimension
comes from observations of the cosmic radiation
left over from the
Big Bang. This Big
Bang radiation is visible in
every direction!
So where the hell was the Big Bang? Point up
in England, it happened there! Point up in Australia.
It happened there! Where ever you point, from
what ever spot on the Earth's round surface,
you will point to the direction of the Big Bang.
It happened Everywhere! Including inside your
body. Every point of space was the centre of
the Big Band Explosion. Wacky eh?
Imagine you are minuscule and flat and live
inside the thin soapy surface of an expanding
bubble. You can only peer
into the surface
of the bubble, not "outwards" away
from the bubble nor "inwards" towards
the bubbles centre. Lets imagine that light
travels so slowly within the surface of the
bubble that it has only had time to travel a
short distance compared to the bubble's circumference.
Peeking at light traveling within the surface
of the bubble, you would see the explosion of
the bubble's creation, but it would be
visible
in all directions within the 2D surface of the
bubble! Now go from living and peeking within
a 2D bubble surface to living and peeking within
a 3D bubble surface. This is YOU NOW! Our Universe
is the 3D surface of a 4D bubble. The Universe's
creation, the Big Bang, is seen in all 3D directions
of our amazing and expanding 4D bubble Universe.
Here is another weird quirk of our universe:
if you travel faster than light
in a straight
line away from England into space, eventually
you will arrive in Australia from below. This
is like circumnavigating the bubble in a straight
line in the curved bubble-surface "space". Why
don't we "feel" the curvature of our Universe?
We don't "feel" that the earth is
round, but it is. The earth just seems flat
on our personal distance scales. Same goes with
the Universe. (Why travel faster than light?
Because if you didn't, you wouldn't be able
to move through space fast enough to overcome
the Universe's racing expansion. Remember, even
though you cannot beat the light speed limit
through space, space itself can expand as fast
as gravity will allow it. The Universe is expanding
more hastily than light!)
"What is outside the expanding four dimensional
sphere of the universe?" This is analogous
to being trapped in the surface of a bubble
and asking what is inside/outside the surface
of the bubble. The best theories suggest that
this is a real void, a super-void where space,
dimensions and time as we know them have no
existence or meaning. Or
is it empty
after all? The super-void might be swarming
with myriad other universes, like bubbles in
a pint of beer.
There may be an extremely tiny chance of a collision
between our universe and another. If these clashing
universes were able to interact then it's time
to bend over and kiss your arse goodbye.
Total
apocalypse!
Link: To surf to an external site with nice
debate about the Multiverse according to quantum
mechanics, click
here,
but bookmark this site first :)
Add your comment to this page
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| From: |
Phillip Todd White | Subject: | 2001-08-11 07:08:21 |
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| From: |
stephanie | Subject: | 2002-12-15 01:36:04 |
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| From: |
Eduardo Chang | Subject: | 2003-02-02 02:34:49 |
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| From: |
Eduardo Chang | Subject: | 2003-02-02 02:38:37 |
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| From: |
Eduardo Chang | Subject: | 2003-02-02 02:41:22 |
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| From: |
Daniel | Subject: | 2003-03-23 19:26:57 |
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| From: |
Evo | Subject: | 2003-08-19 23:36:35 |
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| From: |
Net | Subject: | 2003-08-31 08:59:45 |
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| From: |
Clayton Carter | Subject: | 2003-11-07 12:55:33 |
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| From: |
Clayton Carter | Subject: | 2003-11-07 12:57:05 |
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| From: |
Clayton Carter | Subject: | 2003-12-07 16:52:07 |
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| From: |
Chris | Subject: | 2004-02-23 15:55:26 |
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| From: |
Polo Salinas | Subject: | 2004-03-04 14:14:41 |
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| From: |
Jim Eadon | Subject: | 2004-03-06 03:43:31 |
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| From: |
Chris | Subject: | 2004-03-13 08:49:55 |
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| From: |
Chris | Subject: | 2004-03-13 09:18:49 |
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| From: |
Jim Eadon | Subject: | 2004-03-13 09:36:49 |
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| From: |
Chris | Subject: | 2004-03-15 10:29:32 |
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| From: |
Sir avalos van-dinkel | Subject: | 2004-04-13 19:40:51 |
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| From: |
Vikki | Subject: | 2004-04-16 20:15:43 |
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Chris | Subject: | 2004-06-03 12:25:49 |
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eric | Subject: | 2004-06-12 01:11:56 |
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eric | Subject: | 2004-06-12 01:13:38 |
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Flappy Jane | Subject: | 2004-08-27 09:56:45 |
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Martyn | Subject: | 2004-09-10 15:59:48 |
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m. britton** | Subject: | 2004-09-27 14:35:58 |
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Clayton Carter | Subject: | 2004-11-19 21:08:14 |
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Thomas | Subject: | 2005-03-06 04:38:19 |
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Taz | Subject: | 2005-07-20 15:59:01 |
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Terry McCreath | Subject: | 2006-06-30 11:39:06 |
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colin beecroft | Subject: | 2006-08-20 11:18:54 |
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| From: |
dr burke | Subject: | 2006-12-18 21:57:41 |
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| From: |
freewebs.com/acrazynerd*Ryan R. | Subject: | 2007-03-28 02:20:49 |
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Dave Downey | Subject: | 2007-10-05 03:30:19 |
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wikibuddha | Subject: | 2008-05-20 23:10:02 |
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stephen cunliffe | Subject: | 2009-05-09 14:21:18 |
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| From: |
EK | Subject: | 2009-11-10 19:33:13 |
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todo | Subject: | 2009-11-22 20:35:07 |
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| From: |
sverker forslin | Subject: | 2010-09-07 11:13:22 |
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| From: |
Adrian Lutchman | Subject: | 2010-12-13 03:58:55 |
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| From: |
Arnstein Martinsen | Subject: | 2011-03-07 12:21:20 |
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| From: |
Richard HArries | Subject: | 2011-03-27 11:00:06 |
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help: how to add your comment Page hits: 24915
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On the talkback comments
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In reply
to Philip Todd White: I understand
those figures you quoted are about right,
thanks for the info. There is, as usual,
a bit of uncertainty about the exact age
of the Universe, as it appears
to be accelerating, due to either something
called Dark Energy, or a departure from
the Newton's laws of motion at extremely
low acceleration. Or there may be an entirely
different explanation no one has thought
of, of course.
In reply to Stephanie: technically,
at the "end" of the Universe is the Big
Bang: this is what we "see". But to take
your question in its true spirit, there
need be no boundary, or "brick wall".
What you need is a boundless space that
is finite anyway. If this sounds impossible,
then think of the surface of the earth.
It is large and seems flat. People used
to believe you could walk (or sail) off
the "edge" of the earth. A similar concept
seems to hold for the Universe. We live
inside the flat-seeming
but curved three-dimensional surface of
a four-dimensional sphere. If you clambered
into a rocket and headed north away from
the solar system for long enough (assuming
you could seriously out-speed the speed
of light) then eventually you would arrive
at the solar system again from the south,
even though you thought you were traveling
in a straight line. (This is like traveling
west from London and arriving at London
again from the east.) You traveled all
the way across the finite Universe and
yet you saw no "brick walls". Space is bent. What bends space? Matter and energy. We experience
bent space as gravity. If you think
that all this is freaky, then this is perfectly
normal. I love the freakiness :)
Thanks for the talkbacks so far
- Jim
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