The Universe

[Brawny]

A good analogy I've seen...at least the most easy to fake yourself into understanding.

Say you have a telephone wire, if you look at it from far away, it looks like it is a single dimension, now take an ant on that wire, it can revolve all the way around left and right, and can go backwards and forwards...2 dimensions, now cut it in half, and we get three.

Not very close to the dimensions the strings vibrate on, but an example showing that it's not always as it seems.

 

[DBloke]

Well, there'd be the normal 3 space dimensions and 1 time dimension which we're all familiar with, plus extra space dimensions which are "folded up" (for lack of a better description) so that they are too small for us to experience. Don't ask me how that works, it's very complicated maths and I won't pretend to understand it.

The others will have pysics that will just be plane wired
Things that will be slod wont be
One might have one where time is all over the place (a bit like that red Dwarf episode that was on last night)
And one will have tv channels that allways have something good on

 

[Gikoku Harakami]

I sometimes see there as being more than just one Universe, like there's multiple universes scattered throughout the infinite space of dark matter/energy, just like we have multiple galaxies, planets, and stars. Why not more than one universe?

 

[crazyman2]

I wonder if some other senative being in another planet/solar system/galaxy/universe is having the same conversation about the universe(s) right now.

 

[Dorkfish]

I wonder if some other senative being in another planet/solar system/galaxy/universe is having the same conversation about the universe(s) right now.

If there is more than one universe and it truly is parallel to ours, then yes, they are, THEY ARE.

 

[Mau]

All I know if that if universe is infinite, someone is asking the same questions as we are all the time. I mean, every second. Who knows how many intelligent living things they are out there.

 

[DBloke]

All I know if that if universe is infinite, someone is asking the same questions as we are all the time. I mean, every second. Who knows how many intelligent living things they are out there.

They can bulid ships that cross the stars

But there not to good at hidein and landin

 

[Gaz]

I sometimes see there as being more than just one Universe, like there's multiple universes scattered throughout the infinite space of dark matter/energy, just like we have multiple galaxies, planets, and stars. Why not more than one universe?

you mean a multiverse

Zero G - Its possible to induce gravity in a spacecraft, i just don't know how.

With simple physics you can easily accomplice this with rotating the space craft, the inertia caused by the spinning of the craft will affect all objects inside the craft and will feel the effect of being pulled into the space craft's hull. this effect can be simulated by holding a bucket of water and spinning it. the faster you spin the harder the water is pushed into the bottom of the bucket (or the more g's the water experiences) the slower you go the less, and of course the greater the chance it falls on your head. this simple effect is also known as centrifugal force.

Really simple text book physics.

 

[Squall7]

All I know if that if universe is infinite, someone is asking the same questions as we are all the time. I mean, every second. Who knows how many intelligent living things they are out there.

Indeed. And there's constantly someone pointing that out too...

:shifty:

 

[DBloke]

Whouldnt it be funny if we are the only ones out there

<Insert the sound of every Star trek nerds dream bein shaterd>

 

[Brawny]

No such thing as centrifugal force. It's just centripetal. :thumbsup:

 

[Gaz]

No such thing as centrifugal force. It's just centripetal. :thumbsup:

first of... Newton's 3rd law of motion... For every force there is an equal, but opposite, force.

second... your wrong.. centrifugal force does exist and centripetal is the opposite force.

for example... a satellite in space is orbiting the earth, it is being held in place by the gravitational field of the earth which is the centripetal force. if there is a person in this satellite floating freely. then they will be pushed into the hull of the satellite, which is caused by the acceleration of the satellite. that is know as centrifugal force..

they are equal and opposite forces.

How can the universe be inifnate ?

The Universe is infinite because it is ever expanding, this has been proven by using the Doppler effect with red light rays, which is known as the red shift. think of the universe as a simple 2d circle.. it has a fixed radius but because the universe is expanding it doesn't have a fixed radius and thus it is classed as infinite even tho it really isn't as everything is just getting further apart.

 

[Brawny]

First, that's not what the third law is talking about, second, it's the first law that applies.

An object in motion tends to stay in motion unless acted upon by an unbalanced force.

The satellite tends to go straight into space while gravity is the unbalanced force acting upon it.

We're using different frames of reference.

 

[Napalmbrain]

No such thing as centrifugal force. It's just centripetal. :thumbsup:

 

[Brawny]

XKCD FTW.

Also, I apologize Gaz, I blame this:

Therefore teachers who need to impress on their students that centrifugal forces have no place in their calculations often do not have occasion to give a matching emphasis to the fact that a centrifugal force does occur in a rotating frame. As a result, even students who master the physics curriculum may leave school with the false impression that it is never scientifically valid to speak about centrifugal forces

Damn teachers.