Come on, admit it, you've had this question. If the Universe is expanding from the Big Bang, what is it expanding into? What's outside the Universe? Ask any astronomer and you'll get an unsatisfying answer. ...

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Thanks for providing a great pod cast generally and this episode in particular.

As I know you are aware this topic is hard to understand and I still “don’t get it”. I wonder if there is any other way of explaining “what is the universe expanding into?”

Great show! I found it helped a lot. Here's how I see it now:

To science - there's "nothing" outside our universe, not even dimensions or time. Even if there is "something" we don't have any scientific terms of reference to describe it or any way of observing it.

There are various philosphical ideas out there to discuss different cool possiblities, but none of them are testable so are not relevant scientifically.

Just my view!

When you write an email to your friend, how many points will that give you in Scrabble? The question doesn't make sense. Scrabble points are only awarded inside the game. Time, size, gravity, etc are concepts only relevant inside the Universe.

__________________
Fraser Cain
Publisher
Universe Today - Free space news delivered by email every weekday.

I kept waiting for one of you to use the analogy of "distance" for time and space.

In other threads I tried to explain it this way.

Imagine you are alone in the empty nothing outside of the universe (if there could be).

And you want to "go ever there". You walk and walk and walk and walk....

Where are you now? You're in the same place you started. You have no reference point from which to determine anything.

There can't be anything outside of our doughnut (universe) - unless there is another doughnut nearby with which to measure ours against.

Most people like to think of the Universe like a galaxy. Where we are in this one, and can (in theory) go to another one. Unfortunatly the universe by the very definition of the word ...is EVERYTHING.

Your friend Phil Plait said it best.

"It's like asking 'What's north of the north pole?'"

OMG my head hurts!!!

I love the show..... still trying to figure out... well everything after the open =/

Never mind space, what is time expanding into?

Just a silly thought. As we look across the universe we see back in time, hey maybe the universe is expanding into time.

Another thought. When a 4 dimensional sphere passes through a three dimensional space you would see a small sphere growing from nothing reaching maximum dia then shrinking back to nothing. What would it look like to a three dimensional being inside the four dimensional sphere? Would it give the impression that the sphere (universe) was growing? when in reality it was just passing through.

the 3 dimentions we can experience are all at 90 degrees from each other.

the 4th dimention is time.

another physical dimention would be 90 degrees from the other 3 first ones, so you would never be able to detect it except to detect it's effects on the other 3.

J. Richard Gott and one of his students at Princeton wrote a paper several years ago proposing the possibility that a time loop existed where each event is preceded and followed by the same event. Like an episode in the Twilight Zone where the main character would wake up to the previous morning, there may have been such a rut that the dimension of time was curled up into. Entropy may have existed before the time loop broke its symmetry and may have been the cause of an asymmetry developing in the loop, allowing an expansion of the time loop into a future of never-before-events to occur.

Time, like space, may have expanded into today.

To ask what all 4 dimensions are expanding into has a relativistic underlying. Something else must not be expanding relative to it and that something else must further have an Aristotelian characteristic of being a special reference frame, violating the Copernican principle.

Very nice episode, I'm going to be thinking about this one for quite some time.

On a side note, Fraser mentioned at the beginning of the episode that the enhanced version of the show was being dropped due to feed confusion. While I understand this, would it be possible to still make the enhanced version available, but only as an optional download? I do not have an iPod or similar device, but quite enjoyed the enhanced version of the show by downloading the .mp4 file and playing it with Windows Media Player.

Thanks for a wonderful show!

Jesse

The enhanced versions took a lot of time to create, so we're going to focus our time on this improvements that more people can enjoy.

__________________
Fraser Cain
Publisher
Universe Today - Free space news delivered by email every weekday.

I have to say that episode blew my mind pretty much out of the water. Funny thing you should be talking about this because I decided to do a little research on how many theories there are on this finite or infinite universe theory and found this on Space.com:

http://www.space.com/scienceastronom...rd_list-2.html

I personally believe that perhaps there is a bubble universe out there with parellel universes right next to ours. I do have question though about how the Universe is expanding...

Q: The pictures I've seen on how our Universe is expanding made me wonder about the two polar regions (I couldn't think of a better word to use to describe it) you see on the top and bottom of the expanding universe. Are we expanding all around (horizontally and vertically) or are we simply expanding just horizontally?

Sorry if that was a "noob-ish" question!

Fair enough.

Thanks again!

Jesse

Awesome show and awesome Podcast. I really have been getting into this lately and this is just what my brain needed, a good frying.Keep up the great shows and content!

i'm a former air traffic controller. the radio beacons that we used were omni directional. i'm wondering if, when the big bang occured, did it explode omni directionally as well? i picture in my mind a universe shaped like a peach, with the location of the big bang, in the center like the pit of the peach. this brings up my real question, if we could look far enough, would we see more of our universe as we look past where the big bang occured?

The main problem with the question is "where".

Before the Big Bang, there was no "Where" Where and when didn't have any reference point.

If you existed to see the universe begin, you would have been in it.

The other question I cannot explain. Many scientists believe that the universe is shaped sort of like a doughnut. No matter where you travel, you will eventually end up where you started.

I personally like to think of it this way....

Like time and space are all one... a bubble... like the earth.... But you can only move in one direction. Forward.

And if you continue in that direction, you will eventually reach a point where you began.

Even if the Earth expanded to the size of the Sun, you still could never traverse the surface without ending up at your starting point again. (provided you were going in a linear path)

Unfortunatly, we cannot deviate (at this date) from the linear path of time.

You can hold a DVD in your hand, and all points of time exist at once in that movie, right there in your hand... yet you can't experience it without watching it in a linear fashion and have it make any coherent sense.

ok.... my daughter and I have listened to this pod-cast an uncountable number of times over the course of this week and we have come to one conclusion..... we want to eat the sprinkles off the dough nut

KimB, I think you are exactly right. The universe is expanding into time. We want to think that the edge of the universe is out there and expanding into space. The edge is right here in every point and it is expanding into the future. The universe is larger today than it was in the past and will be larger still in the future. Every point in the universe has a direct line of time back to the beginning an also into the future. Every point is the center and the edge. The universe is expanding into time right here, not into some space out there. The simple answer to, what is the universe expanding into, is that the universe is expanding into time.
Curry

I love the show, and enjoyed this one.

I actually don't think it is a nonsense question to ask what is outside the Universe. In fact, it seems lazy not to ask the question.

The real answer is no-one knows. It helps science to make people excited and interested in the questioning, even if there is no answer, rather than being dismissive and snobbish about it. (I mean in general not you or Pamela)

It may be (almost certainly is) the case that Time and Space does not exist outside a finite Universe but there may be something else we had never thought about.

Big or small we will ask questions like this forever.


(inverse)
If strings prove to be real... what are they made of? And then what makes them vibrate? And what are those things made of?

"Homer, your theory of a donut-shaped universe is intriguing." -- Stephen Hawking on The Simpsons