Horizon What Happended Before

[gordyb]

About cosmic bounces rips and multiple universes,i don't think i have seen this programme before missed it this evening but it's on again between 1.25am to 2.25am on BBC4. Cheers gordy

[cotterless45]

Cool, really worth watching. Didn't understand much of it first time around ! It's certainly mind stretching . Probably what tv should show a lot more of.

[Tinker1947]

Its says its 3 of 13, but no series link on me Sky box..

[Reggie]

That was really interesting, I've seen a lot of what they've proposed on other programs though. I'm definitely not an astrophysicist but it occurred to me some time ago that there are some fundamental things that are ignored or even patronisingly dismissed.

For instance, the faster expansion of the universe and that expansion moving faster than the speed of light means that there must be something faster than the speed of light.

And I must say that the concept of the big bang being the 'start' of everything also seemed fundamentally wrong. It seems that we call it nothing because we don't have a mechanism to explain it. It also flies in the face of the fact that you're not supposed to be able to create energy, only manipulate it.

So which ones of the theories feel right to you all?

coming from a black hole seems a bit twee, unless the universe actually contained a lot more matter than we think?

Not impressed with the membrane, 10 dimensions + time just feels like bolting on stuff to fix other issues each tme one is encountered.

Swiss cheese also doesn't feel quite right, not sure why though.

Bounce theory is my least worst bet, it seems more intuitively right but the laura mersini houghton theory seems to be unifying things more than any of the others.

Another thought I had, is that I read somewhere that we appear to be able to see 13.8 billion years in any directions, which doesn't seem right, it seems like it places us at the centre of our universe, we've been here before Or did I imagine reading it?

so if we're not at the centre of the universe does that just mean that 13.8 billion light years is just the limit of our 'seeing'? or is the 13.8 billion years and the size of the universe extrapolated from some formulae and takes acellerating expansion into account?

[Imp_Perfect]

13.8 is the extent of the visible universe we may just be seeing a small portion of what is actually in existance, But we will never know as we will not see much further in the future. Maybe 100 billion years in the future we will see 113.8 billion light years, but by then the universe will be so much bigger. We see as much of it as we can but we will never know just how much of it that is,

[Reggie]

so does that mean that we're not sure how long ago the 'event' that spawned our universe actually was? It now feels a bit like 13.8 billion has just been a convenient number to hide behind and feels wrong like the number of zeros on that 1 for the swiss cheese universes.

[todd8137]

very interesting ,they all had there own points on this, but what does it matter how it all came about, we invented time,and mathematics,and it seems that they all have a pointed towards time and maths that we invented ,top and bottom is no one will never no its just endless long blown mathematics to me

say in that i did enjoy it and that was just the top people be in shown on it they did not show the other 300 top people on this subject just a few high ranking over paid people i would like to see a follow up to this one,i did like the gravity wave machine i was lol in at all the alarms go in off the blokes face was worth a million ,when it started to throw a wobble "we have a s20 alarm" great ideas on how we got here, i think we should all look to the future,and not worry about where we came from its where we go in that bothers me its a shame we can not spend all these billions on world peace ,because until we learn to tolerate each other, we will never make the leaps and bounds mankind is capable of untill we all work as one

merry Christmas to you all

[John]

By looking into the past we get knowledge that helps us understand what may happen in the future. The two are interlinked in my view.

So how it all came about really does matter

Just giving up and saying we will never know is not a viable approach, in my view.

Merry Christmas to you too

[Earl]

For instance, the faster expansion of the universe and that expansion moving faster than the speed of light means that there must be something faster than the speed of light.

so if we're not at the centre of the universe does that just mean that 13.8 billion light years is just the limit of our 'seeing'? or is the 13.8 billion years and the size of the universe extrapolated from some formulae and takes acellerating expansion into account?

No physical body is moving (ignoring movement on a local scale as expansion is on a galactic scale), but it is the space that is expanding.

As space is nothing, nothing is moving.

We are the center of our observable universe which is limited to the oldest light possible. this does not indicate we are the center of the universe, as any observer anywhere in the universe will have the same visual phenomenon.

Imagine drawing a circle with a compass and we are the dot made by the point, now draw another circle but with the point on a random point the circle, this will include us on the very edge however there will be a large part of this new circle not within the circle of our vision, we cannot see that but the Observer in the center of the new circle can. and of course you can draw circles which do not intersect at all so will never see each other.

[Reggie]

Hi Earl, I didn't think we were at the centre of the universe, just that it would be the same mistake that put us at the centre of our 'universe' hundreds of years ago

And I just don't buy that 'space' is nothing either, we haven't identified it properly yet, I'll give you that

[Earl]

I do agree on space, well kind of, space is far from empty when you are viewing inside a galaxy any DSO image will show that with massive clouds extending through space, but outside of a galaxy does space change?

Just googled this.

The density of matter in our Galaxy is about 1 particle/cm3 (in the disk, with the halo being less dense). The density of matter in intergalactic space (between galaxies) is about 2 x 10-31 gm/cm3, mainly hydrogen. At these densities, I don't think one has to worry about friction.

Dr. Louis Barbier

[Ian123]

Dont you just love documentaries like this, thats why astronomy is so interesting, more questions than answers.

I find it just mind boggling and fascinating a subject and a fundemental part of being human i guess is to ask questions of why? and how?

As for seeing 13.5 billion light years in every direction no matter where you are in universe seems odd to me. We can view a galaxy 13.5 billion years away at the supposedly edge of time just after the big bang, but say i were in that galaxy, what would i observe?

Would i see the same in every direction? in which case the universe is a whole lot bigger than we can imagine, or observe!

[Reggie]

Indeed, Ian, more questions than answers and I must say I have a particular liking for astrophysicists because they have the chops to say 'we simply don't know' about stuff they don'tknow about

And yup, if it is that we can see 13.8billion years no matter where we are in the universe then that's exactly what I'm getting at, we are seeing the edge of our detecable universe, which makes me think that it's quite possible that we will never, ever know the full story of our universe.

It kind of brings into question these magical numbers that attempt to measure and explain the distribution of 'stuff''.

It also makes me think that we are slightly deluding ourselves if we think we're going to work it out anytime soon, we're a few thousand years in and we've just managed to get to this point.

[Psychobilly]

Its says its 3 of 13, but no series link on me Sky box..

The Beeb are repeating episodes from the last series.. Perhaps just selected ones rather than the whole lot... If your on the UK then you may find more on Iplayer...

I like the "Monkey" qote... will have to dig it out...

[gordyb]

Does anyone have a problem with,if 4% of everything is matter we can see,stars,galaxies etc coming from a single point of light?

The rest is made up roughly 73% Dark Energy and 23% Dark Matter.

[StuW]

Reggie, the laws of physics are properties within our universe, not of the universe itself, therefore the speed of light limit of expansion wouldn't count.

Sent from my Dell Streak using Tapatalk

[Grunthos]

Does anyone have a problem with,if 4% of everything is matter we can see,stars,galaxies etc coming from a single point of light?

The rest is made up roughly 73% Dark Energy and 23% Dark Matter.

Sorry, what's the problem?

a) The matter "coming from a point of light"? or

current theories that most of the Universe is composed of DM and DE which we don't have a clue about? (although we appear to be slowly narrowing the knowledge gap with Dark Matter) or

c) I've misunderstood your comment.

Personally I love the ongoing developments is cosmology (especially all the intellectual arguements going on at the academic fringes!) :-)

[Reggie]

Reggie, the laws of physics are properties within our universe, not of the universe itself, therefore the speed of light limit of expansion wouldn't count.

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Just out of interest, how are the properties of our universe described?

[Reggie]

Does anyone have a problem with,if 4% of everything is matter we can see,stars,galaxies etc coming from a single point of light?

The rest is made up roughly 73% Dark Energy and 23% Dark Matter.

That is entirely what the program is about, epxloring these kinds of ideas, I must say I don't have a problem with 100% of everything coming from a single point, given the strange stuff that happens. thing is, if hubbles constant is wrong, is our thinking of the big bang wrong in itself? Was it a single point, or a single event on a bigger scale?

[StuW]

Just out of interest, how are the properties of our universe described?

What I'm trying to say is that you can't apply the physics inside of this universe to what may or may not be external to the universe, just like the air pressure inside a ball can be different to the pressure outside. At least thats how I see it...

Stu

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[Earl]

Great program, its good to see the out of the box ideas which do not get the mainstream publicity.

But what I did feel from a fair few of the ideas that a Looping system was been used to provide a convenient way of avoiding the question of what started it, by saying it has always been looping, chicken egg maybe copout.

it all get a touch close on the philosophical.

One day we might know, also we might never know.

[Spackbackle]

Missed the programme but I'm gonna have to catch a re run! Sounds very Interesting.

Quote Ian123 - "As for seeing 13.5 billion light years in every direction no matter where you are in universe seems odd to me. We can view a galaxy 13.5 billion years away at the supposedly edge of time just after the big bang, but say i were in that galaxy, what would i observe?"

Doesn't it depend on when you are in that galaxy? Now? or 13.5 billion years ago? If now then a whole bunch of stuff that we can't see on earth as the light hasn't reached us yet! 13.5 billion years ago, possibly not much to see!!

Does the number of light years you can see get bigger as time moves forward??

I of course have no science background so could be completely mistaken but that would be my understanding (It may change after I have seen the programme)