Through The Wormhole

KwackerJack

Great program and head wrecking to

From the big bang to whats next?

What interests me is the expanding universe is apparently going to stop! Why, well all because of gravity.

After the big bang everything went outwards and is still moving but a few scientists have said that eventually gravity will take back over and space itself will fall back in on its self!

So either the energy build up will be so great that gravity will not be able to hold it and 'spit' it all back out or we all going to go bang...a huge bang!

And what really annoys me is people who say we are alone :mad:

There are approximately 30 billion planets in our galaxy alone, and there are over 100 billion galaxies in the observable Universe so that's 1,000000000000000000000 Possible planets that may have life

Mind blowing hey? So with all them planets floating about, if there is not 1 single planet with life like ours looking into space just like we do, well ill eat my laptop!

zenno

KwackerJack wrote: »

Great program and head wrecking to

From the big bang to whats next?

What interests me is the expanding universe is apparently going to stop! Why, well all because of gravity.

After the big bang everything went outwards and is still moving but a few scientists have said that eventually gravity will take back over and space itself will fall back in on its self!

So either the energy build up will be so great that gravity will not be able to hold it and 'spit' it all back out or we all going to go bang...a huge bang!

And what really annoys me is people who say we are alone :mad:

There are approximately 30 billion planets in our galaxy alone, and there are over 100 billion galaxies in the observable Universe so that's 1,000000000000000000000 Possible planets that may have life

Mind blowing hey? So with all them planets floating about, if there is not 1 single planet with life like ours looking into space just like we do, well ill eat my laptop!

The bigger question is...What created the big bang.

KwackerJack

zenno wrote: »

The bigger question is...What created the big bang.

I have ended up with headaches thinking about that.

We all know that if we want something that someone has made it...to think that we all came from 'nothing' is just mind boggling!

There had to be something there before it........Maybe were an alien child's computer game :eek:

zenno

KwackerJack wrote: »

I have ended up with headaches thinking about that.

We all know that if we want something that someone has made it...to think that we all came from 'nothing' is just mind boggling!

There had to be something there before it........Maybe were an alien child's computer game :eek:

Ahh, the cosmic joker playing around with us in the simulation of it's making.

Maybe we are all blind and cannot see, this dark matter they talk about is a theory of which is the "nothing". There is no such thing as nothing, because if there was...the word "nothing" wouldn't exist, so nothing is something but we'll all go bonkers if we don't find out what nothing is now i'm confused.

flanna01

The amount of planets floating around out there is truly mind boggling.

Too think that our little blue dirt ball is the only rock supporting life is ''modest'' too say the very least.

We know for a fact that life can evolve under the certain circumstance's - It happened here! If it happened once, it can happen again.

One hundred years ago, we barely had electricity or infastructures - One hundred years later, we have mobile phones, the internet, and rovers running around on other planets..... (Not to mention Voyager on the verge of heading into deep space..)

As we are a fairly young civilisation, how much further advanced would a million year old civilisation be...?

Getting back to the question - Nobody will ever know what caused the big bang, we can speculate and reconfigure our theories, but that's all it will ever be - Speculation.

My theory (which is as good as any), is that decomposing space gasses ignited, and blew space to kingdom come.... Where did the gasses come from?? Well that's for another thread to decide?.

How do we know that there is not billions of big bangs going off throughout the vastness of the Universe?? We proclaim to be the only life forms in the Universe, we also pat ourselves on the back, claiming to be the only intelligent beings to have ever graced the Cosmos.....

Pleeease.... We really need a reality check! In reality, we are probably just aggressive bugs, destroying our home and race, and everything else surrounding us.... That sounds real intelligent to me!

Beeker

KwackerJack wrote: »

Great program and head wrecking to


What interests me is the expanding universe is apparently going to stop! Why, well all because of gravity.

My understanding is that this will not happen. Dark energy is causing the expanding universe to accelerate leading to a future "big rip" as all mater is torn apart.

endacl

zenno wrote: »

The bigger question is...What created the big bang.

A little bang. Like a primer charge setting of a bigger explosion. What created the primer charge?

AugustusMinimus

Beeker wrote: »

My understanding is that this will not happen. Dark energy is causing the expanding universe to accelerate leading to a future "big rip" as all mater is torn apart.

No one truly knows if the full universe is expanding at an accelerating rate.

What we can tell is that the observable universe is expanding at an accelerating rate.

We.

1. Have no idea what the shape of the universe is or
2. How big the non-observable universe is.

Hence, we can't tell if the universe is actually expanding at an accelerating rate or not. For what we know, the radius of the universe is expanding at a constant rate but our perception of the universe is that of its circumference which would be expanding at an accelerating rate if its radius was expanding at a constant rate.

mickmackey1

So when we say the universe began 14.7 billion years ago, is that the full universe or merely the observable universe?

KwackerJack

mickmackey1 wrote: »

So when we say the universe began 14.7 billion years ago, is that the full universe or merely the observable universe?

Well that's the observable universe....but when we look back so far what we see its actually eh past!

So if we could travel to a specific spot right now it may not even be there any more

AugustusMinimus

mickmackey1 wrote: »

So when we say the universe began 14.7 billion years ago, is that the full universe or merely the observable universe?

That the full universe.

Our biggest problem is that we don't know how big the full universe actually is.


Light travels at the speed of light. Due to the expansion of the universe, galaxies which are beyond the observable universe, are travelling away from us at faster than the speed of light.

This means that the light from these galaxies never reach us and hence, this part of the universe is not observable. As gravity permeates at the speed of light, the gravitational effect of the mass of these galaxies also doesn't affect us.

mickmackey1

AugustusMinimus wrote: »

This means that the light from these galaxies never reaches us and hence, this part of the universe is not observable.

How then do we know they exist at all, especially if their gravity also doesn't affect us?

mr lee

i thought d reason we cant see past d observable universe is because d universe is not old enough for the light to have reached us yet,
im also a bit confused about d universe expanding faster than light,
im no expert but i thought nothing can move faster than light,i understand it not just galaxies moving away from each other,its d space between them expanding,
another thing that puzzles me is if the universe is expanding at such at rate,how come we notice it in our own solar system

Rubecula

Nothing can travel through space faster than light, but that does not mean that space itself can not expand faster than light.

AugustusMinimus

mickmackey1 wrote: »

How then do we know they exist at all, especially if their gravity also doesn't affect us?

True. We have absolutely no idea what or if there is indeed anything past the cosmic horizon.

Zubeneschamali

mr lee wrote: »

im also a bit confused about d universe expanding faster than light

Space is expanding at about 75 km per second per megaparsec, that's 75 Km/s per 3,000,000 light years. So if you look out 6 million light years, you may see something retreating at 150 km/s. An object at 12 million light years will look to be retreating at 300 km/s.

So at 12 billion light years (or thereabouts), an object would look to be travelling away at 300,000 km/s, which is a tad above lightspeed, and therefore invisible.

But notice that nothing is actually moving, it just looks that way as space expands by a tiny percentage across the whole distance.

From here to Alpha Centauri, the expansion would only be 100 mm per second, undetectably small. In addition, both the Sun and Alpha Centauri are gravitationally bound to our galaxy, and hence don't get pushed apart as space expands.

Within our solar system, expansion would be a million times smaller.

mickmackey1

Well explained.

So is there any speed limit on the expansion? Could the furthest objects be 'moving' infinitely fast?

Nerro

mickmackey1 wrote: »

Well explained.

So is there any speed limit on the expansion? Could the furthest objects be 'moving' infinitely fast?

Yes there is.if we understand it right and the universe is expanding due to dark energy at some stage it will rip itself apart.

Rubecula

It is surmised that in the far far future (Trillions of years or more) the universe will be spreading out so fast that even matter will be ripped apart. and it will become forever just energy. The last things to go will be the Black holes.

Zubeneschamali

Rubecula wrote: »

The last things to go will be the Black holes.

Book your place now!

Duff

ps200306

mickmackey1 wrote: »

How then do we know they exist at all, especially if their gravity also doesn't affect us?

It's based on theories of cosmic inflation -- an extremely rapid early expansion of the universe -- which carried parts of the universe over our cosmic horizon which is the edge of the observable universe. Since the subsequent expansion has been slower, we expect that more and more galaxies will come into view over time as our light cone expands. However, some time ago, the universe seems to have entered an accelerating phase due to dark energy. Therefore the size of the observable universe will increase to a maximum before dark energy increases the expansion rate such that galaxies once again start disappearing over the horizon. After that, space gets emptier and emptier.

Tomk1

I just want to add, a friend told me about the show and Morgan Freeman, IMO many discovery shows are well crapist, so had low expectations, but this one is a real gem. Totally blown away by Morgan's presentation, maybe if he didn't become an actor he would have become an astrophysicist. I hope he does more science docs.
Highly recommend the show.

Justin1982

Nerro wrote: »

Yes there is.if we understand it right and the universe is expanding due to dark energy at some stage it will rip itself apart.

I think there is still a bit of science to be done on the whole expanding universe yet.

We have only seen out to something like 75% of the theoretically visible universe, detecting the Supernovae explosions that the "accelerating universe leading to the big rip" theory is based on.

Up until 1998 physicists thought that the only thing to measure was whether the universe was open, flat or closed based on whether gravity was strong enough to pull contents of universe back to the singular point or not.

For all science knows, there could be another quasi or real force similar to gravity that takes over at even larger cosmological scales which only come into effect at larger distances than witnessed so far.

Noone can really predict at this stage.