h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

What was it like before the Big Bang?
If you took all the matter of the universe and spread it all out evenly all you would get is a very thin gas but as you move back in time this gas will get thicker and denser. In the end we get to the point of the Big Bang and at this point to matter is VERY dense. MEGA dense for want of a bigger word. It had and infinite density and infinite density is something that scientist can’t handle. However this is the point of the Big Bang and you are asking about BEFORE the Big Bang. Not just everything in the Universe was created in the Big Bang. The Universe its self was created and so was space. Space it not nothing. It is something but a very smooth evened out something. Another thing that was created in the Big Bang was time. One thing you can’t have is before time was created, because there was no time. The is no before the beginning of time and so there is not before the Big Bang. 1,500 years ago Augustine said that thing change and that is how we know about time. In a world where nothing changes we would not know about time because there is nothing going on in our brains so we don’t notice anything changing. So if there were a world were nothing changed then there would be no time. Then we come to before the Big Bang, a time when nothing had been created yet so there wasn’t anything to change and so there was no time which leads of back to there being no BEFORE the Big Bang.

Humanity, as in upright apes, is around 5 million years old, PSB. You really should check your sources.

Is there any life out there?

A simple answer to the question would be we don’t know. There are certain problems when asking a question like this. First of all we need to know how we define life. You may say that something is alive if it uses energy in an orderly way, it has a boundary and it can reproduce. However this doesn’t work if you think about it. This could mean that a flame is alive because it has a boundary, uses energy and reproduces. However a mule – a sterile cross between a horse and an ass – is not alive because it cannot reproduce. There is also the term ‘life, as we know it’. There is the possibility of life forms that can survive in ways we can’t. In an episode of Star Trek their Tricorders could not detect a life form until they altered them to detect a silicon life from. This means that there could be life forms out there that we don’t even realise are alive.
Another thing we have to look at is if a life form can survive on a planet. Earth is perfect planet. Is has a suitable gravity, it is just the right distance from the Sun to be not too hot and not too cold. It as an oxygen / nitrogen atmosphere and had the elements of oxygen, nitrogen, carbon and hydrogen, It has hydrogen oxide (water) and a magnetic field protecting us from the Suns deadly radiation. This may be what we call necessary to survive but Andean Indians can survive whilst living in mountain villages as an altitude of 17,000 feet (5,200 meters). They have larger hearts and lungs than us so they can breath normally in air that is too thin for us to breath and there is nothing to say that an extra terrestrial life form can’t do the same on a planet with a thin atmosphere. Also Captain Jacques-Yves Cousteau showed us that there is life at the bottom of the Mariana Trench, south-west of Guam in the Pacific Ocean, at the depth of 36,198 feet (11,033 meters). Although it is very cold down here the life gets it heat from volcanic vents (called Black Smokers) but it still has to survive a pressure of 16,000 pounds per square inch (1,000 kilograms per square centimetre). To take this to the extreme there are life forms on this planet than can only survive in sulphuric acid.
However there is a possibility of there being life on other planets. The Galileo probe reported there is life on Earth. This however was a test to see if it could detect life anywhere else in to Solar System and it also reported life on the Jovian moon Europa. It is believed that there is an ocean below its ice-covered surface.
As for life out side our Solar System, we have no evidence one way or another. We have detected planets round other stars and it maybe that these planets or their moons can support life. These stars are much further than our stellar neighbourhood and so sending a probe to these stars could take centuries and we have no guarantee that there is life on the planets. The only extra solar life we have a real chance of detecting is intelligent life.
The term intelligent life means life forms that we can communicate with. In the 1950s, when a young American, Frank Drake, was working in a brand new field of radio astronomy, aliens were something no respectable scientist thought about. But Drake took a much broader view. He knew that radio dishes could pick up naturally produced signals from halfway across the Universe.
They could also be used in reverse to transmit a signal. He wondered if there were other inteligences out there, using telescopes to transmit messages which his instruments should be able to pick up. There is a SETI (Search for Extra Terrestrial Intelligence) project taking place using the Arecibo Radio Observatory in Puerto Rico and there are a few others taking place and others have taken place all in hope that we can pick up a radio signal from another planet. We have had thousands of messages but we have to verify them to make sure they are not from Earth satellites, hoaxes, or naturally produced but we haven’t got that far yet so we really don’t know if there is life out there yet. We’ll just have to wait and see.
Frank Drake devised the “Drake equation” – a formula to calculate how many civilisations might be broadcasting radio signals. This is the Drake equation.

N = R* x fp x ne x fl x fi x fc x L

R* is the rate starbirth.
The number of new stars formed in the Galaxy. This is widely accepted by astronomers to be 10 per year.

fp is stars with planets.
The percentage of those new stars that form planets.

ne is habitable planets.
The number of those planets that are the right distance from their star, and of the right size to be suitable for life.

fl is planets with life.
The percentage of those planets on which life has actually evolved.

fi is intelligent life.
Percentage of planets where life forms have evolved sufficiently for “intelligent” creature to exist.

fc is communicable life.
The percentage of those planets on which intelligent lifeforms have developed technologically so they can communicate with other civilisations.

L is life span of civilisation.
The length of time that a technologically advanced civilisation exists and in which it can send a potentially receive signals.

Here are two examples for outcomes that can come out. One from an optimist and one from a pessimist.
The first person is relatively optimistic. She chooses 100% for the first two answers. 10% for the third, and then 100% again. The next answer is a more cautious 1% for the number of intelligent civilizations that want to communicate, and an optimistic lifetime of 1,000 million years. She ends up with 10 million communicating civilisations in the Galaxy.
The second person is a pessimist. He give answers of 10% to the first two questions, but is more hopeful 100% of life evolving on a suitable planet. He is pessimistic again for the following questions, with answers of 1%, 10%, and a lifetime of only 1 million years. His number of communicating civilisations is just 100.

I have included here a table of how far away the nearest civilization is likely to be depending upon what answer you come up with.

Number of civilisations in Milky Way. Distance from Earth to the neatest civilization in light years (ly).
10,000 million civilizations. 10 ly away.
1,000 million civilizations. 22 ly away.
100 million civilizations. 46 ly away.
10 million civilizations. 100 ly away.
1 million civilizations. 220 ly away.
100,000 civilizations. 460 ly away.
10,000 civilizations. 1,000 ly away.
1,000 civilizations. 2,200 ly away.
100 civilizations. 4,600 ly away.
10 civilizations. 10,000 ly away.
1 civilization. 200,000 ly away.
0.1 civilizations. 3 million ly away.
0.01 civilizations. 10 million ly away.
0.0001 civilizations. 50 million ly away

My source is the Usborne Book of Facts and Lists. Is says the Homo spiens first appear on Earth 14,650 million years after the Big Bang if we assume the Big Bang was 15 billion years ago. This book is dated at 1987 but it was the first one I could find.
Book in my house disappear down black hole that's floating around. I've got a feeling it swallows socks as well!

Thankyou for your post, PSB.

I would say the physical universe emcompasses all matter and energy within all the dimensions, including time.

We can go back as far as the Big Bang. The question is, what caused the Big Bang and what was there before that?

If the Big Bang is the beginning on time there can be NO before the beginning. Anyway the chances of us being able to find that out are quite remote.
If you're interested there's going to be fireing of nuclear accelrator in October that could recreate the conditions a fraction of a second after the Big Bang and this could create micro black holes that will evoprate instantly. If we can create black holes though, maybe we could one day do it in the lab and see what happens. Since it's belived black holes could bud off universes and ours could have come from a black hole in a super-uninverse.

Lets also not forget the Oscillating Universe theory where the Universe will slow down, and fall back in a Big Crunch and then another Big Bang will take place. Maybe it's the previous Big Crunch that's caused the Big Bang. Also don't say what caused the first Big Bang. I don't think time should be thought as like a piece of string if you think about the Oscillating Universe theory. This piece of string has one end tied to the other end so there is no beginning.
Like the North Pole, when you go over the horizon you don't find a singularity. Sorry have I already said this in one of my previous posts? I'll stop becuase I'm sure I'd have said it better the first time!

Also let's not forget that we inhabit three Universe's simultanrously (spelling?). The micro-universe that is everything from the sub-atomic down, the macro-universe that is enerything outside the Earth's atmosphere and the everyday universe that we interact with everyday. All these can be combined the make "the" Universe that is everything that is known to exist (noticed the capital 'U'). Hope someone finds this interesting.

On the mention of all dimensions including time. I find it easier to work in five dimensions. I thing there at least on extra dimension on space and more than one temproal dimension but I'm not going to expand becuase it is terribly complicated and also requires maths that are not appropriate even at half eight on a Wednesday evening!

Where is the centre of the Universe and where is the edge of the Universe?
Firstly there is more than one answer to this since there are two of theories and both will be described.
You may want to ask when you’ve gone through space and you come out of space what comes next. The answer is more space and even when you’ve gone through this there is more space. If you come to the end of space you would find nothing but since nothing is in what space looks like you still haven’t come to end of it. It is thought that the size of the Universe may be infinite and if this is so then there is no edge of the Universe. If there is no edge then the centre of the Universe is everywhere because wherever you are you are the same distance from the ‘edge’ of the Universe. You could argue that since there is no edge there is no centre because there is no where that is the middle.
The second theory is if you went off in space in a straight line you may find your self back where you started. The best way to imagine this if to imagine that you go off in a plane journey and fly due east. In the end you would find yourself back where you started. The navigators compass would be pointing east all the time but until you got to the other side of the Earth you would be going further from the start. After that you would be getting closer to the start. This is because the Earth is a ball. I’m sure you are aware that you don’t go over the horizon and find a singularity. Space may also be like this. It may be curved in another dimension that we can’t see, if this is so then there is again no edge and no centre to the Universe.

If you think about time like this that may make my previous two posts clearer.

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I shall resist the temptation to reply to this for the sake of keeping on topic here now that we seem to have got it back on topic. Maybe we should open another discussion somewhere else to address this.

WOW prof ....that is amazing stuff! and a buncha it i would like to discuss but i need to think about it a bit..

here in this last post tho...

>>> ...because the Earth is a ball. I’m sure you are aware that you don’t go over the horizon and find a singularity. Space may also be like this. It may be curved in another dimension that we can’t see, if this is so then there is again no edge and no centre to the Universe.<<<

maybe the centre of that universe is the centre inside the ball? and the 'edge,' that where it's outside surface ends?

and WG? i rather like both threads going on at the same time in here.... perhaps at some point in the future they may converge!?

...and the headings of each thread keep them separated.. Age of the Universe (or some similar scientific heading) and Evolution (or some similar ... hmmm maybe thats not so good for identifying the more spiritual dialogue) maybe it is.

my initial idea was a smiley at the beginning of each posting to tag it to its thread.... say... or for the scientific? and... or haha im sure SoRB would like this (joke) for the metaphysical thread.

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I know what you mean. I quite like it, too.
Your smiley idea is interesting.

<space.
okay... so what smiley would you vote for for the metaphysical thread?

PSB, what do you think of Fluffy K's suggestion?

I've given in to temptation and decided to say I'm strongly convinced Jesus had an agenda beyond just getting people to be nice.

Apart from Christianity, I've been researching about the origins of monotheism to see where it stems from originally, and the findings have been surprising and very interesting.

Whoops. Forgot the smiley.


Apart from Christianity, I've been researching about the origins of monotheism to see where it stems from originally, and the findings have been surprising and very interesting.

the jury is still out on the metaphysical smiley... RoFL still has to vote.. haha

okay WG i found this on monotheism in wikipedia http://en.wikipedia.org/wiki/Monotheism
and this on pantheism ...what i think i might be if i believed in a god... http://en.wikipedia.org/wiki/Pantheism

i mean SoRB sorry

oh oh im so sorry and the prof and also the others who have been following this