Evolution

[MadLep]

200

YOINK!

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clan |o-bot| - Powering the propaganda machines of several small dictatorships.

[BaM]

It's kinda hard to figure that, Hooker. Assuming the Big Bang / Singularity theory, there would have been no time at that point, so how do you figure out what happened 'before'?

[smudge]

I think inflation theory does describe what could have taken place before the big bang,
higgs fields and stuff like that which are totally over my head, but the layman's explanation was that the universe was like a bubble in foam rubber which was continually expanding.

[Spoon1]

duckstab sez: "I was in town one day and I was having this very same argument (lasted about 1 hour or so). ANYTHING I could say that could possibly discredit his belief system he would retort with the claim that "God put the idea in your head, he is testing your faith child!""

You should have said "..and God has obviously removed them from yours.".

Always after the fact... what a gip

[Soleil-Raid]

Bam: Soleil-Raid: As I'm sure you're aware, the speed objects are travelling is only
relative to the point you're observing from.

Yup.

If our galaxy is on one side of the (lets say) 'centre' of the universe and another galaxy is on the other, and both end up receding from the 'centre' at light speed, how fast does light have to travel to reach our galaxy from the other one? Think of it as an event horizon. The light won't be able to make the trip, effectively putting the other galaxy outside what Stephen Hawking described as a "past light-cone".

Ok, I'm not familier with the 'light-cone' concept (got a link?) But the way I understood (of which I could be wrong, I'm not trying to shoot you down here), the situation as you described, if both galaxies were travelling away from the 'center' at 50% C, then light would still reach us, since the apparent speed of the light from the other galaxy would be 150% C. (which doesn't sound right... ok, now I'm confused).

I'm going to look this up in my text book, I'm sure this was described somewhere...

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SRWOFB; where nothing is anything.

[BaM]

No link, sorry. I'll have to read up on that again in case I got the wrong end of the stick...

There's definitely something about event horizons at the edge of the visible universe though. I'll get back to you on that one.

[OdditY]

re 'before' - i see time as just a thing for stuff to happen in, a sort of container if you like. space happens in time. matter (& energy?) happens in space. etc etc. So i guess the answer to the before question is the same as the answer to this: what does time happen in?
(This was actually in a sci fi book i read quite a while back - 10pts for the book, and it's answer

"Its the devil, thats why, and that would disproove a lot of this bollocks science today." who said that again? pk? funniest thing i've read all week, made my quotes file

heh, chiQ, "man she got some decent repositories on her", cracked me up

[OdditY]

oh yeah, and 3 words:
Buddy Christ!!! aaaaeeeeeeyyyyyyy!

[Endymion]

Have to love the way these things always spin off on a tangent.

[Fred]

Okay, we have had the discussion about light cones before but I'll repeat what I have typed about them here. Essentially one way of looking at how the universe inter-relates is to consider how information about changes made is spread through the universe. And fundamentally everything of consequence is a change of some description in the universe.

So lets take two points seperated by about eight light minutes. Say one on the earth and one on the sun. Assume that for no adequitely explored reason the sun explodes. Point A, on the sun, knows about this immediately and the rest of the universe starts to get filled in on the change as the light of the explosion (and indeed any other effects, ignoring 'spooky' quantum interactions at this stage.) ripples out through the universe at the speed of light. Eight minutes later Point B barely has time to think 'oh shit!' before being overwhelmed by the explosion.

If we plot the progress of that event on a distance vs time graph, picking any spacial axis you care to, then you get a cone shape of the effects of the event spreading out over time. Outside that cone for any given time point and that point in the universe is unaware that the event has occured because the information about it's occurance has yet to reach it. Inside the cone and you know about it.

Now this becomes relevant to the discussion because some places, on the edges of the observable universe, are being pulled away from by the expansion of the universe that there is a very real possibility that we will be shifted outside their light cone - effectively the objects cease to exist as far as we are concerned because their effects can no longer reach/be observed by us.

This leads to your post Oddity, the idea of time 'happening' in a fashion akin a spacial dimension. Unfortunately one of the big realisations that relativity brings to us is that both time and space are highly subjective events. They are deeply affected by our reference frame and, in essence, every particle in the universe experiences them in a slightly different way.

This means that contrary to our common sense the very physical absolutes that we like use don't actually exist. Everything, and I mean everything, depends on how you observe it. Assuming for a moment that the universe is from a big bang and is returning to a big crunch situation then there are particles out there, at the very edge of the universe, for whom the total life of the universe will have been pico-seconds at best as they have been travelling at so close to light speed that they have missed out on seeing the galaxies form, first and second generation stars birth and die and the subsequent events yet to unfold from out perspective.

How you perceive space and how you perceive time is entirely subjective on how you observe it. The one constant in the universe is the time always seems to go forwards and that you can't entirely stop time (or change) from occuring. And even that is under review, some people are seriously questioning why particles can't travel backwards in time - there seems to be no good reason why not.

But that is fodder for another post and a different discussion.

|THAT|-fred
'fred is not dead, fred is resurrected!'

[chiQ]

Who? Wha? Where? Huh? *blondes out*

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[Putrid]

<img src=http://dev.sanderson.co.nz/staff/workout.jpg>

[pinky]

how many ppl take the time to read the really long posts here???
or do you just skip them and read the short ones?

[chiQ]

I haven't got around to reading Fred's latest, but I've read all the rest so far.

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[BaM]

Ta Fred. I suck at explaining that stuff.

[Spoon1]

Yeah, I read 'em.

[chiQ]

OK I've now read Fred's lates and all I can say is "Mmmmmmcones", after all that is how this began

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[Cinclant]

life is all about cones?

[chiQ]

Too right

[Fred]

All I can say is that if you see breasts as being conical in shape then you have been looking at too many Madonna fashion victims.

|THAT|-fred
'fred is not dead, fred is resurrected!'

[chiQ]

Turn of phrase Fred, not literal description...

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[BaM]

As far as expanding universe theories go, <a href="http://www.alexchiu.com/spacestation/blackhole.htm" target="lank">this</a> pretty much explains why you shouldn't believe everything you read on the net.

[chiQ]

BWHAHAHAHA!!! I wash mahseylf weth a raig own a steck.

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[Farmer Joe]

moo

[BaM]

But wait - there's <a href="http://www.alexchiu.com/cell/intro.htm" target="lank">more</a>... 'New Darwinism'...

LOL

[This message has been edited by BaM (edited 19 July 2000).]

[MadLep]

Woohoo!

LOVE THE ALL CAPS in the "our universe is expanding because it was hit by thunder" one.


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clan |o-bot| - Powering the propaganda machines of several small dictatorships.

[Endymion]

I look at breasts all the time and I still have to watch what I eat. Haven't been doing that too well lately.

[Boofhead]

wow... take a day off and 100 posts to read

Can I ask some questions Fred/anybody else who knows the answer? (I'll just assume the answer is yes )
Do Fossils contain enough radioactive material to make C14 dating a viable method for finding out how old they are?

AFAIK, many fossils are dated by association - that is, by dating (usually volcanic) rocks assumed to be from the same time period... I take this to mean they can't be dated using C14?

If fossils can't be dated using C14 and instead must be dated by association (using K-Ar on volcanic rock) and the rocks themselves are <500,000 years old wouldn't this produce erroneus results? (like several million years - as observed when dating 25-50 year old rocks)

According to the Bible, the earth is only about 6500 years old (having begun around 4500 BC). If this was true, then radioactive dating of fossils would all be wrong. (bummer)

Yautja: There are 157680000000000000 seconds in 5 billion years... but the chances against amino acids creating proteins that could be used in living cells are far greater than that... there just isn't enough time for a single living cell to be produced by random elements. (a living cell is very complex)

plenty of good reading material in this thread... I can feel my brain learning already

[Necro]

Im not entirely sure if fred has answered this (/me got confused ... but, if for example you had two galaxies moving directly away from each other at .5c then you would still be able to view the light emitted (Ignoring any funky light bending effects, like gravity . It is only the velocity of the witness that matters. If an object is moving it gives off light which has a contant velocity, it does NOT hold the momentum of the object. So, something travelling at .5c away from a point will still see the point, only the wavelength of the light would be affected by the speed of the viewer. If you managed to go faster than light speed, it is probably that you could not see anything behind you... at all... even your own hand. Everything from infront of you would be seen at more than twice the speed it happened.

Thats probably one of the weirdest and most confusing things about light. It does not have mass, it does not hold momuntum, and yet it is effected by gravity. So what the hell is gravity anyway? My best guess is gravity is an atomic attraction (which is why photons are effected by it), whereas magneticism works on a molecular scale.

As for a definition of time... Time is a measure used to mark observation of change. Time is not an entity or dimention, it is purely a perception. To effectively move backwards in time, all you have to do is put everything in the universe back to where it was at the time you want to be. To jump into the future is simple... close your eyes... now open them again and you have gone forward in time. Close your eyes long enough and you get a big jump in time Of course the real trick is to remove your matter from interaction with the rest of the entire universe, and allow the universe to move along on its merry way without you. That way you can see what has happened at a future time without your existence during that span of time (ie. future travel).

[Mabd]

Having said that Nec, I'm a bit in the dark (heh). What IS light? What is it made up of etc, as you say it has no mass yet it is affected by something that controls mass. ARGH, give me my digging tools, archaeology is easier than this!

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Hail to the King

[Yautja]

Hehehe - that guys just a modern day faith healer . I've read about his immortality device before - apparently it makes him a decent living (media is always interested in crazy people with money). His UFO design should work though, even if its a bit simple .

C14 dating is different to K-Ar, how it works is there is a constant ratio of C14 atom's to C12 in the world (the're being contantly being made). Anyway while something is living this ratio is constant inside of it, but when it dies the C14 atom's start decaying into C12, then you just measure the ratio years later and calculate how much has decayed, then how much time that corresponds to. .

C14 only has a half-life of a few hundred year's (220 ?,K-Ar is over 10,000 i think), so anything after 50,000 year's you be counting individual c14 atom's (which as fred explained, can't be done with current equipment).

So the short of it is - C14 is useless for dating dinosaur fossil's (their bones have been completely mineralised anyway, so im not sure if carbon would still be in them).

Well boof, if you beleive in evolution, then it must of happened (cell's 'evolving') or you wouldn't be here to think about it (that argument is sciences answer to the 'GOD created it that way' one, it work's in any area there is doubt that something happened the way it was needed).

And now for something completely different :- Breast's in space, they'd be so much more interesting to watch in 0-gee's.
Even though sex is extremly difficult in space, it's only a matter of time until a porno is made there - they've been made everywhere on earth already (Breast's.... The Final Frontier ).
Maybe the International Space Station will be worth while afterall.

(sorry for the big post pinky, but i can't be bothered with heaps of little ones)

[Yautja]

The deal with stuff traveling away from us has more to do with (the theory) that space inbetween us is expanding at a constant rate throughout the entire universe (hubble constant - the further something is away from us ,the more space that is expanding between us , so the faster it moves.) So in order for something to be traveling toward's us it has to be faster than this expansion - that's is why mainly only the galaxy;s that are in our local group that are moving towards us due to gravity.
This theory also explain's red shift because as the light travels through this expanding space it gets streched , causing a longer wavelenght.

I think light does have mass (E=MC^2, you can calculate the energy of light [forgot this formula] so u stick it in and get M=E/C^2, they come out as tiny amount though because of C^2 is a really big number), It does have and momentum , you can see this from those solar windmill's that turn in a vacum by reflecting light off mirrored blades.

Manetism dosn't affect light beacause it dosn't have any charge.

Any theory's involving time are really hard to grasp (due to the fact time is always constant for us - its the only thing that is). There are problems with sending matter/energy back in time (not really with the same mater/energy esisting in the same universe twice - there's nothing that makes matter/energy any special from any other matter/energy), if you could do this just sending 1 atom back right to the start of the universe could change the way it look's completely - making the difference between it being closed, open or you could even make it flat if you wanted.
There are theory's of about the nature of time that could account for this

infinite time- where from every point in time there are infinite path's that time can take, so there's no way you could be able to send matter/energy close enough to the start of the universe to affect every timeline. (seeming time doe's not have unit's like we give it, it is infinite so we could never get matter to the start of the universe, no matter how close you get you can always get closer).

Then there's the fact that if you send something back, it already exists in your timeline, so would have no affect on the present.

I don't see any problems with matter traveling back in time , because it would keep going back to the start of the universe so it would already exsist in all timelines . It just when it stop's things get complicated.

Basically don't think about time or time travel too much or youll end up going insane.

Same thing apply's to interaction's with gravity - look what happened to einstein - he spent the last half of his life on that.

(sorry for another big post - but my computer's stuffed and can't play quake)

[Fred]

> Do Fossils contain enough radioactive material to make C14 dating a
> viable method for finding out how old they are?

General answer, no. Usually with fossilisation the carbon has been replaced by other elements making the application of C14 dating pointless. There are exceptions to this with more recent fossilisations because the term fossil does tend to get used quite loosely. Remember some fossils are little more than the impression made in soft rock by the dead animal as sediment accumulated around it. These are some of the
most tantalising fossils because they preserve soft body structure instead of just skeletal structure.

> AFAIK, many fossils are dated by association - that is, by dating
> (usually volcanic) rocks assumed to be from the same time period... I
> take this to mean they can't be dated using C14?

Yep. Hard to use a carbon technique if their ain't no carbon.

Also you can't use KAr, or I think ArAr, directly on fossils for two reasons :-

1) most fossils are deposited in sedimentary rock formations and the technique can not be used to date sedimentary rocks. (Due to the
reliance on the trapping of gas as the rock cools which is missing from a sedimentary process at the time of deposition.)

And 2) because mineralisation occurs as a gradual process after deposition and you can't easily get a handle on that process.

> If fossils can't be dated using C14 and instead must be dated by
> association (using K-Ar on volcanic rock) and the rocks themselves
> are <500,000 years old wouldn't this produce erroneus results? (like
> several million years - as observed when dating 25-50 year old rocks)

If you used purely the KAr technique, then yes. But remember there are quite a few decay sequences available for dating - each with their own time range, foibles and processing techniques. Off the top of my
head there is the Argon Argon series, Uranium series, Strontium series and I think there is a Thorium series but I'd need to check that.

> According to the Bible, the earth is only about 6500 years old (having
> begun around 4500 BC). If this was true, then radioactive dating of
> fossils would all be wrong. (bummer)

If this was true, then radioactive dating of _any_ rock would show a young age below the discrimination level of most techniques. This isn't the case and unless you care to invoke the assumption that the biblical God created a world 'pre-aged' then you have a contradiction between the Bible and scientific result. This wouldn't be a new thing, lets just say 'mustard seed' and leave it at that.

> Yautja: There are 157680000000000000 seconds in 5 billion years... but
> the chances against amino acids creating proteins that could be used
> in living cells are far greater than that... there just isn't enough
> time or a single living cell to be produced by random elements. (a
> living cell is very complex)

Completely random spontaneous assembly from scratch? Yep, the chances are pretty low to leap from random material to, say, a self replicator of RNA's complexity. But that doesn't seem to have been the first step.

The question that needs to be asked is what is _the_ simplest self replicating compund that you have to have. And what are the chances of that arising?

After all once you have replication occuring then selection automatically starts 'directing' progress into the form of the most efficient replicator for the environment. Then you no longer have
spontaneously random creation but rather directed selection of random difference for the more efficient replicator. And that is a very powerful system.

I'd recommend some of Richard Dawkins written work if you are interested in the topic of abiogenesis and it's probabilities, particularly 'The Blind Watchmaker'.

|THAT|-fred
'fred is not dead, fred is resurrected!'

[Necro]

Ok, so I managed to mangle a few techincal terms

What I meant to say was that light seems to have a constant velocity regardless of the velocity of that which emits it. My vague recollections of 5th form science suggests that light consists of photons, an odd little particle that is produced when an electron moves from a lower energy shell to a higher one (If you did 5th form science you should know what an energy shell is). By odd I would say it has the properties of having no mass, yet still conforms to some of the effects that mass holds. One way of trying to account for this is the definition of mass. Mass is the measure of Atomic Structures present in a substance. Photons are sub-atomic particles, much like electrons. That is why photons have no atomic mass, but still have properties of mass.
So is it sub atomic gravity that holds inversly charged particles like protons and electrons together in an atom?

Ah, I better stop before I go spouting more quasi-science

[Fred]

Okay, corrections time people :-

1) Electromagnetism _is_ a significant force at the sub-atomic level. It is one of the primary forces that regulates the upper size of an atom's nucleus and keeps the electrons in their respective valence shells. (Upper nucleus size is determined by the attractive power that the weak and strong nuclear forces have to over come the repulsive strength the electromagnetic force has between all the protons in the nucleus.)

2) The concern over light cones and the expansion of the universe is because the expansion may indeed produce a velocity that, to a select group of observers, looks like an FTL speed and removes the object from our perception. Whether this actually happens is open for a lot of debate and certainly there are arguments over whether such an effect would invalidate relativity. See 'A Brief History of Time' by Stephen Hawkings for a fuller explanation of what is going on. Yautja's summary is pretty much spot on though and it is a cumulative effect of constant expansion.

3) Magnetism _does_ affect light. This was one of Micheal Faraday's many discoveries, namely that a magnetic field will polarise and re-orient light. A simple experiment is to organise a beam of polarised light to pass through a volume of space where you can apply a magnetic field. Placing a second polariser in alignment with the first on the other side of this space means that any change in the orientation of the light will cause the second polariser to cut the light out.

Do this experiment and whenever you introduce a magnetic field the light beam does not pass through the second polariser. This is why light is placed on the eletro-magnetic spectrum and was the key to unifying the previously mysterious & seperate forces of magnetism and light together.

4) Gravity appears to be a curvature of space/time. An easy way to visualise it is to consider space/time to be a trampoline, mass to be heavy balls of varying weights placed on it and gravity is the curvature of the trampoline. This model allows stuff like orbits, the inverse square law and the like to fall out quite simply and naturally. What fries everyone's brain right now is considering why gravity is an inverse square relationship when the other fundamental forces are higher powers. Electromagnetism is an inverse cubed relationship for instance.

There may be a way to explain it that comes out of superstring theory - the idea that space/time is really about seven physical dimensions but with most of the higher dimensions folded tightly into small spaces. The ins and outs of super string theory are definitely very odd and beyond my ken for the most part. But from what I understand the fundamental forces fall out of super string theory as being curvatures of space/time at varying dimensional levels.

So Gravity falls out as a fourth/fifth dimensional curvature, Electromagnetism as a fifth/sixth, etc... Because the curvature is expressed more in a higher dimension then it's effect, as observed in the regular three/four dimensions we use, becomes less. This gives the nice inverse relationships and why they vary. Indeed if right all the forces could be expressed as the one effect - just that the curvature is expressed in different dimensions.

Okay, gotta dash. But that should keep y'all quiet for a while.

|THAT|-fred
'fred is not dead, fred is resurrected!'

[glacier]

this is one fucking huge topic

i havent read most of it. i n fact ive been trying to stay away from it for a while now.
but i thought id have a little look since its been near the top of the board for a long time.

anyways. once i did a big project about evolution when i was at school. i learnt a hell of a lot doing that project.

very interesting stuff. i have my own views on the evolution subject but havent got the time to write them all out like u chaps have been doing.

[FB]

Just had one thing to say to the chewing gum...

Do you think the world is made of atoms? - because this is just as much theory as Evolution is.. its just backed up with evidence thats all.

And if there is a god, then which religion is right? all of them? christianity?
If their all right then the world should have ended by now (all the milennium drama) according to one of them (not sure which one.. would be interested to talk to someone who is part of that religion tho..)

I love physics / Science topics like this - get my brain wirring :P

Bam - never knew you were so... scientific..

FB

[Endymion]

Of course the universe is made up of atoms. But then, they're obviously made up of smaller and smaller particles too.

[[oOalienOo]]

The problem with discrediting most armageddon type prophecies is usually they're translations of much older scripts, and since they're translations they're not only open to language differences, but if one wants to be cynical about it, they're open to control by those who translate them.

Translation problems and difference in interpretation are the two more frequent excuses I've heard for the world not ending.

I may be chewing gum, but I am fresh and minty!

But nah.

Tad different. You can actualy go right there and then and test theorys with chemical reactions and molar comparisons etc etc, but I dont think evolution is quite as easy to prove as that, well.. it cant be, because its not true.

What about time. Anyone figured that time never started and never could have?