[watsisname]

Nothing in science can be known with absolute certainty.

exactly. I think that is all he said.

Well bob, with all due respect, does that mean someone would be right in claiming that the theory of evolution is not conclusive?  What about gravity?

Just because we can never be 100% certain doesn't mean we cannot be certain beyond a reasonable doubt.  I and the vast majority of climate scientists seem to think it's well beyond a reasonable doubt that human activities are responsible for the current warming trend.

Also since I think this thread is too interesting to continue to muck up with climate-debate, I'll just leave this here and suggest that anyone with doubts on the issue watch it.  It's a very good presentation on climate-altering forces.

[Bobboau]

Nothing in science can be known with absolute certainty.

exactly. I think that is all he said.

Well bob, with all due respect, does that mean someone would be right in claiming that the theory of evolution is not conclusive?  What about gravity?

yes

[QuantumDelta]

That's exactly how science is based.
Nothing is infallible, only very strong, the more challenged the theory is the stronger it becomes. We don't really know enough right now to be able to call anything 100% definitive though.

[TwentyPercentCooler]

Yep, Bob pretty much hit it on the head there.

Look, I'm not saying I disagree with the notion that we will wind up negatively impacting our climate permanently if we go on like we have. I support the green movement (the real green movement, not the fake hipster crap that involves "hybrid" cars and legendary levels of smugness) and I think that we need to start treating nature and our environment with the respect its due, because it's been showing us lately what we are - dust that can be wiped away effortlessly.

All I was saying is that I'm not 100% convinced yet that this particular current warming trend isn't part of a natural cycle. I think we should take action like it is (I'm reminded of the xkcd "What if it's all a scam and we create a better world for nothing?" comic), but the La Nina/El Nino cycles, solar output variations, carbon dioxide being released from melting ice (which is a cascading process that only needs a trigger, that can be natural or artificial), methane released from natural processes...none can deny that there are a lot of variables here, and we have no "control group," so to speak.

Like I said, we should act like it is our fault and make appropriate changes. I think the people that are sticking their fingers in their ears and shouting LALALALA I CAN'T HEAR YOU when anyone talks about man-made climate change is either ridiculously shortsighted or stand to lose something from clean-up efforts, such as big businesses that are going to have to dip into their record profits, god forbid.

[Nuke]

i never considered earth climate as a static entity. if you had managed to clone a t-rex it probably wouldn't survive long in our atmosphere. the air was denser and hotter back then. and yes i do think we have been tweaking the atmosphere with our emissions. however i think that the projections of what our climate will be like in the future if we dont reduce our emissions, are grossly exaggerated. further more im more concerned about surviving the next ice age than the global temperature going up slightly. we may actually need to make the planet warmer at some point. will definitely give us a crash course in atmospheric engineering.

[watsisname]

Nothing in science can be known with absolute certainty.

exactly. I think that is all he said.

Well bob, with all due respect, does that mean someone would be right in claiming that the theory of evolution is not conclusive?  What about gravity?

yes

Right, I almost forgot it's just as likely everything poofed into existence ten thousand years ago, and the moon's just a light stuck on the sky-carpet.

[Black Wolf]

Relative likelihoods remain, obviously, current theories are far more likely than creationist ideas. It's just that that likelyhood never reaches 1.0. 0.999999999 is a possibility, though.

[MP-Ryan]

Fundamental premise of science:  you can never prove a hypothesis, you can merely show a lack of data that would suggest it's wrong.  Same goes with theories, which are simply hypotheses with a lot of collected data that don't contradict them.

The theories of gravity and evolution both have piles of data behind them, very little of which says they're wrong, which means they're the best explanation we have.

The fact that theories are, by their nature "un-provable" does not give credence to people who scoff and claim "that's just a theory."  Our modern society is built on the premise that a lot of theories are mostly-correct and the best explanation we have to date.  True facts don't really exist in science.

[Nuke]

newtonian physics is solid reliable in the engineering world, as is general relativity and quantum mechanics. they are close enough to be able to base working technologies on. but theres still a lot of room left to better define the laws of nature.

[Mongoose]

The theories of gravity and evolution both have piles of data behind them, very little of which says they're wrong, which means they're the best explanation we have.

In addition, basic gravitational attraction and natural selection can be more specifically referred to as scientific laws, meaning that they describe the results of repeated observation.  For instance, in a "weak" (i.e. everyday) gravitational field, we can verifiably measure that two objects with mass are attracted to each other by the inverse square of their distance apart.  In the same way, individuals of a species that have a certain advantageous trait are able to better survive and pass on their genes than those that don't, which we can see in action with something like bacterial resistance to antibiotics.  Laws are pretty much the closest science comes to stating something with complete certainty, since they basically proclaim, "This is something we're directly seeing happen, and here's what we're seeing."  That isn't to say that certain laws don't become defunct, or apply in every single situation, but they are things that tend to stand the test of time.

[Flipside]

We should always be aware, though that is possible for incorrect theories to actually produce correct results, take, for example, certain markers in Egypt that still predict the Suns' rise on certain days despite the fact they were based on the assumption the Solar Systems was Geocentric. Often it is tiny errors in those predictions that uncover the mistake, in this case I believe it was retrograding that first opened people's eyes to the idea of Heliocentrism.

That said, the possibility of finding such a vast error as that in something as stringently peer-reviewed as stuff on Evolution and Gravity would be phenomenally unlikely, our knowledge of the Sun wouldn't affect us much so long as it comes up at the right time in the right place if your only interest in it is 'when to plant the crops' etc, however, both Gravity and Evolution are the bases of large pyramids of discovery and very little of that pyramid has made more than minor changes to the basic theories.

I'd say we know more about Evolution than Gravity though, oddly enough.

[TwentyPercentCooler]

We should always be aware, though that is possible for incorrect theories to actually produce correct results, take, for example, certain markers in Egypt that still predict the Suns' rise on certain days despite the fact they were based on the assumption the Solar Systems was Geocentric. Often it is tiny errors in those predictions that uncover the mistake, in this case I believe it was retrograding that first opened people's eyes to the idea of Heliocentrism.

That said, the possibility of finding such a vast error as that in something as stringently peer-reviewed as stuff on Evolution and Gravity would be phenomenally unlikely, our knowledge of the Sun wouldn't affect us much so long as it comes up at the right time in the right place if your only interest in it is 'when to plant the crops' etc, however, both Gravity and Evolution are the bases of large pyramids of discovery and very little of that pyramid has made more than minor changes to the basic theories.

I'd say we know more about Evolution than Gravity though, oddly enough.

That's probably true enough; we know the mechanics and equations that predict the effects of gravity, but its mechanism of action is still pretty much a complete mystery.

It's also true that sometimes the smallest anomalies can shoot a huge hole into a theory, like how the unexplained precession of Mercury's orbit led to the hole in classical mechanics that led to GR.

[Flipside]

I do think a lot of confusion arises with regards to Evolution as a science because it is, in no way, predictive. Lots of people learn that science is the art of prediction through observation, I could tell you with 95% accuracy where Jupiter would be in the sky at this moment in 5000 years time, for example. We can, with effort, trace a fair chunk of the paths various animals took to become what they are today, but we cannot, and I doubt we ever will be able to tell you what would happen in the future.

Evolution is a much more chaotic science, but the interesting part is that it is not alone in that respect, anyone who has ever encountered Boyles laws and things like Brownian motion know that not all sciences are capable of dealing with specifics because it would be impossible to deal with the number of uniquely interacting variables.

[Mikes]

newtonian physics is solid reliable in the engineering world, as is general relativity and quantum mechanics. they are close enough to be able to base working technologies on. but theres still a lot of room left to better define the laws of nature.

For example... it could still turn out that we are all sentient programs run in some mad science experiment in the *real world*.

Heck, we could even be their version of a perverted RealityShow: MyUniverse 2.0: Watch the pathetic earthlings try to understand the laws of the universe that randomly change in every new season"!!! Mwahahahaha good fun! Look, this season, in the medieval period, they are roasting each other on stakes again over a disagreement!

What? Don't anyone dare tell me it's any less plausible than "uh god dunnit!". The evidence available to support, or discard, either "theory" is exactly the same.

[QuantumDelta]

Not impossible flipside, just beyond our current capabilities!
Enough computer power and enough information and eventually we'll be able to run 'true to life' global simulations, which will include the genetic codes of all life on an individual basis as well as communal..

Eventually......!

[Mikes]

Not impossible flipside, just beyond our current capabilities!
Enough computer power and enough information and eventually we'll be able to run 'true to life' global simulations, which will include the genetic codes of all life on an individual basis as well as communal..

Eventually......!

Yeah... and maybe we all are actually part of one of these models being run :cough:

I mean...for example, imagine a civilization attempting to compute the longterm effects of a terraforming package...  assuming obscene amounts of computing capacity, genetic/evolving algorithms, etc. ... that's how it would be done, wouldn't it? We already use the principles of evolution, on a very basic level, to perfect our own engineering designs after all.

Granted... in that case someone propably forgot to "turn us off"... or just enjoys being a galactic voyeur.

[MP-Ryan]

Not impossible flipside, just beyond our current capabilities!
Enough computer power and enough information and eventually we'll be able to run 'true to life' global simulations, which will include the genetic codes of all life on an individual basis as well as communal..

Eventually......!

Yeah... and maybe we all are actually part of one of these models being run :cough:

I mean...for example, imagine a civilization attempting to compute the longterm effects of a terraforming package...  assuming obscene amounts of computing capacity, genetic/evolving algorithms, etc. ... that's how it would be done, wouldn't it? We already use the principles of evolution, on a very basic level, to perfect our own engineering designs after all.

Granted... in that case someone propably forgot to "turn us off"... or just enjoys being a galactic voyeur.

Been reading "The Hitchhiker's Guide to the Galaxy" lately, have we? =)

[Flipside]

Well, the thing about Evolution is that it is, quite literally, powered by random chance, that's why I don't think we'll ever produce a mathematical model for it.

Interaction with the Envvironment and each other is what defines 'fitness', but the actual motor for the changes that take place is random mutation, and nature can find very strange solutions to problems, I'm not sure it could ever be predicted.

[Bobboau]

it can be predicted to an extent, for instance microbes WILL develop resistance to drugs that kill them.

[MP-Ryan]

Well, the thing about Evolution is that it is, quite literally, powered by random chance, that's why I don't think we'll ever produce a mathematical model for it.

Interaction with the Envvironment and each other is what defines 'fitness', but the actual motor for the changes that take place is random mutation, and nature can find very strange solutions to problems, I'm not sure it could ever be predicted.

Well...

Mutation rates ARE predictable (even with today's technology), so it is possible to determine the chances of a particular bp mutation in a whole genome (roughly speaking).  As most mutations are single bp replacement, then it's a matter of determining bp's that can cause codon changes, which would produce proteins with altered functionality.  For that matter, duplications and translocations/transversions tend to occur in particular places (which are sort-of predictable, even now).  Don't get me wrong, it's spectacularly complex, but ultimately all it really comes down to is some crazy statistics and background knowledge of the biochemistry.

What's toughest about predicting evolution is predicting what types of selective pressures are going to be exerted, rather than when or how mutation is going to actually occur.  But if we know the selective pressures exerted on the system, there's a pretty good chance we'll eventually be able to reliably and accurately predict when and what type of adaptive traits will arise in the population - at least in the short term.

In fact, we've already [sort of] done this - there was a journal piece published in Science a few years back about predicted and observed evolution of formerly ground-dwelling lizards after the introduction of a terrestrial predator.  The little buggers split into two populations - long-legged ones that could run faster and dig deeper, and short-legged varieties that could climb trees to escape.  And what's craziest is this was documented over only 2 years.

it can be predicted to an extent, for instance microbes WILL develop resistance to drugs that kill them.

<nitpick> Technically, they already have the resistance, it's just the very few resistant individuals will now outcompete those that aren't resistant. </nitpick>