A Question for Atheists?

Whoever said the universe had to fit into human concepts?

Actually, the lifespan of all of those things you mention can't be calculated with accuracy. When they say that some star will "die" in 3.8 billion years (or whatever number), that's just an estimate--it could easily be hundreds of millions of years different from that.

Furthermore, stars, galaxies, etc. are relatively simple--if you know what they are composed of, they follow pretty simple patterns of formation, change, and dissolution. Humans (or any other animal), on the other hand, are far far more complex, since they interact with the world in varying ways.

As a good comparison--if you were taking a subway from one side of New York to the other, it would be pretty easy to make a pretty good guess about how long it would take, because the train follows fixed schedules, and only has a few things that can interfere with it. If you wanted to calculate how long it would take by car, it would be far more complex, because there are far more things that can change the time (traffic, accidents, signals, etc.).

As a side note, I'm not an atheist, but I don't see why they would have any different way of looking at this.

I'd say that this is more a characteristic of life, than just of humans. We do not know precisely how things like brain activity work and determine the best actions to take and therefore cannot predict how an animal will react 100% of the time. We can make judgement calls from experience of course but there is no way we could make assumptions before hand.

The planets and stars are very different. They move based on the gravitational pull of other celestial bodies and their own momentum. The reason we can make predictions is we more-or-less know the math - it's fairly basic trigonometry to determine where an object will be based on a small portion of its orbit. There are no maths equasions to tell how someone's brain is going to react to any given stumuli.

To be honest I'm not sure why you would even ask this? Should we be able to make such predictions in your opinion? And why did you direct this at atheists?

"Why can a human beings movements, reactions or life span be *NOT* calculated to such accuracy?"

Too many variables. Too much goes on with us, compared to say, the orbit of a planet.

I think a sufficiently powerful computer could calculate human responses, but we're far from anything that powerful.

Whoever said the life of a star can be calculated with any degree of accuracy? The average lifetime may be known for different classes of star but this is no more accurate than using an actuarial table to calculate the life of a human.

The previously mentioned moving objects (Earth Moon Planets Stars Galaxies etc.) are not "living organisms". Living organisms which are self directed like animals (cats dogs pigs sheep humans etc) move in order to survive, and in response to changing environments and other competitors in the environment. The first set of objects move in simpler ballistic paths called orbits and are simpler to calculate because they are not self directed.

A human's movements, reactions and lifespan cannot really be predicted very well, for this reason.

Oh dear.

Did you know the human brain has about as many neurons as there are solar systems in the galaxy? And that each of those neurons is far more complex than a solar system? And that the interactions between them are much, much more complicated than those of stars?

On the other hand, the behaviour of humans in large groups can be predicted with reasonable accuracy.

Try Heisenberg's uncertainty principle for a start. It basically says that it is impossible to measure location and movement of a particle at the same time. That means that even if the movement of every particle is predetermined (which is still a matter of debate) it will be impossible to measure it and make calculations on this basis. You can argue whether free will really exists, but for all practical purposes it does.

Everything in the universe behaves probabilistically. However, in some systems the probabilities involved are so close to binary that they can be treated as deterministic.

Simple mechanical systems like planets orbiting a star are constrained a lot more tightly than animals capable of making and acting on decisions.

They can be but it's difficult to do so since we still have a very limited understanding of the human psyche. We are unlike any other animal, we don't adapt to nature as much as we adapt nature to our needs. The growth of our mental capacity made us distance ourselves from what is natural for every other animal. We don't hunt for food, we buy it at the supermarket, males don't fight other males to prove they are worthy of mating, they put nice clothes on and use charm to do that and so on. You can predict with some accuracy what a human being with a specific psychological make up will do but the psyche is mostly influenced by our individual life experiences so they vary greatly from one individual to another. Profiling is the science that does just that, predicts human behavior based on known patterns and the study of the individual and his actions. (mainly used for capturing criminals)

The abiotic components of the universe work on predictable laws. Biological organisms often don't.

Not just humans - it's not possible to judge the lifespan of any living thing with much accuracy.