On my previous post about the falsehoods of Pascal's Wager, some anonymous user (who I assume I know in real life since I've promoted my new blog via facebook), wrote this comment:
Science cannot prove anything to an absolute certainty, only point strongly in the direction that something is most probably most correct at explaining a (set of) phenomenon.Now many diehard science-believers would take offense at this. "Science is the ultimate truth! Blah! Blah! Let's go make fun of religion!"
A pretty clear example of this would be astronomy/astrophysics as we see a movement away from geocentricity towards heliocentricity. This of course was supplanted by elliptical orbits, newton's laws, and now relativity. Each new theory proved to be more adept at predicting the path of heavenly bodies, supplanting the previous ones as the most probable explanation of how----
Ignore that. I don't feel like finishing my reply. Try to guess at what I wanted to say.
But whoever this anonymous poster is has a valid point. Sort of.
What is absolute certainty? For some, to be absolutely sure of something all that is needed is someone telling you that it is true. When a kindergarten teacher reveals the shocking truth that the world is round (actually technically it's not perfectly round, either), some of the kids in that class are absolutely convinced 10 years later that this is true just because the person who knew the most in the world, a teacher, told them it was. We tend to grow out of this to an extent, some more so than others, but there are, for most people, a few individuals who speak the unadulterated truth always.
Some need something that they can see with their own eyes. A brick and a light bulb fall at the same rate, despite the massive difference in density. A steel can will implode if you boil water in it and then cork it before the steam condenses (this is really cool).
And finally, some need things that they can prove. Taking the derivative of position with respect to time really does give a velocity function. The derivative of a quadratic function really is a straight line.
But all three of these systems have inherent flaws. You may believe people, but people lie. People have misinformation. People say one thing and mean another.
You may believe in your own senses. But then explain why dreams feel as real as reality. Explain optical illusions. Sometimes your senses lie as well.
Believing in proof is not bad, but eventually this "belief" is just one that boils down to one of the above two. You can construct a mathematical proof of most anything nowadays, but each proof is based ultimately either on postulates, which are statements that are based on observations (which could be faulty) and are "commonly believed to be true".
My point in this elaborate buildup is that NOTHING can prove ANYTHING absolutely. Eventually you have to realize that whatever you take as truth could be tainted by assumption and error. You assume I, Jeff, wrote this article because it's absolutely loony and posted on my blog. But what if my blog got hacked? What if I've been replaced with a stunt double? What if somebody secretly taped an article to your screen when you blinked? (You can test the last one, by the way, by scrolling up and down.) Eventually you have to assume that because these things have a very low chance of happening, they probably aren't the case. But you can never be certain.
And any observation can be taken with this grain of salt. Look at the wall in front of you, or out the nearest window? What color is it? Are you sure? What if the light is hitting the wall in a strange way? What if the sky is actually turning red because the sun has prematurely engulfed the earth but you've developed a neurotic condition that causes you to see red as blue, another condition that kills your ability to sense temperature, and deafness that lets you block out the screams of the human race in it's final throes of life?
Even someone who claims not to believe in anything ("If I turn around and can't see you and can't otherwise sense you, you aren't there!") is relying on their own senses. Unless they have replaced their declarative mood with a perpetual subjunctive, they are placing faith in their observations and knowledge.
Eventually, you have to accept that whatever you believe to be true might, even if it is unlikely given your experiences, be false. Nobody can be absolutely certain of anything. The debate over Science vs. Religion is not a question of whether faith is valid, it's a question of how much faith is valid and in what this faith should be.
So as you live your day to day life, remember that everything is based on a set of observations and common knowledge. Nobody can ever be absolutely certain of anything. I think.