> How is atheism any less based on faith and therefore any less ridiculous?

feelin' lazy :

http://atheism.about.com/library/FAQs/ath/blathm_nat_disproof.htm
Myth:
You cannot prove that God doesn't exist; therefore, atheism is based on 
faith.



Response:
Too often theists will try to place atheism and theism on the same plane by 
arguing a particular equivalency: theists cannot prove that god does exist 
and atheists cannot prove that god does not exist. Frequently this comes 
after the theist's attempts at proof have failed and a new tactic is 
required.

Just frequently, this is used as a basis for arguing that there is no 
objective means for determining which is preferable because neither has a 
logical or empirical advantage over the other. Thus, the only reason for 
going with one or the other is something like faith and then, presumably, 
the theist will argue that their faith is somehow better than the atheist's 
faith.

Unfortunately, the above claim is more often false than true. It relies upon 
the erroneous assumption that all propositions are created equal and, 
because some cannot be conclusively disproven, then therefore none can be 
conclusively disproven. So, it is argued, the proposition "God exists" 
cannot be disproven.

But not all propositions are created equal. It is indeed true that some 
cannot really be disproven - for example, the claim "a black swan exists" 
cannot be disproven. To do so would require examining every spot in the 
universe to make sure that such a swan did not exist, and that simply isn't 
possible.

Other propositions, however, can be disproven - and quite conclusively. 
There are two ways to do this. The first is to see if the proposition leads 
to a logical contradiction; if this is so, then the proposition must be 
false. Examples of this would be "a married bachelor exists" or "a square 
circle exists." Both of these proposition entail logical contradictions - 
pointing this out is essentially the same as disproving them.

Similarly, if someone claims the existence of a god, the existence of which 
entails logical contradictions, then that god can be disproven in the exact 
same way. Many atheological arguments are based upon exactly that - for 
example they argue that an omnipotent and omniscient god cannot exist 
because those qualities lead to logical contradictions.

Another means of disproving propositions is a bit more complicated - it 
involves careful observation and testing. Consider the following two 
propositions:

1. Our solar system has a tenth planet.
2. Our solar system has a tenth planet with a mass of X and an orbit of Y.

Both proposition can be proven, but there is a difference when it comes to 
disproving them. The first could be disproven in theory if someone were to 
examine all of the space between the sun and the outer limits of our solar 
system and they found no new planets - but such a process is beyond our 
technology. So, for all practical purposes, it is currently not disprovable.

The second proposition, however, is disprovable with current technology. 
Knowing the important and specific information of mass and orbit, we can 
devise specific tests to look and see if such an object exists. If the tests 
repeatedly fail, then we can reasonably conclude that the object does not 
exist and that the proposition has been disproven. Note that this would not 
mean that no tenth planet exists. Instead, it simply means that this 
particular tenth planet, with this mass and this orbit, does not exist.

Similarly, when a god is defined adequately, it can be possible to construct 
empirical or logical tests to see if it can exist. We can look, for example, 
at the expected effects which such a god might have on nature or humanity. 
If we fail to find those effects, then that god with that set of 
characteristics does not exist. Some other god with some other set of 
characteristics may exist, but this one has been disproven.

An example of this would be the common Argument from Evil - an atheological 
argument which proposes to prove that an omniscient, omnipotent and 
omnibenevolent god cannot exist at the same time as a world like ours which 
has so much evil in it. If successful, such an argument would not disprove 
the existence of some other god; it would instead merely disprove the 
existence of any gods with a particular set of characteristics.

Thus, it is possible to prove that a god does not exist - but obviously this 
depends upon getting an adequate description of just what this god is and 
what characteristics it has. We need that in order to determine either if 
there is a logical contradiction or if any testable implications hold true. 
What happens when we don't get an adequate description?

Well, obviously atheists cannot prove that it does not exist and theists 
cannot prove that it does exist. However, in such a case believers have 
abandoned too much in the attempt to find a god which is immune to disproof. 
Without a substantive explanation of just what this god is, how can there be 
a substantive claim that this god is? In order to reasonably claim that this 
god matters, the believer will have to provide substantive information 
regarding its nature and characteristics; otherwise, there is no particular 
reason for anyone else to care.

It should also be noted that arguing about how atheists "cannot prove that 
God does not exist" often relies upon a misunderstanding about atheism 
itself. It seems to be generally predicated upon the assumption that the 
atheist claims "God does not exist" and so should be expected to prove that. 
It should be pointed out to the theist in such cases that atheists merely 
fail to accept that their claim that "God exists" and, hence, the initial 
burden of proof lies with the believer.

If the believer is unable to provide good reason to accept the existence of 
this god, it is unreasonable to expect the atheist to try and construct a 
proof that it does not exist - or even care very much about the claim in the 
first place. Such an expectation is only reasonable when the atheist in 
question has specifically claimed that this or that god does not or cannot 
exist.