> What's fascinating in itself though is that no person, however sceptical, can immediately rule out the possibility that stuff like this is some form of life or even evidence of non-human technology.
You can never completely rule out that possibility, regardless of how much evidence you collect, but it's a matter of semantics at that point. Immediately and without collecting anymore data, we can dismiss the hypothesis that this is non-human technology as unworthy of our attention. It's not merely that the hypothesis has an immense burden of evidence to heft, but that it's a waste of time to even consider it.
Seeing possible evidence of extraterrestrial life in every unexpected observation is nothing more than a superstition.
"Seeing possible evidence of extraterrestrial life in every unexpected observation is nothing more than a superstition."
I agree, and I hope I didn't give the impression that this is what we should be doing. This thing is still just an observation - it's not evidence of anything yet. My point was this: we know of things that would effectively rule out the 'life as we know it on Mars' hypothesis (e.g. absolutely no evidence of any water, liquid or otherwise), but we're not seeing them.
It's true that we keep trying to dream up new ways of allowing the possibility of life on Mars to counter existing hurdles (e.g. hypothetical microbial life buried underground to shield from radiation), but if there were some solid evidence that would allow us to say 'yeah, there was almost certainly never any life on Mars, and neither is there any life on it today,' we would accept that filter.
We could then put Mars in the same category as the Moon when it comes to the life hypothesis. This is not the case - so I'd say a search for evidence of life on Mars (past or even present) is justified.
If you want to understand the "huh?" reactions you're getting, you might want to wrap your mind around the idea that it's effectively impossible to prove a negative.
I'm sort of annoyed by the notion that "you can't prove a negative". It's true when we're talking about empirical evidence, but it's only a specific case of "you can't prove anything". There's nothing at all special about negatives. It's just that at no point can we ever say "Well, that's it, our confidence in this belief is now 100%" (even though we can get damned close). Of course, sometimes people say "proved" to mean "supported by evidence to the point that all reasonable people should believe it". In that case, you can prove negatives just fine.
I think that the "can't prove a negative" thing must originate from the subtler "it's hard to confirm the null hypothesis", but even that one isn't a hard rule, so long as you have lots of statistical power.
You're totally correct. I should also consider the fact that you can prove that negative voltages exist. The opportunities for pedantically ignoring the context of the discussion at hand are endless.
You didn't stop at the "discussion at hand". You invoked the general principle of "proving a negative" and Russel's teapot (which is rather naive reasoning in itself).
Well, proving a negative is certainly feasible:
>In some circumstances it can be safely assumed that if a certain event had occurred, evidence of it could be discovered by qualified investigators. In such circumstances it is perfectly reasonable to take the absence of proof of its occurrence as positive proof of its non-occurrence.
>We could then put Mars in the same category as the Moon when it comes to the life hypothesis. This is not the case - so I'd say a search for evidence of life on Mars (past or even present) is justified.
Of course searching for evidence of current or past life on Mars is justified. But there is a huge difference between searching for evidence, and declaring every anomalous discovery to be potential evidence. In addition, the hypothesis "a technological civilization has lived on/visited/probed Mars" is a minuscule subset of the hypothesis "there is, or has been, some form of life on Mars".
There's a [dead] reply taking me to task on my use of the word "superstition" because apparently Wikipedia thinks that superstitions have to be beliefs in the supernatural. Like all semantic arguments, this is boring and dumb, but in point of fact, the first definition in every dictionary I can find supports my usage.
Here's Random House:
a belief or notion, not based on reason or knowledge, in or of the ominous significance of a particular thing, circumstance, occurrence, proceeding, or the like.
You can never completely rule out that possibility, regardless of how much evidence you collect, but it's a matter of semantics at that point. Immediately and without collecting anymore data, we can dismiss the hypothesis that this is non-human technology as unworthy of our attention. It's not merely that the hypothesis has an immense burden of evidence to heft, but that it's a waste of time to even consider it.
Seeing possible evidence of extraterrestrial life in every unexpected observation is nothing more than a superstition.