Mark _australia said..
^^ Yes indeed they are.
So let's think about anything that analyses a spectrum, say a GC mass spectrometer in a lab. The tiniest bit of crap in there will ruin the results.
Or the level of cleanliness required of all kinds of measuring equipment with vacuums or dry gas purged environments blah blah cos even water vapour will skew results.
If you believe that in 10K light years - an unimaginable distance full of dust n gasses etc - that there is no interference then you have a lot of faith.
You can't extrapolate or calculate for such errors as you can only do that if somebody has been to the site (ie so we know what is there and then the readings from here so we KNOW what the error is.
Bit like if I say an object at about 1km away is 20m high and we have no frame of reference. You would not believe me and rightly so.
Faith.
Well yes. I'm no expert but the scientific community displays utter confidence in spectrum analysis. They've been doing it for yonks. They know the problems etc and science is self correcting so I believe they know what they are doing and the probability that they are wrong when they make a strong assertion based on well established techniques is vanishingly small. It's not just alcohol that they have discovered. There are many organic molecules out there.
You can call it "faith". It would be churlish of me to assume you are attempting to disparage reasonable confidence by conflating it with religious "faith" so I will just assume you're not :)
