> Truth is relative.

This is a dangerous misconception to be spreading. It is not at all related to your other claims, namely:

> Sampling can skew results. Scientists are people too. We all have flaws.

These are of course correct statements. But they do not influence truth. They may well influence people's understanding of what the truth is, but that's different.

If you really believe truth is relative, walk to the grocery store tomorrow without wearing clothes and convince yourself that it will be fine. Or run a lighter under your hand - maybe it won’t burn today? Of course you wouldn’t to those things though because, at the end of the day, we rely on truth for everything we do. We just don’t always know what it is. Relativism is not the same as “it’s hard to figure out because it’s so complex”

Are you implying that the probability of someone going to a store named and getting out of it without harm is zero? There’s plenty of photographic and video evidence of the contrary. Probably not the best example.

Same for a lighter, there are many factors involved, and playing with lighters that way was a party trick where I grew up.

We use truth as a concept every day as an approximation, but the universe is not bound to follow. Very unlikely things happen all the time.

Truth is an unhelpful concept anyway (in science at least). What’s more useful is the likelihood to get a given result from a given experiment and the ability to make predictions.

And yes, when we put things that way it brings a lot of possible issues with sampling, processing, and measuring (and who’s doing the measuring). Some of these things would be harder to control for in a study of the effectiveness of advertising.