Are you ignorant of the big bang theory or do you deny it?

Do you think that science can only deal with things that we observe?

Are you pulling my leg?

: Believed to be.

For good reason. This stuff isn't just a matter of opinion. We have the microwave background radiation and direct observation of the spectra of distant stars.

: No, you believe that to be true, because you weren't there, and no one else
: was.

This is scary stuff, you are in denial of the very basis of scientific thought. And you sound like Ken Ham (and that is not good). We don't need to directly observe something to be reasonably sure that it happened. And in astronomy we have the advantage that we can look back in time to see the state of the universe soon after the big bang. So, in a sense, we are there.

: The framing of the events you describe have, as I've explained, not
: been observed and repeated , only presented together as an explanation
: of past events that must be trusted as truth, based on presumptions about
: the past. However "reasonable" the explanation may be, it is
: none-the-less, an explanation, not a direct observation.

There is no such thing as a direct observation: there are only conclusions based on interpretations of sensory impressions. You are making a false dichotomy.

: And I fully expect you think I'm stupid or ignorant for not jumping on the
: bandwagon, and for thinking critically (which btw does not include
: disbelief) about any explanation of past events, whether yesterday, 1000
: years ago, or 1 billion years ago. It simply means realizing that any
: explanation for an unobservable event - no matter how reasonable the
: explanation - may change at a moment's notice.

You are throwing the baby out with the bath water. In an attempt to avoid being too certain you have devalued what we do know. You have come to a position were all assertions have to be treated the same. Nonsense now has the same weight as reasoned evidence and validated observation.

: Do you believe in magic? I don't. I just believe what I see.

Have you seen the vital spark? If not then stop believing in it.

: And yet, we have this term "biological" which is a basic term we
: use to refer to things that are classified as "living
: organisms". So. How do you separate biological from non-biological?
: Seems like you're saying there is no difference. Scientists say otherwise.

We have a set of rules that we use to try to delineate the two cases but we know that the rules are flawed. They don't work perfectly - for example: are viruses alive? But we understand the problems and find the effort worthwhile.

I don't have access to a text book but the criteria are (roughly):

• metabolism
• perception (reacts to stimuli)
• motility
• reproduction

The rules are deliberately vague because we generally know it when we see it and it usually doesn't matter if something doesn't entirely fit. And note that the textbooks don't include 'vital spark' in the list.