Would Carl Sagan agree with today's cosmologists about the very young cosmos?

The point of science is that you can apply it to anything. So why not? Just because we can't go back and see it again doesn't mean it's not useful or something worth knowing. What's so different about a fraction of a second then versus now? I'm not really sure why exactly you're upset about this. Something about it has obviously upset you, but why? Scientific models of how the universe and physics work should be applicable to anything, so why not apply them to everything and see what it predicts? That's how we figure things out. There's a ton of evidence to support what we think happened in those fractions of a second, and they actually do make predictions we can test - and we don't know what they are until we check.

"Oh hell, why not go all out and say 10^-86 seconds? Forget Planck time, quarks, speed of light, and quantum mechanics & nuclear physics in general."

Thing is, cosmologists never mention 10^-86 seconds after the Big Bang. In fact the farthest back we go is to 10^-35 seconds which is Planck time when the universe would have been trillions of degrees Fahrenheit based on the assumption that all matter in the universe was once compact. Cosmologists don't say that they know that the universe was compressed with certainty, that is why there are varying theories on how it happened, but the time scale fits the generally accepted model.

Also, we don't have to directly prove that mathematics match reality, we can justify this purely in our everyday experience and we don't need empirical evidence to solve a problem like this, that's like saying you need empirical evidence to solve a crime when all that you need to do is follow the clues.

What you need to do is actually learn about something before criticizing it.

"Can you test whether they match reality? No."

You don't seem to understand falsifiability. It doesn't mean being able to go back in time to test it - if that were the case, then the big bang theory isn't a scientific theory either. We can make observations NOW that either agree or disagree with a model. That's where a theory can be falsified.

It also doesn't mean we must recreate something experimentally. Again, see the big bang theory - the cosmic background radiation isn't something we can reproduce - but it is observation that can be used to falsify a theory.

"This means cosmologists can claim damn near anything they want. I mean, who's going to prove them wrong? Nobody,"

Other cosmologists are the ones capable of debate. Of course, you can't see that because you don't know what you're talking about.

Shut up, learn some science before you open your mouth. Otherwise you look like the fool that you are now.

Hey this has nothin to do with this question. You just answered mine about that guy I hate. I'm not spoiled or a beeyatch. Or nasty. I seriously am not in that group of people. And that kid has already driven me insane. So yeah just saying without giving you points.

Carl Sagan would probably be flummoxed by the magnitude of the straw man you just perpetrated. He would certainly recognize the false premise of your question.

So what's your point. Do we just stop searching for answers and say God made it all? That may be your idea of scientific advance, but it ain't mine.