To predict something scientifically, you do not necessarily need to have the entire equation fully defined.
That's bad phrasing. Better to put it this way: To predict something, you don't need to have the entire equation fully defined. But the prediction is just that: A prediction, which may have a highly variable outcome, somehow related to the nature and scope of the unknown or poorly understood variables in the equation that determines the outcome.
To state something is a scientific fact, indisputable, based on the natural laws of the universe, you do, in fact, need to have the entire equation fully defined. A belief in the outcome of an unscientifically defined prediction is a matter of faith.
But the fact that I can't fully define the entire process doesn't mean that I can't make scientifically accurate predictions regarding the results based on what I do know.
Again, bad word choice. You might make accurate predictions, but they won't be based on scientific method. There is an important difference.
For example, I can predict with scientific accuracy that the offspring won't be a kangaroo.
You are inventing phrases to lend the credibility of scientific method to prediction. "Scientific accuracy" is a meaningless term. The kind of term the media invents to misapply the label of science to matters that are less defined than science.
I can also predict, based on knowledge of breed characteristics, dominant/recessive traits, etc., what the offspring will likely look like--and based on that knowledge, and on whatever knowledge I have about the bloodlines of the parents, I can even express scientifically accurate predictions on the likelihood of those characteristics.
When you can define all of the inputs and precisely state the output for all of the traits you listed, and do it repeatedly in controlled circumstances, that is a scientifically validated outcome. Educated guesses don't count. You are confusing hypothesis and theory. You are making a hypothesis. If you can repeatedly show it happens with 100% certain by demostrating it in a controlled way, you have a valid scientific theory.
This is one of the biggest problem I have with some of the global warming deniers--many of them try to claim that because we don't know every detail of how the climatic universe works, it's impossible to make any objective, scientifically-based predictions regarding what is going to happen. And this simply isn't true.
There is a huge gulf between making educated guesses and proving something by scientific method. Anthropogenic global warming is a hypothesis, and any objective scientist, when presented with all available data and potential unknowns, will identify the problem as dramatically under defined. There are enormous unkowns and contradictory data.
Bill, take a look at the track record of long term prediction throughout history. Horribly inaccurate.