Direct and indirect evidence in science

Direct evidence for a conclusion are facts that establish the conclusion without any need for drawing inferences. In the strict sense, the only direct evidence is eye witness testimony of the conclusion. Maybe a video recording can be considered direct evidence.All other evidence is indirect. And using the strictest definition, all but the simplest scientific theories, and essentially all scientific facts are established indirectly. For example, we don't have direct evidence that the sun produces energy by nuclear fusion, because no one has ever even seen an atom. There is no direct evidence that hydrogen even exists on the sum. We know only indirectly that the earth has an iron core. The distance of the earth to the moon is measured indirectly. On the other hand, we know from direct evidence that the moon is more than an arm's length away.When you take the temperature of the inside of a roasting turkey with a meat thermometer, you indirectly infer that the turkey has a given temperature given the thermal response of some element within the thermometer.A radar gun measures your car's speed indirectly.Usually, we don't use indirect and direct so strictly. Instead, we say that facts are determined directly when there is some acceptably straight forward and nearly indisputable inference. Of the examples I've given above, some people would consider that measuring a turkey temp with a thermometer is an example of direct evidence of the turkey's temperature.Among theories we don't have direct evidence for are that cigarette smoke causes cancer, that HIV infection causes AIDS, or that human activity affects the global climate. Interestingly enough, many Creationists won't find those examples very convincing because they doubt that one or all of those conclusions are true.Absent a time machine, we'll never be able to see a human evolve from some ancient ape that is a common ancestor to humans and chimps. All of the genetic and fossil evidence for that conclusion areOn the other hand, there is evidence that micro-organisms evolve, and some of it would probably be considered direct using a non-strict definition. Indirect evidence is good enough, because there is nothing wrong with drawing correct inferences from data, and because we can falsify theories by making predictions of the indirect evidence we should not expect if the theory was correct. Yes, we can and should question the inferences, but to pretend that making inferences is always unacceptable is wrong and probably dishonest. It's actually far easier to come up with examples theories based on indirect evidence than it is to come up with theories based on direct evidence. Perhaps a good debating tactic would be to discuss and debunk claims that other branches of science use direct evidence.Creationists do not believe in evolution because they believe it contradicts the Bible. They are not going to change their minds even in the face of direct evidence, but they can pretend to be open minded by saying that direct evidence would be convincing.

I only said maybe. [qs]How about an electron microscopy of a cell, would that be considered direct evidence of a cell?Perhaps. Evidence can be direct for one conclusion but require inference to be drawn to reach a different conclusion. We might accept an electron microscopy image as direct evidence of a virus, but indirect evidence that the virus causes some particular illness. Probably not. You need some inferences to get from spectra to atoms and molecules. Yes. But most people accept the inferences as being minor as long as fakery can be eliminated. If you want to call it indirect, that's fine with me. You are exactly right. Creationists have no problem with inferences that don't conflict with dogma. That's debatable in my opinion. Do you consider views through optical telescopes and microscopes to be indirect? How about electronically captured images viewed in essentially real time? Are photographs direct evidence? I'd suggest that those things are direct evidence for whatever is captured in the image. Good luck with that. The entire argument is just stupid apologetics anyway. Labeling evidence as indirect is his current excuse for rejecting evolution. He'll find others.

Nobody cares what you label you use, or what branch of science is used. Unless you can give some reason why a particular branch of science is invalid, and you never do, then evidence from that branch of science can be combined with evidence from any other branch of science. If you don't like the term biological research, then call it scientific research.

Got any evidence that Byers is a flat earth believer? I did a quick Internet search that turned up a bunch of goofy Robert Byers posts in the same vein as his stuff here, but no flat earth assertions.