From the article:
Actually, facts are useful and important, but they are far from being the most impor- tant elements of a scientific explanation. In science, facts are confirmed observations. When the same result is obtained after numerous observations, scientists will accept something as a fact and no longer continue to test it. If you hold up a pencil between your thumb and forefinger, and then stop supporting it, it will fall to the floor. All of us have experienced unsupported objects falling; we’ve leaped to catch the table lamp as a toddler accidentally pulls the lamp cord.
We consider it a fact that unsup- ported objects fall. It is always possible, however, that some circumstance may arise when a fact is shown not to be correct. If you were holding that pencil while orbiting Earth on the space shuttle and then let it go, it would not fall (it would float). It also would not fall if you were on an elevator with a broken cable that was hurtling at 9.8 meters/second2 toward the bottom of a skyscraper—but let’s not dwell on that scenario. So technically, unsupported objects don’t always fall, but the rule holds well enough for ordinary use. One is not frequently on either the space shuttle or a runaway elevator, or in other circumstances in which the confirmed observation of unsupported items falling will not hold. It would in fact be perverse for one to reject the conclusion that unsupported objects fall just because of the existence of helium balloons.
Other scientific facts (i.e., confirmed observations) have been shown not to be true. Before better cell-staining techniques revealed that humans have twenty-three pairs of chromosomes, it was thought that we had twenty-four pairs. A fact has changed, in this case with more accurate means of measurement."
This is what I wrote in my previous post: Agree, but not completely: Human understanding have change/modified over the years. But the real meaning of the facts still in place. In 1687 Newton’s law of universal gravity define gravity as differently of what Einstein thought in 1915. Although Newton's theory has been superseded, most modern non-relativistic gravitational calculations are still made using Newton's theory because it is a much simpler theory to work with than general relativity, and gives sufficiently accurate results for most applications.
That doesn't mean that they changed. "Adjustments", yes changes, don't think so.
A fact is something that has really occurred or is actually the case. The usual test for a statement of fact is verifiability, that is whether it can be proven to correspond to experience. Standard reference works are often used to check facts. Scientific facts are verified by repeatable experiments.
The understanding have been changed/modified. In this example; "humans have twenty-three pairs of chromosomes, it was thought that we had twenty-four pairs."
That doesn't mean that our first understanding was that we have something else, and them it change to say that we have chromosomes.
Ismael