Oh yeah, some Paleontologists just can not bring themselves to drop that hypothesis. And early studies that showed that idea was wrong were met with fierce opposition.
The White Sands Footprints (22000? years ago)-Cooper’s Ferry in Idaho and Monte Verde in South America go back 14000 years, and even earlier-
The one article I read said that while there are pieces of evidence that humans were in the Americas well before the traditional 14,000 years -give or take - the problem is that evidence for humans spreading and multiplying to occupy the continents widely does not pre-date that. It’s hard to imagine humans failing at the job of “go forth and multiply”, given unlimited vistas, and some big game unfamiliar with humans as a threat (which allegedly led to their demise).
Not sure what more evidence they want. Here’s a graphic from the link Tamerlane gave. Lots of early evidence for the Americas. Admittedly, not all are convincing, as shown by the color coding.
Sorry, I’m late to this thread but after reading through it I’m struck by how fast and loose people are playing with the term “proof.” Saying things like “Newton proved x” seems to contradict my understanding of science. It wasn’t until the post above that anyone even addressed this point. Are we all just agreeing to be casual about what we mean by proof? Does a positive proof even exist in science?
To my way of thinking, scientists should avoid talking about “proof” but it’s natural to adopt the more casual non-scientific usage. Scientists make predictions and try to make observations to disprove them - but in most cases, the observations are better called “good confirming evidence” rather than proof.
Actual scientists and philosophers of science would disagree. Richard Feynman writes here
I come now to an important point. The old laws may be wrong.
How can an observation be incorrect? If it has been carefully checked, how can it be wrong? Why are physicists always having to change the laws? The answer is, first, that the laws are not the observations and, second, that experiments are always inaccurate. The laws are guessed laws, extrapolations, not something that the observations insist upon.
They are just good guesses that have gone through the sieve so far. And it turns out later that the sieve now has smaller holes than the sieves that were used before, and this time the law is caught. So the laws are guessed; they are extrapolations into the unknown. You do not know what is going to happen, so you take a guess. For example, it was believed—it was discovered— that motion does not affect the weight of a thing—that if you spin a top and weigh it, and then weigh it when it has stopped, it weighs the same. That is the result of an observation. But you cannot weigh something to the infinitesimal number of decimal places, parts in a billion. But we now understand that a spinning top weighs more than a top which is not spinning by a few parts in less than a billion. If the top spins fast enough so that the speed of the edges approaches 186,000 miles a second, the weight increase is appreciable—but not until then. The first experiments were performed with tops that spun at speeds much lower than 186,000 miles a second. It seemed then that the mass of the
top spinning and not spinning was exactly the same, and someone made a guess that the mass never changes.
How foolish! What a fool! It is only a guessed law, an
extrapolation. Why did he do something so unscientific? There was nothing unscientific about it; it was only uncertain. It would have been unscientific not to guess. It has to be done because the extrapolations are the only things that have any real value. It is only the principle of what you think will happen in a case you have not tried that is worth knowing about. Knowledge is of no real value if all you can tell me is what happened yesterday. It is necessary to tell what will happen tomorrow if you do something—not only necessary, but fun. Only you must be willing to stick your neck out.
Every scientific law, every scientific principle, every statement of the results of an observation is some kind of a summary which leaves out details, because nothing can be stated precisely. The man simply forgot—he should have stated the law “The mass doesn’t change much when the speed isn’t too high.” The game is to make a specific rule and then see if it will go through the sieve. So the specific guess was that the mass never changes at all. Exciting possibility! It does no harm that it turned out not to be the case. It was only uncertain, and there is no harm in being uncertain. It is better to say something and not be sure than not to say anything at all.
It is necessary and true that all of the things we say in science, all of the conclusions, are uncertain, because they are only conclusions. They are guesses as to what is going to happen, and you cannot know what will happen, because you have not made the most complete experiments.
That is one.
A “proven” theory means it has overwhelming empirical evidence and no contradictory data.
Since the rise of the scientific method, and the application of its methods, no theory that has both overwhelming empirical evidence and no contradictory data has been proven wrong.
Note that Feynman never actually says that Theories are proven wrong.
Isn’t it that everyone agrees you can’t travel at the speed of light? We’re always slower than light, but for all we know there’s something that’s always faster than light..
Is there really any such thing as absolute proof? Mathematical proof come close but, it always starts with some sort of assumption and definitions. Any one who goes through any kind of jury duty hears about legal levels of proof, beyond reasonable doubt, preponderance of evidence, etc. You don’t even need to make it on to the jury to hear about that.
Even scientific evidence that contradicts the accepted theory normally leads to some modifications, not absolute rejection. That would require explaining all of the existing evidence in favor of the current theory.
Even saying “no contradictory data” is too strong. There are always a few oddball experiments that nobody can explain. Most likely they were mistakes. Maybe they were just errors, but extreme outliers on the error distribution. It could even be that they’re falsified. Possibly, just possibly, they’re real signals of some phenomenon that we’re not yet aware of.
There’s a difference between “proven(?) wrong” versus “not a complete description”.
Continents move - that flatly contradicts “continents don’t move” unless you consider that it meant “except in geological time” which does not appear to be what was meant. Similarly, the expanding universe contradicts the steady-state universe.
Meanwhile, Newtonian simple physics is just a simplification of Einstein physics when the special case is velocity, mass, etc. are near to our real-world experience and higher-order changes in the numbers are so miniscule as to be (almost) irrelevant.
In retrospect we can say that “no continental drift” means “no continental drift except at rates so slow it only has macro effects over geological time scales” and “Newton’s laws apply except for every fast motion, etc.” but the people who made the first statement didn’t include the caveat, and Newton didn’t expect any exceptions to his laws at high speed.
The observations that there’s no landmass drift over a human lifespan, and that ballistics are adequately modeled by Newton’s laws are still accurate, but the extrapolations made from those observations failed.
Is this really the current scientific use of the this nomenclature? Overwhelming? I’m pretty sure Karl Popper would be horrified that science has become so sloppy.
In my mind, it takes nothing away to recognize that positive proof is impossible. Ok, I guess if you’re talking to people who insist that legal proof is the same as scientific proof you’ve got to do some explaining, and that’s inconvenient. But I think we should be comfortable recognizing that every positive assertion is falsifiable or it isn’t much use.
There are some “existence proofs” in science that are extremely well established. Pluto exists, as established by a century of photographic evidence and flyby missions, and neptunium exists, as verified every time a nuclear reactor makes it. But I suppose it’s theoretically possible that some combination of mistakes, misinterpretations and fraud have created all this evidence, and that therefore it’s possible that someday the existence of Pluto and neptunium will be seen as scientific mistakes of the 21st century.
And many of them are wrong, but that does not mean they were proven Scientific theories. I mean “The Sun goes around the Earth” was an “old rule” but hardly scientific.
True, and probably a few have, but I can not find any such.
Well, it is a one line version. It is not wrong.
A scientific theory is an explanation of an aspect of the natural world that can be or that has been repeatedly tested and has corroborating evidence in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results. Where possible, theories are tested under controlled conditions in an experiment.[1][2] In circumstances not amenable to experimental testing, theories are evaluated through principles of abductive reasoning. Established scientific theories have withstood rigorous scrutiny and embody scientific knowledge.
A scientific theory differs from a scientific fact: a fact is an observation, while a theory connects and explains multiple observations. Furthermore, a theory is expected to make predictions which could be confirmed or refuted with additional observations. Stephen Jay Gould wrote that: “…facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world’s data. Theories are structures of ideas that explain and interpret facts.”[3] A theory differs from a scientific law in that a law is an empirical description of a relationship between facts and/or other laws. For example, Newton’s Law of Gravity is a mathematical equation that can be used to predict the attraction between bodies, but it is not a theory to explain howgravity works.[4]
The meaning of the term scientific theory (often contracted to theory for brevity) as used in the disciplines of science is significantly different from the common vernacular usage of theory.[5] In everyday speech, theory can imply an explanation that represents an unsubstantiated and speculative guess,[5] whereas in a scientific context it most often refers to an explanation that has already been tested and is widely accepted as valid.[1][2]
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