I've heard multiple explanations for what exactly killed the dinosaurs off, and every time the person giving them has been fairly certain and had a good explanation for why. Hearing another explanation is always going to make me skeptical now. Edit: To give some more details this still doesn't explain why dinosaur specie diversity was going down before the impact, or why no small non-avian dinosaur species survived anywhere in the world when so many mammal, reptile, and avian-dinosaur species did.

Thank you for your response.

I am asking because I am interested in the communication and presentation of scientific results to diverse audiences.

I have observed that the notion of 'current best explanation for the observed results' can be misinterpreted. All science is the process of people trying to find an alternate explanation, other than the one proposed, that fits the evidence and can make predictions about evidence that has yet to be found. It is the totality of the observed facts that the explanation explains, and the ability to accurately predict other facts that will be found assuming the explanation is the one that really explains things.

What I've observed is, as you have described, that during the evolution of the scientific investigation, especially when hypotheses are shown to be incomplete and are updated, that communication is heard as a "different" answer rather than as a more refined answer. As my daughter observed about meteorologists predicting rain, "they don't really know, they are just guessing." And that is true with all science, there is no Arc of Knowledge where we can look up the answers to the questions in the back.

The author of the article clearly felt convinced, based on the evidence presented, that this hypothesis about the events that took place is the most accurate idea we have to date. And they showed how other possible explanations had been explored, how predictions (about Iridium) had been made and validated, how estimates of mass and size were made, how the physics of the impact compared to those on other planetary bodies that don't have erosion, Etc. And that confidence they felt came across as 'certainty'.

And yet, their own confidence and their sharing of how they came to have that confidence is off putting. Which is, I am fairly certain, exactly the opposite of what the author had hoped for. They had hoped to share their understanding so that the reader could be confident in their own belief that this is, to the best of our knowledge, exactly what happened so long ago.

I too am interested in this. I have a grandfather who is otherwise thoughtful and open-minded and exceptionally intelligent, but he finds the asteroid impact theory of extinction completely impossible. Attempting to convince him has been fun in that we have a good relationship and he'll readily respond to me without turning it into a fight. If I can learn what works and what doesn't when changing his mind with available evidence, then that might work with other more difficult people.

In his case, there are a few issues:

1. Related to the other commenter's point, he's not fond of statements of absolute certainty. He likes to say, "well, we weren't there, were we?" I liked the article a lot, but I can see how it was doing really well right up until the very end, where it accelerated into story mode. Everything before that was more carefully written; "we think this because...", "it could have been this other thing, but probably not because...". For people willing to consider evidence that runs contrary to their belief system, a preponderance of evidence coupled with consideration of differing opinions is way more convincing.

2. It stretches the limits of his imagination. On human scales, imagining a global catastrophe like this can be difficult. Media, artist's depictions, CGI and so on don't seem to help much here (caveat: unless they're really, really good). Examples from other parts of the solar system do help a little.

3. He wants all of his questions answered. From that standpoint, this article is excellent. People want puzzles tidied up into nice, neat little arrangements with a bow on top. Why did some things survive and others didn't? If it just got really cold, why did the dinosaurs in the ocean die out? If it was so big, why can't we find the asteroid that did it? Weren't things already dying out anyway? What if the dinosaurs just got so big that they couldn't reproduce anymore? These are all actual questions he's had. It can be a very frustrating dialogue for scientists and the science-interested, where we learn not to expect answers to all questions right away and any answer that begins with "I don't know" is regarded as evidence contrary to the theory, but the more answers that can be provided, the better, even if they're our best guess at this time. So then you have to know your subject matter really, really well, better than the majority of hobbyists do.

4. Constant exposure helps a lot. I think people that become comfortable with lack of certainty also tend to become averse to argument and conflict, and that doesn't help their cause in the long run. You have on the one hand someone who will argue a case from a position of ideological certainty, and on the other hand someone who says "maybe" and "we don't really know" and "at this time we think" a lot. If you know nothing about some given subject, who would you tend to believe? Imagine it's someone presenting arguments for a subject you have tenuous opinions about, but not a lot of expertise or domain knowledge. I think this is why people like NDT and Nye and Dawkins are more popular in the mainstream while being somewhat distasteful among other intellectuals. They present evidence-based views with the same conviction and tonality and theatre as you might expect from a preacher.

That last point runs somewhat contrary to the first, but I think there's a happy medium where I can just send grandpa a really good article, like this one, about once a week or so, and say, "here, this does a good job of answering some of your questions, what others do you have?"

Earlier explanations of the dinosaurs' demise were pretty speculative. Impact and Deccan traps volcanism were the about the only hypotheses that had specific physical evidence to support them.

According to Stephen Jay Gould, it turned out that the claim of declining dinosaur (and ammonite) diversity was exaggerated through poor statistical analysis, failing to account for the fact that a species' last appearance in the record does not mean that it became extinct immediately afterwards. Furthermore, when paleontologists specifically looked into diversity up to the boundary, they found it. Diversity is always changing, so some decline beforehand is not fatal to the theory.

Gould also believed that many geologists resisted the impact hypothesis on the basis of a somewhat dogmatic objection to 'catastrophism' in any form. This kept competing theories alive longer than perhaps they should have.

FWIW, I am not entirely satisfied with the explanations of how some classes (especially birds) survived, but in any case there were not so many survivors; terrestrial vertebrates came fairly close to total extinction. When the odds are long, chance can make a big difference.

Journalists often want a simple story to tell, and the myth of the dispassionate, objective scientist is largely just that: they will present the ideas they favor in the best light that evidence permits, and sometimes beyond. Furthermore, the evidence increases over time, whether for or against a hypothesis. When a hypothesis accumulates more, and more diverse, evidence consistent with it, its plausibility goes up, and if you want an informed opinion (of anything), you have to follow those developments.

Thank you for this response. I am really interested in your first sentence.

As I understand your response, I paraphrased a description of the scientific method and you were affronted by it. Is it science in general?

Your last paragraph was especially illustrative for me, while I am not familiar with a "fallacy of accepting the alternative" as I read it, your statement "rejecting one hypothesis is not evidence in support of any particular other hypothesis" does not explain to me the evidence you used to reject one hypothesis over another.

Please correct me if I'm wrong, but it reads like you feel that any hypothesis would be acceptable as an alternate. However that is not true, either in science or in Sherlock Holmes novels. As you probably know, in a Sherlock Holmes story at the end is the big reveal in which all of the facts are put together by the detective so that all of them can be true at the same time. Sometimes he does this by finding an additional clue which binds together two seemingly unrelated bits of evidence. But the great detective would not entertain a theory that the "Easter Bunny did it" in the absence of any possibility that the Easter Bunny could have done it.

In order for an alternative hypothesis to be considered valid by a scientist, it must first explain every fact that we already know to be true. Further, if the alternate needs an entirely new thing that hasn't been discussed before (your "God of Winter" for example), then it also has to have the evidence that was used to establish that new thing. As a scientist you have to accept that your hypothesis and your new thing will be challenged until nobody can find a single fact that would have to be different or a way in which your evidence can not be verified or reproduced. Of course during that process of challenging a lay person might hear one scientist who supports on hypothesis and one who supports a different hypothesis.

But would this be offensive to you? And if so what generates the offense? The lack of an answer or the multitude of answers?