http://news.bbc.co.uk/2/hi/science/nature/5045024.stm

WTF with "no way could it have been an earth impactor - it must have been a supervolcano or a dust storm or solar radiation or the coming of the Great Handkerchief"

What's the problem with an impactor being another alternative to be evaluated until we can prove one of them?

I think scientists are often the most intolerant folks around.

I don't see that quote on the URL you provided.

"Earth may well have been hit by extraterrestrial objects, but it is unlikely there was some killer punch from space, these other researchers contend."

Why is it unlikely? "Oh sure, we were wrong when we said the OTHER mass extinction wasn't caused by a meteorite. But this one wasn't - we're positive this time."

So why is an adversarial approach OK in the courtroom but not in scientific debate? Surely there is a great similarity since the objective in both cases is to attempt to find the truth given fragmented and sometimes inconsistent bits of evidence?

It must have been concluded over the years that taking opposite positions and attempting to defend those positions against all arguments is a robust way to filter out bullshit and get at whatever can be properly substantiated. So I don't have a problem with scientists taking sides and duking it out in a similar manner.

"Earth may well have been hit by extraterrestrial objects, but it is unlikely there was some killer punch from space, these other researchers contend."

It seems all they are saying is based on the evidence they have, it is unlikely it was a meteorite. "Unlikely" does not translate into "No Way" or "We're Positive" as you seem to be suggesting. Unsure as to why this would rile you up so. Does your religion require that you believe that the earth has been hammered by giant meteorites?

No; I'm just annoyed by a long track record of scientists appearing to be pretty closed-minded - once they're on the track of their line of inquiry, anything that challenges it is met with derision. (Not the universal case, but certainly seems to happen far more often than it should for "enlightened people")

Two mass extinctions on record. When the evidence became pretty compelling that one was caused by a meteorite, it seems to me when looking at the other one you *start* with the earthstrike and look for evidence to rule it out.

There is an assumption here that you're getting a accurate portrayal of the people and positions but you cannot count on that.  There's no story if there's no conflict.  Maybe the media is playing up the disagreements or purposely picking squeeky wheels.

"once they're on the track of their line of inquiry, anything that challenges it is met with derision"

That is the whole point of science. The outside viewpoint gets roasted until there is quantifiably enough evidence to suggest otherwise.

But often it seems the prevailing theory gets a free ride by virtue of being the prevailing theory, instead of "because the majority of the evidence favors it"

Look at the alternative theory described: "The prevailing theory is that several factors - including supervolcanism and extensive climate warming - combined over thousands of years to strangle the planet's biodiversity."

I'm sorry, but that sounds like "We really aren't sure, but it's probably volcanos and global warming and stuff" - and AFAIK, that's just "best guesswork" - nobody's really sure *why* the PT extinction happened.

...except that we're pretty sure it wasn't an asteroid *that* time?

Well yeah, that's how it works. Structure of Scientific Revolutions by Kuhn. Might be annoying in the short term, but in the long term the more probable theory works itself out. Otherwise we'd still be fully grown homocumuli and flies would arise from rotted meat.

The reason that an asteroid was proposed for the dinosaurs was a layer of iridium at the KT boundary. There isn't one at the PT boundary. 

Not all extinction events are down to meteorites - the Holocene Extinction isn't.

because it's anathema to say : "we don't really know for SURE". Even if that is actually the truth.

Well, they actually are saying "we don't know for sure, but probably not." Whereas Philo is adding the absolutism to make whatever misguided point he's trying to make.

I was answering the general case. You didn't expect me to actually read that article did you ... ?

well, the current mass extinction event isn't being caused by a meteorite impact, so maybe we should be searching for evidence of global civilizations, too.

Or at least global domination of one species.
You would have expected some kind of fossil evidence of that by now.

Yeah.

Not when you consider that 70% of dinosaur genera are as yet undiscovered.

http://www.newscientist.com/channel/life/dinosaurs/mg19125684.600-plenty-more-dinosaurs-still-in-the-ground.html

I bet they'll be dead too when they discover them.
Not only that, they will have died around the same time as their fellow d'saurs. (give or take a few million years)

"The reason that an asteroid was proposed for the dinosaurs was a layer of iridium at the KT boundary. There isn't one at the PT boundary."

IIRC, until the Yucatan crater was discovered a large number of paleontologists denied that the KT extinction was caused by an earthstrike, too.

Here's another example - Modified Newtonian Dynamics:
http://en.wikipedia.org/wiki/Modified_Newtonian_Dynamics

The observed angular velocity of galaxies doesn't fit with Newton's equations, so the astrophysics community invented "dark matter" to explain it. There is zero evidence of dark matter except for the observed rotational problem.

Then in 1983 Mordehai Milgrom suggested if you simply make a slight modification to Newton's equation, it properly predicts the observations (and still works with all the experiments done to date)

Hm - 23 years ago. Funny we hven't heard of him or seen this modified equation. Why? Because he's been completely ignored. "In the eyes of most cosmologists and astrophysicists, MOND is considered a possible but unlikely alternative to the more widely accepted theory of dark matter."

Note that there is NO EVIDENCE of dark matter - it's been wholly invented to explain the observed deviations from Netwon't laws, which MOND also does. But since dark matter was "invented" first, it gets the benefit of the doubt.

Now I'll grant that I'm on the outside looking in, but time after time, theory after theory, it seems like new theories or discoveries aren't treated with "healthy skepticism" but rather with scorn and derision, especially if they threaten someone else's research or sacred cow.

Dark matter exists (even I'm with philo on this one and I bet the next year they will said they were wrong on the dark matter thing)

http://www.nasa.gov/home/hqnews/2006/aug/HQ_M06128_dark_matter.html

http://cosmicvariance.com/2006/08/21/dark-matter-exists/

Apparently MOND does not explain the gravitational effects of clusters that well.

With regard to the extinction of the dinosaurs the problem was finding the crater. Once the crater was found (there were two I thought with one being in Siberia) then the meteorite theory was quickly accepted.