Why do extraordinary claims require extraordinary evidence?

[JoeTheJuggler]

Interesting. the problem comes then that we are judging by the sensationalism or impact of the claim.

No--it's not at all by the sensationalism, but rather by how costly it is in terms of requiring more explanations. Basically, I'm counting the weight of all the evidence that has already been put forth in establishing those fields of science that would all be overthrown by this purported claim. It's a matter of parsimony.

If someone demonstrates a PMM, it would pretty much mean that the laws of thermodynamics are invalid--despite decades and decades of evidence supporting them. You can bet, if someone demonstrates such a device, I want all the innards exposed and every measure taken to ensure that there's no monkey business going on before I'm ready to accept the claim and toss out (or severely modify) the laws of thermodynamics.

If my ex fudged the measures on her plant revision--unless it was a major overhaul that conflicted with the work of many of her colleagues--my guess is that no one would notice or even care that much. She would be silly to do so (and she wouldn't do so, I must add) since the specimens and measures are all out in the open for anyone to check if they feel the need.

 

[fls]

e.g. the prestige of those in the highest academic positions, corporations that may suffer from new evidence coming to light, the military, academic reputations... basically anyone who has a valuable stake in the status quo, which in practice will tend to be those in authority.

Yeah. The Chinese have enough separation from the US power structure to enable them to use the luminiferous ether for their GPS system. I believe the Europeans, without academic and military independence, have elected to purchase a special license for the use of Relativity.

Linda

 

[athon]

I still think it's the "extraordinary" bit which causes me the problem.

Extraordinary claims require perfectly ordinary evidence, exactly the same evidence as anything else. If ESP exists, it should be provable by perfectly normal criteria of evidence, for example. If goblins live in your wardrobe, normal scientific proof should count.


The extraordinary bit makes it sound like sceptics want more - and mkes us sound unreasonable. Mind you I have forgotten most of the discussions we had about it since i started it back in April! this thread rose from the dead pretty suddenly.
cj x

If you read earlier posts of mine, I'd agree. However, recently I've been thinking of this again, and came to a slightly different conclusion.

If an alleged phenomenom is extraordinary, we'd need evidence to account for why it is extra ordinary. If levitation was real, why is it currently so difficult to demonstrate it as being ordinary or natural? If ghosts are real, why is it so difficult to describe them as such? They are extraordinary claims because they aren't accepted as ordinary things.

The evidence, therefore, needs to account for this. As ordinary things don't need this form of evidence (being ordinary), the evidence itself must be extra ordinary.

I might well be twiddling the semantics here, as extraordinary also has connotations of being more significant, rather than just merely being out of the usual.

Athon

 

[athon]

haha

what you wrote was a complete non-sequitir from what I wrote

Perhaps. Still significant, though. Care to address it, or is it easier for your comfortable beliefs to ignore it?

Athon

 

[schlitt]

By its very nature, the evidence for an extraordinary claim would itself be extraordinary.

If i were to claim i could fly to the moon, and as proof, flew to the moon, collected a moon rock, and was verifiably photographed on the moon.
That evidence would be as extraordinary as the claim.
Really nothing less would be acceptable for you to beleive me.

If however i was to simply state;
"I can fly to the moon, and my evidence is this peice of paper with my friends statement saying he has seen me do it", this evidence is neither extraordinary or beleiveable.

It is just a way of saying if you are claiming something amazing, we will not just accept it at face value.

 

[fromdownunder]

haha

what you wrote was a complete non-sequitir from what I wrote

What an amazingly sceptical response that was. You may actually be learning something

Norm

 

[scotth]

I'm not. You are redefining extraordinary in a sense it does not hold in popular usage.

I am NOT. I am explaining the usage in this instance.

This is what extraordinary means in this usage. Period.

 

[timhau]

it's a built-in bias designed to maintain the status quo and protect vested interests

It's a built-in bias to maintain the status quo the same way "if it ain't broke, don't fix it" is a built-in bias to maintain the status quo.

 

[cj.23]

I am NOT. I am explaining the usage in this instance.

This is what extraordinary means in this usage. Period.

Then it is a meaningless statement, as extraordinary does not mean that in any other usage?

cj x

 

[scotth]

Then it is a meaningless statement, as extraordinary does not mean that in any other usage?

cj x

Look. When Carl Sagan (the populizer if not originator if the phrase) used it, he made quite clear his meaning in the surrounding text.

To argue against any other meaning is total waste of time (and dishonest).

You have now been (repeatedly) informed as to the intended meaning of the phrase. You are free to complain that you don't like his usage, that is fine. But to redefine the phrase contrary to what was specifically elaborated in the surrounding text and then argue against the redefinition is a (can you guess?) strawman falacy.

Words and phrases can often have meaning other than their most common in certain contexts. This is one, get over it.

 

[Miss Whiplash]

The phrase has never bothered me and is self explanatory. From the interview with Sagan posted by Beady:

..It would be an absolutely transforming event in human history. But, the stakes are so high on whether it's true or false, that we must demand the more rigorous standards of evidence. Precisely because it's so exciting. That's the circumstance in which our hopes may dominate our skeptical scrutiny of the data. So, we have to be very careful. There have been a few instances in the [past]. We thought we found something, and it always turned out to be explicable... - Carl Sagan

(my bold)

Simply, claims that challenge the laws of science must have irrefutable proof to back them up.

 

[Miss Whiplash]

e.g. the prestige of those in the highest academic positions, corporations that may suffer from new evidence coming to light, the military, academic reputations... basically anyone who has a valuable stake in the status quo, which in practice will tend to be those in authority.

Tell us about the status quo. Is there some hidden cabal of skeptics controlling the world? Are they reptilian?

 

[timhau]

Is there some hidden cabal of skeptics controlling the world?

Don't tell me your cabal meeting invitation got lost in the mail. It's your turn to bring the Christian children this time!

 

[Hellbound]

Interesting, I just composed a post that touch on this issue here.

Specifically, this part:

As to the weight of evidence required, this does vary. If someone says "I had a hamburger for dinner last night", I really don't need any evidence to accept this as likely true. People eat dinner, hamburgers exist, and they're fairly common and easy to get. No known physical laws are broken or even stretched, and (assuming I know the person and they like hamburgers) there's no reason to doubt the statement.

Now, take something like "I can read minds instantaneously by quantum entangling my brain with someone elses". This requires a heck of a lot more evidence. In this simple satement, the two best-tested theories in the history of physics, relativity and QM, are both violated. They'd have to be wrong. IN this case, the weight of evidence required to accept this claim as true would, reasonably, be equal to the weight of evidence that currently exists for relativity and QM. That's a lot more than one study out of hundreds, or a 5% confidence level in a statistical study. Similar arguments apply for ghosts, UFOs, life-after-death, and others. They either posit things which would violate known, well-tested laws...or they posit things that, even if true, would be (by their own definition) impossible to ever discover...which means they cannot affect the observable universe in any detectible fashion.

And that, IMHO, is what is meant by "extraordinary evidence". For example, take a claim that would require time dilation and mass increse in relativity to be wrong. Seems like a small thing. However, these are part of the basic equations of relativity, so the entire theory would have to be wrong for the new idea to be right. This makes it an extraordinary claim. Not only is it new, it is contrary to existing, very well tested physical law. It needs more evidence than a new theory that didn't overturn existing ones. It needs MORE evidence than the theory it will overturn (or direct, repeatable evidence that the old theory is incorrect). This is not required in claims that don't violate existing laws.

Likewise, a claim that is new needs more evidence than one which isn't. For example, claiming "I've discovered a graviton" requires more evidence than "I've isolated an electron". IN the previous case, we want to know how. It's been tried, and no one's been able to do it yet. You need to show the entiore process, including results, to "prove" this claim In the second case, procedures are relatviely well-understood and this has been done multiple times. Simply showing results from your equipment is enough to "prove" this claim.

 

[cj.23]

Look. When Carl Sagan (the populizer if not originator if the phrase) used it, he made quite clear his meaning in the surrounding text.

To argue against any other meaning is total waste of time (and dishonest).

You have now been (repeatedly) informed as to the intended meaning of the phrase. You are free to complain that you don't like his usage, that is fine. But to redefine the phrase contrary to what was specifically elaborated in the surrounding text and then argue against the redefinition is a (can you guess?) strawman falacy.

Words and phrases can often have meaning other than their most common in certain contexts. This is one, get over it.

Can you cite his original usage? I read the explanation offered very reasonably from The Vampire, but I am unaware of the original context? Truzzi originated the phrase, not Sagan, so I'd be interested to see hsi original context as well.

And no I'm not dishonest. The phrase is not usually employed with reference to it's original context, so appears on the face of it misleading.

This is no strawman. Please calm down. It's not a dogma, it's an aphorism which may or may not be useful - it's utility is all we are interested in establishing, and I'm pretty sure before the thread was revived it was explained well, but I have to run to catch a train - so I'll read it back tomorrow, and quite probably concede, as i can't recall what was written in april!

cj x

 

[Hellbound]

it's a built-in bias designed to maintain the status quo and protect vested interests

You are just almost right here. It's interesting how you can be so close to correct, but yet utterly wrong at the same time.

It is a built-in bias of science, yes. It is designed to maintain the satus quo (to a degree). It is not because of vested interests. And that's a good thing.

The built-in bias prevents us from wasting resources haring off after every hair-brained scheme and idea that anyone puts forth. It's a bias that requires evidence at least equal to that of the theories and ideas it would overturn. It's a bias that keeps us from changing direction every month or two when someone claims to have proved something else on the basis of a couple questionable studies slectively chosen from hundreds done, and claim that this somehow trumps the literally thousands upon thousands of studies that support thoeries in direct opposition.

Someday, perhaps, you'll understand this. But I suspect your own built-in bias prevents you from viewing the evidence evenly. So far, you've shown you can't even view the actual position you're arguing against correctly.

 

[Steven Howard]

Truzzi originated the phrase, not Sagan

Truzzi wrote "Extraordinary claims require extraordinary proof." Sagan paraphrased Truzzi, changing proof to evidence. Truzzi himself was paraphrasing David Hume and Pierre-Simon Laplace, as he says here:

In his famous 1748 essay Of Miracles, the great skeptic David Hume asserted that "A wise man...proportions his belief to the evidence,"and he said of testimony for extraordinary claims that "the evidence, resulting from the testimony, admits of a diminution, greater or less, in proportion as the fact is more unusual." A similar statement was made by Laplace, and many other later writers. I turned it into the now popular phrase "extraordinary claims require extraordinary proof" (which Carl Sagan popularized into what is almost the war cry of some scoffers).

 

[strathmeyer]

haha

what you wrote was a complete non-sequitir from what I wrote

plumjam, I want that $20 you owe me.

 

[scotth]

cj, it is past time that you go read Demon Haunted World for yourself.