Extraordinary claims require extraordinary proof

[robinson]

The researchers said yesterday that visible and detectible matter -- the atoms in everything from gases to elephants and stars -- makes up only 5 percent of the matter in the universe. Another estimated 20 percent is subatomic dark matter, which has no discernible qualities except the ability to create gravitational fields and pass through any object without leaving a trace. The rest, they said, is the even more mysterious dark energy, which fills empty space with a force that appears to negate gravity and push the universe to expand ever faster.

http://www.washingtonpost.com/wp-dyn/content/article/2006/08/21/AR2006082101139.html

Everything we know, everything we can detect, is only 5% of the entire Universe! - Extraordinary claim!

20% of the Universe is something we can't see or detect, that doesn't obey the laws of physics, except it has mass, but passes through everything, including itself, and leaves no trace. - Extraordinary claim!

75% of the Universe is energy that defies known laws of physics, it negates gravity, can't be detected, and causes the entire Universe to go faster, with no known source for the energy involved in causing that! - Extraordinary claim!!!

The evidence is circular, these things have to be there, to make the formulas work. The formulas are based on what is observed, but they don't work, so these extraordinary "things" are believed to exist, or the formulas are wrong.

The "proof" then is observation of celestial events that are a collision between an enormous cluster of galaxies more than 3 billion light-years away, which proves dark matter (and dark energy) have to be real. Because, once again, the theories that predict what should happen are wrong, unless invisible matter and energy is there.

I'm not saying there is no unknown or invisible "stuff" in the Universe. Or that there is nothing strange going on, especially in regards to gravity, light and really big clusters of really big objects rotating and smashing into each other, billions of light years away.

I'm saying Extraordinary claims require extraordinary proof, and claiming observations of unexplained stuff billions of light years away is nowhere near extraordinary proof.

Yet I read people already claiming "dark matter" has not been disproved!

It is like claiming nobody has disproved there is a God, or Demons, or Angels or something. It is putting the cart before the horse. Sure you can shove the cart along with a horse behind it, but people are going to look at you funny, because it doesn't work that way. You don't get to claim something like this is real, then start saying nobody can disprove it!

No, you are required to provide extraordinary proof. And lots of it.

I've heard some whoppers before, but claiming that 95% of the entire Universe is invisible mythical "stuff" that defies all known knowledge about matter, energy and the laws of Physics, is without a doubt an Extraordinary claim. It is about the most Extraordinary claim I've ever heard.

Why would skeptical inquiry give such a claim a free pass? Discussing this with "skeptics" who claim to be scientific in their views, is like running across true believers online.

It is amazing. No really, the insults, the name calling, the diversions, the lack of evidence, the claims that the scant evidence is "overwhelming", or that it "has to be true" is like debating a religious person.

 

[seayakin]

First, my caveat, I only have had a high school physics course and one college level astronomy course (20 years ago) and the only other knowledge I can claim is that I have read and understood parts of scholarly articles and books on the topic.

However, if my understanding is correct, there have been no specific claims about what dark energy and matter are except that certain unaccounted for forces or force are need to explain the observed evidence of an ever expanding universe. I still have trouble understanding how this was deduced but leaving that aside, this seems similar to how other objects in our solar system were deduced to exist and then found due to mathematical calculations based on perterbations of the orbits of known planets and other objects.

 

[ben m]

20% of the Universe is something we can't see or detect, that doesn't obey the laws of physics, except it has mass, but passes through everything, including itself, and leaves no trace. - Extraordinary claim!

Um? Dark matter obeys all of the laws of physics. It has mass, responding to and generating gravity in the totally normal way. We already know about particles that "pass through everything, including itself"---they're called neutrinos, they're extraordinarily reluctant to interact, and we can only detect them because they can be created (by the Sun, reactors, and accelerators) in incredibly large numbers. Once you know that neutrinos are real, dark matter should be no surprise---it has almost exactly the same properties as a very-massive neutrino. If you think that "passing through everything" somehow breaks the laws of physics, you're wrong.

75% of the Universe is energy that defies known laws of physics, it negates gravity, can't be detected, and causes the entire Universe to go faster, with no known source for the energy involved in causing that! - Extraordinary claim!!!

Agreed. That's why we didn't believe it until we had extraordinary evidence---that evidence being the direct SN1a observations. The rest of cosmology had been hinting at the 75% dark energy for a long time, but many people didn't believe it because it was an extraordinary claim. but now we have extraordinary evidence. The fact that you "think it's weird" is hardly compelling. Am I misrembering that you're the JREF poster who couldn't believe that flashlight beams are made of photons? Exactly how reliable is your personal "weirdness" detector, anyway? More or less reliable than, say, Saul Perlmutter's data analysis team?

The evidence is circular, these things have to be there, to make the formulas work. The formulas are based on what is observed, but they don't work, so these extraordinary "things" are believed to exist, or the formulas are wrong.

Sorry, wrong. We have lots of tests of General Relativity, both on Earth and in nearby space. GR has one free parameter, "G", which is tuned to match the data---everything else agreed with no further tuning. This is called "science". You come up with a theory (fitting parameters to data if necessary), make predictions, and future observations are supposed to agree with those predictions. That's how we know GR. Ditto for cosmology. The Hubble parameter was not invented to gin up agreement with the Cosmic Microwave Background---the Hubble constant was pre-measured, and it made a prediction for the CMB, and the prediction was confirmed. Ditto for dark matter---Fritz Zwicky made a prediction which was confirmed by Vera Rubin, the CMB, LSS, and so on. Heck, that's how we know that Earth goes around the Sun---multiple lines of evidence all agreeing with a single model.

It is amazing. No really, the insults, the name calling, the diversions, the lack of evidence, the claims that the scant evidence is "overwhelming", or that it "has to be true" is like debating a religious person.

It's more like you walking into my house and saying,

You: "Your dog has fleas."
Me: "Hang on, I've lived with this dog for ten years, I'm a doctor of veterinary medicine, and I did three separate flea tests over the past week."
You: "I dunno, lots of dogs have fleas, I bet your tests were wrong."
Me: "Shall I show you my test results?"
You: "Meh. Fleas are invisible anyway, you're probably missing them. You're going to have a hard time convincing me that your dog doesn't have a single flea."
Me: "Um? Fleas are not invisible."
You: "Oh yeah? How do you know? Someone who doesn't know that fleas are invisible and can teleport has no business making wild claims about flealess dogs."

Arrrrrrgh!

 

[baron]

A general comment: I've never bought that the "extraordinary proof" referred to in that phrase should refer to proof that is someone more stringent than proof required for anything else. That would require experimental design to be based around subjective judgement. It would require statistical threshholds to be altered dependent on the perceive weirdness of the phenomenon being studied.

The proof is extraordinary only by proxy.

However, I do agree that the claim in question is extraordinary, in a subjective sense.

 

[MattusMaximus]

Why would skeptical inquiry give such a claim a free pass? Discussing this with "skeptics" who claim to be scientific in their views, is like running across true believers online.

Skeptical inquiry doesn't give claims about dark matter and dark energy a free pass. You have to understand that these ideas, though they have only recently made their way into the public consciousness, were being knocked around long ago in astronomical circles. It took many years for the scientific community to accept these ideas, and many of the details are still being explored with strong disagreements about the nature of these things.

And yes, there is strong and consistent evidence for dark matter...

http://en.wikipedia.org/wiki/Dark_matter#Observational_evidence

... and here's more info on dark energy and its discovery...

http://en.wikipedia.org/wiki/Dark_energy#Evidence_for_dark_energy

So yes, these are extraordinary claims that qualify as "weird" - but I should note that quantum mechanics is pretty damn weird, yet we know that it accurately describes the small scale structure of our universe. We know that quantum mechanics works so well, in fact, that you and I are both using computer technology that was a direct result of that theory.

So just because something is "weird" doesn't mean it's wrong, it just means it's outside of our everyday experience.

Check out those links I provided on dark matter & dark energy. I know it's Wikipedia, but it'll be a good place to start for a layperson. One more cool link to check out is this one about the Large Hadron Collider coming online at CERN; it is hoped that the LHC could be used to probe the nature of dark matter and dark energy...

http://en.wikipedia.org/wiki/Large_Hadron_Collider

Enjoy the reads!

 

[sol invictus]

Robinson, please enlighten us: what do you think is a claim about the universe that is less extraordinary than the existence of dark matter and dark energy plus general relativity?


(Before you answer, please bear in mind that any claim which conflicts with observational data is almost certainly more extraordinary than one which does not, since it requires all that data to be wrong.)

 

[shadron]

Everything we know, everything we can detect, is only 5% of the entire Universe! - Extraordinary claim!

20% of the Universe is something we can't see or detect, that doesn't obey the laws of physics, except it has mass, but passes through everything, including itself, and leaves no trace. - Extraordinary claim![/QUOTE

Robinson, I'd say that you lack perspective in this extraordinary claim field. Before Galieo, no one had any concept that there was anything Out There but the visible stars and the planets. In one stroke our universe was added to by a factor of thousands as stars were found in what was presumed to be some kind of cloud - the Milky Way. Similarly, until the stars in the Andromeda galaxy could be resolved (less than 100 years ago) there was no evidence of anything beyond the Milky Way galaxy's edges, and all of a sudden the universe expanded by a factor of billions (conservatively). That makes this 20-fold increase in matter rather trivial, doesn't it? Would you have considered the resolution of stars in Andromeda to be extraordinary evidence, enough to justify a billion-fold increase in the matter of the universe? Hmmmmm?

Obviously not, yet it was correct.

 

[robinson]

It's more like you walking into my house and saying,

You: "Your dog has fleas."
Me: "Hang on, I've lived with this dog for ten years, I'm a doctor of veterinary medicine, and I did three separate flea tests over the past week."
...

That is so wrong. It is like this:

You: "My dog has invisible fleas."
Me: "Hang on,there is no such thing as invisible feas."
You: "I dunno, lots of dogs have fleas, I bet there are invisible fleas."
Me: "How can you say that?"
You: "Fleas are invisible anyway, you're probably missing them. You're going to have a hard time convincing me that my dog doesn't have a invisible fleas."
Me: "Um? Fleas are not invisible."
You: "Oh yeah? How do you know? Someone who doesn't know that fleas are invisible and can teleport has no business making wild claims about dogs with invisible fleas!."

 

[robinson]

To continue:

You-There has to be invisible fleas. We eliminated all fleas, and the dog still scratches.
Me-It could be something else.
You-Nonsense. There is nothing else that can make a dog scratch.
Me-Sure there is.
You-No, there is not. It has to be an unknown flea.
Me-It could be another skin condition.
You-Nonsense! There is no other reason a dog scratches like that!
Me-Sure there is.
You-No. And since I'm sure there are invisible fleas, you can't prove otherwise.
Me-What is your proof?
You-We have observed several dogs scratching, and they have no fleas!
Me- Uh, are you on any mediciation?

 

[This is The End]

Define visible....... and switch small with unfathomably tiny!

 

[robinson]

Hey! He started in with the invisible fleas. It's not my problem.

 

[robinson]

It is sort of like a rule. If you make some kind of Extraordinary claim, we get to demand extraordinary proof. Trying to switch the situation, and claiming now we have to disprove the Extraordinary claim, is not allowed.

 

[tkingdoll]

Only because 'extraordinary' means 'not ordinary'.

Richard Wiseman puts it something like this:

If I tell you there's a red car parked outside my house, you'd probably believe me without any further enquiry, because red cars parked outside houses is a common sight and I have no reason to lie.

If I tell you there's a UFO parked outside my house, you're probably going to want to check that out for yourself.

 

[sol invictus]

I repeat:

Robinson, please enlighten us: what do you think is a claim about the universe that is less extraordinary than the existence of dark matter and dark energy plus general relativity?


(Before you answer, please bear in mind that any claim which conflicts with observational data is almost certainly more extraordinary than one which does not, since it requires all that data to be wrong.)

 

[robinson]

If I tell you there's a UFO parked outside my house, you're probably going to want to check that out for yourself.

You-There is a UFO parked out front.
Me-what?
You-A UFO! In my driveway!
Me-what is a UFO?
You-You know, an unidentified flying object!
Me-what? what does that even mean? Did you see it fly? Did it land?
You-No, it is just parked.
Me-what? then how can it be a flying object?
You-It looks like one.
Me-what? what does a UFO look like?
You-A flying saucer! You know, a space ship! Aliens!
Me-what? have you been drinking today?
You-No! I'm telling you, it is a UFO!
Me-what? How do you know that?
You-Just come see it!
Me-I don't think so.

 

[m_huber]

I found the abstract through my university. The full text was not available, but it is doubtful that most of us would understand it, anyway.

From "Constraints on the Dark Matter Self-Interaction Cross-Section from the Merging Cluster", by Doug Clowe:

We compare new maps of the hot gas, dark matter, and galaxies for 1E 0657-56, a cluster with a rare, high-velocity merger occurring nearly in the plane of the sky. The X-ray observations reveal a prominent bow shock and a bullet-like gas subcluster just exiting the collision site. The optical image shows that the gas bullet lags behind the subcluster galaxies; the weak-lensing mass map reveals a dark matter clump lying ahead of the collisional gas bullet, but coincident with the effectively collisionless galaxies. From these observations, one can directly constrain the cross-section of the dark matter self-interaction. That the dark matter is not fluid-like can be seen directly from the maps; more quantitative limits can be derived from four simple independent arguments. Our most sensitive constraint, σ/m<1 cm2 g−1, comes from the consistency of the subcluster mass-to-light ratio with the main cluster (and universal) value, which rules out a large mass loss due to dark matter particle collisions.

(I hope I'm not violating any rules here; this is the abstract, which is usually available to the public at no charge. I only have my university-specific link, but someone could probably find this online and available to the public)

So, without seeing the full text, it looks like they had pretty straightforward evidence of x-ray dispersal due to gravity produced by dark matter. Once you know the gravitational effect of dark matter, it is a somewhat simple matter to extrapolate how much of it must exist to explain other phenomena that are gravity-dependent, such as the expansion of the universe. This is a particularly exciting study, since they are demonstrating that dark matter is measurable (contradictory to your claim in the OP).

I don't understand your problem with this.

 

[sol invictus]

Are you going to answer my question, Robinson?

If you can't, you have no basis for calling the existence of DM and DE extraordinary claims.

 

[Darth Rotor]

http://www.washingtonpost.com/wp-dyn/content/article/2006/08/21/AR2006082101139.html

Everything we know, everything we can detect, is only 5% of the entire Universe! - Extraordinary claim!

20% of the Universe is something we can't see or detect, that doesn't obey the laws of physics, except it has mass, but passes through everything, including itself, and leaves no trace. - Extraordinary claim!

75% of the Universe is energy that defies known laws of physics, it negates gravity, can't be detected, and causes the entire Universe to go faster, with no known source for the energy involved in causing that! - Extraordinary claim!!!

== snip fun post==

It is amazing. No really, the insults, the name calling, the diversions, the lack of evidence, the claims that the scant evidence is "overwhelming", or that it "has to be true" is like debating a religious person.

As I understand "dark matter" and "dark energy" as labels, they are placeholders, like a variable x or y that is used when solving an algebraic problem.

Dark, as described in some of those threads, is a term used due to the challenge of detecting this stuff that isn't easily quantified using light and EM based sources.

Again, the analogy to the wind. You don't see it, you see its effects. Thus, you don't see the wind, you see what it does to the trees, the flag, the airplane crabbing on final approach, the kite, your date's hair.

Consider the use of light and EM detection as the human eyeball, analogy time continues, and this dark matter as the wind. Then, remove from your observation the ability to box in and experiment in a lab. You can't use lab controls, there is no wind tunnel, you can't break down the metal alloys to find out why the DeHavalind crashed. (Metal fatigue due to thermal stress due to cold temps at high altitude.) You have to stick with using secondary effects to provide your evidentiary clues.

Humans are very visual critters, in particular laymen. Lacking a good visual cue has not stopped humans from detecting sub atomic particles, but it requires some esoteric tools. (How many humans have worked an electron microscope competently? ) While those tools, in the form of mathematics or better observational kit, are being developed the place holder remains in the realm of the dark. If the tools are restricted to primarily analytical methods, in order to explain what is going on, then we have the higher order mathematics as our metaphorical electron microscope, and the layman is indeed left in the dark.

*political announcement voice*

I am a Dark Sith, and I approve of this message.

DR

 

[Soapy Sam]

Perhaps we might think it possible that "Ordinary" and "Extraordinary" are relative terms dependent on the knowledge of the observer?

For example, competent mathematicians have tried to convince me that square roots of negative numbers are just as real as the number 3.

I'm sure they're right.
I no longer believe "3" is real, either.

 

[sol invictus]

Perhaps we might think it possible that "Ordinary" and "Extraordinary" are relative terms dependent on the knowledge of the observer?

Yes, that's part of it. But I think it goes beyond that. We're talking about the matter and energy content of a universe far beyond our direct experience. We simply have no basis (other than theories of physics) to make a judgment about what is ordinary and what is extraordinary.

We build physics models to describe what we observe. When we make new observations, sometimes they conflict with our models and we need to change them. Recently, it became clear that our old model for the universe - Einstein's general relativity plus the standard model of particle physics, with all the matter in the universe being baryonic, and zero dark energy - did not match observations. The simplest known modification of the model is to add dark matter (for example a new stable particle with some reasonably heavy mass) and dark energy (for example a small positive cosmological constant).

Is that extraordinary? I would say just the opposite - it is by far the most ordinary and conservative option. It requires modifying our current model (which after all works extremely well for almost everything) in the smallest possible way. If someone comes along and is skeptical, that's fine - but unless they have an alternative model that is better (meaning it matches the data just as well and doesn't involve lots of new parameters), I'm not going to take them seriously.