Lambda-CDM theory - Woo or not?

[Michael Mozina]

If a direct failure in the lab won't do it, what exactly WOULD it take to falsify Lambda-CDM anyway?

 

[ben m]

You're confused.

SUSY = one of many reasonable hypotheses about particle physics.
LCDM = by far the best hypothesis about the mass density of the Universe.

Sure, if SUSY is true then it's possible that the CDM is made of SUSY particles. If SUSY is not true, than the CDM must be made of something else.

 

[edd]

If a direct failure in the lab won't do it, what exactly WOULD it take to falsify Lambda-CDM anyway?

Measurement of w =/= -1, measurement of a deviation from GR, measurement of non-uniform dark energy... to name a few.

 

[edd]

Oh, now we have faster than light speed expanding "dark goo" theories with metaphysical "negative pressure" features no less. What's next? "Invisible elves"?

I thought you'd have liked it Michael! It suggests you can do away with negative pressure and replace it with plain old viscosity, after all.

 

[Michael Mozina]

You're confused.

SUSY = one of many reasonable hypotheses about particle physics.
LCDM = by far the best hypothesis about the mass density of the Universe.

Sure, if SUSY is true then it's possible that the CDM is made of SUSY particles. If SUSY is not true, than the CDM must be made of something else.

Like what? Surely you must realize how much this sounds like a "mythical exotic dark matter of the gaps" argument, right?

 

[Michael Mozina]

Measurement of w =/= -1, measurement of a deviation from GR, measurement of non-uniform dark energy... to name a few.

But therein lies the rub edd, you can't even tell me where dark energy comes from! It's really a little like whack a metaphysical mole around here. I can demonstrate that all those papers that astronomers wrote about mythical WIMPs doing gamma ray dances at midnight went up in smoke in the lab.

Nobody knows where "dark energy" comes from, let alone demonstrate it actually has a material effect on anything. The inflation entity is dead, so the odds of seeing it do anything to anything in a real controlled experiment on Earth are zip. The one and *ONLY* sky entity I could ever hope to falsify or verify was the "dark matter" genie, but alas it too seems to be incredibly impotent around the lab.

If a direct failure of exotic brands of "dark matter" mythologies in a multi-billion euro lab won't kill of the dark matter mythology, what will?

 

[edd]

There's a fair number of candidates for a dark matter particle. Pretty much all (if not all) come about from particle physics and aren't motivated by cosmology or astronomy. It's hardly the fault of cosmologists that they have particle physicists falling over themselves to offer suggestions.

 

[edd]

But therein lies the rub edd, you can't even tell me where dark energy comes from!

Nope, noone knows yet. Noone said our work was done either. Maybe one day we'll know where it came from and know more about what it is, maybe one day we'll find a different explanation for it all, but that doesn't mean it must be wrong if we don't know now.

Nobody knows where "dark energy" comes from, let alone demonstrate it actually has a material effect on anything.

If it didn't have a material effect on anything how would we know about it??

 

[Michael Mozina]

There's a fair number of candidates for a dark matter particle.

Ya, including ordinary matter. I've yet to hear you folks address that "dust" in space revelation from a few years ago, or that revelation that galaxies are twice as bright as first thought, or that "stellar recount" data that that shows that small stars were underestimated by a factor of FOUR! About all I see are papers claiming "SUSY did this in the sky, SUSY did that in the sky". SUSY seems to be dead. What justification do you even have for exotic forms of matter at this point?

Now what? It seems like the whole thing is based more upon an emotional attachment to already falsified theories, than by physical findings from the lab.

Pretty much all (if not all) come about from particle physics and aren't motivated by cosmology or astronomy.

Perhaps, but particle physicists have never claimed SUSY theory was a "mainstream" theory to begin with. Whatever concept you latch onto next is bound to be "sold" to the public as a "great idea" because it "solves" a mystery in astronomy. In other words, we're right back to justifying your beliefs, based upon your own beliefs, which are ultimately based on "faith" in something that you have never seen in the lab. It's a circular feedback loop and it's a "religion".

It's hardly the fault of cosmologists that they have particle physicists falling over themselves to offer suggestions.

IMO it is your fault for failing to consider the fact that your ordinary mass estimated were probably (now known to be) botched to begin with, and no real steps have ever been taken to MINIMIZE the need for exotic types of mass.

 

[Michael Mozina]

If it didn't have a material effect on anything how would we know about it??

That's just it. You don't! You don't even know where it comes from!

 

[Michael Mozina]

I thought you'd have liked it Michael! It suggests you can do away with negative pressure and replace it with plain old viscosity, after all.

Alright. I'll at least read the paper if you think plain old viscosity does the trick.

 

[edd]

That's just it. You don't! You don't even know where it comes from!

I think you and I have different ideas about the meaning of 'material effect'. There's certainly an obvious gravitational effect, and there's not supposed to be any other kind of effect. That's what the word 'dark' is doing there in its name.

 

[edd]

IMO it is your fault for failing to consider the fact that your ordinary mass estimated were probably (now known to be) botched to begin with, and no real steps have ever been taken to MINIMIZE the need for exotic types of mass.

That's just not true. If there were a theory that explained the observations that didn't require extra particles or extra physics people would be all over it, as it would blatantly be a better theory.

 

[Michael Mozina]

I think you and I have different ideas about the meaning of 'material effect'.

Evidently so.

There's certainly an obvious gravitational effect,

Er, no. There is no physical link between gravity and 'dark energy' except in your head. Gravity doesn't do any repulsive tricks in the lab.

and there's not supposed to be any other kind of effect. That's what the word 'dark' is doing there in its name.

IMO that line of reasoning is exactly what makes it sound like a 'dark thingy of the gaps' argument rather than anything related to actual physics. In other words your already "making up" various properties that you want this matter to posses, aka "darkness", only because you don't want to address your botched normal mass estimates IMO.

How about that dust problem? What about that stellar recount problem? Don't you think it would make sense in light of recent laboratory analysis to go back and revisit your ORDINARY mass estimates with the express intent of minimizing or doing away with exotic brands of matter? Even if we assume that "acceleration happens", how do you know "dark energy" exists, let alone that it related to gravity?

 

[nvidiot]

Like I said, regurgitation.

The above conversation has been had countless times in this thread, and others by Mozina. He is not ignorant of the facts, he is willfully ignorant of the facts. Any educational value this thread will produce will have already been repeated within it several times.

 

[ben m]

Like what? Surely you must realize how much this sounds like a "mythical exotic dark matter of the gaps" argument, right?

Nope. The dark matter is observed, gravitationally, and confirmed by a dozen independent measurements of its gravitational effects. There is nothing mythical or exotic about that.

That evidence doesn't just go away if the LHC doesn't tell us what the dark matter is.

 

[Michael Mozina]

That's just not true. If there were a theory that explained the observations that didn't require extra particles or extra physics people would be all over it, as it would blatantly be a better theory.

I realize that you personally honestly believe this to be true edd, and in some ways it is "kinda of" true of you personally. I think however as an "insider", rather than from the outside looking in, you grossly underestimate the 'problems' that you folks have created by elevating mathematics to the level of "sky godhood" without respect to empirical physics here on Earth.

IMO, no theory based PURELY on empirical physics is going to be 100% mathematically competitive with your theories, certainly not based on EXACTLY THE SAME ASSUMPTIONS (AKA redshift is related to expansion). There's nothing that can touch mainstream theory in terms of the mathematical fit to data because all Lamba-CDM theory is is math with make-believe ad hoc entities. Of course it 'fits the data' you want it to fit. If it doesn't fit you simply tweak more ad hoc variables.

IMO there already is a "blatantly better" theory, you just judge things from the wrong standards, on math alone rather than empirical physics.

Assuming I ever see you folks actually make a real attempt to minimize the need for exotic brands of matter, I might believe that you're more attached to physics than to religion. Right now, it seems like there is still an emotional attachment to "everything dark".

 

[Michael Mozina]

Like I said, regurgitation.

The above conversation has been had countless times in this thread, and others by Mozina. He is not ignorant of the facts, he is willfully ignorant of the facts.

I'm certainly aware of the fact that SUSY particles have *CONSISTENTLY* failed to show up in the lab for over 20 years now, including those billion dollar LHC experiments. I'm aware of the fact that virtually all the papers used to support the 'cold dark matter' aspect of Lambda-CDM are based on SUSY particles. What's it going to take to falsify a falsified theory anyway?

 

[Michael Mozina]

Nope. The dark matter is observed, gravitationally, and confirmed by a dozen independent measurements of its gravitational effects. There is nothing mythical or exotic about that.

There's nothing "mythical or exotic" until you claim that your 'missing mass' isn't composed of "normal" matter. All those things show you Ben is that your industry botched the normal mass estimates in a big way. When did you intend to remedy that?

That evidence doesn't just go away if the LHC doesn't tell us what the dark matter is.

What in the universe makes you believe it's made of anything other than the normal matter we find on Earth?

 

[D'rok]

In the interests of finding some common ground, I ask this:

Michael Mozina, do you agree that a gravitational effect has been observed and measured, yes or no?

If yes, and without any speculations whatsoever on the cause, do you agree that that effect must necessarily have a cause, yes or no?

If you can't anwser yes to both those questions, then there really is no point at all.