What every layperson should know about string theory (Synopsis)

"I just think too many nice things have happened in string theory for it to be all wrong. Humans do not understand it very well, but I just don't believe there is a big cosmic conspiracy that created this incredible thing that has nothing to do with the real world." -Edward Witten

You don't have to be a fan of string theory to understand why it's such a promising area of scientific research. One of the holy grails of physics is for a quantum theory of gravitation: that describes gravity on the same footing as the other three forces, in very strong fields and at very tiny distances. Surprisingly, by looking at analogies between gravity and field theories, replacing particles with strings might be the answer.

Feynman diagrams (top) are based off of point particles and their interactions. Converting them into their string theory analogues (bottom) gives rise to surfaces which can have non-trivial curvature. Image credit: Phys. Today 68, 11, 38 (2015). Feynman diagrams (top) are based off of point particles and their interactions. Converting them into their string theory analogues (bottom) gives rise to surfaces which can have non-trivial curvature. Image credit: Phys. Today 68, 11, 38 (2015).

It's an incredibly difficult concept to understand why this would be the case without a slew of advanced mathematics, but last year, the world's leading string theorist, Ed Witten, tried. That is to say, he wrote a piece for other physicists entitled, "What every physicist should know about string theory." But what if you want to understand it and you're not a physicist?

Gravity, governed by Einstein, and everything else (strong, weak and electromagnetic interactions), governed by quantum physics, are the two independent rules known to govern everything in our Universe. Image credit: SLAC National Accelerator Laboratory. Gravity, governed by Einstein, and everything else (strong, weak and electromagnetic interactions), governed by quantum physics, are the two independent rules known to govern everything in our Universe. Image credit: SLAC National Accelerator Laboratory.

Here's my attempt at making the same physics concepts accessible to everyone. Here's what every layperson should know about string theory, including it's issues and its great possibilities!

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Ethan,
There are a few things you should also mention to the 'layperson' about String Theory besides the very outdated hype you are pitching.
I've been following the science journalism of ST for over twenty-five years. It's greatest contribution so far has been grabbing public attention to hype interest in science, creating plot devices and techno-babble for science fiction, and not actual science.
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In fact, string theory has NOT been very promising for over a decade. Peter Woit wrote a great book around ten years ago called "Not Even Wrong", which has been far more accurate at predicting the theory's inability to predict anything than the theory itself has been at predicting anything at all, largely because ST isn't actually a theory so much as a loose and very inelegant collection of mathematical formulas and speculations which produce 'the landscape problem" to the order of 10^500, which is one hell of a haystack to find your needle in.
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As a theory of everything (TOE), String Theory has failed miserably, though it has been propped up/repurposed several times as being potentially useful to developing new theoretical mathematics despite it not being able to deliver as it was originally pitched. The LHC was supposed to have revealed exotic new particles/dimensions and physics which was hoped would support ST in some way, So far this has most definitely not happened.

#1 CFT you are a blowfly...

By Quentin Rowe (not verified) on 26 Nov 2016 #permalink

Quentin, your response to CFT indicates you are ignorant of what you are ignorant of. I would say that to navigate through life it's usually more important to know what you do not know than to have a lot of knowledge. In general, people give too much respect to individuals with lots of knowledge but little understanding of where they lack knowledge. Our last presidential election is a classic example of that happening. You are doing it too.

By Eric Habegger (not verified) on 26 Nov 2016 #permalink

Quentin,
Actually, no.
And you apparently have no argument. Good luck with that.

In fact, string theory has NOT been very promising for over a decade. Peter Woit wrote a great book around ten years ago called “Not Even Wrong”

If you're going to invoke Peter Woit, it might have behooved you to have reviewed the post and comments at his place about the Witten item, rather than once again leaping to the landscape and hence blurting out weird remarks such as

a loose and very inelegant collection of mathematical formulas and speculations

and
it has been propped up/repurposed several times as being potentially useful to developing new theoretical mathematics despite it[s] not being able to deliver as it was originally pitched.

I'll readily aver that random Feynman diagrams (with different orientations, IIRC)* pretty much doomed this entry in terms of being anything but bafflegab for the nominal layman, but the subject really seemed to be a quantization of gravity. The post noted – perhaps too briefly – that there was no experimental evidence in general.

You, on the other hand, seem to be having a kneejerk reaction to the very mention of the subject.

* I have exactly one browser that will render Forbes without crashing, and this takes about 15 minutes to load.

^ I hope the broken blockquote following "and" standing by itself is obvious.

Narad,
I 'seem to be having a kneejerk reaction...', No, actually. I've been following this train wreck since the early 80's when the multi-dimensional pillow talk was all new and fresh, and watched it rot out the core of academic physics for over a quarter of a century. So, no, it is not so much a 'kneejerk reaction' as it is an old wound that will not heal.
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The simple reason String Theory is still getting any traction or hype (since it has nothing to with science or physics) is the very human nature of those who spent their lives peddling the idea. There is a lot of prestigious sheepskin invested in ST marching towards their respective funerals one at a time (Max Planck was so right) , and as a result ST has pretty much academically, financially and intellectually smothered many other ideas over the last 25 years, and wasted the intellectual genius of thousands of man-years. Woit called it 'putting all your eggs in one basket'. I will admit, it does pain me to see the heads of science departments in the universities screaming about diversity, when they eschew it for intellectual consensus and conformity at every opportunity.
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Your little gem of a comment that the post "..noted - perhaps too briefly.." that the theory has predicted nothing IS the point of my little 'knee jerk' reaction, and should have been made at the beginning of both Ethan's post, and yours.

as a result ST has pretty much academically, financially and intellectually smothered many other ideas over the last 25 years

Which ones?

Narad,
Good question with a lot of answers. A place to start might be with reading Peter Woit's book, Not Even Wrong. You could also try The Trouble With Physics by Lee Smolin. Far more harsh in its critique and a harder read is Farewell to Physics by Jim Baggot. All three books have different angles of attack, but they pretty much come to the same conclusion that a diversity of approaches to solving several problems is better than everyone trying to focus on one big problem the same way. ST advocates have been pushing 'The only game in town' con for decades which has resulted in driving many talented young people out of pursuing physics, they can tell ST is metaphysical bullshit spinning it's wheels while it waits for someone to die, and they also know they have no chance of advancement in the field unless they fawn and worship at the alter of those who are ST true believers. This view is shared by the authors who have been in academia for decades and have a good working understanding of the culture.
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"as a result ST has pretty much academically, financially and intellectually smothered many other ideas over the last 25 years"

Your anti-science ideas and conspiracies are as loony as those of see noevo

Good question with a lot of answers. A place to start might be with reading Peter Woit’s book, Not Even Wrong. You could also try The Trouble With Physics by Lee Smolin. Far more harsh in its critique and a harder read is Farewell to Physics by Jim Baggot.

Perhaps you could try actually providing one rather than hand-waving, then. Remember, this is your assertion:

ST has pretty much academically, financially and intellectually smothered many other ideas over the last 25 years

"Quentin, your response to CFT indicates you are ignorant of what you are ignorant of."

Or very well aware of what CFT is.

"it might have behooved you to have reviewed the post and comments at his place about the Witten item, rather than once again leaping to the landscape"

However, this would be devastating to CFT's ego and mission statement: make shit up and badmouth science.

Ergo, not gonna happen.

PS CFT, if everyone else is calling you a jerk, the possibility is that you are one.

@Wow#13,
"PS CFT, if everyone else is calling you a jerk, the possibility is that you are one."....
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Wow, You are a true font of continuous irony. Thank you for the good laugh.
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While it is true I am skeptical of all experts and their claims, I use actual arguments. You rely almost exclusively on pompous snark. Science is a methodology, not an exclusive club for fanboys and me-too zealots who are looking for religious belonging. It is also an arena of thought where ideas compete and clash and change. Sometimes the debate is calm, often not. It has no place elitist snobbery, and by that I mean you certainly don't speak for 'science', whatever that means, you just speak for you.

@Narad #11,
Here is a site called Resonances, it's a very hard science site by someone in the HEP field, and he's saying plenty about the search for Dark Matter. The prospects for the theory are looking increasingly dim due to lack of any kind of observation. More and more ranges of possible candidates for Dark matter/energy particles are being ruled out, and a great swath has already been cut through pre LHC dark matter theory.
http://resonaances.blogspot.com/

Google is your friend, you know how to use it. If you had you might have found:
h[]tps://aeon.co/ideas/has-dogma-derailed-the-scientific-search-for-dark-matter
MOND is one of the contending theories which has been pretty much paved over by ST zealotry.

MOND? After throwing out random books with no reference to anything specific inside them (aside, of course, from "a harder read"), when pressed, you come up with MOND?

@Narad #11,
Here is a site called Resonances [sic], it’s a very hard science site by someone in the HEP field, and he’s saying plenty about the search for Dark Matter.

I'm not sure what the closing non sequitur is there for, but I'm well aware of Jester's site.

As far as I can tell, you're having some sort of (posturing) conniption over the fact that you've witnessed a blog post that wasn't simple condemnation of string theory. I certainly think that SUSY's dead – in fact, a picture of Charlie Brown, Lucy, and the football might summarize things well in one sense – but you're just adding noise and no signal: Look here! Look there! Google it!

You seem to have nothing specific to say about Ethan's post other than "yuck." Repeatedly. And yes, my patience is especially short at the moment.

"I use actual arguments. "

When?

@dean,
I guess you would have to read past entries to find out, wouldn't you? If you are merely snarking, then snark/off.

Narad,

My problem with Ethan's blog is that he is acting like a mainstream cheerleader/fanboy of ideas that have been stagnating (almost literally) and going nowhere for decades. If he is going to peddle the merit of science theory, he should be openly skeptical as well, and discuss the actual debate about the ideas, not the unicorn and rainbows fantasy of uniform agreement that only exists in science PR and propaganda.
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You asked for a single example, I gave you one. You didn't like it, so meh.
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If you can't even locate 5% of the universe in order to jibe with existing understanding and theory, the answer is not 'make up shit' (fudge factor) until you fill in the 95% you can't account for, this is exactly what ALL dark/whatever theory does heuristically. When you are off by 95% or more, you do not pat yourself on the back on how right your assumptions are like Beverly Crusher, "it's not me, it must be the universe".
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As for your disdain for MOND, get a grip, it's scientists actually trying to work within a framework of working theory and observation. Do you think believing in imaginary 'dark' substances no one can locate or even imagine its basic structure is scientific? I provided the link to Resonances to show you how that snipe hunt is working out. You might as well say, 'I'm completely correct about my ideas about gravity (GR) based off a model that doesn't reflect reality (it really can't accommodate more than one mass in a given space time, look it up), it's just that pesky invisible phlogiston I need to find to make it all work out...' This is not good science, this is wishful thinking at best.

"I guess you would have to read past entries to find out, wouldn’t you?"

I just read you diatribe against dark matter. No argument there, just "I don't like it so it's wrong" comments.

You haven't yet made a case that you are serious.

Drat the no preview/edit key situation.

You (cft) haven't done any more than whine that you don't like things in any of your other posts either. When it comes to your "arguments" - there is no "there there".

If he is going to peddle the merit of science theory, he should be openly skeptical as well, and discuss the actual debate about the ideas

He's published several times on MOND, the example you gave of an alternate theory you think the mainstream is ignoring. Perhaps you should take your own advice and read past entries to find out.

Do you think believing in imaginary ‘dark’ substances no one can locate or even imagine its basic structure is scientific?

Dark matter has been located through gravitational lensing effects. How does MOND explain the gravitational lensing around the bullet cluster? Oh that's right, it doesn't. The MOND and DM hypotheses both make testable predictions about lensing about large cosmological structures, and we looked to see which one was consistent with observation. DM was. MOND wasn't.

Its true that pretty much none of our cosmological ideas explain all the things we see. But I think you have to ignore a lot of observations to claim that DM is "imaginary" and not scientific. The hypothesis that there is matter which interacts only through the gravitational force leads to testable predictions. We've done the tests, and the hypothesis has held up. That doesn't mean its a locked-in guarantee to be correct, but it means that your derogatory analogies to unicorns, pesky invisible phlogiston, etc. utterly misunderstand both science writ large and DM's status in science. No CFT, we don't have to directly observe something to have confidence it's there. And no CFT, the fact that we have indirect observations of the effects of DM but not direct observations of it, does not mean its an unscientific fantasy. MOND is not an unscientific fantasy either, of course. But then again we mainstreamers that you accuse of bias aren't the ones throwing around such insults; they appear to only be coming from the "unbiased" you. Huh.

eric,
If you can not detect 'X', and it is essential that 'X' be there for your theory or model to work, you don't then get to say 'well, we can't find it, but since our theory needs it so, it is so, and thus our theory/model is proven correct.' This kind of tautological nonsense is what turns any scientific premise on its head into dogmatic mush, and discredits the concept of evidence entirely. Y

When you stack several such presumptive theories atop one another you get an even bigger problem, if anything turns out to be wrong, whatever is stacked on top of it also collapses, like a poorly constructed house. Because everyone fears the collapse and what it might mean to their own personal prestige and fortunes, they become more concerned with propping the house up, than doing science, or admitting they were wrong, and going back to the drawing board...this is the crucial point where science stops being a careful inquisitive methodology and becomes an unquestionable dogma. Read some science history and you will find this kind of thing has happened several times before...and given that human nature hasn't changed, most likely is going to happen again.

If you can not detect ‘X’, and it is essential that ‘X’ be there for your theory or model to work, you don’t then get to say ‘well, we can’t find it, but since our theory needs it so, it is so, and thus our theory/model is proven correct.’ This kind of tautological nonsense is what turns any scientific premise on its head into dogmatic mush, and discredits the concept of evidence entirely.

Congrats, you just threw out most of particle physics and the discovery of every element above Z=100 as "tautological nonsense" and "dogmatic mush". None of these elements have ever been observed; instead, what we detect are photons and lower-z particles whose combined masses, trajectories, and energies are best explained by the formation and decay of an unobserved heavier particle. The same is true for much of particle physics.

So, what's it going to be? Throw out huge chunks of science in your irrational biased rejection of a hypothesis you don't like? Or accept that an hypothesis that you test by observing predicted indirect effects of a particle can be science?

. Because everyone fears the collapse and what it might mean to their own personal prestige and fortunes, they become more concerned with propping the house up, than doing science, or admitting they were wrong, and going back to the drawing board…

This is just ludicrous conspiracy theory. DM was generally rejected by the scientific community for about the first 50 years after it was first suggested. It only really gained credit in the 1980s. The idea that the entire scientific community feels compelled to support an hypothesis that is literally younger than one of my sweatshirts...its silly. Sorry CFT, but any grand unevidenced sociological defense of DM is all in your head. If future additional experiments continue to support it, the community will gain greater confidence that it's right. If it starts failing tests, or some alternate hypothesis comes along that explains the same observations better, the community will reject it. Its just normal science. I'm sorry you don't like it or find it absurd. But fortunately, science doesn't operate using the "ask CFT's his opinion on a theory" method of theory evaluation.

When you stack several such presumptive theories atop one another you get an even bigger problem, if anything turns out to be wrong, whatever is stacked on top of it also collapses

You mean like monist materialism and plural minds? Perhaps you should proceed more systematically.

^ Don't forget the Axiom of Choice while framing the house, or whatever. Afterward, make sure that renormalization is really legitimate. It's time to clean things up!

eric,
I depend upon actual evidence where science is concerned, not excuse heavy heuristic fudge, no paradoxes, no appeals to authority , or complexity, and certainly not faith in experts or zealous fan boys who have forgotten Occam's Razor and seem to think science is their personal club house.
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If you think my position a ' ludicrous conspiracy', or just my 'opinion about theory', you would seem to be very uninformed, and appear to know about how many scientists think about this just about as much as scientific pollsters knew about who's was going to win the presidency. How is that discovery of bunches of new theoretical particles actually working out?
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It isn't. That's the problem. That isn't an opinion, that's a fact. It has quite a few physicists talking about it too for some reason... go figure.
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The LHC (or anyone else) is not finding ANY of the many zoo particles that were predicted by HEP over the last thirty plus years. Not just some of them, NONE of the them. No SUSY, No WIMPS, No DM, No new dimensions, No wormholes, No ridiculous backward propagating time traveling particles, No silly virtual particles, No ST (not that it ever could anyway), NADA. The fact that it took quite a few monte carlo computer simulations to find a 'Higgs' at all tells me 1.) They were utterly desperate for a detection at that point since monte carlo simulations are what you use as a last resort to manipulate raw data until it screams or a pattern drops out of pure static, and 2.) For all the claims about what a Higgs Boson would reveal about (fill in the cosmic blank and awe garbage), they still have nothing but a 'claim' of discovery, and nothing else. Not one new insight into mass or any of the happy hype the search was over sold on. This really doesn't surprise me since the only reason the Higgs exists at all was because it was required (much like DM) to fudge over the half baked gauge math which predicted no particle masses.
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Fortunately for me, science (and government funding) doesn't depend upon your wishful thinking and lack of actual evidence to make it go.
When your unicorns and dragons are discovered and you have actual proof, let me know how wrong I am just to rub it in my face and make yourself feel better.
Until then, you literally have nothing.

CFT,
I happened to agree with you on one thing (3rd comment down.) I wish now that I hadn't said anything. Are you like this all the time? It seems you are much more of a victim of not knowing what you don't know than Quentin Rowe ever was. You give some people a little support and they are dangerous.

By Eric Habegger (not verified) on 29 Nov 2016 #permalink

Eric Habegger,
Relax, I'm not on a rampage, I'm just not into groupthink, and I didn't base a thing I said on your comment. I also had no idea pointing out the emperor of HEP has no clothes was considered 'being a victim of not knowing' when it would appear it is actually the science groupies who do not seem to be aware of the lack of any discovery.
You also mention my voicing dissatisfaction and disbelief with mainstream academic science and research as being dangerous, if you were being honest, you really have no idea of what dangerous is, as dissent is also a part of science. It would be wise to start listening to perspectives outside of an echo-chamber of the like-minded, what you learn might surprise you.

I depend upon actual evidence where science is concerned

Gravitational lensing is actual evidence. Do you agree or disagree?

How is that discovery of bunches of new theoretical particles actually working out?

About as well as expected by mainstreamers, which means much better than your hyper-skepticism would predict. Meaning that the elements with measured higher cross-sections and half-lives amenable to experimentation have been reproduced and re-reproduced in many experiments successfully (but again, we only see decay products consistent with the element's formation - never the element itself). The heavy elements that have very low cross-sections and short half-lives have not been reproduced as much, because of the practical difficulty of doing so (along with the limited funding in the field). I haven't kept up with the literature but there's probably hundreds of atoms-worth of experiments on Rf, for example. But none of these experiments ever observe it, they only observe the decay products. So, in your opinion, do those findings count as science? They're reproducible. They're in fact reproduced. They're all empirically-based measurements. They align with and thus provide confirmatory support for one or more theories of atomic structure and nuclear stability. But they fail your criteria of direct observation. So, do you count it as science or not?

"I’m just not into groupthink"

Neither, apparently, are you into science. Your 'dissent' is not based on any bit of science, it is based, as you make clear, on your views that
a) Scientists are not doing science the way you want it to be done
b) There is some conspiracy of silence where the theme is it is better to keep quiet about observable problems and preserve what you foolishly believe to be massive amounts of funding than it would be to publish new work that revolutionizes things.

The stupidity of those two points is mind boggling. There is really nothing there that differentiates you from the losers who argue against vaccination.

@32: his requirement of direct observation also appears to be very selectively applied to the ideas he doesn't like. Observing light bending, taking this as evidence of the existence of magnetic fields that nobody can directly observe? Ah, that's good science. Observing light bending, taking this as evidence of the existence of DM? Clearly not science! Fantasy! The Emperor has no clothes!

dean,
You are into denial, apparently. And are just outright oblivious of what goes on outside of your happy day glow safe science space. Ever heard of Tommaso Dorigo? On a hedged guess, I'm willing to bet he knows a few things about discovery (or lack thereof) you don't.
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http://www.science20.com/a_quantum_diaries_survivor/the_five_stages_of_…
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As for the conspiracy of silence you mention, I'm willing to bet you also think they only happen frequently in the lowly private sector, like with new drug trials, car crash tests, toy safety, FDA approval, and tobacco testing? Such things don't also happen in the pristine pure world of academic science and research for many of the same very human reasons? Like publish or perish?

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I am not pushing a unique, extremist, uneducated or uninformed view, which you would know by now if you were more widely read. Please just stop with the conflation of anyone who disagrees with you with 'anti- science anything' or '(fill in the blank)- ists', you hardly have any claim to objectivity when you sound like a pissed off teenager. I never said 'all scientists', so quit pretending I did, I was even specific what kinds of 'science' practices I was criticizing.
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P.S. what is truly mindboggling is your ridiculous straw-man argument involving vaccination and ad-hominem, none of which is tied to any of my arguments...or yours for that matter. 'Losers'? Seriously? What, are you twelve?

eric,
You want to argue an issue, go for it. But you only get to make up your arguments, not mine. I wasn't aware we EVER discussed bending light, refraction, or the electromagnetic spectrum we actually observe around us all the time. Aurora Borealis, rainbows, Magnets and iron filings, heat, visible light? UV? You mean those unobservable EM fields that we observe all the time and measure frequently? Whatever your point was, you didn't actually make it.
Your argument basically is : You disagree with me, because of that you feel justified in trying to shame/insult/ marginalize me and my position by any means necessary including straw man statements I never made and/or uninformed statement you made. This is not how you debate and win from a strong position in science, this is how you lose from a weak position in a political argument.
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"As for the conspiracy of silence you mention,"

The point is that there is no conspiracy of silence, whether you mean the one you talk about among scientists or the one anti-vaccination folks talk about concerning vaccine safety.

"I am not pushing a unique, extremist, uneducated or uninformed view...
Well yes, you are. You are no different than they are: both you and the anti-vaccination groups believe your ideas, based on lack of knowledge, trumps what the people who actually study the topics are doing. Yes, in the world of ideas, yours and theirs lose.

I wasn’t aware we EVER discussed bending light

You have not discussed it. But I've mentioned gravitational lensing twice, because that's an observable bending of light predicted by DM but not by MOND. You haven't answered my questions on it, so I'll ask one more time: is the observation of gravitational lensing scientific evidence?

This is not how you debate and win from a strong position in science, this is how you lose from a weak position in a political argument.

LOL I doubt anything you and I say will alter NSF's position on whether DM research is worth funding. Publication of results and peer review is how you debate and win from a strong position in science. That's the only way you're going to change minds about DM. And as far as I can tell, you don't have that.

You have a philosophical argument that science ought to discount indirect evidence in this case - that unless we can directly observe DM, we have no 'actual' or 'scientific' evidence of it (and yet you refuse to say whether we should discount similarly indirect evidence in other specific cases, several of which I've asked you about).

You have a claim that there's some secret conspiracy among a large number of scientists to fool the public and keep the DM theory going for venal reasons.

Lastly, you have a claim that Ethan is ignoring MOND, even though he's written several articles about it which, evidently, you weren't aware of.

Did I miss any of your arguments?

“I’m just not into groupthink”

Strange. So when everyone sees a bus, you see an ostrich wearing a gimp mask?

"Wow, You are a true font of continuous irony. Thank you for the good laugh"

Irony: you don't appear to know the word. Who has called me a jerk? Was it everyone?

Moreover, tu quoque is no defence to the accusation. Not for anyone over the age of 5, anyway. Try again.

And please this time include the answer Narad pointed out was an absolute requirement for your blithering to be of any value or point whatsoever: explain your knowledge that led you to the claim you made, not just the claim.

I depend upon actual evidence where science is concerned

Gravitational lensing is actual evidence. Do you agree or disagree?

Of COURSE not, eric!, after all, that evidence is evidence of DM, which CFT "knows" is wrong, therefore it can't be REAL evidence, right?

"“As for the conspiracy of silence you mention,”

The point is that there is no conspiracy of silence, whether you mean the one you talk about among scientists or the one anti-vaccination folks talk about concerning vaccine safety."

As is evidenced by his claim that "nobody is talking about MOND" when it's very VERY clearly talked about a hell of a lot.

The "silence" he talks of is the "silence" of "not accepting it as mainstream proven fact". Which isn't silence at all, it's just the lack of words he wants to hear.

You are into denial, apparently. And are just outright oblivious of what goes on outside of your happy day glow safe science space. Ever heard of Tommaso Dorigo?

Doubling down on your already-noted bad habit is not the brightest idea. Were you planning to get on that question about renormalization? I'm sure your insights about the differences between the Lesbesgue and Riemann integrals would be fascinating.