That paper that proposed that most cancers were due to bad luck, that is, that they were a consequence of biological factors that could not be controlled, has been surprisingly controversial. I thought it was a fairly unsurprising paper that confirmed what we already suspected, but wow, the furious pushback has been something to behold.
Today, though, a couple of MDs have responded to the paper and reinforce what I said.
Steven Novella thinks the general logic is sound.
This is an interesting study and it will be interesting to look at replications and other methods, if they are available, of making the same sort of estimation. What this study suggests is that at least 2/3 of all all cancers are due to random mutations – bad luck. The figure may be higher once breast and prostate cancers are included. Of the remaining third it is not clear how much is due to inherited genes vs lifestyle factors.
The logic of the study is sound, in my opinion. The authors assume that lifestyle and genetic factors affect the risk of tissue specific cancers, but not cancer in general. This study would miss, however, lifestyle or genetic factors that affected the risk of all cancers (regardless of tissue type) equally. One might argue, therefore, that it overestimates the role of random mutations, but that is only if you accept that there are universal risk factors out there.
David Gorski emphasizes that the result actually fits well with prior estimates of the relative contribution of environmental/genetic factors and a probabilistic component.
That cancer is due to a combination of random probabilistic processes, environmental exposures, and heredity is a non-controversial statement. What is controversial are estimates of the relative contribution of environment, given that the percentage of cancers due to inherited cancer-causing mutations is known and low. Take the example of breast cancer, which is a cancer for which environmental and lifestyle contributions are not particularly high, with perhaps 27% of breast cancers being due primarily to environment (which includes diet and exercise, as well as hormone replacement therapy). The vast majority of those environmental contributions come from obesity and alcohol consumption, neither of which reaches the double digits, percentage-wise. Yet there are organizations that promote the idea that “chemicals” in our environment are a major cause of breast cancer. Unfortunately, about 5-10% of breast cancer is inherited, while perhaps up to 27% has a strong environmental component. That leaves around 60% of breast cancer (or, even using higher estimates, at least 50%) as falling into the “we don’t know” or “stochastic” category, with, sadly, nothing that we know of right now that can be done to prevent these cases, while the 10% of hereditary cases can only be prevented by aggressive means, such as chemoprevention or prophylactic surgery.
I still find it interesting, though, that so many people have complained to me about ascribing phenomena to chance — there are some serious misconceptions floating about out there, and I’ve always taken these ideas for granted. I guess I can’t. David Colquhoun and I spent an enlightening afternoon yesterday trying to get through to a few people on Twitter who could not believe we actually thought chance was a reasonable explanation for anything. I did not have the impression that these were anti-science people, or creationists, or anything absurd like that — they just had a striking psychological antipathy to the whole idea of random effects.
@pzmyers @JeromeNowe @david_colquhoun @jwbelmon no not chance. There must be factors of which we are unaware. U can't abandon sci. method!
— Christopher Penny (@ChristoPenny) January 4, 2015
no not chance. There must be factors of which we are unaware. U can’t abandon sci. method!
@pzmyers @JeromeNowe @david_colquhoun @jwbelmon Luck, by definition, has no cause therefore unscientific.
— Christopher Penny (@ChristoPenny) January 4, 2015
Luck, by definition, has no cause therefore unscientific.
@david_colquhoun @pzmyers @JeromeNowe @jwbelmon random does not mean without a cause – which is what luck means :-)
— Christopher Penny (@ChristoPenny) January 4, 2015
random does not mean without a cause – which is what luck means :-)
Fascinating. Random events are not even scientific? Where did this idea come from? Everything has to have a “cause” of some sort? Weird.
Maybe it’s because a lot of my early training in biology was in genetics, and there you acquire a strong appreciation for the importance of chance events. Genetic gene mapping, for instance, is done by looking at recombination frequencies — the probability that a meiotic crossover event will occur between two genes on the same chromosome, which is a factor of the physical distance separating them. We understand the physical basis of this event, which involves a protein, Spo11, that binds to a random location on the chromosome and induces a double strand break. Why does it land on a particular spot? It’s all about the higgelty-piggelty jiggling of proteins in the cellular environment — there isn’t a magic finger telling Spo11 to go to a pre-defined place on the chromosome, it simply does its job wherever it happens to find itself.
You could say the recombination event has a specific cause, the protein complex that cuts and swaps strands of DNA, but the question at hand — why does it recombine at a particular spot in a particular chromosome? — is not specified by any causal agent in the cell. It’s random.
It’s not unscientific. We can study chance processes statistically, no problem. If we threw out all study of chance as unscientific hocus pocus, well, there goes genetics. And epidemiology. And chemistry. And any science that uses statistics. Dang.
Why do they reject chance? One idea that emerged is that they have an excessive faith in causality, and paradoxically, too much trust in the ability of science to give complete, exhaustive explanations for everything.
@ChristoPenny A deeper and better understanding of DNA will erase the concept of luck/random.@david_colquhoun @pzmyers @jwbelmon
— Jerome Nowe (@JeromeNowe) January 4, 2015
A deeper and better understanding of DNA will erase the concept of luck/random.
No, it won’t. The more I learn about chemistry and biology, the stronger the value of understanding chance becomes.
I think the idea is that all we have to do is catalog all of the efficient causes to work out every step of an event. Your cancer was caused by a cosmic ray striking and damaging the short arm of your 12th chromosome, creating a defective RAS oncogene. That cosmic ray originated in a supernova 15,000 light years away. That exploding star condensed from a cloud of matter that originated in the Big Bang, so all we have to do is map how every atom, from the beginning of the universe to that detonation in a distant star, and further, every molecular event in the evolution of that RAS oncogene that put it in that particular location on the chromosome, and then every event in your life that led to that cell and your body to be in that specific location to intercept that cosmic ray, we’ll finally understand why you have cancer.
It takes a very deterministic attitude to find that explanation at all satisfying.
No matter how hard we work, we will never have a sufficiently detailed explanation of every feature of the universe to negate the importance of chance. I think quantum physics is also drilling down deep into the nature of how the universe works, and finding that chance plays a role; but even if it were found that the universe is completely deterministic, the complexity of the phenomena and the number of parameters means that those kinds of causes are unknowable, and randomness is a good higher-level description of what is going on.
So get used to it. Why did you get cancer? Bad luck. Chance. But of course, the odds might also have been skewed by inheriting a gene that predisposes you to cancer, or by a poor diet, or by your odd habit of spiking your morning tea with N-ethyl-N-nitrosourea.
I recall lots of creationists being clueless about “chance”, too. Science-based people should know better. “Chance” or “random” is the label we apply to phenomena (coin flips, genetic rad-damage, etc.) for which the antecedents are so obscure or complicated that we can’t possibly trace them, so all we can do is treat the outcomes statistically. Which shouldn’t be that hard a concept to grasp.
Though of course, take note of this hypothetical:
Just because only 2% of people with cancer got it from chemical X doesn’t mean chemical X has a low chance of causing cancer if you are exposed to it. Maybe it has a 99% chance of causing cancer if you are exposed to it, but it’s statistically unlikely for people to be exposed to it.
That’s very funny considering the prevalence of randomness all around us. Statistical thermodynamics explains macroscopic events in terms of random motion of submicroscopic particles. Random chance explains why the air in a room spreads throughout its volume instead of gathering in one corner. It’s pretty random which grain of pollen clings to a bee’s leg and is deposited on an anther to form a new seed. And so on. There are a million examples.
I think it’s because people interpret calling something “luck” as akin to saying “we don’t and can’t know”. Instead it should be “we know, it’s a percentage chance thing and here’s what has to happen…”.
People hate the idea that misfortune is ultimately attributable to bad luck–it means that all their exercise and wheat-grass juice and gluten-free dieting (irony intended) is in vain. Many people need to feel like they are in control–or if they are not in control, that some benevolent sky daddy is.
Talk to any cancer survivor and I’ll bet they’ll tell you a story of some asshole suggesting that their cancer is a result of their lifestyle or their exposure to some toxin/stress or their “anger”. It’s the same reason a lot of people blame rape victims–it is important that the victim did something wrong so that they can avoid doing that thing wrong and avoid being raped. Humans are ingeniously stupid.
Also, luck is inherently a probabilistic entity. There are at least two types of probability. Subjective probability depends on our state of knowledge–we can improve our bets if we improve our knowledge. This is also called Bayesian probability.
Then there is intrinsic probability–it doesn’t matter how much we measure and learn. We’ll never make the problem deterministic. Quantum mechanics is inherently a probabilistic description of the world. However, even in classical physics, some phenomena are inherently indeterministic–e.g. the simultaneous interaction of 3 or more bodies.
Science is not magic. One of the most important things it does for us is tell us that some things are impossible.
It’s pretty much the same sort of linguistic drift that gets wrapped around words like ‘theory’ and ‘racist’, where the colloquial connotations are just a bit off from the formal ones, and so people get confounded when they are essentially debating while both using the same letter-arrangement to mean something significantly different. I suspect that in this case, you’re dealing with a lot of pro-science types who are exhausted from dealing with people who use ‘random’ to mean ‘uncaused’ (and probably abuse the hell out of the word ‘quantum’) as a way of then getting back-door justification of their favored brand of woo (because if an event can be said to be ‘random’ = ‘uncaused’ then maybe that’s how God/chi/souls/whatever ‘influences’ the world, right?). After awhile of that, your cosmic ray example seems like the only way to refute the woo, and so attributing cancer to ‘chance’ in the more formal meaning of the word sounds like ceding linguistic victory to the faitheads.
The products of chemical reactions, such as may result in point mutations, are also random. When and where they occur cannot be predicted.
All reactions have side products: there are none that give 100% of the thermodynamic or kinetic product. Even a very small percentage of side products means that someone’s going to get one, sometime, in one thing or another. If one randomly occurs in you, on some molecule of importance, and it happens to be an error that persists and isn’t repaired by enzyme activity, you had bad luck. That side product happend to occur in you, in a place that made a difference.
And, given the more-than-astronomical number of times reactions occur in a human body, even extremely small percentages of such errors add up to a significant number of people affected.
I think the insistence that there must be a discreet and identifiable and direct and non-random cause for everything is just a cognitive bias. It has been useful for our species to look for the causes of effects and so we do. It has helped us figure things out. It is just not as generalizable to every sort of phenomenon and every level of analysis as we would wish.
Yes, A ray @ 5 too. The wish to be able to blame victims, to find the smoking gun, to have control + the cognitive bias.
“Luck” is a deepity. It can be interpreted in two ways, one reasonable and one not.
The reasonable meaning of “luck” makes it equivalent to chance, randomness, and factors in the physical causal stream which aren’t controlled by our choices. The irrational, spooky meaning involves magic taking place on the spiritual level, where one’s “luck” can be manipulated by charms, rituals, words, behavior, right thinking, and so forth.
My guess is that some people equate “chance” with “luck” — and then drag in the second interpretation. If it happened by chance then there isn’t a physical explanation — the explanation is ‘metaphysical.’
As an atheist I always feel a bit odd wishing someone “good luck.” I hope the random chances fall your way, but there’s nothing anyone can do about it and my wish doesn’t mean a thing. But it’s a deepity. If supernaturalists CAN interpret it as support for their views, they WILL.
a_ray_in_dilbert_space @6:
My favourite example is the double pendulum. Looks simple, is anything but.
all I can say to this pushback is, error-bars on graphs are not what you think they are. They are there because Every Measurement Has some Noise/Variation Associated With It. Even the “hardest” of sciences recognize that noise is inherent, and must be accounted for in any conclusions. Random is Definitely Science. Science has an entire discipline of accounting for and compensating for random noise. I spent many years working in a hard-science engineering field (disk-drives) and had to deal with random noise events continuously. To say:
“Luck, by definition, has no cause therefore unscientific.”[1]
“random does not mean without a cause – which is what luck means”
is just bafflegab. Luck is a label we use to describe extremes of random distribution. Luck does not mean “without a cause”, It only means: the cause is too complex to explicitly determine the result beforehand, and we’ll just guess what the result will be. If we guess correctly == lucky, guess incorrectly == unlucky. Which, on second thought, makes [1], above, correct. Luck is precisely unscientific to rely on guesswork and not being able to predict the result of an experiment. And Luck has no cause because it aint an event, just a label WE add ex poste facto to another event. Still such events (that we later assign ‘luck’ or ‘bad luck’ to) do happen, do not discount the label so rigorously. ‘Random Event’ is a category label of actual physical events. Do not discount the cause just because you disagree with the label others attached to it.
…
…[I think this here reply to the OP is “noise”, attempting to add to PZ’s response but adding very little, if any.] Maybe they’re right: Everything is caused by something, of which there is a long list of possibilities and to label that list as “random” without itemizing that list, is unscientific. Okay, so go itemize that list of all possible causes and the probability associated with each item. That should keep you busy for several millennia.
Double pendulum.
So that’s where gymnasts get their routines.
Maybe people would find it easier if the results had been phrased as, “Most cancers due to ‘shit happens.'”
I really buy into the idea that humans are storytellers. We need to have a story. There’s the classic example from one of my English classes:
The Queen died.
The King died.
We cannot read those two separate statements without adding a reason in our own heads. It’s why conspiracies are so popular. We don’t want to believe that some random nutjob can assassinate a president in the middle of a parade. We have to add in all of these reasons for it.
That’s why luck, that’s why people can’t understand that sometimes random events just happen.
@5
Yes, more people should take this quote from Babylon 5 to heart:
The analogy that comes to mind for me is tornadoes. Yes, they tend to happen in a semi defined area, but whether my house gets destroyed and my neighbour’s doesn’t is down to chance, the proverbial butterfly effect. There’s a cause, somewhere, but we will never have the ability to trace it.
For me, this is why most languages have an idiom meaning “nothing you can do about it, shit happens”.
Novella:
Not exactly.
What the study says (at least in the brief excerpts I read in the previous post) is that they found a correlation between the total number of cell divisions and the cancer risk for a given tissue. The coefficient of correlation was 0.804. That means that the number of cell divisions accounted for 65% of the variance in cancer risk. Due to the vagaries of sampling error, that percentage actually falls in a broad range, from 39% to 81%, with a confidence interval of 95%.
The variance is a statistical measure of how scattered the data are. To say that you can account for 2/3 of the variance is not the same thing as saying that you can account for 2/3 of the cancers.
Furthermore, the study applied a logarithmic transformation to the cancer risk numbers before doing the statistics. That trick makes the calculations easier, but it further muddles the relationship between “percent of the variance” and “percent of the cancers.”
My kneejerk objection to this perspective, in the context of cancer, is that some could interpret “chance” as a way of getting the producers and distributors of known carcinogens off the hook. (Note that our esteemed host managed to produce hundreds of words on causation of cancer without once saying “carcinogen”…)
I’m fairly sure that my odds of developing tumors – though still ultimately unpredictable – rise and fall in proportion to my exposure to PCBs, ionizing radiation, aflatoxin, etc, etc. We as a society can and should shave the dice accordingly.
William Clark @16: Good old Marcus! I also liked this from Zathras;
Christopher Penny, please allow me to introduce you to a field known as “quantum mechanics”…
Dunc @21: Never mind quantum mechanics. As a_ray and CaitieCat pointed out, even the classical domain is rife with uncertainty. Vary initial conditions ever so slightly (even undetectably), and your house gets blown away, or an asteroid wipes out the biosphere.
I have to wonder how much “chance” is really pure randomness and how much of it is “a myriad of tiny factors beyond our control accumulated over decades that we can’t accurately measure”. Yes, there is the Uncertainty Principle but there’s also that time you had to spend five minutes standing downwind from a cigar smoker 4 years ago.
I also wonder if the resistance to “chance” is the human desire to associate a cause and effect as well as the idea that if something bad happens to you that you somehow did something to deserve it (and its counterpart, if something good happens to me it’s because I worked hard and earned it).
Sounds like people are echoing Einstein — “God does not play dice.” The irony being that this was one of the things Einstein was famously wrong about.
My go-to example of where randomness and probabilities indisputably enter into biology is in the tautomeric shifts (redistribution of electron orbitals) in the bases in DNA.
There are two different tautomeric shifts which can lead to mutational changes. While the normal amino form of adenine pairs with the normal keto form of thymine, the rare imino tautomer of adenine can pair with cytosine. Similarly, while guanine normally pairs with cytosine, thymine, in its rare enol tautomer, will also pair with guanine.
If a tautomeric shift takes place during replication, either in the template chain, or in the deoxyribonuceotide being added by the DNA polymerase, then since the shifted form retains its rare mis-matching structure for only a brief period, the next replication cycle will most likely find it reverted to its normal form, and the polymerase will pair it with its normal mate. Thus, in two cycles of replication, an A-T pair is changed to a G-C pair, or vice versa. This, in turn, can result in a change in a triplet code, leading to an amino acid substitution in a protein.
In a somewhat simplistic description, the shift involves a rare relocation of an electron from a nitrogen through a purine or pyrimidine ring. Any more complete technical description of that, to the best of the ability of modern physics and chemistry, must be a quantum description, which must contain an ineradicable component of uncertainty or randomness (according to the Copenhagen interpretation), or perhaps can be seen as a deterministic result involving quantum correlations with, potentially, the entire universe (according to the Bohm interpretation). In either case, it is part of the absolute unknown, or the absolute elsewhere, both of which can be described by human science only in terms of probabilities. Randomness (or a deep systematic uncertainty) is as undeniable in biology as it is in quantum physics and chemistry.
It means that no prediction of the genetic future of living organisms, from the fate of a single zygote to the projected trajectory of evolution as a whole, can ever be accurately and honestly stated in any other terms than probabilities.
Chance is a dangerous concept for the successful. If chance might kill them, then perhaps chance is involved in their success, and that would never do.
As PZ alluded to, I think the confusion arises because there is a fundamental contradiction between two of our basic models of the world: Our Classical/Quantum theories are deterministic (with a caveat for QM), while Statistical Mechanics/Thermodynamics are inherently probabilistic. This is actually an unsolved problem!
Stat mech relies on an assumption known as the ‘Ergodic hypothesis’ which is in some sense unjustified: Even though in CM/QM we know that the current position of gas particles in a box can be determined from their positions in the past, in thermodynamics we make the (unjustified) assumption that their positions are actually random and independent of their previous positions.
Reconciling these two models is a major ‘foundations’ problem in physics. In fact, one of the winners of the fields medal this year won it for his work in understanding how chaos arises in deterministic systems (both classical and quantum). http://www.quantamagazine.org/20140812-a-brazilian-wunderkind-who-calms-chaos/. Many physicists and mathematiciams have tackled this problem, eg famous results relate to poincare recurrence, and the logistic map, and ergodic theory.
Biology and Chemistry are founded on thermodynamics, so they lean more towards explanations due to ‘chance’. I would guess the people who don’t believe in chance learned their newtonian mechanics but didn’t get to stat mech!
This conversation is strikingly similar to the one I have with people regarding success in business. When an entrepreneur succeeds, everyone talks about xir intelligence, or vision, or drive, or whatever mix of positive and enviable attributes. No one ever talks about the very real contribution that luck provides, being in the right place at the right time with the right combination of finance, partnerships, contacts, market forces and product. And when I point this out, I always hear “I make my own luck.” What a fucking ridiculous platitude. You can’t control everything, and I’d argue you can’t control many of the most important factors in a business operation. You can reduce risk, you can optimize your strengths, you can manage production flow, etc. In the end, it’s all inputs and outputs, and a fervent hope that the decisions you made to position your business were the right ones. Luck always deserves some, if not most, of the credit.
I work in a cancer research biobank and talk with cancer patients nearly every work day about tissue donation and research projects. Typically this is a day or two before a surgical resection. I have noted to my colleagues how frequently cancer patients talk about causation and purpose. Many patients either want to know why they got cancer or already have some firm notion about lifestyle, events in their past, genetics, religion etc. that caused their cancer. I sometimes tried to reassure patients in the past that there may not be a “reason” for their cancer, but it may just be “bad luck”. Some patients do not like (or are even hostile to) this idea and they really seem to think that there HAS to be a reason (that’ s why I stopped suggesting “bad luck” and random chance – now I just listen and try to steer the conversation back to tissue donation and the informed consent process).
For some, it seems easier to undergo a major surgical procedure thinking that their cancer is a punishment for some past transgressions. I wonder if these individuals think the same way about good events. Is it more comforting to think “good luck” is random, but “bad luck” always has a cause and a meaning?
Rob Grigjanis,
That (double pendulum) is the example I use when I want to show people just how crazy the behavior of a simple system can be. Clockwork Universe, my ass!
Have these people ever heard of radioactive decay?
The fuck happened to these so-called sceptics and scientists? It’s not as though anyone having this conversation on this side of the sceptic/woo divide actually thinks that luck is some force in the universe rather than uncontrollable, random chance.
It’s really strange to see people who probably accept that it is impossible to predict which atom in a given sample of radioactive material will next decay and when it will because of randomness, but when it comes to DNA replication errors that cause cancer, can’t accept that it’s the exact same kind of randomness that causes them.
Do they really think that randomness doesn’t scale?
I have so much trouble believing that people won’t accept chance that I begin by assuming they are saying something else. E.g., take the comment by Christopher Penny. Let’s assume that a cell became cancerous due to a copying error. So we have this strand of DNA replicating, and one base is waiting around for its complement. But lots of molecules are moving around, and what do you know? A different base gets stuck there instead. It is not as stable a bond as the complement, but it’s there (actually not sure if this exact scenario is entirely plausible). When the strand replicates again, the wrong base is copied as a mutation and eventually goes on to produce many copies of cancerous cells.
So you could say it has a “cause”. The cause is that a process that almost always matches complement bases just happened to match the wrong one in this case. On the other hand, there is absolutely nothing you can do by changing your environment or behavior to prevent such a cause. So is it deterministic or luck?
What if a stray cosmic ray from a distant supernova just knocked out part of the cell’s DNA? You could say it has a “cause” but what are you going to do about it?
If you’re just allergic to the word “luck” you can call it whatever you like, but it is definitely beyond your control.
Now it’s very obvious to me that everything is subject to hazard, and the best you can hope for is to manage risks, not to “do everything right” and prevent bad things from happening. Is this not obvious to someone like Christopher Penny, or does he believe the same thing, but just doesn’t like to call it luck?
Not sure about any particular individual. I think there really are people who believe nothing bad happens without someone to blame it on, but this view is so alien to me, that I am inclined to give most everyone the benefit of the doubt.
I suspect that the reaction to the idea of chance or random events in biology and cancer stem from the same attitude people have to gambling and games of chance. Not to say that it is the same person but the attitude stems from the same emotional place I am pretty sure.
If we did not tend to have such an irrational attitude toward chance there would not be such places as Las Vegas or Indian Casinos nor would there be lotteries with such astronomical odds against winning as to be almost absurd.
deep down we still seem to want to believe in magic.
uncle frogy
a_ray_in_dilbert_space @ 30:
It’s a clockwork universe, all right. It’s just that the chaotic nature of clocks (and the hard work it takes to keep them regular enough for our purposes) is so easy to ignore.
Oops! I’m late for a meeting again — my watch is slow.
We have a ‘double deepity.’ While many people use random and chance as synonyms (and chance and luck as synonyms), there is a distinction. When throwing a dice, there is a one in six chance of a 3. But a fair dice means that all six outcomes are equally likely, i.e. the out come is random. Or, put another way, while the asteroid striking your house was chance (or luck), It was not random in the sense of one of any number of equally likely outcomes concerning your house. I always laugh when creationists use the phrase ‘random chance.’
I suspect that this type of deterministic thinking, or perhaps the manner in which many are attracted to this kind of deterministic thinking, is a consequence of lingering religious authoritarianism in our culture (even among the less devout), or perhaps a manifestation of the same desire for authoritarianism that itself underlies the appeal of religious authoritarianism. Humans are predisposed to think that all things must have a reason to be, to be part of some larger plan, and if not a plan, then at least a predictable sequence of events that lead logically one to the other. Little disturbs the human psyche more than the idea of unpredictableness.
I think this attitude, “luck-denial” is due to a couple of factors which are particularly strong when it comes to cancers. First, most of us don’t like to think we are not in control of our lives. I’m sure all of us can think of the person who always insists on driving rather than being a passenger, often that person is ourselves. So the idea that we can be struck with an aggressive and fatal illness and there isn’t a damn thing we can to to ward it off is both frightening and even offensive.
Second, is the unfortunate tendency to lump all assaults on our health as “diseases”. So our Type II diabetes that is due to our crappy eating habits, and the flu we got from our office mate who just came back from China and then sneezed on us, and pancreatic cancer, are all of a kind linguistically. So, as the saying goes, “they can put a man on the moon, and they can give us a vaccine for flu, and they can tell us how to avoid diabetes, so why can’t “they” cure or prevent my cancer? Heck, president Nixon even declared a “War on Cancer”, as if all we need is another Jonas Salk and our cancer worries will be over.
Is it too obvious to say that luck is another way of saying random occurrence in the human state. And is it not the case that luck is the one thing theists can’t handle, apart from the truth!
At the deepest of all levels, chemical reactions occur when molecules bump into one another with just the right speed and orientation relative to each other to react. DNA replication is a chemical reaction like any other. The “right” base being inserted into the chain is a reaction. The “wrong” base being inserted into the chain is another, alternate reaction, that occurs at a much lower rate. ie there are many more combinations of speeds and orientations that enable the “right” base to be inserted than there are for the “wrong” base to be inserted, and the shape and chemical properties of the polymerase enzyme complexes impact this. The same is true for all the other kinds of spontaneous mutations.
So perhaps, one day, we will understand the nature of these reactions so well that we will know exactly how and why a mutation occurs, exactly what orientations of atoms and molecules at what specific moments will produce the “wrong” base mutation 100% of the time.
But I cannot foresee how such knowledge could actually allow us to do anything from a practical point of view to prevent or avert the mutation occurring, short of a wholesale genetic re-engineering of the entire polymerase enzyme complex.
And, at the root of it all, the reason that molecules bump into each other with particular speeds and orientations is Brownian motion, and brownian motion is random.
It’s surprising how many people haven’t heard that Laplace’s Demon has long been exorcised.
I’m sort of curious, though: Anyone else find this denial of chance to be extremely similar to Dawkins &co.’s extreme emphasis on the role of adaptive selection in evolution?
@Amphiox #39:
Absolutely true. And this leads us to the obvious 100%-effective* cure for cancer: freeze all human bodies down to absolute zero.
(*Shh! No-one’s allowed to mention anything quantum.)
The thing about chance is that it interferes with a belief in personal responsibility and individual control over one’s own destiny. It supports the belief that some kind of socialized support system for those struck at random and their dependents is a common sense measure. Obviously, the libertarian and libertarian-leaning crowd need chance misfortune not to exist and unfortunately, the libertarian-leaners loom large in a number of cultures, and are not under-represented amongst atheists.
“Luck, by definition, has no cause therefore unscientific.”
Then quantummechanics is unscientific too hence nuclear bombs don’t work. As a teacher physics this makes me smile.
I think there is confusion between ‘random’, meaning equal likelihood, and ‘stochastic’, meaning a bell curve distribution
That’s not what either of those words mean.
Statistician here. Since neither of those terms has the meaning you’ve ascribed to them — at least, not as statistical jargon — there is indeed a confusion. Random and stochastic are synonyms; one uses them to note that one is modeling some real-world phenomenon using the mathematical notion of a random variable. Usually we reserve the word “stochastic” for use as a descriptor of “stochastic processes”, which are infinite collections of random variables with certain consistency properties imposed on them. Equal probability we would call “uniformly distributed”; for the bell curve we say “normally distributed”. This is not exhaustive.
But what I really came here to write was that the idea that everything has to have a “cause” of some sort goes a long long ways; Leibniz, for one, called it the Principle of Sufficient Reason. (Not defending, just noting the history.)
(goes back a long long ways)
Here’s a rather extreme example of this attitude. In my post that PZ links to above, I referenced an article by all purpose crank, quack, and Alex Jones-inspired conspiracy theorist Mike Adams that I had blogged about before here:
http://www.sciencebasedmedicine.org/mike-adams-on-dr-mehmet-ozs-colon-polyps-spontaneous-disease/
Key excerpt:
Alt med is rife with this sort of deterministic thinking, and alt med advocates latch onto every latest scientific field to try to justify it. For instance, lately it’s been epigenetics:
http://www.sciencebasedmedicine.org/epigenetics-it-doesnt-mean-what-quacks-think-it-means/
PZ, I was beginning to worry where you were going with this until you stated:
“…but even if it were found that the universe is completely deterministic, the complexity of the phenomena and the number of parameters means that those kinds of causes are unknowable, and randomness is a good higher-level description of what is going on.”
Well put!
I note that prostate cancer is excluded from the study. The following may be important for male readers. I claim no expertise, just reporting what I’m told by a relevant specialist.
One-in-eight men will get prostate cancer; that figure increases to two-in-eight if your father or a brother has been so diagnosed and rises again to five-in-eight (that’s odds-on folks) if both of them (or two of your brothers) have prostate cancer. The advice is that the sons of men at odds-on risk start getting annual PSA (Prostate Specific Antigen) tests at age 45 (I know they’re not terribly accurate – but get them anyhow).
It’s been almost 90 years since Heisenberg’s uncertainty relation was published, and still most people don’t know that reality is inherently blurry.
This is a massive failure of the school systems of the world.
Radioactive decay has been mentioned. Not only is it truly random*, it is a cause of cancer, and that includes living on top of granite.
* In classical physics, radioactive decay is impossible (at least in the vast majority of cases), because the energy needed for a particle to leave the nucleus is just not there. It is quantum-mechanically borrowed out of nowhere and then disappears again. It is impossible to predict when a particular nucleus will decay, except by stating the nuclide’s half-life; and it is impossible to influence when that will happen, except that the probability can be shifted a bit by the quantum-mechanical means of interacting with the nucleus (“measuring”, “observing” it) again and again.
David Gorski #48 wrote:
In addition to complete empowerment, there also seems to be a strain of magical thinking in alt-med which leans more towards the Spiritual Narrative. Nothing happens by chance, nothing is a coincidence, nothing is random or undetermined. Everything Happens For a Reason — the Universe (Cosmic Consciousness/God/Universal Mind/Spirit) knows what you need in order to learn and grow spiritually. To the believer this can look like they’re giving up power and control. Or so they will argue.
People get cancer then because there is something they will Learn from it. It’s a gift. Alternative medicine is “holistic” and thus takes account of the Spiritual Narrative: disease (or anything distressing, for that matter) will help you in your journey back to the simple, accepting, peaceful view that reality is Love (or whatever the story is this time.) We need to dis-empower ourselves and accept the control of Higher Wisdom. Then we will “heal.”
So both a desire to be in total control of physical reality and a desire to not be in control of anything but your own state of mind would seem to war with each other — but strangely don’t. Both of them emphasize the Power of the Mind and its triumphal battle against the physical world and materialism. And both know that nothing happens without a reason.
Randomness in processes involving genes? Inconceivable! Impossible! That would imply that my unique and special genetic sequence is the product of a shuffling and recombination process that is more or less random and that therefore I am not a special snowflake put on this earth for a specific purpose.
#51
Apparently, that is not completely true:
Source
Tellingly, iodine-129 doesn’t shoot out neutrons if left to its own devices. It undergoes ordinary β decay: rather than leaving, the neutron turns into a proton, which stays, and an electron and an antineutrino, which leave.
I’ve never understood this desire to be a machine that was built for a purpose, for performing a particular task. I can’t empathize with it. *shrug*
David Marjanović @51:
This wording is nonsense, implying there is something mysterious going on. I’d call it a classical hangover.
The possibility of decay follows from the Schrodinger equation, which allows quantum tunneling through classically forbidden regions. There is no borrowing of energy.
I think a lot of people really need to be in control, for many of those people religion is how they try to control what is really the uncontrollable . For a subset of those people science fulfills the same purpose of trying to control the uncontrollable. Science is much more helpful when it comes to controlling certain events but luck, both bad and good is going to play a major factor in almost anyone’s life.
David Marjanović #55
I think when people say they exist for a “purpose” they’re not talking about some kind of function. I think they mean “purpose” in the metaphysical sense, in that vague sort of “I exist because of a grand, significant, greater plan.”
While the conclusions may be correct, the number of assumptions that went into those estimates of total stem cell divisions make the path to those conclusions somewhat suspect in my opinion.
I’d say that there might be some very good reasons to avoid the specific word “luck”, which is overloaded with plenty of superstitious nonsense as others have noted, but the other words don’t really carry that baggage, so I don’t know why “random” or “chance” should cause legitimate objections.
I’m not an expert so I may botch this, but my understanding is that in classical physics, the technical term for many things that are often described as “random” is actually “chaotic”. A chaotic system is any system where small uncertainties in initial conditions result in increasingly large uncertainties as the system evolves. (I think I have that right.) In principle, everything in the system is obeying the laws of physics deterministically, but because there is no escaping at least some uncertainty in initial conditions, there’s no way to directly calculate the outcome. So, you model it statistically, which often requires treating certain events as purely random, and you get a useful answer.
Maybe you could avoid some of the pushback by, when appropriate, using “chaotic” instead of the seemingly more loaded word “random”, but … you know … probably not.
Well, some phenomena in classical physics are chaotic. They are deterministic in principle, but sensitivity to initial conditions makes exact predictions far into the future impractical. (With what “far into the future” means depending on the system being studied.)
Chaotic and random are not synonyms.
I believe they are having much better results for prostrate cancer diagnosis by using MRIs in post PSA testing for targeted biopsies.
I don’t think so Tim. I’ve seen the “orbits” of chaotic behavior in reactors. Actually, what happens is that pattern is regular enough that after X orbits, the dye in the non-newtonian fluid actually lines back up (almost) like when it was added. Very interesting.
I don’t know a whole lot about this stuff but this description does not paint an accurate picture of the whole process. It leaves one with the impression that recombination events are completely random throughout the genome. Take PRDM9 for instance, which codes for recombination hotspots, differentiated from nearby DNA which is recombinatorially suppressed. The magic finger turns out to be a zinc finger!
Pierce R. Butler @19: that is of course the argument constantly made by people getting rich off selling carcinogens. The problem is that it’s hard to sound-bite how much environmental factors can affect one’s risk of developing cancer even though that risk remains small. If exposure to a particular toxin changes the odds from 1 in ten million to 1 in a million, that’s a huge increase in your risk – but the excuse becomes “well, it must just be chance, because only one in a million people get it.”
People don’t like feeling helpless. They don’t want to think that one could get cancer no matter what you do. So they try to find causes of cancer that they can control. I am approaching 50 years old and I am thinking, well, I’m past the age when I could have gotten an autoimmune disorder. But now I’m approaching the decades when I could get cancer. Then I remind myself not to dwell on this thought because it will lead to too much anxiety. I just found out my 12 year old niece has type 1 diabetes. I don’t want her to have this disease but there is nothing I can do. It’s just hard to realize there was nothing that could be done to prevent her getting diabetes.
Just because something is a matter of luck doesn’t mean you always have the same outcomes. If you have money, the stupid little things that happen randomly in anyone’s life only have minor consequences. Your car breaks. You pay to fix it. You get sick. You take time off and get medical care until you recover. Those are random events. If you are poor, your car breaks and you might lose your job, get kicked out of your house and so on. If you get sick, your life goes to hell. Chance is a major factor in medical bankruptcies, but not everyone is playing with the same payouts.
You can also influence the odds. Driving is a matter of luck. You can’t actually pay attention to what is in front of you, on the left and on the right all at the same time. You need to manage a mixed strategy and learn to hedge your bets. That guy might come out of the driveway on the right, so slow a bit and shift to the left. Wear a seat belt, so if luck fails you don’t slam into the windshield. It pays to be sober; it gives extra milliseconds when executing your mixed strategy. Chance is a big factor, but there are things that can improve the odds.
It’s like in Las Vegas. There are better and worse strategies for every game, even if the game is just a matter of luck. You’ll still lose money, but you do have some control. (For example, journalists know the old roulette trick of betting one color and a number of the opposite color to maximize table time while on the job.)
Rob Grigjanis, @22:
That’s true. Perhaps what I should have said was “Christopher Penny, please allow me to introduce you to a successful type of business known as a ‘casino’.”
And this whole business is a perfect example of why they’re successful.
#63.
There is a very close connection. A chaotic system exhibits sensitive dependence on initial conditions: anything less than perfect knowledge of initial conditions will soon lead to exponential divergence of orbits, which means that after a characteristic time scale, distance of two close-by initial points will double, after the same interval it will quadruple, etc. But, the orbits usually stay within a bounded area/volume, which means we can calculate the frequency of visiting a certain “locus” fairly accurately.
That is why, in chaotic systems, we can usually have an excellent statistical description, while we cannot have a detailed description of an orbit. Very often, any set of initial conditions will spread almost uniformly on the whole area, which means the statistical picture is absolutely clear: “anything goes, on an equal footing”.
This actually models chance IRL very well: Think of car accidents: we can never know that driver X will collide with driver Y, but we can predict average number of accidents accurately enough to calculate insurance fees.
Continuing on #71: There is, however, a difference between randomness caused by chaotic behaviour and stochastic randomness.
Chaos can result from fairly small and simple causes: Rob Grigjanis already mentioned the double pendulum, a very good example. Stochastic randomness, OTOH, results from a multitude of factors that act independently and on the average cancel each other. One of the challenges in the study of dynamical systems is to find ways to discern stochastic randomness from chaos.
@ William Clark, #16:
Sorry, but that argument is completely backwards: if life were fair, then all these terrible things wouldn’t happen to us, because we wouldn’t deserve them!
It’s pushback because, no matter how rational we want to try to be, realizing how much of life is chance puts paid to concepts like “free will” and “responsibility.”
God does play dice with the universe. In fact it’s like a great big D&D game: roll 3d20 and if they all come up zero you get asteroid breakfast. So much for your healthy lifestyle.
What really fascinates me about this stuff is how we understand causality. It’s like it’s nature, not nurture, that we scope causes so tightly that we boil things down to a single cause for a single effect, when the reality is that causality is a huge web. Why did the chicken cross the road? Because of the big bang. For animals that evolved as hunter-gatherers that’s probably not a view of causality that encourages survival as much as “the chicken crossed the road to get away from me because I wanted to kill and eat it.” But we always want ONE answer to questions “why?” When there are really many: “it crossed the road because chickens evolved from dinosaurs that survived…” If we actually tried to process cause and effect that way our distant ancestors would have starved to death.
We still have a responsibility to manage risk, independent of the outcome. Unfortunately, people who take foolish risks often get credit if the outcome is good. E.g. Ronald Reagan is more likely to get credit for causing the fall of the Soviet Union than blame for nearly starting WWIII.
Neither are exactly true, since the USSR was already falling apart, and a nuclear war could have started under any mid-to-late 20th century president. But it was a bad historical period to have a movie cowboy in the White House and the fact that by luck we made it through does not make Ronald Reagan an exemplar of great decision making.
Or for a less loaded example, if I told you that I had pocketed $50k over 50 years by somehow avoiding fire insurance, would you call me smart or an idiot? Does it make a difference if my house burnt down or not?
In short, there is still a lot to be said for free will and responsibility, but you cannot look at an individual outcome and conclude that it was the “deserved” consequence of leading life in a particular way.
Probably a good idea, considering that there are deterministic versions of quantum mechanics (Everett and Bohm, for instance) which match the predictions of theories/interpretations which say things are intrinsically random. (They also don’t say “measurements” or “observations” are magical and inexplicable violations of the deterministic evolution of the wavefunction, or some such nonsense.) How could that be, you might ask? It should be clear that there’s a big difference between the world being a certain way on the one hand and us knowing/detecting/predicting things about it on the other. The one which actually matters to us in most cases is our inability to detect or predict what does/will happen, based on the limited data we can have. And of course, besides that, you can very well have statistics dealing with ensembles of things (which aren’t all exactly identical) in a deterministic world. It shouldn’t be surprising at all that there are probabilities or distributions or chaotic behaviors or what have you, because the world’s a big complicated messy place.
That’s funny, because countless people throughout history have claimed exactly the same thing about determinism. So determinism and indeterminism don’t seem to have anything to do with it — just the confusions people conjure up about what all of these things supposedly mean.
consciousness razor,
I don’t know any physicist who takes Bohm seriously, and the Many Worlds Intrpretation (Everett’s) is simply looked on as a curiosity. These approaches do not solve the measurement problem and provide no metaphysical (or any other) advantages over the conventional approaches.
By the way–part of the problem is the difficulty of defining “random”. No one has yet developed a satisfactory answer.
consciousness razor @76: Determinism in a black box you can never open hardly merits the name.
Just for fun: Norton’s Dome: A Simple [apparent] Violation of Determinism in Newtonian Mechanics.
Maybe you don’t know many physicists. But since this isn’t a popularity contest and your claim has nothing to do with the science, I’ll just let that go without any further comment.
I have no idea where you got that idea, because they do solve it. Since you give no argument for that, I won’t bother with one either, and we’ll just contradict one another. I doubt Everett is even coherent and can account for our experiences properly, but that’s neither here nor there when it comes to whether or not it’s a deterministic theory with the same empirical content as indeterminstic ones, which is the point I wanted to raise.
GRW is another which also solves the measurement problem, yet it is an example of a probabilistic/random theory which actually has collapses and takes those seriously as real things which need to be understood and explained. It also may very well be wrong, but it’s at least an attempt to make a coherent and scientific hypothesis about it, instead of the handwaving bullshit which is usually offered. The thing is, I don’t especially care either way about determinism or indeterminism at the fundamental level (as I already said, we have to deal with a practical kind of being-unable-to-determine stuff either way). But those are the sorts of options we actually have. What’s your proposal, if it’s not somehow equivalent to one of them? And what exactly is different about it?
As for metaphysical advantages, if you can’t tell me how exactly I’m in this location right now, as opposed to somewhere else, because I’m made of “probabilities” somehow or because those are all spread out all over the universe or because there’s no such reality at the “micro” level or there’s nothing which is really the case until you “observe” me, I think any that nonsense is a huge metaphysical problem for you. However, I’m not sure which you consider the “conventional approaches.” The one in which you can kill a cat with your mind by looking at it certainly has its share of metaphysical problems, along with being completely fucking absurd.
In Bohm, for example, there’s a very clear ontology: there are particles which move, and (not surprisingly) the laws of motion describe how the particles move. In most other cases, I can’t tell what the fuck the theories are even saying about the world, because it’s just pure gibberish. That’s a non-starter for me, determinism or no determinism. Maybe you don’t worry about it very much, but it’s definitely something.
consciousness razor #76
I don’t think it is confusion as much as a tendency to internalize credit and externalize blame (or the other way around for certain personality types). Then, to avoid making this look completely arbitrary, you wrap a philosophical veneer around it. So it does not result from confusion. Rather, the confusion is maintained (usually without conscious effort) in order to assign blame and credit as you see fit.
I would argue that credit and blame are both primarily human accounting mechanisms. I believe they serve as the underpinnings of ethics and our sense of purpose. I’m not a nihilist. These things are just as real as anything else humans care about. But I don’t think they arise in any way from our understanding of physics, whether stochastic or deterministic.
“The authors assume that lifestyle and genetic factors affect the risk of tissue specific cancers, but not cancer in general. This study would miss, however, lifestyle or genetic factors that affected the risk of all cancers (regardless of tissue type) equally.”
Exactly my point from the previous thread.
Everettian QM is most definitely not “just” a curiosity: a recent major exposition, The Emergent Multiverse by David Wallace, last year won the Lakatos award for best philosophy of science. People are taking it seriously – and for good reason too. You’ll also find that many physicists are, in fact, Everettians to some degree, even if they are themselves unaware. Basically anyone who thinks that decoherence is a dynamical substitute for collapse is ready to bite the Everettian bullet of many worlds. :)
As for stochasticity in Everett, the entire universe evolves purely deterministically, but if you restrict your attention to a particular subsystem, an observer, you’ll see that their experience of quantum measurements can be, to a good approximation, described as stochastic. So the randomness is there, but only emergently. So PZ’s hunch that quantum physics kicks the ladder under determinism as experienced by agents is absolutely correct under the Everett interpretation.
consciousness razor @76: My formal training in QM ended after undergrad physical chemistry (my graduate training was in molecular biology), but what you say about the QM situation is pretty much how I have understood it since Bernard D’Espagnat’s article “The quantum theory and reality” (Scientific American 1979).
Your first point where I agree: Whether you prefer your QM to be local but indeterminate (Copenhagen) or non-local and determinate (Bohm), the important point is that what we can know/detect/predict has limits, not just as a matter of practicality, but by the nature of the universe in which we find ourselves.
I thought D’Espagnat explained the trade-offs very well, but I couldn’t understand why he preferred the Bohm interpretation (as apparently you do too; my non-technical intuitive take was that they were really equivalent, as I understand many physicists do take them to be). But the Templeton folks and other peddlers of spiritual quantum woo saw some advantages — if the absolute truth is “out there,” even in the “absolute elsewhere,” as a “veiled reality,” and is not just made up locally as it goes along as Bohr suggests, then there must be a god who is privy to it all, and if we pray hard enough, maybe he’ll give us a peek. And Jesus has a plan for your life which he has revealed to me… To his credit, even after he won the Templeton prize, I believe D’Espagnat never himself endorsed any of the theological speculation that was tied to the non-local interpretation.
As for Everett, I don’t know enough about it to judge, though I am encouraged when Dominik Miketa (@82) says “the randomness is there, but only emergently.” If not skeptical, I would at least be disappointed in any interpretation that eliminates randomness (or otherwise thoroughly hidden parameters) and so gives shelter to those who would claim access to occult knowledge. Does anyone know of an article or book that explains it as well as D’Espagnat did for locality/non-locality? Is “The Emergent Multiverse” by David Wallace suitable for non-specialists?
And the second point where I agree: Once we are free of the falsely certain predictions of religion, or purely Newtonian physics, (or misrepresented QM), then determinism and indeterminism don’t have anything to do with questions of free-will and responsibility. Dan Dennett finally convinced me of that in “Freedom Evolves”. We can either face the uncertainties with a limited but evolving and expanding “free-will worth having”, or, as Dennett says, we can choose to make ourselves so small that we simply disappear.
Scientismist,
Yes, The Emergent Multiverse is a wonderful book and if you’ve had undergraduate training in QM, you’ll be perfectly able to follow most of the meaty material! :) There are a few more technical chapters but as with any work of philosophy, you’re free to skim and skip. The author was a physicist before turning to philosophy, so he’s very down-to-earth in his writing. Also, if you’ve liked Dennett, you’ll find a lot that you like in this, too. (Full disclaimer: David’s my teacher so I may be a bit biased.)
As a taster, have a look at .
Biology is statistics. Also, just because something is statistically random doesn’t mean there’s not a mechanistic cause. We know what factors can cause the genetic mutations that lead to cancers, but whether or not those factors lead to cancer is what is random.
Damn – something happened to the link. I meant https://www.youtube.com/watch?v=GRJT9qY21nA
Sure, that’s a fine point, and I don’t have much reason disagree with it. The nature of the universe is such that, for instance, we never have simple cases like Norton’s dome to ever worry about something like that being a realistic situation. It’s actually much worse than that, as far as predictability goes. It’s not so much a “practical” issue that the world is enormous and enormously complicated: of course that is the case in reality, no matter what you want to say about practicality or our practices/methodology.
I would argue you can’t get away from some kind of nonlocality if you’re going to make the right predictions. (Of course, it’s hard to say what locality or nonlocality would even mean according to Everett, but I mean leaving that aspect of it aside.) But there are more and less extreme and nonsensical ways of dealing with nonlocality, I think. The nonlocality in “Copenhagen” just isn’t noticeable anywhere in any equation, because the game there is basically to say “then a miracle occurs” whenever there is a collapse. What supposedly happens according to their story? The wavefunction of the entire universe, including of course spacelike separated regions, decides instantly that you make a measurement/observation (or more simply that some particle/field/whatchamacallit interacts with the object in question). The point is to say the equations work … except when they don’t. But say it in a very sophistimicated way using lots of jargon. Then you’re out of equations, so you jam in a “solution” by hand when necessary. Then, as is traditional, you’re supposed to pretend like this isn’t really a problem and no real physicist ever really believed any such thing. Of course, you’re also supposed to claim that according to Einstein (you know: relativity guy), the biggest problem is supposedly the “indeterminism” or that “God plays dice”! Not the (at least apparent) conflict with relativity, oh no. There’s no problem with that; nothing to see here.
The real miracle here is that they managed to pull that kind of shit for so long, with such an extraordinarily powerful theory, while making such great predictions/experiments/etc. But you say Copenhagen is supposed to be “local”? Unless it’s supposed to be wrong or not even about reality, I just don’t know about that. It’s definitely absurd.
I think people’s problem with “luck” specifically is its association with the odious but catchy notion of fate, karma and positive energy, with pop superstitions suck as lucky socks or lucky rabbit’s feet, all things which we definitely don’t consider “science”.
But of course there’s another luck, and that’s appropriate when talking about things like cancer: in our human lives influenced by a set of individual chance events we interpret them to create meaning. Getting cancer is bad luck.
Scientismist @83: You might be interested in a critique of Wallace (and others) by Adrian Kent: (PDF) One world versus many: the inadequacy of Everettian accounts of evolution, probability, and scientific confirmation.
Consciousness razor, sorry to disappoint, but I am a physicist with over 30 years of experience. I used to write for a physics magazine. I have no problem telling you where you are, as you are a macroscopic object, and the uncertainty in your position is too small to measure, even in principle. Why do you think the same rules should apply to objects with masses 10^32 times smaller? No physicist I know (and I know a few thousand of them) takes the Everett theory seriously. No one I know teaches it. No QM text treats it seriously.
consciousness razor @87:
If you think this is Copenhagen, we’ve been reading very different sources. The wave function is an expression of the observer‘s knowledge of a system, nothing more. The double-slit experiment doesn’t have a “wavefunction of the entire universe” in it, as far as I know.
I’m not sure what you mean by this. Can you give an example?
a_ray_in_dilbert_space:
Sean Carroll takes it seriously. Philosophers of physics – the people whose job it is to make sense of QM – are starting to take it very seriously, as evidenced by the recent prestigious award. There are reasons why textbooks don’t tend to teach it and that’s a) the interpretation, in its strongest form, is fairly recent and b) it requires decoherence to make sense, and decoherence isn’t typical undergraduate material. That said, some of the recent textbooks, including James Binney’s, do cover decoherence at least in a rudimentary way, and they do make the connection to wavefunction collapse. The Everett interpretation is then only a few steps away.
I’d also wager that there may be a lot of geography at play here, too. Everett tends to be more accepted in Britain, especially around Oxford – I know that the current lecturer of undergrad QM at Oxford holds Everettian QM in high regard, even as he stays a bit on the fence. He also doesn’t teach it to undergrads (at least right off the bat), precisely because it’s more technically involved and requires decoherence. When you look at the States, on the other hand, then you have some Everettians at the West Coast, but otherwise they’re few and far between. So far! :)
Just out of curiosity, are you acquainted with the current state of the Everettian programme? I understand that it must seem positively wacky if you haven’t looked more closely at the technical nitty-gritty of it, but it’s really quite neat and requires only that you jettison the collapse postulate; everything else (arguably) follows.
Rob Grigjanis:
Kent’s article’s from Many Worlds (2007 I believe) and a huge chunk of The Emergent Multiverse (2012) reacts to a lot of those criticisms, especially when it comes to theory confirmation in an Everettian universe. It’s good to know that dissent exists, but there are naturally also responses available. Which one of Kent’s criticisms do you think’s the most damning?
Rob Grigjanis:
You and consciousness razor are, I think, both correct: “The Copenhagen interpretation” refers to multiple (incompatible) ideas on how to think about QM. It’s becoming customary to refer to consciousness razor’s understanding of the Copenhagen interpretation as “the textbook interpretation”, which I feel captures it fairly well. It’s a realist interpretation, where the wavefunction indeed represents a physical state. The collapse is an actual physical process changing the wavefunction with a probabilistic outcome. And that seems to be more on the right track than Copenhagen because, after all, quantum interference is a real thing responsible for e.g. shapes of orbitals of atoms and molecules, or indeed the outcome of the double-slit experiment. It may be a personal fault of mine, but I’ve never been able to understand how an epistemic explanation of the double-slit experiment, a la Copenhagen, could ever work.
Dominik @92:
Cripes, I’ve only read the intro. It’s on, but far down, my own ‘to read’ list, I’m afraid. Just thought it might be of interest. My own attitude towards interpretations is fairly well summed up by Alain Aspect here.
Rob Grigjanis:
Haha that’s okay. :) It’s always good to flag critics.
I think I know where Aspect’s coming from: you can do physics perfectly well without settling on an interpretation, so if what you care about is the process of doing physics, you’re totally fine without one! But I feel you’d give up on trying to understand what the world’s like, which is what science has always been about – with the possible exception of QM. It’s a really weird exception and almost makes one think that maybe we’re just doing QM wrong.
Dominik: I’m a simple man. I always enjoyed doing the calculations, but the Deep Thinking just made my head hurt. :)
What role did Johnny Walker Black play in Hitchens’ oesophageal cancer? What role did smoking play in John Wayne’s lung cancer?
One cancer is not the same as another, and while there are cancers that as far as we know today are probably mostly attributable to bad luck or winning the wrong kind of lottery, such as certain brain cancers or hematological cancers, there are others like the ones mentioned above that were at least “encouraged” by environmental factors like smoking, drinking, exposure to chemicals(like asbestos).
I read that and wondered what it actually means. Say I get bladder cancer because I worked in the wine industry and was exposed to pesticides, and then get a brain tumour on top of it? That’s bad luck then?
I think this discussion, from a medical point of view, is lacking a bit of nuance. Not every cancer has the same cause, probability, genetic susceptibility, environmental susceptibility. And of course, ignore the base rates at your peril.
Crap.
I’ll try again:
Tunneling is what I was trying to talk about: as you say, it’s impossible in classical physics, because the particles in question don’t have the energy that’s necessary to get through the barrier.
I agree, however, that putting it in terms of borrowing energy may not be the best way to talk about it. Another way to put it, as far as I can tell, is that their energy is uncertain enough that the uncertainty includes values higher than the barrier.
Yet another way to put it, as far as I can tell, is that their location is uncertain enough that it includes values on the other side of the barrier.
That just means their function is to carry out their part of that plan. :-|
Also, you’re not a single object, not even a Bose/Einstein condensate. You consist of 10^32 (or whatever) particles plus their interactions.
re @99:
You got my Quantum weirdness started. I.E. the idea that particles exist as discrete objects with certain values of energy is merely the “classical” theory. Quantum theory is built around the concept that we can only measure those values with a minimum amount of mismeasurement (noise). The model then goes on to describe everything in terms of ‘probability of detecting it at this place/time.’ Tunneling accounts for the probability function having a non-zero value on the other side of an energy barrier. Thus, there is a chance of detecting the particle on the far side of the barrier; where classical theory would declare impossible. The kludgy concept of ‘borrowing energy’ to get over the barrier, is definitely a kludge, as the probability of detecting the particle with that borrowed energy is Zero. One just has to accept probability functions as the “ultimate model of ‘spooky’ particles.” (particles are “spooky” cuz we can model them as either objects or waves, and it is impossible to pin them down as particle or wave) [and tunneling is especially “spooky”]
twas brillig @100:
To Einstein, it was entanglement, which he called “spukhafte Fernwirkung” (“spooky action at a distance”). Yeah, it’s classically weird. So what? It doesn’t violate causality. It just makes some folk talk about “instantaneous wave function collapse”, which doesn’t make any sense to me. If A measures something, A might then be able to say what B will measure, but how does this “instantaneous collapse” affect B “instantaneously”? It doesn’t. B may go on to measure, and they will find the complementary result. A and B may then communicate and see that there is correlation. The problem seems to arise from taking a God’s eye view (and a classical one at that). QM don’t work that way. Embrace the weirdness!
I’ve had a chance to think about randomness and causality recently, and the idea that randomness is often considered (incorrectly) to mean “uncaused”, and I realized that randomness is really about *correlations* between two variables. For example, if we take a time series of temperatures every day we’ll see a definite pattern (nonrandom) over the year, with warmer temperatures in the summer for the Northern hemisphere and colder temperatures in winter. But there will still be a lot of variation around that trend, and if we subtract the trend we may find this variation corresponds to random noise – i.e. mathematically speaking the distribution is indistinguishable from a random one. We might get the same thing if instead of looking at the temperature every day over a year, we looked at the temperature on the same day every year for a century (and global warming didn’t exist).
The difference between the trend and the noise isn’t that one is caused and the other isn’t; the temperature of a given day is completely caused, by many factors such as the elevation of the Sun in the sky, cloud cover on that day, the temperature on the previous day, etc. It’s just that one of these factors is correlated with the time of the year (elevation of the Sun), and the others aren’t. If instead of taking a time series over the year we’d plotted the temperature on a given day vs the temperature on the previous day we’d have had a completely different trend, and we’d still have had random noise left over, to account for the causes of temperature that aren’t related to the temperature on the previous day.
That’s why flipping a coin is random; every outcome has completely deterministic causes, but those causes are completely unrelated to our X-axis of choice, i.e. “this is the nth toss”.
So really things are only ever random with respect to something else. When we say cancers are random we aren’t saying they’re random with respect to everything, i.e. uncaused. If we plotted the movements of molecules at every cell division vs odds of cells becoming cancerous we’d find correlations. But aside from being impractical, that wouldn’t give us much practical helpful information; we’re interested in the relationship between cancer and macroscopic factors we can control or easily measure. And it’s relative to those factors that cancer is largely random.