Is Dark Matter Supernatural?

No, it’s not. Don’t be alarmed: nobody is claiming that dark matter is supernatural. That’s just the provocative title of a blog post by Chris Schoen, asking whether science can address “supernatural” phenomena. I think it can, all terms properly defined.

This is an old question, which has come up again in a discussion that includes Russell Blackford, Jerry Coyne, John Pieret, and Massimo Pigliucci. (There is some actual discussion in between the name-calling.) Part of the impetus for the discussion is this new paper by Maarten Boudry, Stefaan Blancke, Johan Braeckman for Foundations of Science.

There are two issues standing in the way of a utopian ideal of universal agreement: what we mean by “supernatural,” and how science works. (Are you surprised?)

There is no one perfect definition of “supernatural,” but it’s at least worth trying to define it before passing judgment. Here’s Chris Schoen, commenting on Boudry et. al:

Nowhere do the authors of the paper define just what supernaturalism is supposed to mean. The word is commonly used to indicate that which is not subject to “natural” law, that which is intrinsically concealed from our view, which is not orderly and regular, or otherwise not amenable to observation and quantification.

Very sympathetic to the first sentence. But the second one makes matters worse rather than better. It’s a list of four things: a) not subject to natural law, b) intrinsically concealed from our view, c) not orderly and regular, and d) not amenable to observation and quantification. These are very different things, and it’s far from clear that the best starting point is to group them together. In particular, b) and d) point to the difficulty in observing the supernatural, while a) and c) point to its lawless character. These properties seem quite independent to me.

Rather that declare once and for all what the best definition of “supernatural” is, we can try to distinguish between at least three possibilities:

  1. The silent: things that have absolutely no effect on anything that happens in the world.
  2. The hidden: things that affect the world only indirectly, without being immediately observable themselves.
  3. The lawless: things that affect the world in ways that are observable (directly or otherwise), but not subject to the regularities of natural law.

There may be some difficulty involved in figuring out which category something fits, but once we’ve done so it shouldn’t be so hard to agree on how to deal with it. If something is in the first category, having absolutely no effect on anything that happens in the world, I would suggest that the right strategy is simply to ignore it. Concepts like that are not scientifically meaningful. But they’re not really meaningful on any other level, either. To say that something has absolutely no effect on how the world works is an extremely strong characterization, one that removes the concept from the realm of interestingness. But there aren’t many such concepts. Say you believe in an omnipotent and perfect God, one whose perfection involves being timeless and not intervening in the world. Do you also think that there could be a universe exactly like ours, except that this God does not exist? If so, I can’t see any way in which the idea is meaningful. But if not, then your idea of God does affect the world — it allows it to exist. In that case, it’s really in the next category.

That would be things that affect the world, but only indirectly. This is where the dark matter comparison comes in, which I don’t think is especially helpful. Here’s Schoen again:

We presume that dark matter –if it exists–is lawful and not in the least bit capricious. In other words, it is–if it exists–a “natural” phenomena. But we can presently make absolutely no statements about it whatsoever, except through the effect it (putatively) has on ordinary matter. Whatever it is made of, and however it interacts with the rest of the material world is purely speculative, an untestable hypothesis (given our present knowledge). Our failure to confirm it with science is not unnerving.

I would have thought that this line of reasoning supports the contention that unobservable things do fall unproblematically within the purview of science, but Chris seems to be concluding the opposite, unless I’m misunderstanding. There’s no question that dark matter is part of science. It’s a hypothetical substance that obeys rules, from which we can make predictions that can be tested, and so on. Something doesn’t have to be directly observable to be part of science — it only has to have definite and testable implications for things that are observable. (Quarks are just the most obvious example.) Dark matter is unambiguously amenable to scientific investigation, and if some purportedly supernatural concept has similar implications for observations we do make, it would be subject to science just as well.

It’s the final category, things that don’t obey natural laws, where we really have to think carefully about how science works. Let’s imagine that there really were some sort of miraculous component to existence, some influence that directly affected the world we observe without being subject to rigid laws of behavior. How would science deal with that?

The right way to answer this question is to ask how actual scientists would deal with that, rather than decide ahead of time what is and is not “science” and then apply this definition to some new phenomenon. If life on Earth included regular visits from angels, or miraculous cures as the result of prayer, scientists would certainly try to understand it using the best ideas they could come up with. To be sure, their initial ideas would involve perfectly “natural” explanations of the traditional scientific type. And if the examples of purported supernatural activity were sufficiently rare and poorly documented (as they are in the real world), the scientists would provisionally conclude that there was insufficient reason to abandon the laws of nature. What we think of as lawful, “natural” explanations are certainly simpler — they involve fewer metaphysical categories, and better-behaved ones at that — and correspondingly preferred, all things being equal, to supernatural ones.

But that doesn’t mean that the evidence could never, in principle, be sufficient to overcome this preference. Theory choice in science is typically a matter of competing comprehensive pictures, not dealing with phenomena on a case-by-case basis. There is a presumption in favor of simple explanation; but there is also a presumption in favor of fitting the data. In the real world, there is data favoring the claim that Jesus rose from the dead: it takes the form of the written descriptions in the New Testament. Most scientists judge that this data is simply unreliable or mistaken, because it’s easier to imagine that non-eyewitness-testimony in two-thousand-year-old documents is inaccurate that to imagine that there was a dramatic violation of the laws of physics and biology. But if this kind of thing happened all the time, the situation would be dramatically different; the burden on the “unreliable data” explanation would become harder and harder to bear, until the preference would be in favor of a theory where people really did rise from the dead.

There is a perfectly good question of whether science could ever conclude that the best explanation was one that involved fundamentally lawless behavior. The data in favor of such a conclusion would have to be extremely compelling, for the reasons previously stated, but I don’t see why it couldn’t happen. Science is very pragmatic, as the origin of quantum mechanics vividly demonstrates. Over the course of a couple decades, physicists (as a community) were willing to give up on extremely cherished ideas of the clockwork predictability inherent in the Newtonian universe, and agree on the probabilistic nature of quantum mechanics. That’s what fit the data. Similarly, if the best explanation scientists could come up with for some set of observations necessarily involved a lawless supernatural component, that’s what they would do. There would inevitably be some latter-day curmudgeonly Einstein figure who refused to believe that God ignored the rules of his own game of dice, but the debate would hinge on what provided the best explanation, not a priori claims about what is and is not science.

One might offer the objection that, in this view of science, we might end up getting things wrong. What if there truly are lawless supernatural actions in the world, but they appear only very rarely? In that case science would conclude (as it does) that they’re most likely not supernatural at all, but simply examples of unreliable data. How can we guard against that error?

We can’t, with complete confidence. There are many ways we could be wrong — we could be being taunted by a powerful and mischievous demon, or we and our memories could have randomly fluctuated into existence from thermal equilibrium, etc. Science tries to come up with the best explanations based on things we observe, and that strategy has great empirical success, but it’s not absolutely guaranteed. It’s just the best we can do.

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60 Responses to Is Dark Matter Supernatural?

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  2. Ron says:

    Obligatory quote from Roger Zelazny’s “Lord of Light”:

    “Then the one called Raltariki is really a demon?” asked Tak.

    “Yes—and no,” said Yama. “If by ‘demon’ you mean a malefic, supernatural creature, possessed of great powers, life span, and the ability to temporarily assume virtually any shape—then the answer is no. This is the generally accepted definition, but it is untrue in one respect.”

    “Oh? And what may that be?”

    “It is not a supernatural creature.”

    “But it is all those other things?”


    “Then I fail to see what difference it makes whether it be supernatural or not—so long as it is malefic, possesses great powers and life span and has the ability to change its shape at will.”

    “Ah, but it makes a great deal of difference, you see. It is the difference between the unknown and the unknowable, between science and fantasy—it is a matter of essence. The four points of the compass be logic, knowledge, wisdom and the unknown. Some bow in that final direction. Others advance upon it. To bow before the one is to lose sight of the three. I may submit to the unknown, but never to the unknowable. The man who bows in that final direction is either a saint or a fool. I have no use for either.”

  3. Moshe says:

    There is one point that bothers me in your position, which is that science makes a sharp distinction between regularities – repeatable phenomena that are subject to precise laws, and contingent facts that are viewed as accidents of history and thus not in need of an explanation (lawless, if you wish). You may believe, as I do, that science can in principle explain every observed phenomena, but in practice there is always a boundary between these two types of observations, and that boundary is time-dependent, culture-dependent, and theory-dependent.

  4. pheldespat says:

    Dark matter is fictional. So is dark energy.

  5. AnotherSean says:

    Since I hold the probability of our memories being a result of random fluctuations at zero, my guess is that science can explain all events and objects in the natural world. Is everything in the natural world? That isn’t clear at all to me. What about the natural laws themselves? Surely science must believe in them. What else do we search for? Then we face the question of the rest of mathematics, that part of the Hilbert space that doesn’t seem relevant for physics. But take it away and we are left without foundatioin to construct field theory. I just think these are incredibly difficult issues and no simple position seems adequate.

  6. DamnYankees says:

    Sean, your final argument doesn’t make a lot of sense to me. You state that it would be possible for evidence to pile up which would force scientists to conclude that a lawless force was the best answer, but all I could think of was…how? What possible events could *ever* cause scientists to conclude and come to a consensus on a lawless force?

    Putting aside the whole notion of a “lawless force” being rather meaningless to me, I fear you haven’t done the heavy lifting necessary to explain how this could happen. Wouldn’t any collection of observable data merely lend itself to theorizing new laws? At what point would it ever be possible to make the leap from “unknown law” to “lawless”? I really don’t get it.

    And this is always my biggest problem with the supernatural, and it’s something you never addressed – what is the difference between “unknown natural” and “supernatural”? Both practically and analytically, I don’t think there is one. I think it’s literally the exact same thing, and it’s a semantic shell game to let people inflate the word “supernatural” into anything other than nonsense.

  7. HFB says:

    To follow up on Moshe: There are indeed among us “things that affect the world in ways that are observable (directly or otherwise), but not subject to the regularities of natural law” — Human beings. Our behavior is quite unpredictable. Reductionists believe this is the result of ignorance only, and eventually a theory will emerge that can describe, and predict, human behavior with mathematical precision. This belief is founded on the philosophical (I might almost say “religious”) assumption that science can explain all well-observed behavior. However, based on the evidence to date, might we not be justified in concluding, if only as a working assumption, that “the best explanation” for human behavior is “one that involved fundamentally lawless behavior”?

  8. Doug Watts says:

    Dark matter is fictional. So is dark energy.

    Explain the documented rotational velocity of galaxies without the former.

    Then remember Paul Dirac predicted the existence of antimatter solely because a mathematical solution allowed a positive and negative solution.

  9. whoschad says:

    Wouldn’t the “Multiverse” be considered supernatural? It’s certainly not ‘natural’ in the sense that it exists as part of our universe. At the very least, it would be supranatural.

  10. AJKamper says:

    I love this post, because it’s something that nagged at me for some time. I once suggested that there were two types of unpredictable behaviors: 1) Stuff that was unpredictable because they were too complex for us to handle, and 2) Stuff that was unpredictable because it was fundamentally “lawless,” to use your word. (I called such phenomena “perverse,” after how Riviera described himself in Neuromancer, and because it’s an awesome word.)

    As does Damn Yankee, however, I end up disagreeing with your conclusion, because of that Type I unpredictability. In order to convince ourselves that a phenomenon was fundamentally lawless, it would have to be explored so thoroughly that all complexity about the object was thoroughly understood. This is conceivable, I guess, but in the long run unlikely. More probably, such phenomena would arise from a situation where there were so many confounding variables that scientists would simply determine there was some other cause that was as yet undiscovered.

    I’ve always thought–and HFB touches on this as well–that the hypothesis of “free will” is the perfect test case for lawless behavior, because it’s essentially lawless by definition, asserting that an entity’s action can not be predicted from the initial conditions and the laws of physics. So to try to ground this question, could science ever conclude that free will exists? What would it take? Is it possible, practically speaking, to develop such a comprehensive knowledge of the brain that all natural explanations could be ruled out?

    Fun stuff.

  11. Joseph Smidt says:

    So if dark matter weighs as much as a duck then….. a witch! It’s Supernatural!

  12. Sean says:

    To take this question seriously, we first have to be willing to imagine the existence of truly lawless phenomena (not reducible in terms of patterns) that intervene substantially in the world. If you can’t believe any such thing could exist, the question becomes pointless, granted.

    But if there could be such a thing, how do you think that science would deal with it? Do you really think that, even in principle, there is no point at which scientists would accept (what by hypothesis is) the truth and say “Well, we’d love to find some regularities here, but we’ve looked and looked and just can’t do it. The best we can do, given the knowledge we have, is to classify this as truly lawless behavior, subject of course to revision if we get better information or new ideas.”

    I see no reason why that couldn’t happen. Scientists try their best to deal with reality as it is, whatever that may be.

  13. DamnYankees says:


    I understand what you are saying, but I simply can’t get past the “can this thing even exist as a coherent word” thing. It seems to me that you (and other like Coyne) are doing your darndest to simply work around this question, which to me is folly. Jerry Coyne has had multiple posts the last few weeks about this question, an in every comments section there are legions shouting for him to please give a coherent definition of the supernatural, and unless I missed it he hasn’t yet done it.

    I am totally in agreement with you that *given* coherence, we should be able to make parameters for detecting a certain phenomenon. But lawlessness is incoherent! I mean, that’s just so key I don’t even see how we make it to the next step. As people interested in truth, as I hope you are, it seems you are devoting a rather small amount of attention to this rather massive problem. Asking for scientists to entertain the possibility of using lawlessness as an explanation is paradoxical on it’s face, because it’s impossible.

    Unfortunately, I don’t think you’ve managed to answer the question I posed. In your initial post, you said there could be a time where a pile of evidence would force us to entertain the possibility of lawlessness as a possibility. And then I asked you how this point could ever be reached – it seems theoretically impossible, due to the Humean-miracle-probablity problems.

    And to answer your direct question to me, I in fact would hope that scientists would never try to classify anything as lawless, because that’s an incoherent claim. It makes no sense. It would seem to me to take a very arrogant scientist indeed to say “I’ve discovered the principle of lawlessness which breaks all known laws of reality” when that person could say “there’s a law here to be learned, just like there has been for all of our history of scientific endeavors – let’s get back to work.”

    How could we ever cross that gorge from “we don’t know what law underlies this” to “no law underlies this”. Isn’t this just Intelligent Design and an argument from incredulity wrapped up in a bow of theoretical philosophizing? This is the Intelligent Design of Isaac Newton, pointed out by Neil DeGrasse Tyson.

  14. Phil says:

    “there is data favoring the claim that Jesus rose from the dead: it takes the form of the written descriptions in the New Testament. Most scientists judge that this data is simply unreliable or mistaken, because it’s easier to imagine that non-eyewitness-testimony in two-thousand-year-old documents is inaccurate that to imagine that there was a dramatic violation of the laws of physics and biology. ”
    But isn’t there some sort of eyewitness testimony in the New Testament? The author describes appearances by Jesus to some of his disciples. Not sure if that consititutes “eyewitness testimony”.

    “Similarly, if the best explanation scientists could come up with for some set of observations necessarily involved a lawless supernatural component, that’s what they would do.”
    So how come the scientific community doesn’t conclude that the Big Bang was caused by God and that the laws of physics, as well as the constants of nature, were planned by God? I mean, the laws and constants are just right for the existence of life. If the cosmological constant were just a little bit off, in either direction, the universe might not be hospitable for life. That’s what the observations suggest. We have not observed, directly or indirectly, the existence of a multiverse containing universes with a spread of different laws and constants. We have no reason to think — yet at least — that string theory is correct. So how come scientists just say, “Ah, this looks like the work of a supernatural entity.”?

  15. AJKamper says:

    Damn Yankee, you’re going to have to do a lot more legwork before you can possibly assert the incoherence of “lawlessness” as if it were unimpeachable fact. Maybe you did on Coyne’s blog (I’ve never gotten around to reading it). But I think that the simple suggestion that our understanding of causation is mistaken and too-grounded in our limited reality might create room for lawlessness to be coherent.

  16. SteveB says:

    @Ron. Thanks for reminding me of the Zelazny passage. Good fit.

    As to:

    1.The silent: things that have absolutely no effect on anything that happens in the world.
    2.The hidden: things that affect the world only indirectly, without being immediately observable themselves.
    3.The lawless: things that affect the world in ways that are observable (directly or otherwise), but not subject to the regularities of natural law.

    I agree with @whoschad and would put Multiverse into (1) — apologies if I read you wrong.

    Now (2) and (3) have a place in science. Hard work over many years has moved many things that were in those catagories to commonly accepted scientific fact or theory. I think dark matter and dark energy are currently hidden, but, as Sean points out, there are some hypotheses that try to provide falsifiable tests for them. I think a lot of work is left there, but one should not dismiss them out of hand. Come up with a better explanation if you don’t like the current favorite.

    What I might put into (3) are turbulence, or fracture mechanics, or weather forcasting. One can get a good estimate, good statistics, but it will never be perfect. (I know you were referring to more spectacular hidden phenomena and you have answered in Item 12.) The closest I have ever been to being satisfied with a scientific description of them from close to first principles is how Stuart Kaufman describes the products of interacting non-linear systems and the resulting (“emerging?”) complexity.

    No interest on my part bringing religion into this.

  17. DamnYankees says:


    Fair enough. I’ll try to explain it.

    To me, lawlessness means that an observation can’t be reduced to an interaction of facts. Independent facts. So, for example, when we talk about throwing a baseball, that baseball moves as a relationship between the matter in the ball, the matter of the air and the weather, and various other variables. The relationship between those things is what is the “law” – matter moves by the laws of gravity and the force of the throw blah blah blah.

    So what would it means for something to be lawless? It would mean that something happens and there’s no relationship we can decipher. There’s no constituent parts. There is no way to say “this happening is a relationship between X and Y”. And as far as I know, EVERY “event” in the history of the known world can be described this way. After all, every event takes place in space and in time, and thus has to obey those laws.

    So what would it mean to look at an event and say it obeys no laws? I literally have no idea. I can’t fathom what such an event could ever be. Any possible event you propose to me would obey these parameters. I admit I come up against what seems to me to be impossible. And therefore, the “lawless” can’t exist, because I can’t even concieve of such a thing in theory. Like a square circle.

    Now, I can see you objecting that I’m merely making an argument from incredulity or ignorance. Fair enough – but that’s what I’m faced with. Please provide me with an example of something (or a type of something) which would be lawless, as opposed to something which merely obeys unknown laws, and I’ll reconsider. In other words, give me some alternate definition to work with and I’ll go so if I find it compelling.

  18. JimV says:

    Phil @14, please see this on the issue of “fine tuning”:

    My short version is that it is no surprise and no coincidence that our body chemistry is well-adapted to the the physical laws of this universe – because we evolved in this universe. In a different universe, with different laws, different creatures would evolve. And as universes go, this one is not especially hospitable to our kind of life (look at all the empty real estate in it). We happen to occupy a very small niche, and yet somehow manage to tell ourselves that the whole thing must have been created with us in mind. That has always seemed kind of arrogant to me.

    In addition to the categories Sean gave, which I like, I think there is another, which a previous commenter alluded to: stuff that is too complex for us to understand. Chimpanzees have some reasoning ability, but they probably will never be able to figure out the laws of electricity or combustion. I suspect there are things which will remain beyond our ken also – trivially true in my case, but maybe also true for our greatest thinkers.

    There needs to be some further gradation of lawless also, I think. There are lots of things which we can describe probabilistically, like radioactive decay, but which cannot be predicted as individual events. Is “lawless” just another way of saying the probability distribution is unknown?

  19. Ossicle says:

    AJK (#10),

    Good comment. However, in terms of human (apparent) free will, I can’t help but think it belongs in the same category, however vastly different it is in its particulars, as chaotic phenomena like the weather. If the weather, consciousness, etc. were to turn out to be things we could call lawless because we were never able to (slight paraphrase here) “explore them so thoroughly that all complexity about them was thoroughly understood,” such “lawlessness” seems categorically different than the sort of lawlessness anyone talks about when they talk about the “supernatural.” For one thing, the weather and the human mind occur within very mundane substances, i.e., the atmosphere and the brain, so even if they were to prove intractably complex, it seems (again) categorically different than “supernatural” phenomena, which seem, in general, to be rogue causal agents. (“Where’s that ghost who haunts my house live?” “Where do those angels go when they’re not around?” “What are they made of?”) If these things were to exert influence in the world, they would be more baffling, and in a different way, than the emergent behavior of air currents and nerve impulses.

    Sorry, #10, not sure how much this has to do with your comment, in the end! Was just what made me think about the above.

  20. Blake Stacey says:

    To take this question seriously, we first have to be willing to imagine the existence of truly lawless phenomena (not reducible in terms of patterns) that intervene substantially in the world. If you can’t believe any such thing could exist, the question becomes pointless, granted.

    If by “reducible in terms of patterns” we mean “predictable using a well-defined combination of computations”, then “lawless” is just a synonym for random, and we can reason about “lawless” phenomena using ordinary probability theory. A long sequence of observations of a “lawless” phenomenon should have high Kolmogorov complexity, or else we could propose a scheme for predicting the results of observations to come; but it should also have low Kolmogorov complexity, or else it would be Martin-Loef random and thus susceptible to probabilistic description.

    In other words, nobody has been able to explain to me what they mean when they talk about “lawlessness”.

  21. I’d prefer not to go off on a tangent on how C. S. Lewis defined Miracles and grappled with some metaphysical paradoxes about them (which today would be reformulated in terms of Closed Timelike Curves).

    Blake Stacey makes several cogent points in #20, which affect how one interprets “the free will theorem of John H. Conway and Simon B. Kochen, which states that, if we have a certain amount of “free will”, then, subject to certain assumptions, so must some elementary particles. Conway and Kochen’s paper was published in Foundations of Physics in 2006, has a newer axiomatization, and provoked a flood of arXiv papers about “lawlessness” as embodied in this strange take on “free will.”

    I had quite an interesting conversation with Gregory Chaitin and
    Stephen Wolfram at the conference in Boston that I attended 3 or 4
    years ago, where I ran the Physics track of the international event…

    Chaitin was quite convincing in pointing out things that Leibniz wrote
    that only now make sense to a modern Mathematician, and still in
    possible conflict with some deep musings of my friend Feynman.

    The key issue being whether we live in a LAWFUL universe. Determined
    by the complexity of the system of natural laws. Which presupposes
    that there are a finite number of natural laws, does it not? Feynman
    was not sure of this. Could there be an infinite number of natural
    laws, but finitely generated from meta-laws?

    Jim Stasheff asked me or Chaitin, I forget which, whether “‘natural
    laws’ formed an algebra.”

    He said: “there could easily be infinitely many generated by finitely
    many or is that what you meant by ‘meta’ as opposed to ‘of some higher order.’

  22. Lab Lemming says:

    If you look at prevailing scientific theory as having the greatest explanatory utility, then the treatment of outlier events can be considered as follows: Does complicating the theory to include such events reduce its applicability to ‘well behaved’ data? If so, then you can compare the frequency of outliers to the reduction in normal predictive ability to see whether inclusion or exclusion of outliers produces the best overall prediction.

  23. KWK says:

    The idea of multiple universes was raised by a few commenters, and while I also think they fit into category 1) due to their lack of observability, more interesting to me is their relationship to 3). Multiple universes have allowed many people to engage in what appears to me to be some really shoddy philosophy and (meta-)physics, hiding any proposed “lawlesness” behind a fig leaf of infinite (but untestable!) statistical resources:
    “Our universe is highly fine-tuned with respect to X, for no known reason? Well, umm…the Multiverse did it! Problem solved!”

    I don’t see how this is any different than saying “God did it!”–which is obviously not a scientific statement either, but at least (most) theologians are honest about the nature of their claim.

  24. DaveH says:

    I think using “lawlessness” to describe some hypothetical supernatural event is creating a generalized subcategory which has no specific examples. When someone posits the supernatural they never mean just a lawless event; they usually mean there is some supernatural entity causing the event.

    I think you are making an unnecessary (and meaningless) concession to the idea of supernatural causes, Sean.

  25. DamnYankees says:


    The difference between “the multiverse did it” and “god did it” is vast. The latter is an explanation which attempts to explain the particulars of our Universe to the whims of an intelligent agent, staking it’s credibility on the foundation that our universe is indeed unique. The multiverse explanation is entirely different, making the claim that our universe is in fact *not* unique, but merely one of many, and we just happen to live in this one.

    They are extremely different claims. Analogize to a poker game where you are dealt a Royal Flush. One person says “man, you were lucky – of all the possible combinations you got that one!” and someone else says “clearly a wizard arranged your perfect hand”. You think these are the same kinds of explanations for your good luck?