Category Archives: Uncategorized

When Wholes Become Parts

By Robin Hanson · January 18, 2019 2:15 pm · Comments (0)

Here’s a nice simple general principle to describe many kinds of systems. When once self-sufficient wholes join together to become parts of a new whole, the parts get simpler and also more different from one another:

The emergence of a higher level entity with functional capabilities is ordinary accompanied by the loss of part types within the lower-level organisms that constitute it. Thus … cells in multicellular organisms will have fewer part types than fee-living protists. … The lower-level organisms are transformed into differentiated parts within the higher-level entity. Along with this, as size increases, parts emerge at an intermediate scale, between the lower level organisms and the higher-level entity. …

In the evolution of multicellularity, cells are transformed from organisms into different tailed parts. Then, as the size of the multicellular entity increased, cells combined to form larger parts, intermediate in scale between as cell and the multicellular organism as a whole. … Cells in metazoans and land plants have fewer part types on average than free-living protists. … found a power law relationship between size and number of cell types in multicellular organisms. Also, the degree of morphological, physiological, and/or behavioral differentiation – in insect societies increases with colony size.

From: Daniel McShea and Carl Anderson. (2005) “The Remodularization of the Organism”, in Werner Callebaut and Diego Rasskin-Gutman, eds., Modularity: Understanding the Development and Evolution of Natural Complex Systems, pp. 185-206, MIT Press, May.

That is, while each cell might in essence need legs, eyes, a mouth, and a stomach, when cells join together they can each live without such things, and they may specialist in order to become part of a leg, eye, etc. for the new organism.

This has an obvious implication for our future. As we humans join together into larger more complex social organizations, our descendants will likely also become simpler and more differentiated. Of course there are limits on how fast these things can change today. Also, the cells in each organism now have a great many parts, and remain similar to each other in a great many ways. Change would likely become much faster if ems become possible.

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Have A Thing

By Robin Hanson · January 10, 2019 1:40 pm · Comments (1)

I’m not into small talk; I prefer to talk to people about big ideas. I want to talk big ideas to people who are smart, knowledgeable, and passionate about big ideas, and where it seems that convincing them about something on a big idea has a decent chance of changing their behavior in important ways.

Because of this, I prefer to talk to people who “have a thing.” That is, who have some sort of abstract claim (or question) which they consider important and neglected, for which they often argue, and which intersects somehow with their life hopes/plans. When they argue, they are open to and will engage counter-arguments. They might push this thing by themselves, or as part of a group, but either way it matters to them, they represent it personally, and they have some reason to think that their personal efforts can make a difference to it.

People with a thing allow me to engage a big idea that matters to someone, via someone who has taken the time to learn a lot about it, and who is willing to answer many questions about it. Such a person creates the hope that I might change their actions by changing their mind, or that they might convince me to change my life hopes/plans. I may convince them that some variation is more promising, or that some other thing fits better with the reasons they give. Or I might know of a resource, such as a technique or a person, who could help them with their thing.

Yes, in part this is all because I’m a person with many things. So I can relate better to such people. And after I engage their thing, there’s a good chance that they will listen to and engage one of my things. Even so, having a thing is handy for many people who are different from me. It lets you immediately engage many people in conversation in a way so that they are likely to remember you, and be impressed by you if you are in fact impressive.

Yes, having a thing can be off-putting to the sort of people who like to keep everything mild and low-key, and make sure that their talk has little risk of convincing them to do something that might seem weird or passionate. But I consider this off-putting effect to be largely a gain, in sorting out the sort of people I’m less interested in.

Now having a thing won’t save you if you are a fool or an idiot. In fact, it might make that status more visible. But if you doubt you are either, consider having a thing.

Added 11p: Beware of two common failures modes for people with things: 1) not noticing how much others want to hear about your thing, 2) getting so attached to your thing that you don’t listen enough to criticism of it.

Note also that having things promotes an intellectual division of labor, which helps the world to better think through everything.

Added 11Jan: Beware a third failure mode: being more serious or preachy than your audience wants. You can be focused and interesting without making people feel judged.

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Gender Is Big

By Robin Hanson · January 9, 2019 8:00 am · Comments (1)

Consider the possibility of discrimination against the left-handed. Such discrimination might make efficiency sense in contexts where expensive-to-change complementary equipment is designed for the right-handed. Such as pilots. In other contexts, one might justify mild discrimination based on weak correlations, such as between handedness and intelligence, gender, and health. But these other factors tend to be directly observable, and correlations are weak. So stronger correlations of handedness with success, especially where not explained by these other correlations, are suspicious.

What do we suspect? One possibility is political equilibria wherein an established group of insiders arbitrarily favor people like them against outsiders. We might especially suspect this if we saw people rewarding others for discriminating against the left-handed, as something like this would need to be part of an insiders-favoring political equilibria. It is plausible, though not obvious, that disrupting such an insider-favoring equilibria is good for the world. So we might consider prohibiting or at least hindering discrimination against left-handers. (One might also just think we are in a bad choice out of multiple equilibria, and not blame insiders so much.)

This all makes sense as a way to think about discrimination for what are arguably relatively minor, or small, features such as height or hair-length. But now consider gender. It seems to me that the above framework is far less useful for gender, as gender is not remotely a small feature.

For most people, their main long-term spouse is the most important relationship in their life. And most care greatly about the gender of that spouse. It isn’t just ordinary “straight cis” people who think this way. Gay/lesbians also mostly agree that the genders differ greatly in important features, and they have a strong preference for one end of the gender spectrum. In part because others care about gender, most people also care greatly about how others see their own gender. Most transgender people also care a lot (almost by definition) about how others see their gender; they just make unusual choices about that. So most everyone agrees that most everyone cares a lot about the genders of their associates, and the genders that others assign to them.

Some may postulate gender as an innate atomic feature of the universe of human concerns, so that when we desire that an associate have a certain gender that has nothing to do with their many other associated features. But that seems crazy to me. Much more plausibly, what we like about a gender is strongly tied to the set of associated features that tend to go along with that gender. That is, we like the package of features that “are” a gender. In this case, the fact that we strongly care about genders suggests that different genders differ greatly in many features that are important to us. These features probably include habits, attitudes, preferences, and abilities. Gender is big, and it matters a lot.

Because gender is big, we expect it to correlate substantially with many features that we care about when assigning people to roles. But this means that even strong correlations of gender with success in particular roles is at best only a weak cause for suspicion about insider-favoring or other bad equilibria. There are just too many other good reasons to expect to see large gender-role correlations.

Now you might argue that today’s large correlations between gender and important features are largely a legacy resulting from a bad past. And change takes time. So creating pressures for low gender-role correlations today will push us to move faster toward a better future, even if that costs us today in terms of matching people to roles well.

However, the prospects for a world anytime soon where different genders correlate little with other important features seems to me quite low. (As low as the chance that communist governments would rapidly “whither away” to produce “true” communism.) Yes, gender correlations have changed across societies and across time, but almost always there have been strong correlations between gender and important things. The fact that societies with weaker gender roles have more strongly gendered personalities also (weakly) suggests to me that we fundamentally want genders to differ, even if we aren’t that stuck on most particular differences. We want gender to be big; we want to love and be loved by people that differ from us in big known ways.

Thus I don’t see gender-success correlations as by themselves offering much of a justification for anti-discrimination efforts today to suppress such correlations. At least they don’t in terms of disrupting insider-favoring or other bad equilibria, or in terms of promoting a low-gender-differences future. But I do see some other justifications, which I may write about in future posts.

It seems to me that our public discussion about gender has for a while been somewhat in denial about the likely long continuation of strong gender correlations with important features. If the genders continue to act differently on average, then observers will naturally form gendered expectations based on such behavior. That is, there will be gender roles. We can and should talk about what we want those gender roles to be, but we can’t do that until we admit that such roles will exist.

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Replication Markets Team Seeks Journal Partners for Replication Trial

By Robin Hanson · January 8, 2019 1:20 pm · Comments (2)

An open letter, from myself and a few colleagues:

Recent attempts to systematically replicate samples of published experiments in the social and behavioral sciences have revealed disappointingly low rates of replication. Many parties are discussing a wide range of options to address this problem.

Surveys and prediction markets have been shown to predict, at rates substantially better than random, which experiments will replicate. This suggests a simple strategy by which academic journals could increase the rate at which their published articles replicate. For each relevant submitted article, create a prediction market estimating its chance of replication, and use that estimate as one factor in deciding whether to publish that article.

We the Replication Markets Team seek academic journals to join us in a test of this strategy. We have been selected for an upcoming DARPA program to create prediction markets for several thousand scientific replication experiments, many of which could be based on articles submitted to your journal. Each market would predict the chance of an experiment replicating. Of the already-published experiments in the pool, approximately one in ten will be sampled randomly for replication. (Whether submitted papers could be included in the replication pool depends on other teams in the program.) Our past markets have averaged 70% accuracy, and the work is listed at the Science Prediction Market Project page, and has been published in Science, PNAS, and Royal Society Open Science.

While details are open to negotiation, our initial concept is that your journal would tell potential authors that you are favorably inclined toward experiment article submissions that are posted at our public archive of submitted articles. By posting their article, authors declare that they have submitted their article to some participating journal, though they need not say which one. You tell us when you get a qualifying submission, we quickly tell you the estimated chance of replication, and later you tell us of your final publication decision.

At this point in time we seek only an expression of substantial interest that we can take to DARPA and other teams. Details that may later be negotiated include what exactly counts as a replication, whether archived papers reveal author names, how fast we respond with our replication estimates, what fraction of your articles we actually attempt to replicate, and whether you privately give us any other quality indicators obtained in your reviews to assist in our statistical analysis.

Please RSVP to: Angela Cochran, PM acochran@replicationmarkets.com 571 225 1450

Sincerely, the Replication Markets Team

Thomas Pfeiffer (Massey University)
Yiling Chen, Yang Liu, and Haifeng Xu (Harvard University)
Anna Dreber Almenberg & Magnus Johannesson (Stockholm School of Economics)
Robin Hanson & Kathryn Laskey (George Mason University)

Added 2p: We plan to forecast ~8,000 replications over 3 years, ~2,000 within the first 15 months.  Of these, ~5-10% will be selected for an actual replication attempt.

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Umpires Shouldn’t Be On Teams

By Robin Hanson · January 7, 2019 2:00 pm · Comments (1)

There are many complex issues to consider when choosing between public vs private provision of a good or service. But one issue seems to me to clearly favor the private option: rights. If you want to make rights-enforcing rules that are actually followed, you are better off having courts or regulators enforcing rules on a competitive private industry.

Consider this excellent 2015 AJPS paper:

Many regulatory policies—especially health, safety, and environmental regulations—apply to government agencies as well as private firms. … Unlike profit‐maximizing firms, government agencies face contested, ambiguous missions and are politically constrained from raising revenue to meet regulatory requirements. At the same time, agencies do not face direct competition from other firms, rarely face elimination, and may have sympathetic political allies. Consequently, the regulator’s usual array of enforcement instruments (e.g., fines, fees, and licensure) may be potent enough to alter behavior when the target is a private firm, but less effective when the regulated entity is a government agency. …

The ultimate effect of regulatory policy turns not on the regulator’s carrots and sticks, but rather on the regulated agency’s political costs of compliance with or appeal against the regulator, and the regulator’s political costs of penalizing another government. One implication of this theory is that public agencies are less likely than similarly situated private firms to comply with regulations. Another implication is that regulators are likely to enforce regulations less vigorously against public agencies than against private firms because such enforcement is both less effective and more costly to the regulator. …

We find that public agencies are more likely than private firms to violate the regulatory requirements of the [US] Clean Air Act and the Safe Drinking Water Act. Moreover, we find that regulators are less likely to impose severe punishment for noncompliance on public agencies than on private firms. (more)

See also:

There is evidence … that [public entities] are [better] able to delay or avoid paying fines when penalties are assessed. (more)

Public sector employees experienced a higher incidence rate of work-related injuries and illnesses than their private industry counterparts. (more)

I’ve tried but failed to find stats on public vs private relative rates of abuse, harassment, bribery, embezzlement, nepotism, and test cheating. (Can you find more?) But I’d bet they’d also show government agencies violating such rules at higher rates.

This perspective seems very relevant to criminal justice reform. Our status quo criminal justice system embodies enormous inefficiencies and injustices, but when I propose changes that involve larger roles for private actors, I keep hearing “yes that might be more efficient, but won’t private actors create more rights violations?” But the above analysis suggests that this gets the comparison exactly wrong!

Yes of course, if you compare a public org that has a rule with a private actor to whom no such rules applies, you may get more rule “violations” with the latter. And yes, enforcement of central rules can be expensive and limiting, so sometimes it makes sense to use private competition as a substitute for central rules, and so impose fewer rules on private actors. But once we allow ourselves to choose which rules to impose, private orgs seem just overall better for enforcing rules.

Note that when a government agency directly contracts with a specific private organization, using complex flexible terms and monitoring, as in military procurement, the above theory predicts that this contractor will look much more like an extension of the government agency for the purpose of rule enforcement. Rule enforcement gains come instead from private orgs that compete to be chosen by the public, or that compete to win simple public prizes where public orgs do not have so much discretion over terms that they can pick winners, but get blamed for rights violations of losers.

It is these independent private actors that I seek to recruit to reform criminal justice. We will get more, not less, enforcement of rules that protect rights, when the umpires who enforce rights are less affiliated with the teams who can violate them.

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Most Progress Not In Morals

By Robin Hanson · January 6, 2019 8:00 pm · Comments (1)

Everyone without exception believes his own native customs, and the religion he was brought up in, to be the best. Herodotus 440bc

Over the eons, we humans have greatly increased our transportation abilities. Long ago, we mostly walked everywhere. Then over time, we accumulated more ways to move ourselves and goods faster, cheaper, and more reliably, from boats to horses to gondolas to spaceships. Today, for most points A and B, our total cost to move from A to B is orders of magnitude cheaper than it would be via walking.

Even so, walking remains an important part of our transport portfolio. While we are able to move people who can’t walk, such as via wheelchairs, that is expensive and limiting. Yet while walking still matters, improvements in walking have contributed little to our long term gains in transport abilities. Most gains came instead from other transport methods. Most walking gains even came from other areas. For example, we can now walk better due to better boots, lighting, route planners, and paved walkways. Our ability to walk without such aids has improved much less.

As with transport, so with many other areas of life. Our ancient human abilities still matter, but most gains over time have come from other improvements. This applies to both physical and social tech. That is, to our space-time arrangements of physical materials and objects, and also to our arrangements of human actions, info and incentives.

Social scientists often use the term “institutions” broadly to denote relatively stable components social arrangements of actions, info and incentives. Some of the earliest human institutions were language and social norms. We have modestly improved human languages, such as via expanded syntax forms and vocabulary. And over history humans have experimented with a great range of social norms, and also with new ways to enforce them, such as oaths, law, and CCTV.

We still rely greatly on social norms to manage small families, work groups and friend groups. As with walking, while we could probably manage such groups in other ways, doing so would be expensive and limiting. So social norms still matter. But as with our walking, relatively little of our gains overtime has come from improving our ancient institution of social norms.

When humans moved to new environments, such as marshes or antic tundra, they had to adapt their generic walking methods to these new contexts. No doubt learning and innovation was involved in that process. Similarly, we no doubt continue to evolve our social norms and their methods of enforcement to deal with changing social contexts. Even so, social norm innovation seems a small part of total institutional innovation over the eons.

With walking, we seem well aware that walking innovation has only been a small part of total transport innovation. But we humans were built to at least pretend to care a lot about social norms. We consider opinions on and adherence to norms, and the shared values they support, to be central to saying who are “good” or “bad” people, and who we see as in “our people”. So we make norms central to our political fights. And we put great weight on norms when evaluating which societies are good, and whether the world has gotten better over time.

Thus each society tends to see its own origin, and the changes which led to its current norms, as enormously important and positive historical events. But if we stand outside any one society and consider the overall sweep of history, we can’t automatically count these as big contributions to long term innovation. After all, the next society is likely to change norms yet again. Most innovation is in accumulating improvements in all those other social institutions.

Now it is true that we have seen some consistent trends in attitudes and norms over the last few centuries. But wealth has also been rising, and having humans attitudes be naturally conditional on wealth levels seems a much better explanation of this fact than the theory that after a million years of human evolution we suddenly learned how to learn about norms. Yes it is good to adapt norms to changing conditions, but as conditions will likely change yet again, we can’t count that as long term innovation.

In sum: most innovation comes in additions to basic human capacities, not in tweaks to those original capacities. Most transport innovation is not in improved ways to walk, and most social institution innovation is not in better social norms. Even if each society would like to tell itself otherwise. To help the future the most, search more for better institutions, less for better norms.

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Tales of the Turing Church

By Robin Hanson · January 2, 2019 3:25 pm · Comments (0)

My futurist friend Giulio Prisco has a new book: Tales of the Turing Church. In some ways, he is a reasonable skeptic:

I think all these things – molecular nanotechnology, radical life extension, the reanimation of cryonics patients, mind uploading, superintelligent AI and all that – will materialize one day, but not anytime soon. Probably (almost certainly if you ask me) after my time, and yours. … Biological immortality is unlikely to materialize anytime soon. … Mind uploading … is a better option for indefinite lifespans … I don’t buy the idea of a “post-scarcity” utopia. … I think technological resurrection will eventually be achieved, but … in … more like many thousands of years or more.

However, the core of Prisco’s book makes some very strong claims:

Future science and technology will permit playing with the building blocks of spacetime, matter, energy and life in ways that we could only call magic and supernatural today. Someday in the future, you and your loved ones will be resurrected by very advanced science and technology. Inconceivably advanced intelligences are out there among the stars. Even more God-like beings operate in the fabric of reality underneath spacetime, or beyond spacetime, and control the universe. Future science will allow us to find them, and become like them. Our descendants in the far future will join the community of God-like beings among the stars and beyond, and use transcendent technology to resurrect the dead and remake the universe. …

God exists, controls reality, will resurrect the dead and remake the universe. … Now you don’t have to fear death, and you can endure the temporary separation from your loved departed ones. … Future science and technology will validate and realize all the promises of religion. … God elevates love and compassion to the status of fundamental forces, key drivers for the evolution of the universe. … God is also watching you here and now, cares for you, and perhaps helps you now and then. … God has a perfectly good communication channel with us: our own inner voice.

Now I should note that he doesn’t endorse most specific religious dogma, just what religions have in common:

Many religions have really petty, extremely parochial aspects related to what and when one should eat or drink or what sex is allowed and with whom. I don’t care for this stuff at all. It isn’t even geography – it’s local zoning norms, often questionable, sometimes ugly. … [But] the common cores, the cosmological and mystical aspects of different religions, are similar or at least compatible.  …

Even so, Prisco is making very strong claims. And in 339 pages, he has plenty of space to argue for them. But Prisco instead mostly uses his space to show just how many people across history have made similar claims, including folks associated with religion, futurism, and physics. Beyond this social proof, he seems content to say that physics can’t prove him wrong: Continue reading "Tales of the Turing Church" »

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Toward An Honest Consensus

By Robin Hanson · December 31, 2018 3:15 pm · Comments (2)

Star Trek original series featured a smart computer that mostly only answered questions; humans made key decisions. Near the start of Nick Chater’s book The Mind Is Flat, which I recently started, he said early AI visions were based on the idea of asking humans questions, and then coding their answers into a computer, which might then answer the same range of questions when asked. But to the surprise of most, typical human beliefs turned out to be much too unstable, unreliable, incoherent, and just plain absent to make this work. So AI research turned to other approaches.

Which makes sense. But I’m still inspired by that ancient vision of an explicit accessible shared repository of what we all know, even if that isn’t based on AI. This is the vision that to varying degrees inspired encyclopedias, libraries, internet search engines, prediction markets, and now, virtual assistants. How can we all coordinate to create and update an accessible shared consensus on important topics?

Yes, today our world contains many social institutions that, while serving other functions, also function to create and update a shared consensus. While we don’t all agree with such consensus, it is available as a decent first estimate for those who do not specialize in a topic, facilitating an intellectual division of labor.

For example: search engines, academia, news media, encyclopedias, courts/agencies, consultants, speculative markets, and polls/elections. In many of these institutions, one can ask questions, find closest existing answers, induce the creation of new answers, induce elaboration or updates of older answers, induce resolution of apparent inconsistencies between existing answers, and challenge existing answers with proposed replacements. Allowed questions often include meta questions such as origins of, translations of, confidence in, and expected future changes in, other questions.

These existing institutions, however, often seem weak and haphazard. They often offer poor and biased incentives, use different methods for rather similar topics, leave a lot of huge holes where no decent consensus is offered, and tolerate many inconsistencies in the answers provided by different parts. Which raises the obvious question: can we understand the advantages and disadvantages of existing methods in different contexts well enough to suggest which ones we should use more or less where, or to design better variations, ones that offer stronger incentives, lower costs, and wider scope and integration?

Of course computers could contribute to such new institutions, but they needn’t be the only or even main parts. And of course the idea here is to come up with design candidates to test first at small scales, scaling up only when results look promising. Design candidates will seem more promising if we can at least imagine using them more widely, and if they are based on theories that plausibly explain failings of existing institutions. And of course I’m not talking about pressuring people to follow a consensus, just to make a consensus available to those who want to use it.

As usual, a design proposal should roughly describe what acts each participant can do when, what they each know about what others have done, and what payoffs they each get for the main possible outcomes of typical actions. All in a way that is physically, computationally, and financially feasible. Of course we’d like a story about why equilibria of such a system are likely to produce accurate answers fast and at low cost, relative to other possible systems. And we may need to also satisfy hidden motives, the unacknowledged reasons for why people actually like existing institutions.

I have lots of ideas for proposals I’d like the world to consider here. But I realized that perhaps I’ve neglected calling attention to the problem itself. So I’ve written this post in the hope of inspiring some of you with a challenge: can you help design (or test) new robust ways to create and update a social consensus?

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Perpetual Motion Via Negative Matter?

By Robin Hanson · December 30, 2018 11:30 am · Comments (2)

One of the most important things we will ever learn about the universe is just how big it is, practically, for our purposes. In the last century we’ve learned that it it is far larger than we knew, in a great many ways. At the moment we are pretty sure that it is about 13 billion years old, and that it seems much larger in spatial directions. We have decent estimates for both the total space-time volume we can ever see, and all that we can ever influence.

For each of these volumes, we also have decent estimates of the amount of ordinary matter they contain, how much entropy that now contains, and how much entropy it could create via nuclear reactions. We also have decent estimates of the amount of non-ordinary matter, and of the much larger amount of entropy that matter of all types could produce if collected into black holes.

In addition, we have plausible estimates of how (VERY) long it will take to actually use all that potential entropy. If you recall, matter and volume is what we need to make stuff, and potential entropy, beyond current actual entropy, (also known as “negentropy”) is they key resource needed to drive thus stuff in desired directions. This includes both biological life and artificial machinery.

Probably the thing we most care about doing with all that stuff in the universe this is creating and sustaining minds like ours. We know that this can be done via bodies and brains like ours, but it seems that far more minds could be supported via artificial computer hardware. However, we are pretty uncertain about how much computing power it takes (when done right) to support a mind like ours, and also about how much matter, volume, and entropy it takes (when done right) to produce any given amount of computing power.

For example, in computing theory we don’t even know if P=NP. We think this claim is false, but if true it seems that we can produce vastly more useful computation with any given amount of computing power, which probably means sustaining a lot more minds. Though I know of no concrete estimate of how many more.

It might seem that at least our physics estimates of available potential entropy are less uncertain that this, but I was recently reminded that we actually aren’t even sure that this amount is finite. That is, it might be that our universe has no upper limit to entropy. In which case, one could keep run physical processes (like computers) that increase entropy forever, create proverbial “perpetual motion machines”. Some say that such machines are in conflict with thermodynamics, but that is only true if there’s a maximum entropy.

Yes, there’s a sense in which a spatially infinite universe has infinite entropy, but that’s not useful for running any one machine. Yes, if it were possible to perpetually create “baby universes”, then one might perpetually run a machine that can fit each time into the entrance from one universe into its descendant universe. But that may be a pretty severe machine size limit, and we don’t actually know that baby universes are possible. No, what I have in mind here is the possibility of negative mass, which might allow unbounded entropy even in a finite region of ordinary space-time.

Within the basic equations of Newtonian physics lie the potential for an exotic kind of matter: negative mass. Just let the mass of some particles be negative, and you’ll see that gravitationally the negative masses push away from each other, but are drawn toward the positive masses, which are drawn toward each other. Other forces can exist too, and in terms of dynamics, it’s all perfectly consistent.

Now today we formally attribute the Casimir effect to spatial regions filled with negative mass/energy, and we sometimes formally treat the absence of a material as another material (think of bubbles in water), and these often formally have negative mass. But other than these, we’ve so far not seen any material up close that acts locally like it has negative mass, and this has been a fine reason to ignore the possibility.

However, we’ve known for a while now that over 95% of the universe seems to be made of unknown stuff that we’ve never seen interact with any of the stuff around us, except via long distance gravity interactions. And most of that stuff seems to be a “dark energy” which can be thought of as having a negative mass/energy density. So negative mass particles seem a reasonable candidate to consider for this strange stuff. And the reason I thought about this possibility recently is that I came across this article by Jamie Farnes, and associated commentary. Farnes suggests negative mass particles may fill voids between galaxies, and crowd around galaxies compacting them, simultaneously explaining galaxy rotation curves and accelerating cosmic expansion.

Apparently, Einstein considered invoking negative mass particles to explain (what he thought was) the observed lack of cosmic expansion, before he switched to a more abstract explanation, which he dropped after cosmic expansion was observed. Some say that Farnes’s attempt to integrate negative mass into general relative and quantum particle physics fails, and I have no opinion on that. Here I’ll just focus on simpler physics considerations, and presume that there must be some reasonable way to extend the concept of negative mass particles in those directions.

One of the first things one usually learns about negative mass is what happens in the simple scenario wherein two particles with exactly equal and opposite masses start off exactly at rest relative to one another, and have any force between them. In this scenario, these two particles accelerate together in the same direction, staying at the same relative distance, forevermore. This produces arbitrarily large velocities in simple Newtonian physics, and arbitrarily larger absolute masses in relativistic physics. This seems a crazy result, and it probably put me off from of the negative mass idea when I first heard about it.

But this turns out to be an extremely unusual scenario for negative mass particles. Farnes did many computer simulations with thousands of gravitationally interacting negative and positive mass particles of exactly equal mass magnitudes. These simulations consistently “reach dynamic equilibrium” and “no runaway particles were detected”. So as a matter of practice, runaway seems quite rare, at least via gravity.

A related worry is that if there were a substantial coupling associated with making pairs of positive and negative mass particles that together satisfy relative conservation laws, such pairs would be created often, leading to a rapid and apparently unending expansion in total particle number. But the whole idea of dark stuff is that it only couples very weakly to ordinary matter. So if we are to explain dark stuff via negative mass particles, we can and should postulate no strong couplings that allow easy creation of pairs of positive and negative mass particles.

However, even if the postulate of negative mass particles were consistent with all of our observations of a stable pretty-empty universe (and of course that’s still a big if), the runaway mass pair scenario does at least weakly suggest that entropy may have no upper bound when negative masses are included. The stability we observe only suggests that current equilibrium is “metastable” in the sense of not quickly changing.

Metastability is already known to hold for black holes; merging available matter into a few huge black holes could vastly increase entropy, but that only happens naturally at a very slow rate. By making it happen faster, our descendants might greatly increase their currently available potential entropy. Similarly, our descendants might gain even more potential entropy by inducing interactions between mass and negative mass that would naturally be very rare.

That is, we don’t even know if potential entropy is finite, even within a finite volume. Learning that will be very big news, for good or bad.

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Choose: Allies or Accuracy

By Robin Hanson · December 28, 2018 12:15 pm · Comments (3)

Imagine that person A tells you something flattering or unflattering about person B. All else equal, this should move your opinion of B in the direction of A’s claim. But how far? If you care mainly about accuracy, you’ll want to take into account base rates on claimers A and targets B, as well as more specific specific signs on the accuracy of A regarding B.

But what if you care mainly about seeming loyal to your allies? Well if A is more of your ally than is B, as suggested by your listening now to A, then you’ll be more inclined to just believe A, no matter what. Perhaps if other allies give a different opinion, you’ll have to decide which of your allies to back. But if not, trying to be accurate on B mainly risks seeming disloyal to A and you’re other allies.

It seems that humans tend to just believe gossip like this, mostly ignoring signs of accuracy:

The trustworthiness of person-related information … can vary considerably, as in the case of gossip, rumors, lies, or “fake news.” …. Social–emotional information about the (im)moral behavior of previously unknown persons was verbally presented as trustworthy fact (e.g., “He bullied his apprentice”) or marked as untrustworthy gossip (by adding, e.g., allegedly), using verbal qualifiers that are frequently used in conversations, news, and social media to indicate the questionable trustworthiness of the information and as a precaution against wrong accusations. In Experiment 1, spontaneous likability, deliberate person judgments, and electrophysiological measures of emotional person evaluation were strongly influenced by negative information yet remarkably unaffected by the trustworthiness of the information. Experiment 2 replicated these findings and extended them to positive information. Our findings demonstrate a tendency for strong emotional evaluations and person judgments even when they are knowingly based on unclear evidence. (more; HT Rolf Degen)

I’ve toyed with the idea of independent juries to deal with Twitter mobs. Pay a random jury a modest amount to 1) read a fuller context and background on the participants, 2) talk a bit among themselves, and then 3) choose which side they declare as more reasonable. Sure sometimes the jury would hang, but often they could give a voice of reason that might otherwise be drown out by loud participants. I’d have been willing to pay for this a few times. And once juries became a standard thing, we could lower costs via making prediction markets on jury verdicts if a case were randomly choose for jury evaluation.

But alas, I’m skeptical that most would care much about what an independent jury is estimated to say, or even about what it actually says. For that, they’d have to care more about truth than about showing support for allies.

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