Tag Archives: Physics

Impossible Is Real

By Robin Hanson · October 21, 2011 8:45 am · Comments (35)

Fermi famously argued that either aliens aren’t out there, or they can’t or don’t want to get here, since we see none around us. An undated Stephen Hawking lecture makes a similar argument about time travel:

If sometime in the future, we learn to travel in time, why hasn’t someone come back from the future, to tell us how to do it. Even if there were sound reasons for keeping us in ignorance, human nature being what it is, it is difficult to believe that someone wouldn’t show off, and tell us poor benighted peasants, the secret of time travel. … If governments were hiding something, they are doing a pretty poor job of extracting useful information from the aliens. … Once you admit that some are mistakes, or hallucinations, isn’t it more probable that they all are, than that we are being visited by people from the future, or the other side of the galaxy? If they really want to colonize the Earth, or warn us of some danger, they are being pretty ineffective.

Many people seem quite resistant to the idea that fundamental limits might apply to our descendants, limits that continue even after trillions of years of advancement. But if we have vast hordes of descendants over trillions of years, almost none of them have the ability and inclination to travel back in time to visit us now. Because almost none are visiting. Some things really are impossible.

GD Star Rating
loading...
Tagged as: ,

Physics vs. Economics

By Robin Hanson · September 13, 2011 11:30 pm · Comments (74)

At my prodding, Sean Carrol considered the differing public treatment of physicists and economists:

In the public imagination, natural scientists have figured out a lot more reliable and non-obvious things about the world, compared to what non-experts would guess, than social scientists have. The insights of quantum mechanics and relativity are not things that most of us can even think sensibly about without quite a bit of background study. Social scientists, meanwhile, talk about things most people are relatively familiar with.

Hey, economists can talk obscure technical jargon just as easily as physicists. We don’t actually do that so much in public, because the public respects us less. Talking more technically wouldn’t make the public respect us more. Continue reading "Physics vs. Economics" »

GD Star Rating
loading...
Tagged as: , , ,

Still Scandalous Heat

By Robin Hanson · August 3, 2011 3:00 pm · Comments (24)

Me in ’09:

Physicists have long considered [thermodynamics] the physics area least likely to be overturned by future discoveries, in part because they understand it so well via “statistical mechanics.” Alas, not only are we far from understanding thermodynamics, the situation is much worse than most everyone admits! (more; related posts)

Many hope the theory of inflation can solve this, by predicting that a universe like ours would arise naturally out of “chaos.” But in the April Scientific American, Paul Steinhardt, a major contributor to inflationary theory, says:

Something peculiar has happened to inflationary theory in the 30 years since Guth introduced it. As the case for inflation has grown stronger, so has the case against. … Not only is bad inflation more likely than good inflation, but no inflation is more likely than either. University of Oxford physicist Roger Penrose first made this point in the 1980s. … Obtaining a flat universe without inflation is much more likely than with inflation — by a factor of 10 to the googol (10100) power! …

Many leading theorists argued that the problems with inflation are mere teething pains and should not shake our confidence in the basic idea. Others (including me) contended that the problems cut to the core of the theory, and it needs a major fix or must be replaced. (more)

Sean Carrol’s latest post reaffirms the point:

Imagine that you want to wait long enough to see something like the Big Bang fluctuate randomly out of empty space. How will it actually transpire? It will not be a sudden WHAM! in which nothingness turns into the Big Bang. Rather, it will be just like the observed history of our universe — just played backward. A collection of long-wavelength photons will gradually come together; radiation will focus on certain locations in space to create white holes; those white holes will spit out gas and dust that will form into stars and planets; radiation will focus on the stars, which will break down heavy elements into lighter ones; eventually all the matter will disperse as it contracts and smooths out to create a giant Big Crunch. Along the way people will un-die, grow younger, and be un-born; omelets will convert into eggs; artists will painstakingly remove paint from their canvases onto brushes. Now you might think: that’s really unlikely. And so it is! But that’s because fluctuating into the Big Bang is tremendously unlikely. (more)

We are not remotely close to having a reasonable account for the incredibly low entropy we seem to see in our past.

GD Star Rating
loading...
Tagged as:

Are Spirits Dark?

By Robin Hanson · August 2, 2011 8:00 am · Comments (40)

We see stars and galaxies moving in ways they should not; … we deduce the existence of hitherto unobserved substances, provisionally called dark matter and dark energy. … [Dark matter] outweighs ordinary matter by a factor of 6 to 1. Galaxies and galaxy clusters are embedded in giant balls, or “halos,” of dark matter. … It has to consist of particles that scarcely interact with ordinary matter. …

Could there be a whole sector of hidden particles? Could there be a hidden world that is an exact copy of ours, containing hidden versions of electrons and protons, which combine to form hidden atoms and molecules, which combine to form hidden planets, hidden stars and even hidden people? …

Hidden worlds cannot be an exact copy of our visible world. … Halos would have flattened out to form disks like that of the Milky Way. … [They] would have affected cosmic expansion, altering the synthesis of hydrogen and helium in the early universe. … That said, the dark world might indeed be a complicated web of particles and forces. … Dark matter may be accompanied by … a hidden version of electromagnetism, implying that dark matter may emit and reflect hidden light. … The observation that small galaxies are systematically rounder than their larger cousins would be a telltale sign of dark matter interacting through new forces. …

The theoretical case for a complex dark world is now so compelling that many researchers would find it more surprising if dark matter turned out to be nothing more than an undifferentiated swarm of [weakly interacting massive particles]. After all, visible matter comprises a rich spectrum of particles with multiple interactions determined by beautiful underlying symmetry principles, and nothing suggests that dark matter and dark energy should be any different. (more)

Many people have a strong intuition that around us there are “spirits”, i.e., unseen intelligences who are usually hidden, but who sometimes touch our lives and world. The hypothesis that these spirits are made of ordinary matter and big enough to see is extremely hard to square with common observations. And the hypotheses that they are made of ordinary matter but too small to see, or usually hiding in space or deep underground but popping into our areas on occasion, are also pretty hard to square with expert observations. We keep getting better at seeing things, and see little evidence of anything remotely similar. Intelligences must eat something, defecate something, have evolved from something, etc., all of which leaves traces.

But physics today does offer one plausible place for a spirit hypothesis, in “dark matter.” We know that our kind of matter (electrons, protons, etc.) makes up less than 5% of the mass of the universe around us. The rest is a mysterious matter that interacts only very weakly with our kind of matter, but could interact more strongly with itself, and in complex ways. And while we know most of this dark matter cannot be made of heavy things that clump tightly like our matter does, a substantial fraction of it (say ~1%) could.

So there could well be complex intelligences made out of dark matter, and there might also be ways for them to rarely interact with our world, though such interaction would probably require them to exert great and careful efforts. And furthermore, since dark matter is a high priority research topic, if there is complex clumping dark matter we’ll probably know about it within a half century. Perhaps even a decade.

We thus face a unique chance for folks with strong intuitions for or against spirits to make testable predictions, and even put their money where their mouth is. Those who think spirits likely should think substantial clumping dark matter is likely, and there should also be many who think neither is likely. I’ll go on record saying I doubt any substantial fraction of dark matter can support complex structures conducive to the evolution of life. What say you?

GD Star Rating
loading...
Tagged as:

Seek Criticism

By Robin Hanson · March 17, 2011 12:00 pm · Comments (27)

Two weeks ago I read Penrose’s new book Cycles of Time. I enjoyed his review of the time’s arrow puzzle, and was intrigued by his proposal that distances fade away in vast infinite futures, allowing them to become tiny flat big bangs again. But not only did Penrose wave his arms pretty wildly on how there could be a metric along which metrics would disappear in approaching the vast-tiny border, he seems to make a very elementary mistake in positing that entropy could have a similar magnitude in our big bang post and our vast distant future, because info is lost in evaporating black holes. The entropy in black hole radiation is more than the holes themselves, which is far more than a tiny flat big bang before.

Raphael Bousso (co-author of that Anthropic breakthrough I raved about in ’08) reviews the book in Science, and seems to agree:

Penrose is at his best when he explains this deep and beautiful mystery, and the book may be worth reading for this chapter alone. However, he compounds the shortcomings of his cyclic universe model when he argues that it can solve the low-entropy problem. At this point, another idea is introduced: like vacuum cleaners, black holes appear to reduce disorder by swallowing matter. By the end of one “aeon,” Penrose argues, most matter has ended up in giant black holes. Very little entropy remains, and the next aeon can commence in perfect order. The second law guarantees that a vacuum cleaner does not actually decrease the overall disorder; at best, it just shifts it around. In fact, the machine creates far more entropy than it destroys (for example, by heating up the air in the room). A black hole, it turns out, is not different. Penrose’s assertion that black holes destroy entropy is flatly contradicted by “the generalized second law of thermodynamics”. (more)

How could such a big-shot make such a simple mistake? One should seriously consider the possibility that he isn’t saying what he appears to be saying, and in fact is saying something much more clever and insightful. But if so why wouldn’t he have devoted more effort to explaining, to avoid the misunderstanding. His book reads as if he didn’t even consider that this criticism would be offered. And that fact leads me to believe Penrose considers himself to be such a big shot that he didn’t even ask colleagues to read and criticize his book before publication. And that sort of isolation makes me more willing to believe that he did in fact just make a simple mistake.

The lesson: no matter how much better you think you are than the lowly incompetents that surround you, you’d still do well to ask for and listen to criticism.

GD Star Rating
loading...
Tagged as: ,

Are Gardens Fertile?

By Robin Hanson · March 8, 2011 10:40 pm · Comments (6)

Cosmologists tend to think that the physics we see around us is not universal. There is instead a vast “landscape” of possible ways a local physics could be, and different (large far away) places in the universe embody or express these different physics.

When adjacent space-time places have different local physics, there must be a common “meta” physics that describes their border. This meta-physics will say how often places of one type lead to places of other types nearby, including “ends” where nothing is nearby.

Let us distinguish two special kinds of places:

  • Gardens support life and possibly civilization.
  • Fertile places tend to lead to more fertile places nearby.

The existence of any fertile place implies an expected infinity of connected fertile places. Thus when meta-physics maintains a one-to-one state map across a time dimension, there should be no finite upper bound to the entropy of a fertile place. Thus the entropy at a fertile place is always vastly lower than is possible, and entropy would increase in some local time direction. Since this low entropy should infect adjacent places, non-fertile places “close enough” to fertile ones should also have entropy increasing away from the fertile side. Thus we can explain our local “arrow of time” by assuming that our place is connected to a fertile place in our distant past.

Is our garden fertile? If both gardens and fertile places are rare, and these properties are not very correlated, then fertile gardens would be especially rare – it would be quite unlikely that our garden is fertile. In this case, while our universe is infinite, our future is finite, and will see and influence only a finite amount before our space and entropy run out.

Cosmologists today, however, tend to think that fertile places are not very rare. They expect places with a “positive vacuum energy” and a “low vacuum decay rate” to generate many “baby universes”, and that many of these baby universes also satisfy this description. In fact, they guess that our place here satisfies this description, and so is fertile. (This is, basically, Sean Carroll’s account of our arrow of time.)

But a whole lot of guess work goes into all this. For example, it could be that vacuum decay rates are much higher, and that baby-universe-generating rates are much lower, than they’ve guessed. My guess is that this property of being fertile is rarer than cosmologists now guess, which lowers the chance of our garden being fertile.

A correlation between being a garden and being fertile might result if civilizations tended to work to increase the rate at which their places lead to more places nearby. But it might be that for most gardens there isn’s much civilizations can do.  In which case if fertile places are rare, then most gardens are not fertile, our future is finite.

Finally, even if our place is fertile, it might be that the border between our place and other different places has no “hair” letting us send specific influences from here to there. In this case, our future influence would still be finite.

GD Star Rating
loading...
Tagged as: , , ,

Signal Mappers Decouple

By Robin Hanson · January 17, 2011 11:10 am · Comments (47)

Andrew Sullivan notes that Tim Lee argues that ems (whole brain emulations) just won’t work:

There’s no reason to think it will ever be possible to scan the human brain and create a functionally equivalent copy in software. Hanson … fails to grasp that the emulation of one computer by another is only possible because digital computers are the products of human designs, and are therefore inherently easier to emulate than natural systems. … Digital computers … were built by a human being based on a top-down specification that explicitly defines which details of their operation are important. The spec says exactly which aspects of the machine must be emulated and which aspects may be safely ignored. This matters because we don’t have anywhere close to enough hardware to model the physical characteristics of digital machines in detail. Rather, emulation involves re-implementing the mathematical model on which the original hardware was based. Because this model is mathematically precise, the original device can be perfectly replicated.

You can’t emulate a natural system because natural systems don’t have designers, and therefore weren’t built to conform to any particular mathematical model. … Creating a simulation of a natural system inherently means means making judgment calls about which aspects of a physical system are the most important. And because there’s no underlying blueprint, these guesses are never perfect: it will always be necessary to leave out some details that affect the behavior of the overall system, which means that simulations are never more than approximately right. Weather simulations, for example, are never going to be able to predict precisely where each raindrop will fall, they only predict general large-scale trends, and only for a limited period of time. … We may have relatively good models for the operation of nerves, but these models are simplifications, and therefore they will differ in subtle ways from the operation of actual nerves. And these subtle micro-level inaccuracies will snowball into large-scale errors when we try to simulate an entire brain, in precisely the same way that small micro-level imperfections in weather models accumulate to make accurate long-range forecasting inaccurate. … Each neuron is itself a complex biological system. I see no reason to think we’ll ever be able to reduce it to a mathematically tractable model. (more; Eli Dourado agrees; Alex Waller disagrees.)

Human brains were not designed by humans, but they were designed. Evolution has imposed huge selection pressures on brains over millions of years, to perform very particular functions. Yes, humans use more math that does natural selection to assist them. But we should expect brain emulation to be feasible because brains function to process signals, and the decoupling of signal dimensions from other system dimensions is central to achieving the function of a signal processor. The weather is not a designed signal processor, so it does not achieve such decoupling. Let me explain.

A signal processor is designed to mantain some intended relation between particular inputs and outputs. All known signal processors are physical systems with vastly more degrees of freedom than are contained in the relevant inputs they seek to receive, the outputs they seek to send, or the sorts of dependencies between input and outputs they seek to maintain. So in order manage its intended input-output relation, a single processor simply must be designed to minimize the coupling between its designed input, output, and internal channels, and all of its other “extra” physical degrees of freedom. Really, just ask most any signal-process hardware engineer.

Now sometimes random inputs can be useful in certain signal processing strategies, and this can be implemented by coupling certain parts of the system to most any random degrees of freedom. So signal processors don’t always want to minimize extra couplings. But this is a rare exception to the general need to decouple.

The bottom line is that to emulate a biological signal processor, one need only identify its key internal signal dimensions and their internal mappings – how input signals are mapped to output signals for each part of the system. These key dimensions are typically a tiny fraction of its physical degrees of freedom. Reproducing such dimensions and mappings with sufficient accuracy will reproduce the function of the system.

This is proven daily by the 200,000 people with artificial ears, and will be proven soon when artificial eyes are fielded. Artificial ears and eyes do not require a detailed weather-forecasting-like simulation of the vast complex physical systems that are our ears and eyes. Yes, such artificial organs do not exactly reproduce the input-output relations of their biological counterparts. I expect someone with one artificial ear and one real ear could tell the difference. But the reproduction is close enough to allow the artificial versions to perform most of the same practical functions.

We are confident that the number of relevant signal dimensions in a human brain is vastly smaller than its physical degrees of freedom. But we do not know just how many are those dimensions. The more dimensions, the harder it will be to emulate them. But the fact that human brains continue to function with nearly the same effectiveness when they are whacked on the side of the head, or when flooded with various odd chemicals, shows they have been designed to decouple from most other physical brain dimensions.

The brain still functions reasonably well even flooded with chemicals specifically designed to interfere with neurotransmitters, the key chemicals by which neurons send signals to each other! Yes people on “drugs” don’t function exactly the same, but with moderate drug levels people can still perform most of the functions required for most jobs.

Remember, my main claim is that whole brain emulation will let machines substitue for humans through the vast majority of the world economy. The equivalent of human brains on mild drugs should be plenty sufficient for this purpose – we don’t need exact replicas.

Added 7p: Tim Lee responds:

Hanson seems to be making a different claim here than he made in his EconTalk interview. There his claim seemed to be that we didn’t need to understand how the brain works in any detail because we could simply scan a brain’s neurons and “port” them to a silicon substrate. Here, in contrast, he’s suggesting that we determine the brain’s “key internal signal dimensions and their internal mappings” and then build a digital system that replicates these higher-level functions. Which is to say we do need to understand how the brain works in some detail before we can duplicate it computationally. …

Biologists know a ton about proteins. … Yet despite all our knowledge, … general protein folding is believed to be computationally intractible. … My point is that even detailed micro-level knowledge of a system doesn’t necessarily give us the capacity to efficiently predict its macro-level behavior. … By the same token, even if we had a pristine brain scan and a detailed understanding of the micro-level properties of neurons, there’s no good reason to think that simulating the behavior of 100 billion neurons will ever be computationally tractable.

My claim is that, in order to create economically-sufficient substitutes for human workers, we don’t need to understand how the brain works beyond having decent models of each cell type as a signal processor. Like the weather, protein folding is not designed to process signals and so does not have the decoupling feature I describe above. Brain cells are designed to process signals in the brain, and so should have a much simplified description in signal processing terms. We already have pretty good signal-processing models of some cell types; we just need to do the same for all the other cell types.

GD Star Rating
loading...
Tagged as: , , , ,

God Near or No Mind Hair

By Robin Hanson · September 13, 2010 10:30 am · Comments (43)

(I wouldn’t be at all surprised if the following argument isn’t original, but I haven’t seen it elsewhere yet.)

If our descendants do not destroy themselves, then over the next trillion years they may become knowledgeable and powerful enough to create new baby universes that expand to look much like the universe we can see. Such a universe might then evolve its own intelligence, which would grow powerful enough to repeat the process. A self-reproducing universe would have a chance p of evolving intelligence, which would then birth an expected number N of similar baby universes, such that p*N >1.

Our descendants might even become powerful enough to imprint themselves upon such a baby universe. An imprinted universe would somewhere contain mind(s) with important specific similarities, such as memories, personality, or values, to the minds of its creators.

One of the following two remarkable conclusions seems likely:

  1. No Mind Hair – Even if our descendants command billions of galaxies and study physics for trillions of years, they still cannot create self-reproducing baby universes, and reliably imprint their minds on them. Such a task is beyond the abilities even of such gods. They are trapped; their baby universes just cannot have “mind hair.”
  2. Gods Nearby – Somewhere out there in our universe is probably hiding the imprinted minds of our universe’s creators. If we search long and far enough and understand physics well enough, we may well find them.

Here’s why. If our descendants can make self-reproducing universes, then there’s a non-zero chance they will do so, and if so there’d be an infinity of such universes. But out of an infinity of expected universes we are quite unlikely to be in the first, making it quite likely that our universe had creators. If such creators could imprint their minds on our universe they probably would have done it. So, either imprinted versions of our creators are probably out there somewhere in our universe, or no feasible power can reliably mind-imprint a self-reproducing baby universe.  Such imprinting could at best succeed rarely. QED. Either conclusion is remarkable.

GD Star Rating
loading...
Tagged as: , ,

Future Discounts

By Robin Hanson · March 19, 2010 6:00 am · Comments (29)

In few billion years our descendants may spread across billions of galaxies. Even so, if they do not drastically change the structure of space-time, then within a trillion years they will fragment into billions of isolated galaxy-sized “universes”.  Standard physics, you see, says that in a trillion or two years all the galaxies near the Milky Way will merge into one big galaxy, and other galaxies will be too distant to see in any way.  For all practical purposes, that merged galaxy will be a separate universe.

If we do nothing to change the situation, then within ten or so trillion years, all current stars will be dead (degenerate), and no more stars will form.  Over the next billion trillion years, stars will occasionally smash in a flash, or pass close enough to each other to throw one out of the galaxy; in the end 1-10% remain in a central black hole.

What if we change the situation?  Most useful resources, such as hydrogen to turn into lead, or mass not yet dropped into the central black hole, will likely be identified and claimed within a few million years.  How fast will folks use up these resources?

In principle, most everything might be burned quickly in a few million years of party-hardy gluttony, or most might be saved to use steadily over the billion trillion trillion years or more before protons decay.  How fast resources are actually used would be determined by the discount factors of the creatures who control resources.  But what would those be?

If unused resources were completely stable and if property rights in resources were completely secure, then we’d mainly have a selection effect in discount rates.  Agents who discount fast would dominate early activity, while those who discount slowly would dominate late activity.  Even if initially only a tiny fraction of agents cared about activity in a billion trillion trillion years, those agents would dominate such late activity.

Any natural rate at which resources decay would set an upper limit on discounting.  There is no point in planning to use resources long after you expect them to decay.  Similarly, insecure property rights would increase discount rates. If you expect a 1% chance that your property will be stolen every million years, you won’t expect to still have much after a billion years, so you might as well plan to use most of it before then.   The same holds if your property is never stolen, but you have to spend 1% of your resources every million years to ensure that fact.

“Switzerlands,” from which theft is naturally harder, might be the last locations of activity in each galaxy.  These might be matter sent on very long secret orbits, to return back to galaxy central after a very long time.  Similarly, resources which simply could not be physically used until a long delay might ensure some late universe activity.

The inhabitants of a galaxy-universe could have different degrees of central coordination; some might have a strong central government, while others lived in anarchy.  With a strong central government, long term activity seems strongly influenced by the discount rate of that government. If this government taxed 1% of resources every million years, and didn’t invest those resources for the long run, then there would be little point in planning to use your resources after a billion years.  No obvious selection effect ensures that galaxy governments take a long view.

Physics may set the ultimate limits on how long resources, and life, can last, but governments and property rights will determine when they are actually used. Resources, and life, will likely die long before their physical expiration dates.

GD Star Rating
loading...
Tagged as: , ,

From Eternity To Here

By Robin Hanson · January 7, 2010 11:35 pm · Comments (28)

Out today, Sean Carroll’s new book, From Eternity to Here, is excellent.  After reading a draft in March, I wrote:

We are far from understanding thermodynamics. … The distributions we would usually use to successfully predict [physical system] futures are completely, totally, and almost maximally WRONG for predicting their pasts!  …  Worse, this “past hypothesis” is ambiguous in several ways … Only a tiny handful of physicists (and philosophers) are trying to explain this past hypothesis; … no one is even remotely close.

Here is Carroll’s proposed solution scenario:

  1. Physics is always exactly locally time-reversible.
  2. Each small region of space has bounded entropy, yet an infinite state space.
  3. So entropy has no upper bound, so systems are never in full equilibrium.
  4. Our local universe is expanding with a weak dark energy.
  5. Our distant future is a forever expanding emptiness at 10-29K.
  6. Very rarely, local fluctuations there build brains like ours.
  7. Far more rarely, local fluctuations pop a tiny new universe.
  8. Tiny new universes are very curved and thus very dense.
  9. Dense regions generically expand to get less dense.
  10. In some dense expanding regions, a dark energy starts eternal inflation.
  11. Inflation makes flat uniform local universes with scale-less fluctuations.
  12. Local universes sit in different local minima with different local physics.
  13. In some, scale-less fluctuations make galaxies etc. and brains like ours.
  14. Those local universes also get empty, then rarely pop tiny new universes.
  15. On average each tiny new universe gives rise later to several more.
  16. So there are an infinite number of local universes.
  17. A region in our past pops tiny universes in both time directions.
  18. There are overall far more brains like ours than fluctuation brains.

Many of these are far-from-proven conjectures, but still it does all hold together. Locally infinite state spaces (#2), might appear to conflict with the holographic principle:

There is a maximum amount of entropy you can possibly fit into a region of some fixed size, which is achieved by a black hole of that size.

But it doesn’t conflict; region size is neither constant nor bounded.  Even so, it is very hard to over-emphasize just how far one must project current physics beyond the accuracy with which we have verified it to talk about tiny new universes popping out of quantum fluctuations in empty space at 10-29K.  It will be truly incredible if we get that right.

On style, I’m again struck by how different is the public’s preferred style for popular physics vs. economics books.  Popular physics books, like Carroll’s, act easy and friendly, but still lecture from on high, sprinkled with reverent stories on the “human side” of the physics Gods who walk among us.  They grasp for analogies to let mortals glimpse a shadow of the glory only physicists can see directly.

The recent popular econ book Superfreakanomics is also excellent, but very different in tone.  Also easy and friendly, this is full of concrete stories about particular data patterns and what lessons you might draw from them, or you might not; hey it is always up to you the reader to judge.  Such books avoid asking readers to believe anything abstract or counter-intuitive based on the author’s authority.

The main difference, I think, is that readers don’t fundamentally care about physics, so can’t get worked up disagreeing with physics authors.  They read to affiliate with great men, and to lord their greater knowledge over lessor associates.  In contrast, people actually care about many economics topics, and our democratic culture, where everyone’s political opinions are officially equally valued, simply can’t accept opaque expertise on such things.

GD Star Rating
loading...
Tagged as: ,