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Comment author: OrphanWilde 02 July 2015 08:40:02PM 0 points [-]

The former. Or rather a set of phenomena which I believe to be more closely related than currently thought.

Comment author: gjm 02 July 2015 09:19:50PM 0 points [-]

OK. Which physical phenomena do you think might be described in that way? I'm pretty sure the stuff in the Standard Model has been measured accurately enough to rule out anything much like what you describe.

Comment author: OrphanWilde 02 July 2015 08:39:21PM 0 points [-]

The full CPT swap also involves reversing the flow of time. So one could attract, and one could repel, and this relationship is CPT-symmetric. (Antimatter chases matte, CPT swap, antimatter (previously matter) chases matter - in the other direction.)

And in terms of curvature, it just means the curve can have positive/negative amplitude. Antimatter would be matter with an inverse curvature. (Predicted by CPT symmetry, as I understand it.)

Note that what we're talking about now is more-or-less mainstream physics, albeit filtered through my probably-a-decade-and-a-half-outdated understanding of it.

Comment author: gjm 02 July 2015 09:18:45PM 0 points [-]

Reversing time doesn't swap attraction and repulsion. (One way of seeing that: attraction/repulsion is a matter of the sign of a second derivative, and d^2/dt^2 f(-t) = (d^2f/dt^2)(-t). No sign change.)

The thing I was saying I couldn't see how to make sense of in the GR picture was having "gravity" and "antigravity" be separate phenomena (which I thought you might be proposing), not "antigravity" as such. I don't think there's any fundamental conflict between GR and having things of negative mass.

Comment author: OrphanWilde 02 July 2015 06:52:10PM 0 points [-]

I've played with formulas; I've come up with something like:

q2 * m1 * m2 * sin(sqrrt(r * C1))/(r * C2)^2

Where q2 is the charge of the nonlocal matter. (This formula calculates the force exerted on m1; the force exerted on m2 may be different.)

I suspect the actual function inside the sin may be more subtle than that. The salient point would be that the wavelength is a function of its distance, and the wavelength increases (exponentially, I think) with distance, which produces a scope-insensitive force.

Comment author: gjm 02 July 2015 08:15:18PM 0 points [-]

I'm sorry -- what is this meant to be describing, exactly? Some already-known physical phenomenon, whose rules you think may be different from those it's currently thought to obey, or a conjectural new force?

Comment author: OrphanWilde 02 July 2015 07:07:49PM *  0 points [-]

The CPT theorem, as I understand it, may or may not suggest exactly that. I've encountered contradictory descriptions on that point. (ETA: After some brief research, apparently the contradictions are in my interpretation of what was being said; antimatter may or may not -emit- antigravity per the CPT theorem, but is almost certainly still -attracted- by normal gravity, also per the CPT theorem. There's ongoing research on the latter point.)

It seems to be an open point of debate, though.

Comment author: gjm 02 July 2015 08:13:02PM 0 points [-]

I'm, oh, let's say 99% certain you're wrong about the CPT theorem suggesting any kind of sign-reversal in gravity.

If antimatter is attracted by ordinary matter, then CPT symmetry tells you (since CPT reversal swaps ordinary matter and antimatter and leaves "attracted" as it is) that ordinary matter is likewise attracted by antimatter. And, of course, if ordinary matter is attracted by ordinary matter then CPT symmetry tells you that antimatter is attracted by ordinary matter.

I suppose CPT symmetry is kinda compatible with there being (let's say) gravitons and antigravitons that somehow do different things, except that (1) in every sketch of quantum gravity I know of gravitons are their own antiparticles, and (2) in general relativity gravity is a consequence of the curvature of spacetime and I can't imagine how a separate antigravity could fit into that picture.

(I am not an actual proper physicist and it's not impossible that I'm confused; hence 99% rather than 99.999%.)

Comment author: OrphanWilde 02 July 2015 03:44:42PM -1 points [-]

I removed the parts relating to that for brevity. Short explanation: All of the forces reverse polarities along with the matter in question.

That adds a -lot- of questions, however, such as what effectively would be anti-gravity coming from electrons would mean, which is why I omitted it in the first place. It does suggest antimatter and matter shouldn't be strictly attracted (one should attract, one should repel, resulting in a "chase", which would end rather quickly when surrounded by other matter).

Comment author: gjm 02 July 2015 06:39:48PM 0 points [-]

All of the forces reverse polarities along with the matter in question.

But gravity doesn't. I mean, really, it just doesn't. (According to best present-day physical theories, anyway. I don't know whether anyone has collected enough antimatter for it to be practical to do an explicit experimental verification that its gravity isn't sign-reversed.)

Comment author: OrphanWilde 02 July 2015 02:05:45PM -1 points [-]

Comment from a crank on alternate theories of reality: We can do some pattern recognition, and notice a pattern:

Strong nuclear force. Weak nuclear force. Gravity. Einstein's Constant/Cosmological Constant/Dark Energy/Vacuum Energy.

Attraction. Repulsion. Attraction. Repulsion.

(Also, below that, Strong Interaction and whatever force keeps neutrons apart, sometimes stated, somewhat nonsensically in the general case, to be the exclusion principle.)

Assuming this pattern holds across all scales (and do we have any reason to believe the range of scales around the one we happen to occupy is special or unique, apart from the fact that they're the range of scales we happen to be capable of observing?), we shouldn't expect the universe to end at all, although our local universe might conceivably run out of exergy.

Comment author: gjm 02 July 2015 03:24:52PM 1 point [-]

Your list of interactions notably omits electromagnetism, which as well as being vastly important in the physical phenomena we observe all the time happens to be neither simply attractive nor simply repulsive.

It is also incorrect to describe the weak interaction as a repulsion; as with electromagnetism its effects can be either attractive or repulsive.

Comment author: Clarity 02 July 2015 01:22:46AM *  1 point [-]

Is this the evident interpretation of Quantpedia's visual statistical summary of data on published quantitative trading strategies : Simple strategy, daily, stock strategy based on trading earnings or earning announcement generally outperforms alternatives?

Comment author: gjm 02 July 2015 01:57:21PM 1 point [-]

Seems more or less like it. But I'd be really careful.

First of all, one minor correction. According to their graphs, "very complex" strategies have alleged performance even better than "simple" ones. I would be skeptical, though; the more complex a strategy, the greater the opportunities for its apparent performance to be the result of (perhaps accidental) overfitting.

Now, some reasons for being cautious about inferring from their summary data that simple daily earnings-based strategies are best:

Do they define what they mean by "performance" (average annualized returns, or some metric Quantpedia has made up, or what)? If the former, note that what you probably actually care about is some combination of risk and return (if you have a strategy with given expected returns, you can always increase that a lot by taking on huge leverage -- but at the cost of greatly increased risk). If the latter, you'll want to look at whether their metric matches what you care about.

I guess these are reported results of published strategies. This means there's a huge selection effect. No one is going to publish their ingenious new strategy that ... loses 5% per year. That would be OK if selection were on the basis of actual future results, but of course selection is actually on the basis of (something like) results on past data, or simulated guesses at what future data might look like. So now imagine two classes of strategy, one of which performs very consistently and one of which has immensely variable results. 100 people try out each class of strategy. The first one returns between 9% and 111% per year, every time. The second one gives measured returns varying wildly between -90% and +90% per year. Then you throw out the failures, and look at the averages. The second class of strategy is going to look a lot better -- even if actually it's just much higher-risk and will in practice most likely bankrupt you quickly.

It could be that for some reason selection effects are different for different kinds of strategies. Consider, e.g., the following (entirely imaginary) sequence of events.

  • In 1980, someone famous publishes a paper claiming to describe an earnings-trading strategy that returns 25%.
  • Everyone reads this and is very impressed. In the following years, no one will publish an earnings-trading strategy that doesn't perform at least about that well in their tests.
    • (Even though when they find one it may usually actually be the result of luck or defective testing.)
  • For other kinds of strategy, though, less impressive results are still publishable.
  • 20 years later, it's discovered that that 1980 paper was completely bogus.
  • But now the earnings-trading strategies in the literature are all impressive, because of selection effects.
  • So even with the old paper thrown out, a literature survey will give the impression that earnings trading is better than everything else.

Generally, the information they make public is so limited that I would be really scared to let any real money ride on inferences from it.

One final remark: If "daily" means that typical holding times are about one day, or that one typically makes trading decisions once a day, and if "trading earnings" means making decisions based on companies' quarterly earnings announcements ... it seems like "daily" and "trading earnings" are hard to reconcile with one another. But probably I'm misunderstanding their terminology, because "daily" is the only timescale category with anything at 70%, and both "trading earnings" and "earnings announcement" (shouldn't those be the same thing?) have strategies at 70%. Or perhaps the categories aren't exhaustive and some strategies don't have a timescale classification at all?

Comment author: gjm 02 July 2015 01:29:26PM 2 points [-]

This is kinda fun, but it seems to me to fall far short of its stated goal:

The purpose of this roadmap is to prove that real immortality is possible

(The above is from the footer of the diagram; the post above says "... of this plan ..." instead.) It falls short because what it does is to list dozens of things we might be able to try but for none of them (so far as I can see) do we know that it's actually possible.

In some cases ("Merge with the universe", "Jump to eternal chaotic inflation level", "We live in a simulation and find a way to persuade its hosts not to disable it", ...) you could equally say "Solve the problem using magic". Others at least seem meaningful and might even be possible. But I didn't see anything in the list that there's good reason to think is actually possible, nor even a set of things in the list for which there's good reason to believe that at least one is possible.

Comment author: VoiceOfRa 02 July 2015 04:44:51AM 0 points [-]

Isn't he rather saying: look, there's all this stuff that's been written, but its basic premises are so far removed from mine that there's no engaging with it?

Except he didn't object to a premise, he objected to the term "sexual access to women".

Imagine reading a lot of material by, let's say, ancient Egyptians, that just take for granted throughout that your primary goal is to please the Egyptian gods.

In which case I could point to a specific false premise, namely the existence of the Egyptian gods. Neither you not DVH have pointed to any false premises. You've objected to terms used, but have not claimed that the terms don't point to anything in reality.

Comment author: gjm 02 July 2015 08:30:07AM 0 points [-]

he didn't object to a premise, he objected to the term "sexual access to women"

Here's the most relevant bit of what he actually wrote:

This is really the issue there - because it is not about strictly defined concepts but about every kind of experience and emotion and value sloshing around inside you and other people, interpreting everything in your own light which can be utterly different from the light of other people. For example the guy who wrote that article uses the term "sexual access to women". I have no idea from what kind of a life could this come from.

"Not about strictly defined concepts". "Your own light which can be utterly different from the light of other people". "For example". "What kind of a life could this come from". The point isn't that there's something uniquely terrible about this particular term, it's that if someone finds it natural to write in such terms then they're looking at the world in a way DVH finds foreign and unpleasant and confusing.

a specific false premise

Falsity isn't (AIUI) the point. Neither is whether the term in question points to anything in reality. The point is that the whole approach -- values, underlying assumptions, etc. -- is far enough removed from DVH's that he sees no useful way of engaging with it. "When discussing human behavior you cannot really separate facts from values, and thus you need a certain kind of agreement in values."

Anyway, I'm getting rather bored of all the gratuitous downvotes so I think I'll stop now. By the way, you've missed a couple of my comments in this discussion. But I expect you'll get around to them soon, and in any case I see you've made up for it by downvoting a bunch of my old comments again.

Comment author: VoiceOfRa 02 July 2015 04:37:06AM 0 points [-]

Something is "objectification" to the extent that we would change it if we attended more to the specifically person-ish features of the other people involved: their hopes, fears, plans, preferences, ideas, etc. (Or: that a decent person would, or that we should. These framings make the value-ladenness of the notion more explicit. Or, and actually this may be a better version than the other three, that they would prefer you to.

I *would prefer it" if you sent me a million dollars. By this definition it would seem that you're objectifying me by not sending me the money?

Comment author: gjm 02 July 2015 08:17:09AM 0 points [-]

Only in so far as the reason why I don't is that I'm not paying attention to the fact that you have preferences.

If I'm perfectly well aware of that but don't give you the money because I don't have it, because I think you would waste it, because I would rather spend it on enlarging my house, or because I have promised my gods that I will never give anything to someone who uses the name of their rival, then I may or may not be acting rightly but it's got nothing to do with "objectification" in the sense I described.

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