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Category: Science

Runaway Feedback Loops in Predictive Policing

Die University of Utah and Prof. Dr. C. Obvious wrote a paper (PDF):

Once police are deployed based on these predictions, arrest data from the neighborhood is then used to further update the model. Since arrests only occur in neighborhoods that police have been sent to by the predictive policing algorithm itself, there is the potential for this sampling bias to be compounded, causing a runaway feedback loop. Indeed, Lum and Isaac have recently shown that this can happen.

To be fair, the paper is about how to remove this kind of bias from precrime systems. On the other hand, predictive systems using past data to predict future actions are obvious sources for feedback messing with the prediction. One would expect this to be taken into account from the start.

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Fermi vs. Fhtagn

There are things, Lovecraft hypothesizes, that Man is not meant to know. This paper is touching on these subjects: That is not dead which can eternal lie: the aestivation hypothesis for resolving Fermi’s paradox.

If a civilization wants to maximize computation it appears rational to aestivate until the far future in order to exploit the low temperature environment: this can produce a 10^30 multiplier of achievable computation.

We hence suggest the “aestivation hypothesis”: the reason we are not observing manifestations of alien civilizations is that they are currently (mostly) inactive, patiently waiting for future cosmic eras. This paper analyzes the assumptions going into the hypothesis and how physical law and observational evidence constrain the motivations of aliens compatible with the hypothesis.

So the Great Old starfaring civilizations exist, the paper suggests, but they are sleeping, waiting until the stars are, literally, right.

So much of Lovecraft is about astronomy and cosmology, and it did not stop with his death, if he actually died.


The Science of People Not Returning Their Shopping Carts

You can Science on Anything, really. Here’s a discussion of “What is the moral reasoning of people not returning their shopping carts?”:

I always return my shopping cart because I don’t want to think of myself as lazy or inconsiderate.


I don’t return my carts on principle. Although I also don’t block parking spaces – i put them on islands and curbs. My assumption is that if the cart wrangler could get a better job, he would. So I’m doing my part to keep him gainfully employed.

The question generated so many comments that the original site had to turn off comments.




This is Neptune. It is the outermost planet of our solar system, full time or most of the time, depending on your view of the status of Pluto (Pluto has a very eccentric orbit, which partially resides closer sunward than Neptune’s orbit).

Neptune was discovered on 23rd Sept 1846, and completed an entire orbit back to the point of its discovery on 2nd July 2011. Right, we know of Neptune’s existence for slightly more than one Neptune-year.

Also, there is a 2:3 resonance between Pluto’s and Neptune’s Orbit, so for 3 Neptune-years there are exactly 2 Pluto-years.

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The Measles vs your immune system

NPR has an article about the measles. It is already known that after a measles infection the immune system goes down for a few weeks and followup infections are common.

It seems that what the infection does is worse than that. With the introduction of measles vaccination it has been observed that other infections went down within 2-3 years after measles immunization took place. Researchers wanted to know why and found evidence that

Like many viruses, measles is known to suppress the immune system for a few weeks after an infection. But previous studies in monkeys have suggested that measles takes this suppression to a whole new level: It erases immune protection to other diseases, Mina says.

So what does that mean? Well, say you get the chicken pox when you’re 4 years old. Your immune system figures out how to fight it. So you don’t get it again. But if you get measles when you’re 5 years old, it could wipe out the memory of how to beat back the chicken pox. It’s like the immune system has amnesia, Mina says.


So parents putting their children into a “measles party” in order for them to “gain natural immunzation” may actually achieve the exact opposite of that.

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