Here's how you arrive at that number: 100 billion neurons (correct), each firing at 200 Hz (big overestimate, all the neurons are never firing at their max speed. A more typical number would be a few Hz), each sending signals to 1000 other neurons (underestimate, I think. The average number of synapses per neuron is about 7000). You now multiply those numbers together and say that that's the total number of calculations. That's how you get 20 million billion.

Let's do the same for a CPU. A modern Intel i7 has 1.4 billion transistors, each cycling at about 4 Ghz. Each transistor is connected to three others. So we get a total of 20 billion billion "calculations" per second.

Wow, that's a lot! But it's also nonsense. A single transistor sending a signal to another transistor isn't a useful calculation. And a single neuron firing at another neuron isn't a useful calculation either. Each neuron fires based on the total firing rate it receives, and a series of pulses is needed to stimulate it to fire itself. Secondly, lots of neurons firing together is needed to achieve even very basic things. The "20 million billion" number for the brain is probably overestimated by at least as much as the "20 billion billion" number for the CPU.

So why is the brain's output so much more impressive than a CPU's output? Probably for the same reason that a 1 MHz computer running quicksort performs better than a 1 GHz computer running bogosort. Algorithms matter.

How do you compute the FLOP equivalent of what the brain does? I would be very interested in seeing how that's done.

I don't think it's obvious that one couldn't do real-time 3D vision and context-sensitive pattern recognition with a low-power modern cpu and beat the brain. It's so hard to do an apples-to-apples comparison here, as there's so much we still don't understand about how the brain does things. When does the object recognition actually take place? How often is this information updated, and for which objects? What spatial and temporal resolution is used for the processing of various parts of the field of vision (and probably some heavier tasks operate on a much lower resolution representation).

The brain clearly uses a very clever algorithm, and a similarly clever algorithm running on today's computer hardware is what one would have to compare with. Sadly, we don't have such an algorithm. But just to illustrate that this really is to a large degree an algorithm issue (though this example goes a bit off-topic when it comes to the energy use): I think you will agree that even a small modern CPU has more processing power than a dragonfly. But we still don't have drones that can compete with a dragonfly in moving through a complex 3d environment at high speed.

To make a planet-eating black hole from an accelerator experiment you need to assume that Hawking ratiation doesn't exist (or is extremely feeble), or those black holes would evaporate instantly before they can accrete any matter. So you would end up with planet-mass black holes orbiting stars.

Even if you turned off Hawking radiation, it would still be hard for a black hole from a particle accelerator to actually eat the planet. Let's say you have an accelerator much more powerful than the LHC, with a center-of-mass energy of 1 PeV. If all that were used to produce a black hole, it would have a mass of 1.8e-21 kg. An electron or proton a single hydrogen radius away from it (which we can use as a typical intermolecular distance in the Earth for simplicity) would feel an acceleration of 1e-11 m/s^2, which is absolutely tiny compared to the electrical forces that govern motion on those scales. A small black hole like that behaves much like a neutrino - it hardly interacts with anything. And it needs to do that to grow. I think we could have lots of these inside the Earth and not even notice (dun-dun-DUUN!).

Even if you included Hawking radiation but somehow only turned it on after the black hole had consumed the planet, you still wouldn't get rid of the planet-mass black hole, as a hole of that size evaporates extremely slowly, and would have a life time of more than 5e50 years.

Planet-mass black holes could be detected via gravitational microlensing. Planets are regularly detected this way. But it may be hard to distinguish those black holes from planets. As far as I know we can't exclude a population of these in orbit around a fraction of the stars in the milky way. The accretion events, when the planets are eaten, would probably be quite bright, and might be visible as mini-supernovas.

There's another basic form of payment one can get as a free software developer that isn't mentioned here (in the summary at least), and that's payment in the form of more free software. You spend some time writing some sofware, make it available under the GPL and encourage others to use it, modify it and share it. If in the end this leads to the production of at least one other free software project of similar size that you find useful, then you've made back the lost time you spend writing your program in the first place. As a bonus, the body of free software has grown by at least two in the process.

As an example, let's say I write a raytracing library, and it takes me 500 work hours to do so. Then somebody uses it to write something like Blender. If Blender saves me 500 work hours over the years, then that by itself makes it worth it. And as a very nice bonus, libraytrace+Blender together will save lots of time for many other people too, since they won't need to implement these things themselves.

The Earth-Sun L1 point is 1.5 Gm from the Earth, pretty much exactly 1% of the distance from the earth to the sun. So to fully cover the sun (as seen from one spot on Earth), the blind would have to be 1% of the Radius of the sun. That's basically the radius of the Earth, or 4 times the radius of the Moon. To cover the sun as seen from anywhere on Earth, you would need a slightly bigger radius due to perspective.

But one doesn't need to cover the whole sun (unless one wants to play the grandparent's nefarious games with Asia). A 1% reduction in insolation would already help a lot. So that gives us about 1% of the area of the earth, or 1.5e12 m^2. With graphene's density, that works out to be 1,120,000 kg for a single layer. For comparison, the international space station's mass is 450,000 kg, so that mass is within the realm of the possible to launch, even to the much greater distance of L1.

But a single layer of graphene is transparent, which isn't a good quality to have for blocking the sun. So much more than 1 layer would be needed. That would very quickly bring the mass into unrealistically high levels, corresponding to hundreds or thousands of space stations. And that still ignores the mass of the supports needed to keep the graphene extended and in the right shape, which would probably weigh more than the graphene itself.

Another problem inherent to such a large surface area is that the solar wind will exert a pretty large force on it. The solar wind has a pressure of about 4nPa, which multiplied with the huge surface area gives a force of 6 kN towards the Earth. So a rockets would have to be mounted on it to keep it in orbit. Or actually, one can compensate for this force by moving solar sail blind closer to the sun, where it would be able to orbit with the same angular velocity as the Earth without any correcing rockets on average. However, the solar wind isn't constant, so it would still need corrective rockets. And it would be in the way for all the current sun-observing satellites at L1. There would also be a tendency for the blind to rotate to show its thin direction to the solar wind, which would need to be counteracted.

This could probably be done, but I it would probably be by far the largest project ever attempted, and much more expensive than other, simpler ways of dealing with global warming, such as polluting less. It's a fun idea, though.

RMS usually presents candid arguments for his positions, and I agree with most of them. I get from the overall tone of your post that we're supposed to disagree with his statements, but you forgot to include the actual argument.

That was meant for unixisc.

Copyright isn't the only way to get paid for writing software. A kickstarter approach lets you collect the money upfront rather than trying to track down people and make them pay post-hoc. Make a page detailing all the neat stuff the software (or the new version) will do, name your price, and see if the world wants it. It's turned out to work very well for computer games, for example.

What's the slight positive effect in the case cutting out skimmed milk?

Some arguments for why mlik may be healthy:
* Pretty much by definition mlik contains all the vitamins and nutrients a mammal needs, in a form they can absorb while they're young. That isn't quite the case when drinking another species' mlik, but not far from it either. Removing the fat removes many of those vitamins, though.
* Lactose tolerance, the ability to digest mlik as an adult, is one of the fastest examples of evolution we know of in humans or other large animals, taking between 2000 and 20000 years. Such fast evolution indicates that it provided a very strong advantage for most of this period. Though of course that's no guarantee that it's still good in modern society.

A typical steak contains 27 g of saturated fat according to google. To get the same amount through skimmed milk, you would have to drink 27 liters or more. That's about a month worth of consumption for a moderate milk drinker. Typical skimmed milk contains 0.1% fat. You definitely don't need to worry about it.