(Chapter "Language", Principles of Neural Science, 5th ed.)
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(Chapter "Language", Principles of Neural Science, 5th ed.)
There are two problems with this line of reasoning. The first problem is that 2) is unsubstantiated. A human can see immediately that 15 = 3 x 5, but this doesn't mean that we have a magical ability to factor integers instantly. By the frivolous theorem of arithmetic, almost all natural numbers are very, very, very large. We have some ability to analyze formal systems, but the systems we have managed to understand are very simple in the grand scheme of things. Almost all formal systems are very, very, very complex, and there is no evidence that we can understand them all and/or that our understanding process actually is correct (consistent) when extended indefinitely. Penrose's actual argument is of course more technical, and others have made more precise rebuttals.
The second problem is that the argument does not solve the problem of consciousness. Scott Aaronson put it nicely: "Even if we supposed the brain was solving a hard computational problem, it's not clear why that would bring us any closer to understanding consciousness. If it doesn't feel like anything to be a Turing machine, then why does it feel like something to be a Turing machine with an oracle for the halting problem?"
The actual cause of this high-level change could be lower-level age-induced differences in neurotransmitter levels or in neuronal function and connectivity. As the article's summary points out, the actual biological basis needs to be investigated in further research.
It's also important to note that this study found a plausible explanation for changes in learning performance under specific circumstances. This is a very important qualification.
Learning in general is believed to involve many different interrelated mechanisms. It's well established that many different cognitive abilities (perhaps most importantly working memory) diminish with age, and some of this degradation is likely related to natural cerebral shrinkage (a healthy 75-year-old has a 15% smaller brain than a 25-year-old).
Certain groups of cells (place cells, grid cells) are known to be involved specifically in the ability to track one's own location and movement within the external world. This ability is likely a very old and important evolutionary invention in the development of higher animals, thus very sophisticated and well integrated with other functions, particularly memory. Think of the method of loci, known already in Ancient Rome and Greece, or indeed how quickly one learns to navigate a new city (or a video game level, say). This probably explains the phenomenon the author describes.
That said, the relative importance of the various spatial-visual subsystems of the brain probably depends heavily on the task, and perhaps also varies between individuals.
It can be calculated to n digits in O~(n^2) time, which isn't really that bad. Something like Brun's constant or the area of the Mandelbrot set is probably a better example of a real number that is "notoriously difficult" to compute.
No reference is made to previous attempts to study Euler's conjecture or similar conjectures (there are surely a dozen other papers that ought to be cited in the introduction).
What led the authors to consider a computer search as opposed to any other approach? Does the method generalize?
It is indicated that the CDC 6600 was used. How was the programming done? How long time did the execution take? The instance is claimed to be "the smallest". In what norm? How can you be sure that the computer program did not skip any smaller examples?
The most serious problem with the paper, however, is that the only contribution is a purely computational statement which, though a counterexample to a conjecture, does not advance mathematical theory in any way.
Due to these shortcomings, my recommendation to the editor is to REJECT the submission.
If you're a programmer and think 10 million lines of code constitutes a complex system, reading about how cells work on a molecular level should be humbling.
Absent macro obfuscation, it is easy to reason about what a snippet of C does and how it translates down to machine code, even taken out of context. In C++, something as innocent as "i++;" could allocate heap memory and do file I/O.
The downside is that C code can become quite verbose, and to do anything useful, it takes a lot of ground work to basically set up your own DSL of utility functions and data structures. For certain applications, this is an acceptable tradeoff and gives a great deal of flexibility. I think teaching this bottom-up approach to programming can be quite useful - in a way, it mirrors the SICP approach, albeit from a rather different angle.
The question is, why are there not more languages that have the same paradigm, but also add basic memory safety, avoid spurious undefined behavior, provide namespaces, with a non-stupid standard library, etc.?
I just use a signed pointer-size type for all sizes and counters, and stay happy...
Baby steps. Beating other bots in deathmatch is a good start. I love that they only use the rocket launcher, giving the careless bot an equal chance of blowing itself up.
Parsing what's on the screen in Doom is potentially a lot easier than in modern games: since there is no texture filtering or anti-aliasing, and due to the 2.5D perspective, most vertical runs of pixels on the screen map exactly to (linearly?) scaled columns in wall textures or sprites. I would not be surprised if you could come up with a fairly simple algorithm to determine the exact position and orientation of the player and the objects on screen within the map, without any real AI/learning involved.
With formula-heavy text, I'm forced to split documents artificially into multiple short pages to make rendering reasonably fast.
KaTeX looks quite promising, but it was missing support for quite a bit of basic markup the last time I checked. Perhaps it's better now.
But there could be an element of truth to it, which might warrant further research. If CEOs really do have a much more limited influence than they are given credit (or blame) for, then incentives perhaps ought to be adjusted, not just in the interest of fairness but also in the interest of finding better ways to actually improve performance.
The PR version: http://today.tamu.edu/2015/10/15/ceo-effect-on-firm-performa...
That is where the wave equation comes in, in the first course on PDEs.
Instead of the nondescript
- Issue #2654: misplaced comma on page 3 of documentation
- Issue #2653: open() should accept relative file path
it should be
- Quetzalcoatl's Rage: misplaced comma on page 3 of documentation
- The Dying Curse of Buluc Chabtan: open() should accept relative file path