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Comment: He was anti-war all life long (Score 5, Informative) 49

by ralfmuschall (#48386699) Attached to: Mathematics Great Alexander Grothendieck Dies At 86

The snippet above ("before abandoning the discipline, taking up anti-war activism") sounds as if he had switched from math to politics in 1970. Truth is, he was an anti-war activist all life long, i.e. against France's Algeria war, and he even gave lectures in Vietnam during wartime (1967). Some biographic texts about him are available at http://www.scharlau-online.de/... (AFAICT in german).

Comment: Re:So let me get this straight... (Score 1) 66

by ralfmuschall (#43577605) Attached to: Robot Snake Could Aid Search and Rescue Operations

My problem with this is that robosnakes seem to get worse. The ones that Gavin Miller build a decade ago were autonomous (and one even could sidewind), the things in the video just looked like bags filled with The Creeping Chaos. Maybe the toy industry should take care of the problem, and then one could add search&rescue tools to cheap smart chinese toy robosnakes.

Comment: Re:Panic Factor (Score 1) 66

by ralfmuschall (#43577525) Attached to: Robot Snake Could Aid Search and Rescue Operations

*First world people* fear snakes, with the bible (Gen 3:1-5) being a significant cause IMHO. In countries where seriously venomous snakes exist, they are venerated a holy animals, and people are aware that trying to kill a snake is a bad idea (it is the snake which you don't see (and therefore step on it) that bites you). A snake being seen crawling around is harmless *unless you attack it*, and even then it will most probably flee.

Comment: Re:May be a social issue with using snakes (Score 1) 66

by ralfmuschall (#43577491) Attached to: Robot Snake Could Aid Search and Rescue Operations

I don't think this is a problem. People in India who suffer from snakebites (the agile cobras cause only a small minority of the accidents, most are vipers which are to lazy to run away (Romulus Whitaker did an analysis of that a few years ago)) get bitten from stepping on them (or rolling onto them whilst asleep in the case of kraits). A cobra seeing you trapped under rubble would simply ignore you for not being a threat. I assume that people in India are aware of these facts (but OTOH I'd expect first-world-people to panic when they have serious problems (like e.g. the smartphone not working properly) and a baby corn snake approaches them).

Comment: Re:overhead wires or third rails (Score 1) 225

by ralfmuschall (#35075050) Attached to: Ski Lifts Can Could Help Get Cargo Traffic Off the Road

The tonnage (proportional to the required strength) of the pulling rope depends only on the mass and the inclination of the path of the goods. The inclination is determined by the terrain profile and by the curvature of the non-moving suspension rope, and the latter can be minimized by having more support posts. Unless on wants to lift very heavy goods up along a steep course, I don't think that friction of the pulling rope plays a big role.

Comment: Re:Does it work ? (Score 3, Insightful) 186

by ralfmuschall (#34072828) Attached to: How Not To Design a Protocol

Your way of thinking is nice, but it is exactly this attitude that gets developers fired (or their bosses broke if they share that attitude and don't fire you, in which case an inferior insecure competing product will dominate) for thinking too much instead of getting the product out. That's why we are up to the neck in inferior goods, protocols just being one example. Not even death penalty (e.g. for melamine in chinese milk) does seem to stop this.

Comment: Re:GPS? (Score 1) 218

by ralfmuschall (#33627738) Attached to: Helicopter Crashes While Filming Autonomous Audi

> Human beings have no business driving

I agree (I hate it when I have to drive). With robo-cars, there is another problem: Lots of traffic laws are routinely and massively broken. In .de (and probably everywhere), the law fixes a minimal safety distance for different speeds and types of road - and the real distance that the drivers keep is a third to a half of that. This is not just bad behavior - tripling the distance would cut the capacity of the road to a third (unless you triple the speed as well, which would not increase safety either), and there are just not enough roads for that (one would need three times the area for roads as well).

Now, if a robot drives a car, he has two options: Follow the law, cause a traffic jam behind himself (or even provoke somebody to cut into the seemingly extremely long clearance) and be hated by everybody; or drive like everyone else and be sued out of business if something bad happens.

Comment: Re:Too soon (Score 1) 218

by ralfmuschall (#33627638) Attached to: Helicopter Crashes While Filming Autonomous Audi

As others already wrote, there is an efficient way to use all lanes and merge directly before the obstacle. But this is not the question - the antisocial personality of those people enables them to afford such luxury cars in the first place. Here in .de, seeing cars of certain brands (those with "builtin right-of-way") automatically means "CAUTION!". Googling for "Wiehltalbruecke" helps.

Comment: Re:Who is it for? (Score 1) 325

by ralfmuschall (#33592490) Attached to: Super Principia Mathematica

There is no equally-named Kemp on arxiv.org (there is a "R.Kemp", where "R." seems to stand for "Roger" in two solid-state chemistry/physics papers), and there are no google hits with his name and +site:.edu.

On http://www.superprincipia.com/About_The_Author.htm is the author's CV, he is essentially a radar engineer (probably a good one given the companies he worked at), and worked as a math teacher at some time. In the autumn of 1989 he suffered an attack of Holy Spirit and seems not to have recovered yet.

Unfortunately the website gives no sample chapters for download. I'd expect the book to be a stylistically pleasant reading, but I cannot tell if the hard core physics stuff is correct (and free from esoteric stuff). When in doubt, I'd stick with Penrose (his two-volume book with Rindler is great, his popular stuff as well (except when he tries to push his unorthodox interpretation of quantum mechanics)).

The wensite says the book requires "basic understanding into algebra, geometry, differential calculus, and integral calculus". Since that little math is not even sufficient to understand the currently generally accepted theories of physics (one needs at least differential geometry, algebraic topology, functional analysis and Lie groups for even the simplest things), I have some doubts whether the book really *explains* physics or just tells a story *about* physics.

The fact that he has no PhD should not matter (he seems not to want one), and even Einstein got PhD his only a year after Special Relativity.
His paper about photons is mostly prose with very few equations in between, and sounds strange (to say it mildly), which has already been mentioned by other commenters here.

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