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Comment Bootstrapping and time travel (Score 3, Interesting) 289

Spoiler alert for the movie Interstellar

It seems he did not get the main idea of the movie. The whole movie rests on the idea that it is possible to manipulate gravity in the past. The traversable wormhole was created by some humans in the far future and allowed the main character to communicate with the past, causing himself to join a space program, which would lead him to the place to communicate with the past, and by this save human kind from some disaster and in the far future allow to develop the technology to create the wormhole and a black hole with strange properties. So, it also involves a form of bootstrapping. Which makes even less sense, if indead traversable wormholes could be made at all.

Comment People are the problem (Score 4, Insightful) 82

Here in the Netherlands the problem is not in getting an AED on the site, but to find someone who can apply it. There are many people trained in using AED's and we here in the Netherlands possibly have the highest density of AED's, and although there is an elobrate system to call trained people to a person with a cardiac arrest, the problem is still in getting enough volunteers to join in. It is no use to have an AED within 200 meters from every house, if you don't have people who can apply them. AED's are not difficult to use, but in a case of emergencie, you need someone who can keep his/her head calm and follow the instructions.

Comment MRI did have some effect with my wife (Score 2) 74

In 2006 my wife reported that her memory improved after she had an MRI taken of her head when she was suffering from memory problems. A few months later, also based on lumbal puncture, she was diagnosed with early-onset Alzheimers disease. She reported that her thinking became much more clear. The effect only lasted for half a day. When I told her neurologists, she laughed it away.

Comment 1978: IBM Fortran to Cyber Fortran (Score 1) 230

The summer of 1978, I spend some time to convert a large Fortran program in the IBM dialect to Fortran on a Cyber mainframe. The program consisted of about 1500 punch cards. At first I would load the whole deck every time. After some time, I discovered it was possible to store the program on disk and edit them by-line using a program called Update. This still requires typing punch cards. Everytime, I checked the cards many times to make sure, I did not make any mistakes. And then it was waiting before the monitors showing he input, the execution, and the output queue, If it was out of the output queue, you still had to wait before the output was dropped in one of the labled boxes, which could take another ten minutes. In those times memory usages was billed in the Kbytes per second. I did it for nothing. Just the fun to work on a real mainframe was enough. Afterwards, I was rewarded with the book `Finite Mathematics' by Seymour Lipschutz.

The person giving me the assignment also wrote programs in some kind of simulation language where the lines could be in any order. Sometimes he would shuffle the cards while standing in line for the cards to be read, just to make fun of the other waiting.

Comment Programming is hard, is because computers are slow (Score 0) 391

One of the main reasons why programming is hard, is because computers are slow. This may sound very counter intuitive, but the fact that computers look like they are fast because they make use of many smart tricks, most of which we are no longer aware off. It is important to realize that computers all rely on the memory piramid, where in the top of the memory there is a little very fast memory and at the bottom there is a vast amouth of slow memory (often distributed in a system called The Internet). The range in speed and size is more than 9 powers of 10. A lot of effort is spend in copy data between the kinds of memory inside this memory piramid. And to be able to implement systems that appear fast, we have to deal with all the small tricks that are used in the system to make it look fast. Knuth has said that very often premature optimization is the root of all problems. The real fact is that almost every act of programming (in an imperative language) is an act of optimization, namely finding an implementation of a function with given constraints. Take for example the simple fact that whenever we deal with an integer in a program, it is an integer within a limited range. But an integer could be arbitrary large. So as soon as you declare an integer in your program, you are performing an act of optimization, because you decide that in your case the range of values within your function are limited to a certain power of 2. (Except if your language has an implementation for BigInt, but even these always have a limit.)

Comment Programming is hard because computers are slow (Score 1) 90

One of the main reasons why programming is hard, is because computers are slow. This may sound very counter intuitive, but the fact that computers look like they are fast because they make use of many smart tricks, most of which we are no longer aware off. It is important to realize that computers all rely on the memory piramid, where in the top of the memory there is a little very fast memory and at the bottom there is a vast amouth of slow memory (often distributed in a system called The Internet). The range in speed and size is more than 9 powers of 10. A lot of effort is spend in copy data between the kinds of memory inside this memory piramid. And to be able to implement systems that appear fast, we have to deal with all the small tricks that are used in the system to make it look fast. Knuth has said that very often premature optimization is the root of all problems. The real fact is that almost every act of programming (in an imperative language) is an act of optimization, namely finding an implementation of a function with given constraints. Take for example the simple fact that whenever we deal with an integer in a program, it is an integer within a limited range. But an integer could be arbitrary large. So as soon as you declare an integer in your program, you are performing an act of optimization, because you decide that in your case the range of values within your function are limited to a certain power of 2. (Except if your language has an implementation for BigInt, but even these always have a limit.)

Comment Very confusing at first (Score 1) 310

Everytime when I stay in Ürümqi, which is the most West 'capital' in P.R. of China and almost two times zones to the west of Beijing, I have a very had time adjusting to the fact that they use Beijing time and do everything two hours later. Working hours are 10 to 14 and 16 to 20. Dinner is around 20:30. I find myself being confused and having to substract two hours from the clock to know what time of the day it is. And also having experienced a change in currency (Dutch Guilders to Euro), I expect it might take at least half a year to get used to the new times.

Comment Google for: "elektrische fiets" (Score 1) 166

Here in the Netherlands, where we have as many bikes as inhabitants, electrical supported bikes, have become very common. Google for "elektrische fiets" for some images of these. The battery packs are either build into the frame or put under the luggage carrier at the back. We installed under the luggage carrier, it often is a battery pack that can be taken out. The electrical motors are build into the wheel and there is a small dial on the steering wheel with which you can control the extra support needed. To still have to padel yourself, but the electronics will add some extra power to it. Often these bike have a display showing you the battery status. From a first glance these bikes look like normal bikes. Both old en young people are using these kinds of bikes.

Comment Re:Cameras and phones (Score 1) 87

It seems that all the good solutions are commercial and that most of the freeware solutions are crappy, meaning that either the UI is difficult or that the output has many artifacts or is incomplete. Still looking for a good solution with which you can create a good 3D-model using a set of pictures, like PTGui, which allows you to tweak the results of the various steps and correcting mistakes made by the automatic steps.

Comment Why? Natural resources. (Score 3, Insightful) 197

Why this arms race? There can only be one reason: access to natural resources. Some natural resources (such as cheap fossile fuels) are on the decline, and China wants to keeps ite growing population happy, otherwise those in power might lose their position. The other superpowers also want to keep their positions. Cheap natural resources (ranging from water to fossile fuels to rare earth metals) are an essential fact for a healthy economy.

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