# Computers

This computer owned by an idiot. I use AVG, which got me through 2 years of Honduran internet pretty well.

(I ended up with some crap on my system when I just couldn't live without watching US sporting events and ended up using a sketchy site to stream NBA games, but AVG wiped out most of it. Somehow there's way more malware just kind of floating around on the internet in Honduras than there is the US, though--I was catching all sorts of shit with scans on a regular basis even when I wasn't using sketchy sites.)You can find specialized uninstaller software for programs that don't want to uninstall themselves. (I use one called IObit.) Honestly, you do need to be careful about free downloads, but I've never been steered wrong on a variety of system issues by going with free-download products recommended by nerds on internet forums. Whenever I have to Google a tech-support issue these days, the results I go to first are the ones on message boards.

A Neural Network Playground. How a Kalman filter works, in pictures. I have to tell you about the Kalman filter, because what it does is pretty damn amazing.

Surprisingly few software engineers and scientists seem to know about it, and that makes me sad because it is such a general and powerful tool for combining information in the presence of uncertainty. At times its ability to extract accurate information seems almost magical— and if it sounds like I’m talking this up too much, then take a look at this previously posted video where I demonstrate a Kalman filter figuring out the orientation of a free-floating body by looking at its velocity. Totally neat! You can use a Kalman filter in any place where you have uncertain information about some dynamic system, and you can make an educated guess about what the system is going to do next.

Even if messy reality comes along and interferes with the clean motion you guessed about, the Kalman filter will often do a very good job of figuring out what actually happened. \vec{x_k} = (\vec{p}, \vec{v}) Hmm. Easy! Paul Ford: What is Code? A computer is a clock with benefits.

They all work the same, doing second-grade math, one step at a time: Tick, take a number and put it in box one. Tick, take another number, put it in box two. Tick, operate (an operation might be addition or subtraction) on those two numbers and put the resulting number in box one. Cryptography Breakthrough Could Make Software Unhackable - Wired Science. As a graduate student at the Massachusetts Institute of Technology in 1996, Amit Sahai was fascinated by the strange notion of a “zero-knowledge” proof, a type of mathematical protocol for convincing someone that something is true without revealing any details of why it is true.

As Sahai mulled over this counterintuitive concept, it led him to consider an even more daring notion: What if it were possible to mask the inner workings not just of a proof, but of a computer program, so that people could use the program without being able to figure out how it worked? The idea of “obfuscating” a program had been around for decades, but no one had ever developed a rigorous mathematical framework for the concept, let alone created an unassailable obfuscation scheme. Over the years, commercial software companies have engineered various techniques for garbling a computer program so that it will be harder to understand while still performing the same function. Too Powerful to Exist. Processors That Work Like Brains Will Accelerate Artificial Intelligence.

Picture a person reading these words on a laptop in a coffee shop.

The machine made of metal, plastic, and silicon consumes about 50 watts of power as it translates bits of information—a long string of 1s and 0s—into a pattern of dots on a screen. Meanwhile, inside that person’s skull, a gooey clump of proteins, salt, and water uses a fraction of that power not only to recognize those patterns as letters, words, and sentences but to recognize the song playing on the radio. Computers are incredibly inefficient at lots of tasks that are easy for even the simplest brains, such as recognizing images and navigating in unfamiliar spaces. Machines found in research labs or vast data centers can perform such tasks, but they are huge and energy-hungry, and they need specialized programming.

Google recently made headlines with software that can reliably recognize cats and human faces in video clips, but this achievement required no fewer than 16,000 powerful processors. Neurons Inside. NSA Snooping Was Only the Beginning. Meet the Spy Chief Leading Us Into Cyberwar. Alexander runs the nation’s cyberwar efforts, an empire he has built over the past eight years by insisting that the US’s inherent vulnerability to digital attacks requires him to amass more and more authority over the data zipping around the globe.

In his telling, the threat is so mind-bogglingly huge that the nation has little option but to eventually put the entire civilian Internet under his protection, requiring tweets and emails to pass through his filters, and putting the kill switch under the government’s forefinger. “What we see is an increasing level of activity on the networks,” he said at a recent security conference in Canada. “I am concerned that this is going to break a threshold where the private sector can no longer handle it and the government is going to have to step in.” And he and his cyberwarriors have already launched their first attack.

The success of this sabotage came to light only in June 2010, when the malware spread to outside computers. The Julia Language.