Mar 28, 2012

Surviving without Google Search, or surviving with Duck Duck Go

Google search has been part of my life. And I assume that is true for many people. But Google has been collecting users' data for a long time. As a commercial company, there is nothing to stop it from putting profit above  our benefits. We'd better to have some alternatives. Duck Duck Go may be such one.

Duck Duck Go claims respect of user privacy. Check their page: https://duckduckgo.com/privacy.html.

One great thing about duck is its high customization of search query. I actually only use it in Chrome, to set search engine for address bar. To set the default search engine in Chrome, go to preference -> basic -> manage search engine. If Duck Duck Go is not in the list (which is the usual case), add it by URL
http://duckduckgo.com/?q=%s&kp=-1&kl=us-en
Here are more parameters you can try.

Mar 16, 2012

standing airplane

I was on a bus, saw something in the sky. It was not moving, so I felt very strange, after all, you cannot see a star at noon. When I looked closely, it turns out an airplane. Strange thing, because it was not moving but rotating! I suddenly realized that's because I was on a moving bus!


The above graph analyzes the case. And as we can see, we have reference objects, trees and houses,  most probably. The point is, with respect to the static reference objects, the airplane was projected to the same observation point. The reason it looked rotating is the view angle is changing. We know from our daily life, the perpendicular angular speed of view is indeed comparable with that of slowly moving bus. Both take seconds to make a sensible change. That explains why this can happen.

Mar 12, 2012

Witten's dog

In Futurama episode "Mars University" (S01E11), Dr. Farnsworth lectured on the mathematics of quantum neutrino fields (aka Math of Wonton Burrito Meals). On the blackboard, one can see the following diagram, "Witten's Dog". Dr. Farnsworth concludes that, " by process of elimination, the electron must taste like grapeade."


According to Wikipedia and this page, " Witten's Dog ", named after Ed Witten, is a parody of the classic Schrödinger's cat paradox. Astrophysicist David Schiminovich created both the equations and the diagram, based on "an equation that constrains the mass density of neutrinos in the universe".