See Part 1. I’ve been exploring a random walk in one dimension, where on object moves either +1 or −1 at each step, at random. On average, it will end up back near where it started (distance = 0), but over time, the likely positions start to spread out. I previously graphed the outcome of 1000 trials for 2000 steps. Although I can see the trajectories start to spread out, I’d like to actually graph the distribution.
Problem: Graph the probability of an object ending up at different distances from the origin during a random walk.
Phoenix, a NASA robotic probe, landed successfully on Mars on May 25. It landed in the north polar region of Mars, at around the equivalent latitude of northern Alaska, and it will study Mars’ soil to look for clues of past water patterns and if it was ever hospitable to life.
Incredibly, as it parachuted down towards the surface, its picture was taken by a satellite orbiting Mars, the Mars Reconnaissance Orbiter(MRO)! From an amazing distance of 750 kilometers (470 miles), it snapped this photograph of Phoenix parachuting towards Mars. This is the first time one probe has photographed another landing on a planet.
This mind map was created by Sharon Genovese, founder of an anti–global warming group called “Live the Solution”. The mind map, as well as several others, are featured in her free e-book Global Warming: A Mind Mapper’s Guide to the Science and Solutions (PDF, 5 MB / 103 pages).
I enjoy seeing different methods used to present and visualize data, and so I found “A Year in Iraq”, an opinion piece in the New York Times by Adriana Lins de Albuquerque and Alicia Cheng to be quite interesting. “The chart … gives information on the type and location of each attack responsible for the 2,592 recorded deaths among American and other coalition troops, Iraqi security forces and members of the peshmerga militias controlled by the Kurdish government.” See the article (free registration required) for the whole graphic and story.
Hours after taking office, Australia’s new prime minister, Kevin Rudd, initiated the process of ratifying the Kyoto Protocol, an international agreement to reduce greenhouse gases to help fight climate change. (See, for instance, the Sydney Morning Herald or the BBC). 174 countries have ratified the agreement; the United States is notably absent, especially now that Australia is joining their ranks.
Map of countries and their position towards the Kyoto Protocol. Green countries have signed and ratified the treaty; yellow countries have signed but not yet ratified it. Red countries have signed but have no intention of ratifying. Gray countries have not taken a position. See full-sized version. Source: Wikipedia.
This beautiful visualization is part of his project “Flight Patterns”, showing the density and path of airplane flights over the United States. The project features several different visualizations in different styles, but I’m partial to blue. He also created several animations that add a whole new level; it’s especially neat to see the wave of increased air traffic travel east to west as morning arrives in each time zone.
Obesity has reached epidemic proportions in the United States. These increased body fat reserves are associated with an increased risk of numerous health problems, including coronary heart disease and heart attacks, diabetes mellitus, stroke, some cancers, and more. Obesity has become so prevalent in the U.S. today that it is difficult to remember that just a couple decades ago, the average American was not overweight, and few were obese. Below is a link to an animated graphic showing the remarkable increase in obesity in U.S. states over time. In the ideal case, the entire map would be colored the aqua color, since there would be data from every state but no obese people.
As is commonly done, obesity is defined here based on the body-mass index (BMI). The BMI is calculated by dividing one’s weight by one’s height squared. It is traditionally given in SI units (that is, kg/m²), so if U.S. customary units are used, they must be converted. BMIs in the range from 18.5–25 kg/m² is considered normal or healthy. 25–30 kg/m² is overweight, and greater than or equal to 30 kg/m² is obese. (40 kg/m² or greater is often considered morbidly obese, or sometimes 35 kg/m² or greater along with other risk factors is included.) The use of BMI is imperfect (for instance, a very muscular person will have a high weight and therefore BMI), but in practice it is usually simple to differentiate obese from muscular people.
For instance, consider a 1.78-m (5 ft., 10 in.) tall person. The healthy range would be from 58.5–79.0 kg (129–174 lb.). Those weighing more than this would be overweight, and over 94.8 kg (209 lb.) would be obese. For a 1.63-m (5 ft., 4 in.) tall person, the healthy range would be from 47.4–64.0 kg (104–141 lb.). Greater than 76.8 kg (169 lb.) would be obese.
It’s easy to calculate your own BMI. There are plenty of BMI calculators and BMI charts on the Internet. But the fastest way is probably to use Google Calculator: just type your calculation directly into the main search box (see example).
The obesity data are taken from the CDC. I reformulated them into an animated GIF since I didn’t care for the original color scheme and also because that presentation isn’t easily exported to other sites. You are free to use the image (direct linking is fine), though I would appreciate a link back here if you do.
The site features a timeline with a slider you can drag. It starts at the big bang, an estimated 13.7 billion years ago. Once the solar system forms some five billion years ago, it focuses on Earth. Since the most interesting things, from a human perspective, have happened recently, there are a series of supplemental sliders to focus on the most recent portion of each timeline. With simple animations, it’s a nice, easy way to visualize the history of our planet, and see just where our little story fits in.
Many people in developed nations like the United States understand that global warming (anthropogenic climate change) is a problem, but don’t appreciate how it will affect them. There is sometime a perception that poor areas in the tropics will face flooding and disease, but that it is not a significant matter for developed nations.
However, global warming will cause (and is causing) effects worldwide. A few may be positive, but they are grossly outweighed by the negative effects. The United Nations Intergovernmental Panel on Climate Change (IPCC, recent Nobel Peace Prize winner) has been working on its Fourth Assessment Report, and recently released the Working Group II (“Climate Change Impacts, Adaption, and Vulnerability”) portion of it. It details the predicted effects of climate change for each continent over the next century.
It’s a thorough report, but daunting for the casual reader. However, Time magazine has created a great (Flash-based) interactive graphic simplifying and summarizing the predictions: