This visualization shows the current location of the International Space Station (ISS), actually the point above the Earth that the station is closest to. It is approximately 260 miles (420 km) above the Earth’s surface The station began construction in 1998 and had its first long term residents in 2000.
The visualization can also show the animated future orbital path of the ISS using ephemeris calculations, which makes a nice, cool pattern over an approximately 3.9 day cycle, where it starts to repeat. The animation allows you to view the orbital patterns on the globe (orthographic projection) or a mercator or equirectangular projection.
One of the cooler features is to drag and rotate the globe view while the orbital paths are being drawn. You can also adjust the speed of the orbit as well as keep the ISS centered in your view while the globe spins around underneath it. If you select the “rotate earth” checkbox, it becomes apparent that the ISS is in a circular orbit around the earth and that the pattern being made is simply a function of the earth’s rotation underneath the orbit.
This visualization only shows the approximate location of the ISS as there are several confounding factors that are not represented here. The speed of the ISS changes somewhat over time as the station experiences a small amount of atmospheric drag, which slows the station over time. But it still goes over 7000 meters per second or about 17000 miles per hour. As it slows, its orbit decays so it falls closer to earth and it experiences even more atmospheric drag. Occasionally, the station is boosted up to a higher orbit to counteract this decay. Secondly the earth is not a perfect sphere and this also causes the calculations to be only approximately correct.
Some other cool facts about the International Space Station:
Other cool space-related orbital art can be seen at the inner planet spirographs.
Here are a couple of images showing the final pattern made by the ISS on different map projections.
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It had always seemed like the most decorated US Olympians tended to be swimmers, so I wanted to see how all the various events are distributed across the different types of sports. Each sport (like swimming) has a number of individual events and are show in a treemap as a collection of boxes. And indeed swimming does have the most individual events of any of the sports in the 2020/2021 Olympics.
I also wanted to see how you can categorize the different Olympic events, so I looked at several different dimensions, which are color coded:
The sports with the largest number of individual events is swimming, then track, cycling, and field. Some the fighting sports have many individual events but they are all exclusive categories (i.e. you can’t compete in two different boxing or wrestling events).
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I wanted to try my hand at creating 3D elevation models and thought trying to model some of the popular (and some of my favorite) national parks would be a good starting point.
Once a 3D elevation model is selected and shown you can manipulated it in multiple ways:
You can select a number of different parks from the drop down menu. If you have suggestions for additional parks, I may be able to add them to the list.
Note: the elevation files are data intensive since the visualization is downloading the elevation across in some cases, many hundreds or thousands of square miles. To keep the data needs down, I’ve reduced the resolution of the elevation data. Though the original data is 90 meter resolution (elevation is specified across every 90 x 90 m square in each park, I’ve averaged these squares together so that each park model only has about tens of thousands of these squares, regardless of the actual area of the park. This improves data loading and rendering times and makes the improves the responsiveness of the model.
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Here are some interactive and educational planning tools that I developed to help you understand the concepts of FIRE and calculate how long it will take to achieve retirement and how likely you are to survive retirement. Click on the tools below to try them out.
Regardless of where you are on your path to FIRE, there are several types of tools that are useful:
Simulating retirement portfolio survival probability and human longevity
Interactive tool lets you explore the concept of historical simulations and understand how to determine a safe withdrawal rate
These tools all focus on the concept of FIRE. FIRE is the concept that revolves around saving and investing to achieve Financial Independence (FI) and to potentially Retire Early (RE). One of the core concepts is that once you can save up enough money, you can retire by withdrawing a fraction of this money annually to cover your living expenses. Other important topics related to this core concept have to do with reducing spending so you can save money and investing so your money can grow and sustain your retirement over many decades.
These tools relate to taxes and stock market returns.
Data Sources and Tools:
See the individual tool to learn more about how it was made.
I wanted to see how often there were exceptions to the spelling rule “i before e, except after c”. I found a website (wordfrequency.info) that had a list of the 5050 most common english words and decided to do some analysis on it to see which words followed this rule and which did not. Below is a treemap graph that shows the words that follow the rule in green and those that do not in red. The size of the box represents how common the word is in regular American English usage (based on the frequency that it shows up in the Corpus of Contemporary American English).
What we see is that while 81% of the 158 most common words with ‘e’ and ‘i’ adjacent to one another do follow the rule, when you take into account how frequently these words are used, the weighted percentage of words following the rule drops to around 60%. This is because some very commonly used words do not follow this rule and if you were to count how many times you use words from this list, it’s likely that about 40% of the time you’ll be using words that don’t follow the rule. For example, the two most commonly used words with ‘e’ and ‘i’ adjacent (their and being) do not follow the rule, since then have the ‘e’ before the ‘i’ but aren’t after a ‘c’.
I was inspired to look into this after seeing a tweet about the rule in the comic Pearls before Swine by @stephanpastis.
Perhaps the most unhelpful spelling rule ever. pic.twitter.com/sW0aud6rA3
— Stephan Pastis (@stephanpastis) March 9, 2021
I asked my kids but they had never heard of the rule so perhaps this isn’t taught in schools anymore.
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The code has been updated to allow for multiple chunks of icebergs now, which can occur via melting if you draw an iceberg a certain way.
I was so impressed with the interactive Iceberger tool that Josh Tauberer (@JoshData) made that I had to modify it and add some additional features. Click here to see the original. My additions allow you to conjure up pre-made “icebergs” to see how they float and also allow some interaction. Try “poking” the icebergs you make.
Josh and I were both inspired by a tweet by Megan Thompson-Munson (@GlacialMeg).
Today I channeled my energy into this very unofficial but passionate petition for scientists to start drawing icebergs in their stable orientations. I went to the trouble of painting a stable iceberg with my watercolors, so plz hear me out.
— Megan Thompson-Munson (@GlacialMeg) February 19, 2021
You can choose between 3 different iceberg creation options:
Once the iceberg has been created, you can also affect it in a couple of different ways:
Some Physics – no equations
The force of gravity (G) affects the entire body regardless of where it is or how it is oriented. If you show the forces, the red dot labeled G shows where the center of mass of the iceberg is. The blue dot labeled B shows where the center of buoyancy is. This is the center of mass of the part of the iceberg that is submerged. The force acting on the submerged part is equal to the volume of water displaced. If the center of buoyancy is below the center of gravity, then the forces will be equal and object will be in stable equilibrium. If the center of buoyancy is somewhere other than under the center of gravity, then the buoyant force will be pushing up on a different place than the gravity force and this will induce a rotation until they are directly over one another.
The code has been updated so that multiple icebergs are now allowed. Melting can separate a single piece of iceberg into multiple pieces, just as in real life. The melting process was a bit difficult to program because of the complexity of shapes that could be produced.
If you have additional suggestions for shapes or countries to add to the list or other improvements to make, let me know in the comments. Also if you are using this as a teaching tool, I’d love to hear how you are incorporating it into your curriculum.
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