Tuesday, February 11, 2014


There are currently about 7.1 billion people on the planet1.  The average American eats about ton of food per year, and the poorest average about half that2.

That works out to 4.8x1012kg, which, compacted, would make a ball about 2km in diameter3.

Here it is compared to some other objects:

Great Pyramid of Cheops0.14x0.23km5.4x109kg
Three Gorges Dam0.18x2km3.4x1010kg
just the meat40.76km2.7x1011kg
asteroid: 1999 KW41.5km2.4x1012kg
asteroid: 1620 Geographos2.0km4x1012kg
how much we eat in a year2.0km4.8x1012kg
asteroid: 2002 CE263.5km2x1013kg
Halley's comet8-15km3x1014kg

To further help comprehend the dimensions, here is a list of the world's tallest buildings.

1 - world population
2 - average food consumption (I used the average of the two numbers)
3 - mean density of compacted food waste is about 1029 kg/m3.
4 - The size of the meatball we consume each year, as a species. See source.

Saturday, February 1, 2014

Explorable Universe

Ever since I saw the peculiar, foam-like arrangement of galaxies, I was intrigued.  Here is an example of what I'm referring to.  Every point of light in this image is an entire galaxy.

This inspired me to create a fly-through visualization that lets you explore nearby stars, galaxies and galactic clusters.  Please be patient while it loads all the data, there's 4MB of galactic cluster data and 2MB for the stars, so it takes a minute or so the first time you load it.
* http://marklipson.com/code-samples/galaxies1/galaxies.html

My favorite is the "galaxy" view - you can see the clustering of galaxies, and you can more or less see the filaments and voids.  The "cluster" view may not quite be correct yet, and the radii and brightnesses could all use some work.  But it gives you a sense of where we are in the universe, which was its purpose.  If any programmers or astronomers feel inspired to help, the code is here.

For a more visually gratifying fly-through, here is one based on the terabytes of data gathered by SDSS:
* http://www.youtube.com/watch?v=08LBltePDZw

Here's a great little demonstration of the scales involved:

And I can't help but include a link to this article about what might lie beyond the meager confines of the observable universe: