Joshua Schroeder - Looking to the Universe as a Whole

Being the astronomer-in-residence at Cogitania for the last month has been a true pleasure. We have generally run two sessions every weekend for different groups of students. The topics we explored started with the Earth as a whole, extended out into the Solar System, looked beyond to the Stars and the structure of our galaxy: the Milky Way, and finally looked out on the Universe as a whole. We looked at dramatic images of planets, stars, nebulae, and galaxies that had to be placed in mathematical perspective that is dramatic and humbling.
 
One of the first activities we did was to make a scale model of the Solar System. But choosing even a seemingly absurd scale of one inch equivalent to ten million miles will force your model to stretch from one end of Cogitania to the other while Earth was less than a foot away from the Sun. At this scale, the next nearest star is 40 miles away!
 
We looked at how astronomers approached the mathematics of large numbers. We are interested in scales, not in precise measurements. We say that the number of stars in the galaxy is 100 billion, but this estimation is just giving us the rough range of possibilities. The true number could be a few times bigger or smaller, but that is not a concern to astronomers: we just want to know how big the amount is in a scaled sense. 100 billion is a huge number, after all. Counting to 100 billion at one number said each second would take 3000 years.

We looked at how craters were formed by making our own. It was an experience of flour, sand, and cocoa powder flying everywhere as objects large and small were dropped into these makeshift planetary surfaces. The same properties of craters we saw in astronomical images could be seen in real life!

We traced out the orbits in gravitational fields. We looked at how to construct circles, ellipses, parabolae, and hyperbolae with straight edges, pencils, and string.

We classified galaxies and compared our scheme to the one developed by Hubble nearly 100 years ago.

We modeled the expanding universe using a balloon.
 
We counted out different colored beads to represent the amounts of various elements in the Universe and compared their paltry amounts to the tremendous abundance of dark matter and dark energy.

We learned about Einstein's Theory of Relativity and explored how space and time are connected.

We even made a cometary nucleus from a recipe.

Astronomy is a science of context. It is a science that encourages us to think about our place in reality. While we are small, it is incredible to realize that using our senses and our brains, we have been able to figure out so much about the grandest of scales.

And hopefully, we will continue to explore. I will be back to Cogitania soon, and remember to always look up!