Astronomy | Brent W. Barker

What if there was a class that attempted to cover all of space or all of time?

I was curious about this, so I chose the shortest scale of each, divided up the power of tens, then spread them out over the course of 10 to 12 weeks.

For example, for time, I chose 1 year as the smallest range to look at – the first week’s topic would cover the past 10 years. Then, since the universe is about 12 billion years old, or $1.2 \times 10^{10}$ years, each week would look back another factor of 10 years. The 2nd week would cover the period from 100 years ago to 10 years ago, and so on.

In practice, this would be the topic coverage for a 1-semester history lesson (I’m obviously glossing over some important topics):

“History” Class

Week	Years ago	Topic
1	10 a	Last 10 years
2	100 a	World Wars, information age
3	1000 a	modern religion, science, industry
4	10,000 a	development of human agriculture
5	100,000 a	development of clothing, fishing, domestic animals, art
6	1 Ma	Homo erectus, neanderthals, Homo sapiens, controlled fire
7	10 Ma	beginning of horses, insect diversification, chimpanzee and human ancestors divide, mammoths, ice age
8	100 Ma	whales return to sea, bees, T. rex, South America leaves Antarctica, Atlantic Ocean forms
9	1 Ga	possible Snowball Earth, first protozoa, worms, fungi, arthropods, continents shift, land-dwelling life starts, Pangea, dinosaurs
10	10 Ga	Big Bang, galaxies form, solar system and Earth form.

“Geography” class

On the other side of things, a space-centered class could break down like this:

Week	Distance away	Topic
1	100 m	South Loop, Chicago
2	10 km	Chicago
3	1000 km	Midwest USA
4	100,000 km	Earth
5	1 au	The sun and inner planets
6	10 au	All planets in the solar system
7	1000 au	Kuiper belt on edge of our solar system
8	1 ly	Oort Cloud on edge of our solar system, nearest star Proxima Centauri
9	100 ly	local stellar neighborhood
10	10,000 ly	Milky Way Galaxy
11	1 Mly	Local Group (of galaxies)
12	100 Mly	Observable universe

Kinda puts things in perspective for me. I forget, sometimes, how big our solar system is, and how recent humans came into being.

Additionally, it strikes me how interdisciplinary either of these courses would need to be. Crossing scales of time and space requires different lenses and tools.

This might sound cheesy, but I find it incredible that we live on a planet that is so very small on the cosmic scale, but so big on a human scale. How insignificant we are, yet how important our actions are on a human scale.

Yuri's Planet, horizon of Earth with lens flare from sun

Earth, as seen from the International Space Station
(Image Credit: ISS Expedition 7 Crew, EOL, NASA)

Also, I found this image while searching for a space picture for my business card (custom-made here). I was looking specifically for images of the Earth seen from space. I honed in on this one and wanted to find out where the original was. As it turned out, many many people had reposted it without citing the source. I eventually used tineye to hunt down all instances of this image on the internet, to bring you the source that the photo is linked to above.

I’m still not sure whether I have permission to use this on a business card. I read their image use guidelines, but I couldn’t figure out whether this would count as “advertising” or not, so I emailed the contact on their advertising guidelines page. I’ll update this page when I hear back from them.