Elevation and Atmosphere


I received this tweet* from Katrina (aka @Astro_yyz), and thank her for the kind wishes. But it got me wondering: what exactly is the difference in atmospheric pressure between sea level and the elevation of Kitt Peak Mountain? To the internet!

The Kitt Peak summit is at an elevation of 2,097 m, just over 2 kilometers above sea level. This is the sign that greets you when you hit the top

Kitt Peak: 6750 feet above sea level

Kitt Peak: 6750 feet above sea level

Sea level atmospheric pressure is (on average) 101.325 kPa (kilo Pascals). The atmospheric pressure reduces as altitude increases, the amount by which can be calculated based on simple physical laws. I used a short derivation of these equations by the Portland State Aerospace Society;^1 their equation 9 gives the value of atmospheric pressure as a function of height:

    \[P=100*\left( \frac{44331.514-height}{11880.516}\right)^{(1/0.1902632)}\]

where ‘height’ is in meters. So subbing in height=2097, the equation gives P=78,543 Pascals, or 78.543 kPa. Therefore, the pressure atop Kitt Peak is:

    \[\Delta P=100\left( \frac{78.543}{101.325} \right) = 77.5\%\]

of the pressure at sea level. Cool! And this lines up nicely with a graph that Wikipedia has:

So does this affect me as Katrina alluded to? It hasn’t so far! and it really isn’t high enough for most people to experience any negative effects (such as dizziness, headache, elevated heart rate). However, walking to the cafeteria every day (up a very slight incline) does seem harder than it should be. Though that may just be because I’m horrendously out of shape.


* My own twitter account is @jesserogerson, however, for the week of 12-18 May 2014 I was tweeting as @AstroCanada. This is the official account of the Canadian Astronomical Society. Each week a different Canadian astronomer will be tweeting from it.

1. A Quick Derivation Relating Altitude to Air Pressure [PDF], Portland State Aerospace Society, 2004
2. Atmospheric Pressure, Wikipedia, accessed May 2014
3. Effect of High Altitude on Humans, Wikipedia, accessed May 2014

3D Printers

The company MakerBot* had a few of its Replicator2 3D printers on display at the Ontario Science Centre over the weekend of 11-13 April 2014. They were there as part of the SpaceApps Toronto event, wherein participants have a weekend to solve an interesting technical problem.
*[CORRECTION: (16 April 2014) It was brought to my attention that it was not MakerBot that was responsible for bringing the 3D printers; it was actually the company MAKELAB that presented the Replicator2’s as part of its sponsorship of the NASA International Space Apps Challenge. Now that the challenge is over, the 3D printers have been brought back to MAKELAB’s workshop. Check out their website to learn more about what MAKELAB is up to.]
In the video above, the first printer is making 3 bracelets, the second printer is developing a robot, by printing each of its parts individually; later a human can put them all together. Unfortunately I never saw that one finish.
The printers work as, what is essentially, big glue guns of plastic. The design is loaded (via SD card), cold plastic is fed into the printer nozzle (which heats the plastic to over 200 C making it a liquid), the nozzle puts one entire layer of the design onto the blue surface, the blue surface then moves down a small amount (based on the resolution you want), and the nozzle starts again with the next layer up. Pretty simple right? You can have your very own Replicator2 for just $2300. Actually not a bad price. But you don’t need to buy one; libraries (Toronto Public Library, for example) and maker spaces (Maker Kids, for example) are starting to have them available for people’s use at a much smaller personal cost.
Space Related: The Marshall Space Flight Center will be launching a 3D printer to the International Space Station aboard a Soyuz spacecraft as part of expedition 39 to test how 3D printing will work in space. The project is called 3D Printing in Zero-G.

The printer can make anything you program it to make, here is a plastic nut/bolt

The printer can make anything you program it to make, here is a plastic nut/bolt

nut and bolt apart

nut and bolt apart

Impromptu Tour of the Bok 90inch

The Kitt Peak National Observatory is not just home to professional telescopes and astronomers, it also has a fully operational outreach program and visitor center. The mandate of the center is to engage with the public, which they do in a variety of ways. They have an informative exhibit in the visitor center, daily tours, daily solar observing (which I wrote about in a previous post), and even night time observing programs. There happen to be a night time observing program for the public on the Saturday of my observing run. Normally, this would not have mattered much as they would observe with their own telescope and then send everyone home; however, there happen to be a lot of clouds this evening. Not only did this mean my colleagues and I couldn’t do any science observing, but the public couldn’t do any recreational observing either. As a result, they were looking for some other fun things to do. I happen to run into the staff organizing the pubic program in the cafeteria before I headed to the telescope to set up for the night and they asked if, should the weather prove cloudy and unusable, we wouldn’t mind giving a quick tour of the Bok ‘scope. I was happy to do so.


Chatting with the public about my research, the telescope, and anything else we could think of. Once a host always a host.

Planet vs. Dwarf Planet? Presenting at RASC Mississauga

The title slide for my talk at the Royal Astronomical Society of Canada, Mississauga Faction.

The title slide for my talk at the Royal Astronomical Society of Canada, Mississauga Faction.

On Friday the 24th of January 2014, I gave a public talk to the Royal Astronomical Society of Canada, Mississauga Faction. I originally suggested I give a talk on my research, which is focused on black holes, however, the past president Randy Attwood indicated they had already invited my supervisor, Dr. Patrick Hall to talk about that. So I used it as an opportunity to develop a new public talk focussing on planets and dwarf planets, one that I had been wanting to build for a while but hadn’t had the motivation to do so.
I find the topic of ‘dwarf planet’ very interesting, specifically how it surrounds our beloved Pluto. Re-classification is the hallmark of science, as it indicates that people have discovered new things and therefore changed how they view a topic. Re-classifying (note, NOT demoting) Pluto only shows us that astronomers are still putting the puzzle pieces of the solar system together.
The talk I gave was based on a book I read called The Pluto Files: The Rise and Fall of America’s Favorite Planet written by Neil deGrasse Tyson. Dr. Tyson gives a fantastic account of how Pluto was found, and how it was re-classified in the infamous decision of 2006 by the International Astronomical Union (I.A.U.). Definitely check that book out.
Here are the full presentation slides (PDF) that I used for the talk, however, I also employed the help of two friends, Harrison Ruess and Ashley Carr, to video record the talk for me, which I’m currently editing for youtube.

Visiting the Aquarium of Canada

I was lucky enough to visit Toronto’s brand spankin’ new Ripley’s Aquarium of Canada. It’s located at the hub of tourism right at the base of the CN Tower, next to the Skydome (ahem…Rogers Centre). Just a few quick highlights:

At the base of Toronto's CN tower you'll find the Ripley's Aquarium of Canada

At the base of Toronto’s CN tower you’ll find the Ripley’s Aquarium of Canada. Ripley’s has two other aquariums located in Gatlinburg, Tennessee and Myrtle Beach, South Carolina. The Toronto aquarium opened to the public on October 16th, 2013 (also my birthday!). Fun Fact: the amount of concrete used in construction of the aquarium is roughly 40% of that used for the CN Tower.

The Megalodon was a large shark that lived approximately 28 to 1.5 million years ago.

The Megalodon was the largest shark that lived (reigning from 28 to 1.5 million years ago). It grew to lengths between 14-18 meters long (which is roughly 1.5x longer than a TTC bus in Toronto), and it’s jaws were big enough to….well. ..ya.


There were a couple of places visitors were able to touch various sea creatures.

There were a couple of places we, as visitors, were able to touch various sea creatures; these are called touch tanks. Here i was able to touch a small Whitespotted Bamboo Shark, but we were also able to touch Horseshoe Crabs.

And of course, I took a few videos: below are a quick one of a jelly fish and another from the Dangerous Lagoon, which featured a moving sidewalk.