Happy Birthday Ramsay

Today is the 167th anniversary of the birth of William Ramsay, the scientist who is credited with discovering the noble gases. Google recognized the event with a doodle on 10/2/2019

When the noble gases were being discovered (Argon was the first in 1894, helium closely thereafter in 1895), Mendeleev was very doubtful they were elements. These new species did not fit within his periodic table. Additionally, they didn’t do anything like other elements (make oxides and hydrides, for example). It wasn’t until 1898, when neon, xenon and krypton were also discovered that it occurred to scientists that a new row of the periodic table had been discovered.

In 1900, the radioactive radon was discovered (although the ideas of radioactivity were still being fleshed out at that time by Marie Curie). The last noble gas to be discovered was oganesson, which happened in 2006.

200 years of climate science

Did you know that our understanding of the effect carbon dioxide has on atmospheric temperature started 200 years ago? I didn’t, at least not until the NY Times morning briefing made me aware of Eunice Foote’s contributions to the science. I had heard of Eunice Foote before, when I visited the Women’s Rights National Historic Park in Seneca Falls this past summer (a great way to spend a morning/afternoon if you are in the area).

Rather than recap Foote’s contributions to science and the challenges she faced as a woman in science, I’ll send you over to this great summary of her work and trials.

Foote was not allowed to read her paper at the meeting because women “couldn’t participate in science”. How times have changed.

LED spectroscopy

I’m working on a project that will include using LEDs as light sensors, and one of the first tasks is to learn a bit more about the wavelengths of light that are emitted by an array of LEDs. Since I’ve recently created a Mathematica interface to an Ocean Optics spectrometer (on a Raspberry Pi, naturally), the first task was pretty straightforward.

Emission spectra of several LEDs. rgb(b,g,r) are in a common cathode RGB led while the others are varieties from Adafruit.
Continue reading

More Particle madness

The graphics in this post will no longer work now that I have started a new project with this particle.

Now that I’ve mastered (!) publishing sensor readings from a Particle device and visualizing them with ThingSpeak, it’s time to step up my game a little bit. I have an old BMP180 temperature and pressure sensor that I thought was toast. I’m glad I didn’t throw it out because it seems to be working well.

A static view of temperature and pressure data from a BMP180 sensor connected to a Particle Xenon.

I was interested in this sensor because it reports two values. If I want to send both values to ThingSpeak using the Particle tutorial, I would have to set up two webhooks (and possibly two channels). That seems like a lot of work. I sought an alternative. The particle community has several discussions (such as this one) that show how to do it.

Continue reading