Skip to main content

Pink Clouds and Science Reruns

A pink cloud was reported in the early morning, (pre-sunrise), sky over Arizona on Wednesday[1]. NASA and the DOD soon thereafter took credit for the cloud.  They had launched a rocket into the ionosphere where it released a vapor that created the cloud.  The purpose of the experiment was to study the effects of the vapor on the ionosphere itself.  The article, referenced above from ABC, said:

"The experiment, which also involved using ground stations to take measurements of the ionosphere, was intended to develop scientific explanations for ionospheric disturbances and their effects on modern technology, officials said."

This has all been done before[2] as it turns out!  In 1956 the Air Force launched two missiles from White Sands Missile Range with payloads of nitric oxide.  The gas released in the ionosphere created a glowing cloud described as being 'yellow-red'[3] in color.  They were studying the ionosphere as well, which, back in 1958, was described with a bit more panache [4]:

"In this electronic age, everybody knows that the ionosphere is an electrified upper atmosphere region that bounces off radio waves around the globe."
The 1958 definition of the ionosphere also nicely explains what the experiment in both cases was looking for: how radio wave propagation was effected, (also shown in the following diagram from the same 1958 piece):

The folks at Mysterious Universe[5] seem a little peeved about the DoD's failure to reveal what the specific released vapor was, but while the vapor could have been a number of things, it's interesting to note the color of light emitted by ionized nitrogen:

1.  ABC News report:

2.  Coverage of the earlier experiment here:

3.  Journal of Chemical Physics coverage of the 1956 experiments, (apologies for the paywall)

4.  1958 Popular Mechanics article describing the first series of experiments

5.  Mysterious Universe


Blogger said…
Did you know you can shorten your links with AdFly and receive money from every visit to your short urls.

Popular posts from this blog

Cool Math Tricks: Deriving the Divergence, (Del or Nabla) into New (Cylindrical) Coordinate Systems

Now available as a Kindle ebook for 99 cents! Get a spiffy ebook, and fund more physics
The following is a pretty lengthy procedure, but converting the divergence, (nabla, del) operator between coordinate systems comes up pretty often. While there are tables for converting between common coordinate systems, there seem to be fewer explanations of the procedure for deriving the conversion, so here goes!

What do we actually want?

To convert the Cartesian nabla

to the nabla for another coordinate system, say… cylindrical coordinates.

What we’ll need:

1. The Cartesian Nabla:

2. A set of equations relating the Cartesian coordinates to cylindrical coordinates:

3. A set of equations relating the Cartesian basis vectors to the basis vectors of the new coordinate system:

How to do it:

Use the chain rule for differentiation to convert the derivatives with respect to the Cartesian variables to derivatives with respect to the cylindrical variables.

The chain rule can be used to convert a differe…

Division: Distributing the Work

Our unschooling math comes in bits and pieces.  The oldest kid here, seven year-old No. 1 loves math problems, so math moves along pretty fast for her.  Here’s how she arrived at the distributive property recently.  Tldr; it came about only because she needed it.
“Give me a math problem!” No. 1 asked Mom-person.

“OK, what’s 18 divided by 2?  But, you’re going to have to do it as you walk.  You and Dad need to head out.”

And so, No. 1 and I found ourselves headed out on our mini-adventure with a new math problem to discuss.

One looked at the ceiling of the library lost in thought as we walked.  She glanced down at her fingers for a moment.  “Is it six?”

“I don’t know, let’s see,” I hedged.  “What’s two times six?  Is it eighteen?”

One looked at me hopefully heading back into her mental math.

I needed to visit the restroom before we left, so I hurried her calculation along.  “What’s two times five?”

I got a grin, and another look indicating she was thinking about that one.

I flashed eac…

The Javascript Google URL Shortener Client API

I was working with the Google API Javascript Client this week to shorten the URLs of Google static maps generated by my ham radio QSL mapper. The client interface provided by Google is very useful. It took me a while to work through some of the less clear documentation, so I thought I'd add a few notes that would have helped me here. First, you only need to authenticate your application to the url shortener application if you want to track statistics on your shortened urls. If you just want the shortened URL, you don't need to worry about this. The worst part for me was that the smaple code only showed how to get a long url from an already shortened rul. If you follow the doucmentaiotn on the insert method, (the method for getting a shortened url from a long one), there is a reference to a rather nebulous Url resource required argument. It's not at all clear how to create one of these in Javascript. The following example code shows how:
var request = gapi.clie…