Lagrange Cats

Space-Time Appropriate Greetings All!

This week was an eventful one in my personal life.  Thursday night we inherited two adult male cats and  the lot of us have spent the past few days adjusting to each other.  Their names are Wilson and Mange (pronounced like the Italian word for "eat!" -mangia, which if you saw him you'd realize is no accident).  Wilson is definitely the more adventurous one.  He spent the first few days exploring the house, waking me up at 4:30am, and figuring out which vocalizations will get my attention fastest.  His brother Mange spent the first few days either under the couch or under the bed, but I'm happy to say he's finally started coming out to socialize, eat, and drink.

I'm also pleased to report that as of this morning Wilson learned that waiting for me to wake up is a better way to get attention (though when I slept past the feeding time we're establishing he started nudging me gently with a clawed paw, which was quite effective at waking me up).  He also seems to be learning that getting between me at my keyboard is a bad idea, so it looks like we're going to get on fantastically.

The learning process hasn't been a one way street.  I've been looking up and practicing my tail readings, so with time both cats and I will be able to read each other like books.

In Other News

NASA had an article up about the James Webb Space Telescope that caught my eye.  The JWST is an infra-red telescope, meaning it will be reading the heat radiance of the galaxy around us as opposed to visible light.  In order for this to work, the telescope itself has to be very cold, and so it is being placed at L2, a point in space where its temperature can drop to 48 degrees Kelvin, (-225 C, or about -370 F).  The information about the new telescope was interesting, but what really got my attention was the explanation of L2.

L2 stands for Lagrange point 2.  I'm willing to bet not many of you know what a Lagrange point is, am I right?

Lagrange points are named after an 18th century Italian astronomer, Joseph Lagrange.  Essentially, he predicted their existence using mathematics as a solution to "the three-body problem."  The three-body problem arises when, using Newtonian gravitational theory, one tries to predict the motion of the moon, the earth, and the sun as they all pull on each other.  The problem is the discrepancy between the mathematical predictions and the observed phenomena.  Essentially, the moon doesn't do what it's supposed to.

Lagrange solved the problem through the proposition of gravitational anomalies that arise when three massive objects are in relative proximity to each other.  I'm summarizing here, but essentially each of the places where these anomalies occur is a point where an object is accelerated by the local gravity fields to a point where it has a stable orbit relative to the nearer of the three bodies (in this case, the Earth).  There are five such places in Earth's local neighborhood; L1 -(roughly the Moon), L2 (approximately 930,000 from Earth), L3 (the point directly opposite Earth in its orbit around the Sun), L4 & L5 (both points are at a 60 degree angle relative to the Earth and the Sun).

Image Courtesy Wikipedia Commons

Lagrange points are important in near space astronomy because as stable orbit areas, they make perfect parking places for satellites that we want to have continuous contact with without the issue of interference from Earth.  In the case of the JWST, L2 makes the perfect place to park an infra-red telescope because it is shielded from the Sun's heat (by Earth's shadow) and it's far out enough to have little interference from Earth's own heat radiance.

The JWST will be joining several other satellites already working at L2 (there's plenty of room as L2 isn't so much an actual point in space as it is an area).  For a detailed explanation of Lagrange Points, including mathematical formulas, some great illustrative pictures, and properties of these interesting areas in space, read the Wikipedia article here.

The NASA article on the James Webb Space Telescope and Lagrange Points can be found here.  The NASA article also includes a greatly simplified illustration relative to the one above.

That's all for this week!  Have a great weekend, and Americans, enjoy the holiday!


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