learndataanalysiswithme

[learndataanalysiswithme]

Hi friends!

A few years ago, I was thinking of becoming an actuary and started this tumblr. I never became an actuary, but am loving my current job in data quality / data operations. I’d love to post more again, but it won’t be actuary-specific content. Hope you all are doing well in whatever career : )

[learndataanalysiswithme]

i don’t plan to start bullet journalling until june (when i begin studying for my actuarial exams) but i had some free time today so i decided to begin setting it up 🤩

[learndataanalysiswithme]

[learndataanalysiswithme]

P-values Explained Through Puppies

[learndataanalysiswithme]

Shameless Self Promotion: The nonprofit I work for is looking for a volunteer HTML/CSS and Javascript web developer for our website. This is honestly the best place I’ve ever worked so thought I’d throw it out there.

[learndataanalysiswithme]

Can you flatten a sphere?

The answer is NO, you can not. This is why all map projections are innacurate and distorted, requiring some form of compromise between how accurate the angles, distances and areas in a globe are represented.

This is all due to Gauss’s Theorema Egregium, which dictates that you can only bend surfaces without distortion/stretching if you don’t change their Gaussian curvature.

The Gaussian curvature is an intrinsic and important property of a surface. Planes, cylinders and cones all have zero Gaussian curvature, and this is why you can make a tube or a party hat out of a flat piece of paper. A sphere has a positive Gaussian curvature, and a saddle shape has a negative one, so you cannot make those starting out with something flat.

If you like pizza then you are probably intimately familiar with this theorem. That universal trick of bending a pizza slice so it stiffens up is a direct result of the theorem, as the bend forces the other direction to stay flat as to maintain zero Gaussian curvature on the slice. Here’s a Numberphile video explaining it in more detail.

However, there are several ways to approximate a sphere as a collection of shapes you can flatten. For instance, you can project the surface of the sphere onto an icosahedron, a solid with 20 equal triangular faces, giving you what it is called the Dymaxion projection.

The Dymaxion map projection.

The problem with this technique is that you still have a sphere approximated by flat shapes, and not curved ones.

One of the earliest proofs of the surface area of the sphere (4πr2) came from the great Greek mathematician Archimedes. He realized that he could approximate the surface of the sphere arbitrarily close by stacks of truncated cones. The animation below shows this construction.

The great thing about cones is that not only they are curved surfaces, they also have zero curvature! This means we can flatten each of those conical strips onto a flat sheet of paper, which will then be a good approximation of a sphere.

So what does this flattened sphere approximated by conical strips look like? Check the image below.

But this is not the only way to distribute the strips. We could also align them by a corner, like this:

All of this is not exactly new, of course, but I never saw anyone assembling one of these. I wanted to try it out with paper, and that photo above is the result.

It’s really hard to put together and it doesn’t hold itself up too well, but it’s a nice little reminder that math works after all!

Here’s the PDF to print it out, if you want to try it yourself. Send me a picture if you do!

[learndataanalysiswithme]

Emmy Noether

Amalie Emmy Noether was a German mathematician known for her landmark contributions to abstract algebra and theoretical physics. And noether’s theorem is one of the most beautiful equation in all of theoretical physics.

The theorem explains the connection between symmetry and conservation laws.

It is remarkably surprising that there are a lot of people who are not aware of Noether’s contribution to physics.

This video by ‘Looking Glass Universe’ does a good job (but does not cover the math) in explaining the essence of the theorem.

Have fun!

[learndataanalysiswithme]

Last year the [California] earthquake authority saw a record increase of 90,000 new customers, compared with an average annual increase of 7,000 over the previous decade.  For reasons related to the way the earthquake authority is capitalized, the sharp increase in customers means the authority has to buy more reinsurance — the insurance that insurance companies buy for themselves to spread risk. This means the authority will be forced to raise rates around 2 to 4 percent annually.

New York Times

[learndataanalysiswithme]

If you can’t remember this formula, set it as your wifi password.

Linear Algebra Professor (via mathprofessorquotes)

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Annie Easley, programmer at NASA, known for her coding on the Centaur rocket

[learndataanalysiswithme]

[learndataanalysiswithme]

How does life insurance work?

Life insurance, like all insurance, is a form of gambling1. In this instance, what you’re gambling on is how long you will live. You are betting that you will die before you have paid more money in premiums than you receive in pay out on your death. The Insurance company is betting that you will live long enough to pay more in premiums than they will pay out on your death.

The insurance company usually wins. This is because they use very detailed actuarial tables to get a very good idea of how long you are likely to live, and charge you premiums accordingly.

That said, it is sometimes a good idea to get life insurance if you are in a higher risk situation, as winning that gamble could mean a lot to those who survive you.

1 It is a gamble compared to taking your premium amounts and just sticking them in a savings account that you won’t withdraw from until you’re dead. Generally, this strategy would end up paying out more than the life insurance does, hence the life insurance company generally ends up “winning”

/u/tass237

(via sdsimple)

[learndataanalysiswithme]

Good luck with finals!

WHEN I HAVE HIT MY 8TH HOUR OF STUDYING

[learndataanalysiswithme]

/ 12.10.15 / Starting my Exam P grind!  

[learndataanalysiswithme]

Me studying for actuarial exams

[learndataanalysiswithme]

I love my iPad Pro. My notes are so pretty.

[learndataanalysiswithme]

Annie Easley, programmer at NASA, known for her coding on the Centaur rocket