Chicago Train Operator Sets Railway Lines on Fire

That's frickin' weird to see, man...

The news this morning reported that it was so cold in Chicago that the train operators were setting the tracks on fire with kerosene-soaked ropes.

I don't know that the exact details there are correct. The video below shows the operators in Alaska using a product call FireSnake. Their website says...

80M010 is based on a special alcohol blend modified with cellulose thickeners and enhanced with special fibers for maximum heat output. Upon combustion, the special fiber material used in this product releases nitrogen, water and carbon dioxide 

.... 

FireSnake® is a smokeless, easy to use, safe replacement for the old repair method of diesel rope.

So apparently the old version is diesel-soaked rope, and now there's a 'better' commercial product.

Either way, the issue that's relevant for us at hand is that metal contracts when it's cold. That means if it's cold enough, the train tracks will actually contract and separate from each other. To repair the lines, the workers need to first get the tracks to expand enough to join. Then they can do the repair.

Hot metal = expand...cold metal = contract/shrink

Colored golds

Yeah, I don't really understand that graph/diagram/visualization.

I was looking around on the web about the various alloys of gold that can produce different colors and happened upon that diagram up there.

So, here's my question, how do I read the graph?

Like, let's say I wanted to make a gold that would be as yellow as the Y in the word yellowish on that diagram.

My reading of that alloy is that it would be about 55% silver,  50% copper, and about 50% gold.

That math doesn't seem to add up.

Can anybody tell me how to read this graph?

Sure, there's a bunch of info on the Colored Gold wikipedia page, but nothing there is terribly helpful either.

Touching plasma - Smarter Every Day 193

Let's get this out of the way first. The video isn't remotely about 'touching plasma'. Yes, somebody touches plasma at 9:30, but it's not elaborated on or explained in the least. The title is oddly useless, something I haven't seen from Destin before.

On the other hand, the video does have three minutes of high quality material science content early. From 1:05 through 4:20, Destin goes to Dr. Kavan Hazeli's lab and shows some of the testing of '3d lattice structures printed by NASA.' They're looking at ridiculously lightweight materials, trying to see how much metal they can take away (though it's created via additive manufacturing) while still leaving the 'material strong enough to withstand a space environment.'

We get to see an impact test as the researchers explore the difference in 'quasistatic' pressure and impact pressure tests to the materials. The sample we see tested in nearly pulverized and comes out 'perfectly flat' and hot.

It's like energy is transferred or something.

The rest of the video sees Destin visit two more labs - testing ion thrusters and exploring the fluid dynamics around a butterfly's wing - but they aren't nearly as material science interesting. Watch 'em or don't. Admittedly, at 4:55, Destin announces, 'are you not entertained,' and I'll admit that I'm not. Meh...

It's probably because I don't really understand what's happening with the ion thruster.

Inside the 23-Dimensional World of Your Car's Paint Job

We're continuing this week with a little more on the art theme. It's a very different kind of art from last week's memory metal flower, but there are still pedals involved. (groan)

Wired magazine has a brilliant article detailing the incredible process of color matching the paint on a repaired part of a car to the paint on the rest of the car. At first blush, the process seems awfully simple - pick up a can of the paint used to paint the car originally. Things are a little more complicated than that, however, as no repair shop is going to stock 50,000-60,000 different paints (the number of car colors on the road according to the article), no car in need of repair looks exactly like it did when it first rolled off the production line. and because the original paint job on most cars involves twenty three different dimensions to the color - sparkles, coarseness, red, blue, green, angle, diffuse coarseness, and so on.

The knowledge and skills involved in color matching are absolutely mind-boggling. There's an art to it all.

Shape Memory Alloy demonstration

Let's start the year off with a little art.

Because the video is so short, I'll simply copy the description from YouTube,

Shape memory alloys are materials that are able to 'remember' their shape under different conditions. Here we show an example where the petals of the flower are made from a shape memory alloy that have been conditioned to a shape representing closed petals at room temperature and an open petal shape at higher temperatures, achieved using a hot air blower. The flower can then be made to open and close by heating and cooling. Whilst this is an interesting example of how shape memory alloys can be used in art, they can also be used in a range of engineering applications from medical devices to automotive valves.

For more information on studying metallurgy and materials science at the University of Birmingham, please go to: https://www.birmingham.ac.uk/schools/metallurgy-materials/index.aspx