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Burning up on re-entry Wed, Jan 31, 2018
There's a lot of confusion regarding why certain objects burn up on re-entry into earth's atmosphere.  There was confusion on my part until I figured out how to explain it to myself, if that makes any sense.  So here's the deal:  it doesn't happen because the atmosphere is hot.  In fact, the atmosphere gets thinner and thinner (i.e. less air) as altitude increases, so it's actually quite cold near space. 

Objects burn up on re-entry because they're going ridiculously fast.  And when a fast-moving object comes into contact with a stationary or slow-moving object (in this case, air), its speed energy gets converted to heat energy.  It's kind of like jumping into a pool.  Your speed slows down because you went from air (low density, easy to travel through) to water (higher density, harder to travel through).  But when you jump in a pool, you don't feel a change in temperature because you probably weren't traveling that fast on the way in. 

It's kind of hard to compare it to something that happens in normal life, because we don't experience those types of speed differences, like ever.  Objects in orbit around the earth are traveling tangentially to earth's surface at about 17,000 miles per hour.  The reason we don't know much about objects traveling at 17,000-ish miles per hour is because they would burn up in our atmosphere!  Some objects in space are moving much faster than that (such as meteors and asteroids that have been flung out of some other orbit).  In that case the speed difference can be much bigger, which tends to make things explode. 

There was a question online about why Felix Baumgartner, the guy who rode a balloon into space and jumped off, didn't burn up on re-entry.  The answer is simply that he wasn't traveling that fast because he didn't start from orbit.  Sure, he sped up on the way down, but only as fast as the air around him allowed.  He didn't start at 17,000 miles per hour.  He started at roughly zero. 

Finally, the way objects can avoid burning up on re-entry is to enter the atmosphere slowly over time instead of all at once.  That's achieved by choosing the right re-entry angle.  There's that line from Apollo 13:  "The re-entry corridor is in fact so narrow ... that if this basketball were the Earth ... the crew would have to hit a target no thicker than this piece of paper." All that's saying is that the angle at which you enter the atmosphere has to be pretty precise, but since the earth is much bigger than a basketball, the angle is much bigger than the thickness of paper.  Sometimes making things sound simple makes them sound more complicated. #science

Evidence at work Tue, Jan 30, 2018
I was in a meeting at work last week where a contractor was going through a Powerpoint presentation about their product, making statements like "it will travel [X] far" and "the sensor will operate accurately" and "our algorithm will avoid common pitfalls".  I was asked for my "expert" opinion afterwards, and instead of questioning every claim they made, I simply said this: 
"The contractor needs to provide evidence for stated claims instead of just assuming we'll believe them because they said it out loud.  In general, there were a lot of statements of fact without any evidence to back them up.  I'm not saying they were lying about anything.  But a simple [plot of results] or [data from a test] would do more to establish a fact than simply writing a sentence on a Powerpoint slide."
It's a little surprising to me that this type of thing needs to be stated.  But at the same time, I have no problem being the person who states it.  I've always been a little skeptical about everything.  And even if the final result turns out to be wrong, at least use critical thinking skills and logical reasoning to make your case.  Arguments from authority and proclamations by fiat are things used by dictators and strongmen.  State your claim, make your case, and prove your point with evidence. #science

Trump outrage levels Tue, Jan 16, 2018
It's surprising to me how different people have different levels of astonishment and outrage concerning the goings-on of Donald Trump.  It feels like it's about once a week where some new person or group of people exclaim, "Can you believe what Trump just did/said/Tweeted?"  Yes, in fact I can.  He Tweet-taunted that North Korea guy?  I can believe that.  He bumbled out an apology for something he definitely did?  Sounds about right.  He called a bunch of countries "shitholes"?  Yep, I can believe that.  I would literally believe anything.  The man is capable of so much more (or less) than that.  I wish I could make a prediction here, but I feel like I'm not creative enough to come up with a terrible enough thing to predict.  Don't worry, he'll continue to surprise and amaze us. 

And obviously (hopefully it's obvious), this is all quite bad.  The elected leader of the free world should not do fucking horseshit like that, and it pains me to have to write that idea as if it's something that needs to be said or written and not just known from birth.  It's embarrassing to witness this, but that's what people wanted. 

Anyway, here's a very related thing I wrote about outrage fatigue. #politics

Timeliness of search results Tue, Jan 09, 2018
A problem I think the tech world needs to address is the timeliness of search results.  For example, I just searched for something about an Android app, and the first search result was from 8 years ago.  And that's searching for relatively modern technology.  It's sometimes completely useless trying to get pertinent information about topics that have existed in some form for quite a while.  Ooh someone else had the same problem with their dishwasher?  Just kidding that website was last updated in 1997.  Oh my favorite band is playing nearby?  Just kidding that band no longer exists, and the venue burned down last century. 

I'd say the primary purpose of the internet is the accessibility of information.  That's why search is such a fundamental part of it.  But when search results are crowded out by obsolete information from eons past, it dilutes the functionality of search, which dilutes the entire internet.  Yes, I know I can sort by date.  But that's not always ideal, and can be easily gamed by nefarious people trying to get pageviews. 

Please, internet, figure out a way to deal with your own aging. #technology

Bumbling to success Tue, Jan 02, 2018
I'm not a fan of this Trump guy, obviously.  He's a tactless fool, and I don't think history will look back too kindly on him or his presidency.  And yet, I've partitioned off a small part of my mind to allow for the possibility that he'll succeed in the end.  It might not be intentional or willful on his part, but some of his policies and actions might actually make things better.  One piece of evidence to support this is the series of heated Senate races that have happened recently.  People are more interested in politics now because they don't want more Donald Trumps.  Similarly, the ongoing sexual harassment upheaval is a direct result of his pre-election behavior.  Bringing attention to social issues and achieving justice is important, and would've likely continued to languish without Trump. 

I think the real question is whether Donald Trump is ignorant of his effectiveness in a Mr. Bean kind of way, or if he's really the grand illusionist that some people think he is, performing seemingly stupid actions all in service of a much larger overall theme.  Time will tell. #politics