Wednesday, June 29, 2016

A shark can smell blood from a mile away....Just how does that work??

We've all heard that a shark's sense of smell is so acute that it can smell a drop of blood from a mile away in the ocean (or a quarter-mile, or whatever--some vast distance, the specific number hardly matters). But how does that work? How can a drop of blood, physically present at point X[1] be detected by a shark nostril at point Y, one mile away?

The answer is--it can't.

It's not like smell is transmitted as a fast-moving wave. It is based on parts per million. The key bit--parts. Molecules have to make their way to the shark nostrils. A molecule a mile away is, by definition, not being detected by a shark's nostrils.

So where does this myth come from? And is it a myth, or just a crude misconstruing of the actual facts?

I strongly suspect it's the latter (with the "a mile" part being a convenient exaggeration...I get the say "a kilometer" in the rest of the world). I think a correct illustration of the sensitivity of shark-smell would to say that a drop of blood, as it diffuses through the ocean, generates enough ppm that a shark can detect blood, at a much later time, after diffusion has spread it out a quarter-mile[2] distant from its origin.

That's not the same thing as saying that when you cut your foot on a rock, you risk summoning all the sharks within a quarter-mile radius.

NOTES
[1] More technically, diffusing slowly out from point X.
[2] Without researching it too heavily, it sounds like 1/4 mile, not a full mile, is the correct distance.

Monday, June 27, 2016

Peter Thiel Tactic for Gun Control

While I deplore Peter Thiel's billionaire bullying of Gawker into near-bankruptcy, I do think his tactic is worth emulating for better causes. Namely, I think the gun-control movement should be aggressively, relentlessly funding lawsuits against gunmakers. Maybe it is just starting to happen organically, but I think this would be a great tactic for well-known anti-gun billionaire Michael Bloomberg to fund.

How Long Till Driverless Cars?

The barrier to the promised land of total, hands-off driverless cars is high, but progress has been rapid--without all that much research effort being focused on it. A couple of considerations make me even more bullish on the realization of the driverless dream.

Driverless cars are making great leaps on existing roads. Imagine if roads started to be modified to help driverless cars. Sensors in the roadway might be expensive and take a long time, but I have to think there are much simpler things that could be done, optically, without digging, to make driverless cars better.

The other consideration is cars themselves. If cars were built to inter-communicate, that would also go a long way to making driverless work better. I am thinking even before 100% of cars are driverless, existing cars could be retrofitted with some sensors and communications devices, to help them interact with driverless cars. I do think this would have to become a regulatory mandate. One hopes that the decrease in insurance costs could self-fund it.

Gerrymandering Must End

Gerrymandering to create safe seats and pack minorities into a minority-majority district is an abomination. It may be the one thing I consistently agree with the WSJ editorial page on. For a long time, I thought maybe the answer would be to create districts algorithmically. But 15 years ago, that seemed to abstract to have any mass appeal. Now that even liberal arts majors have a solid grasp of what an algorithm is and does, though, maybe it is time?

Sunday, June 19, 2016

Diamonds Vastly Overrated

I've never been a big fan of diamonds. I resent the whole industry, starting with the DeBeers cartel, and continuing through to the wretched social expectations, and the utter BS sales line about setting aside 4-6 months' salary for your engagement ring. All for a pretty, shiny, perhaps scintillating--when recently cleaned--but ultimately not all that interesting chunk of carbon.

So for decades I have cherished this thought experiment. Knowing that there are industrial processes to produce gem-grade diamonds, but that they have not been cost-effective, I liked to think--what if someday a top, gem-grade 1-carat diamond could be produced for $100? It would still be as beautiful. Would it still be cherished? Obviously I doubt it would be. It's all scarcity thinking--something else I generally dislike.

Well, it sounds like that day is getting closer. Not $100/carat, but 40% cheaper. Just give it time. 

Tuesday, June 14, 2016

Idiosyncratic Prius V Review


We bought a 2104 Prius V (the wagon-ish large version) 16 months ago. There are plenty of comprehensive review elsewhere, this is my idiosyncratic review.

First thing to understand--this is a "V", the BIG Prius. It is every bit a mid-size car. 6" longer, 3" taller, 1" wider than the standard, compact Prius. I am 6-1, and very comfortable in the rear seats.

Summary

Prius V is a great value. No hybrid premium at all--if anything, maybe a bit cheaper than much of the competition. A little fun-challenged, though.

The Good


  • Price & trimlines. There are only 3 trimlines. We bought the base, which had almost everything we wanted. No heated seats, but those are easily available aftermarket. Sunroof might have been nice. Otherwise, not regrets.
  • Huge shout-out for all 4 windows both having auto-down AND auto-up. This on the base trimeline!
  • The proximity key is very convenient. Walk up to the car, it unlocks itself.
  • Click once on the fob unlocks all doors--not just driver . I've always thought it was a dumb "because we can" feature that you have to double-click to unlock all doors. (I wish proximity did the same)
  • Locking the car with the gob elicits a mild chirp, doesn't beep the dang horn.
  • Acceleration is fine. Nothing to write home about. It is tuned to be mild. But if you need acceleration, stomp on the pedal, you will be fine.
  • Both driver and passenger makeup mirrors have sensors--turn light on and off automatically.
  • Rear-seat space is excellent. What takes it to the next level is fold-back rear seats. Very nice that this is in the base model--the Subaru Forester we recently purchased only includes this simple, but invaluable feature in the +1 trimline.
  • Storage is excellent--2 glove boxes, plus a capacious center console that can accommodate a "boutique" size box of tissue.
  • Low-maintenance. Especially the brakes.
  • The confirmation that doors are locked is a mild beep--not an obnoxious honk.
  • Can fold the passenger seat flat--infrequently needed, but very nice when you do need it.

The Bad


  • Display is U-G-L-Y
  • Pushbutton start is convenient, but the flip side is it messes with longstanding habits. E.g., if you are driving with someone else, it is quite possible to exit the car, key in your pocket, and not realize it.
  • More complicated to jump-start.
  • Copying the proximity key is horrdily expensive.
  • Cup holders are inconvenient--the passenger cup-holder is way over on the right, and doesn't accommodate large sizes.
  • USB port is only for data, does not charge.
  • Center display is kind of goofy.





 

Republican Leaders Are This Generation's Confederates

It is hard for a modern American to grasp the devotion to one's state that many of the founders held (the glorious Hamilton musical provides good reminders of this). This attitude persisted through the Civil War: Robert Lee famously was offered, and turned down, command of the Union Army, and although perhaps not eagerly, served in the same capacity in the Confederate Army.

Without indulging too much in 20/20 hindsight, I think it is fair to say that contemporary Americans are largely dumbfounded by this "my state over my country" attitude. It was the wrong side of history.

I think Republicans leaders who support Trump are a contemporary equivalent of the state-loving Virginians*, except with much less in the way of principles to mitigate their historically abhorrent position. Supporting Trump has been indefensible at least from the date of his outrageous defamation of Mexican illegal immigrants. But after nonstop Trump outrages since, numerous Republican leaders have baldly exposed their morally doomed position: "I wouldn't trust him with the nuclear codes...but I support my party"; "that is the textbook definition of racism...[but I have to support my party]".

*(Sorry, the "my state over my country" attitude wasn't exclusive to Virginians, but that is the most prominent example.)