Simone Giertz is a remarkable young woman. She lives on a boat and invents things, such as an alarm clock that slaps you to wake you up. Skip ahead to 3 minutes and 20 seconds if you just want to see the experiment, but be prepared for some foul language. (She is after all a sailor.)
by 
Jackie Broyles and Dunlap (in real life Tennessee comics Travis and Jonathan) do live commentary on the most recent presidential candidate debates, with the results edited down a bit over ten minutes for the Republicans and under eight for the Democrats. Not their best work — especially in the case of the Democratic debates, since the Republicans gave them more material to work with — but definitely funny in spots, and the first one features free ramen noodles.
The GOP debate on Fox Business:
The Democratic debate on CBS:
Travis and Jonathan’s YouTube channel can be found here.
by I haven’t said anything yet about the barbaric attacks in Paris, mainly because I couldn’t think of anything, but I just saw a news item worth mentioning: At the start of yesterday’s Army-Tulane game, the football team of the United States Military Academy at West Point took the field bearing the American and French flags. Good for them. There’s more, including video, here. As that article notes, the United States Naval Academy also flew the French flag yesterday. (One correction: the article incorrectly refers to students at the Naval Academy as “cadets.” They are midshipmen.)
On 2015 September 12, the day after the United States was struck by terrorists, the French newspaper Le Monde carried the headline “Nous sommes tous Américains” — “We are all Americans” — (the accompanying thoughtful editorial can be found here). There was an outpouring of sympathy from all over the world, with many moving tributes, including flowers and candles lit outside American embassies and consulates. The same has happened again with regard to the attacks in Paris.
We should remember the many other innocent victims of terrorists as well, not just here and in Europe but all around the world.
by Here’s someone whose hobby is building various things with stone-age technology, in this case a hut with a ceramic tile roof and underfloor heating. He doesn’t live this way; he’s just interested in how it might be done. His raw materials are mainly stones, trees, vines, water, and clay. Nothing from a hardware store.
It’s not something I’d have the patience to do, but it’s fascinating to see how it can be one.
If you’re not interested in the details you might want to skip ahead a bit at a time as you watch this, but it’s still worth a look. (Here’s a tip on doing that, by the way: While watching a YouTube video, type J or L lets you skip backwards or forwards a bit, and typing K lets you pause and resume playback.)
Click on the link above for additional details. You can find more of his videos at this link.
His blog: https://primitivetechnology.wordpress.com
“Work fascinates me. I can watch if for hours.” — Mark Twain.
by Here are the latest New Rules from Bill Maher’s HBO show. As usual with Maher this is not for the easily offended. (In fact, even I get offended by some of his stuff.) But much of it is funny, and in this case informative, reminding disgruntled white Americans that despite some recent actual bad news (and a lot of unjustified fears), in reality we’re not exactly oppressed. (To be clear, I don’t mean to suggest I’m a disgruntled white American; I’m most of the time reasonably gruntled.)
by In 1950 physicist Enrico Fermi was having lunch with his colleagues at Los Alamos when he suddenly asked something like “Where are they?” or “Where is everybody?” (recollections differed). Everyone laughed, because while the question came out of the blue, they had earlier been talking about UFOs and a recent flying saucer cartoon. Fermi was asking why we don’t see aliens.
I’ve heard people say that the vast distances between stars rules out interstellar travel, and in fact what we know suggests that there are very serious obstacles even to traveling at a substantial fraction of the speed of light, let alone faster. That’s probably true, but as Fermi et al worked out, even relatively slow-moving spaceships or self-reproducing robot probes could plausibly colonize the galaxy in under a billion years and perhaps a lot less. (For more, search the web for “Fermi paradox” and you’ll find a huge amount of information on the subject.)
In fact, we humans have already launched at five interstellar spacecraft (Pioneer 10 and 11, Voyager 1 and 2, and New Horizons. (See this earlier post for more about them.) While they will long since have ceased to function by the time they reach another star system, many tens or hundreds of thousands of years from now, they’ll get there eventually.
So where is everybody? One possibility is that we might be among the first technological civilizations in our galaxy. The Earth is about a third the age of the universe (quite close to exactly that, in fact). The Big Bang produced hydrogen, some helium, and a bit of lithium, but the heavier elements were created later in stars, and those heavier than iron produced only by supernovae. The earlier a star or other body formed, the less it had in the way of heavier elements.
Moreover, while life seems to have appeared about as soon as the Earth could support it, it took a few billion years for multicellular life to develop, and technology more advanced than termite mounds is very recent indeed. If we can infer anything from our one solitary example, maybe it just takes a long, long time for intelligent technological life to develop, and we could be the first, or at least among the first.
Here’s a short, fascinating discussion of the idea from PBS Studios:
(Updated 2015 Nov 14 to add a few details.)
by This is disappointing news: Based on a number of experimental studies, brain-training exercises and games don’t seem to improve general brain health or ward off dementia.
It is true that practicing specific tasks, such as learning and recalling names or doing math, does improve one’s ability to do those tasks. But the improvements don’t seem to extend to other mental abilities, even some that might reasonably seem related. Here’s a brief video about that, and if you go to the YouTube page you’ll find links to the research discussed.
All that said, it’s conceivable that doing a wide variety of different mental exercises (say, learning languages, taking classes, reading, traveling, meeting new people, etc) might help more broadly than playing games. And even if they don’t they can be worth doing for themselves. That can also be true of games, for that matter.
by This three-minute silent animation shows how the International Space Station was assembled over a period of many years in near-Earth orbit:
There’s not a lot of information given on how the various modules are used, but that’s covered in other information on Johnson Space Center YouTube channel, including this twelve-minute overview of the science done aboard the station over the past 15 years:
Also check out the links on yesterday’s Astronomical Picture of the Day page from NASA (which is where I found the video above).
by An alien humanoid film critic analyzes the hidden meanings in the film Frozen (reviewed here).
(On the outside chance you haven’t seen the movie yet on your planet, be aware that there are some spoilers in this analysis.)
Incidentally, the Fox News morning show Fox & Friends bizarrely denounced the popular film as Foxnewsically Incorrect because it was, they claimed, anti-male. For details, and a clip to show you I’m not making it up to make Fox News look stupid, see this post.
The Fox News oddness provoked an amusing response from MSNBC you can find here.
by Odd questions occur to me once in a while. For example, I recently started wondering how big a lightyear actually is. It’s of course the distance light travels in a year, but exactly how long is a year? The word is ambiguous.
You might have learned in school that a year is the time it takes for the Earth to orbit the Sun. That’s more precisely a “sidereal” year (from a Latin word for “star”), which lasts 365.25636 days. But for many purposes we’re more interested in the “tropical” year, the time period from one March equinox to the next, because that determines the cycle of the seasons. It’s not the same as the sidereal year because it’s affected by wobbling of the Earth’s rotational axis. It currently runs about 365.242189 days but the length isn’t perfectly constant.
Ideally, we’d like our calendar to be in sync with the seasons. For many centuries the standard European calendar was the Julian calendar, introduced by Julius Caesar in 45 BCE. That calendar gives most years 365 days with an extra day every fourth year. (Actually, the Romans managed to misunderstand the rule for a while, making every third day a leap year, until August Caesar straightened them out.) The average Julian calendar year is 365.25 days long, pretty close to a tropical year, but slightly too long, enough to build up three days of error every four centuries, which eventually led Pope Gregory XIII to introduce the slightly different Gregorian calendar in 1582. It skips three leap years in every four centuries, giving it an average length of 365.2425 days, still a little too long, but only by a day in several thousand years.
(A lot of non-Catholic countries using the Julian calendar continued to do so for a while. Britain and its empire stayed on the Julian one into the 1700s, Russia didn’t switch over until after the Tsar was overthrown, and Greece didn’t adopt the Gregorian calendar until 1923. Incidentally, Caesar had the authority to decree a new calendar because managing it was part of his job as the head priest of the official Roman religion. His title was “pontifex maximus,” literally, the greatest “bridge-builder.” Pope Gregory was likewise a Roman pontiff, though obviously not of the same religion.)
But I digress. To answer the original question, it turns out that the International Astronomical Union defines a lightyear as the distance light travels in an average Julian year, that is, 365.25 days. A day has 24 hours, each with 60 minutes of 60 seconds, so if you know how fast light travels in a second, you can work out the length of a year in seconds by multiplying it all out. (If I did it right, there are 31,557,600 seconds in 365.25 days.)
You may remember the speed of light as 186,000 miles per second, but that’s not exact. Because the length of a meter is now defined in terms of the speed of light, light travels exactly 299,792,458 meters per second, exactly. (If you don’t want to memorize that, 300 million meters per second is really, really close.)
Multiply the speed of light in meters per second by the number of seconds in a Julian year and you’ll get the length of a lightyear in meters: 9,460,730,472,580,800.
You can even work it out in inches if you want. The U.S., Britain, and other countries had slightly different standards for yards, feet, and inches prior to 1959, but that year compromised on Canada’s definition, which made the inch exactly 2.54 centimeters. A meter is 39.3701 inches, so multiply that by 9,460,730,472,580,800 and you’ll get the number of inches in a lightyear. I’ll let you work that out.
Incidentally, if you type a phrase like “1 lightyear in inches” into a Google search, Google will return the answer (at least to a few significant figures) and an on-screen calculator. Google does a lot of calculations and conversions for you this way (type “1 million dollars in euros” for example). This is a pretty useful trick to know, and probably the only practical piece of information in this entire post.
In verifying all this I came across a bit of trivia I recall reading somewhere before but had managed to forget: As you may recall an “astronomical unit” (AU) is the average distance of the Earth from the Sun, which makes it convenient for describing distances between bodies inside the solar system. The EarthSky website points out (here) that the number of astronomical units in a lightyear (about 63241.1) is by coincidence very similar to the number of inches in a statute mile (63360). Hence if you were to make a map with the Earth one inch from the Sun, a lightyear would be about a mile, and on the same map the closest star other than the Sun would be about 4 1/4 miles away.
That would be a big map. Reminds me of the person who asked a reference librarian if the library had a globe, and when the librarian pointed one out complained that it was too small. “Do you have one that’s life-size?” The librarian replied, “Yes, but it’s in use.”
by