My two-year-old has been talking for months (before and since) about petting the rhino at our zoo. We'll probably do the elephant, too.

Ten or fifteen years ago, my wife was volunteering at this same zoo and took a preschool zoo-camper on the Last Elephant Ride Ever. As she was climbing down steps from the platform, the elephant shoved her to the ground; he then picked the next volunteer (but not the next child) in his trunk and waved her around in the air. These days... [more]
posted to Ask Metafilter by fantabulous timewaster at 10:35 AM on July 24, 2008

There are competing effects in the thinner/thicker atmosphere question. Red light mostly scatters forward, while blue light scatters omnidirectionally. A sunset is red in the west because the sunlight travels through more air; the blue gets scattered to the people to your west and red is all that's left. I think a thicker atmosphere would be reddish at midday, perhaps east-at-sunset blue-violet at the horizon. Under the ocean it is blue, blue all round with only a hint of the actual... [more]
posted to Ask Metafilter by fantabulous timewaster at 7:39 AM on July 18, 2008

If the light from the sun is unpolarized, and one polarization tends to scatter, the unscattered light is polarized by subtraction. The pattern of polarization across the sky is different for different colors. Apparently some insects use this for navigation (all my links just got eaten, bummer).
posted to Ask Metafilter by fantabulous timewaster at 3:22 PM on July 20, 2008

n.s.t.i.a.g.i., reflection is a special case of scattering. The physics is roughly the same as in Brewster polarization.

Any process that takes unpolarized photons and sends those with a certain polarization one way has to send those with the other polarization some other way. This is because light polarization is related to angular momentum, and as far as anyone can tell, angular momentum is an exact symmetry of nature. Filters... [more]
posted to Ask Metafilter by fantabulous timewaster at 10:02 AM on July 21, 2008

You know, you're right. The separation between the two polarizations is between the light that gets scattered up or down and the light that gets scattered left or right, but the forward-scattered light doesn't have any preferred polarization.

By the way, your video above of the aluminum foil boat, floating on the SF₆ lake, is pretty rad.
posted to Ask Metafilter by fantabulous timewaster at 9:26 AM on July 22, 2008

Alarm clock in bathroom. Cold water on face is better than noise.
posted to Ask Metafilter by fantabulous timewaster at 7:29 AM on July 19, 2008

Our photographers followed us invisibly. They caught marvelous photos of every tender moment between the two of us without us noticing they were there.

My wife and I were talking about this the other day: she was recently at a wedding where the photographer was telling the bride and groom where to put their elbows during the cake cutting. Exact opposite.
posted to Ask Metafilter by fantabulous timewaster at 7:15 AM on July 18, 2008

They look like rebuses. The first is maybe A (letter) (to) Sir L--e Dund(ass):

(Eye) consider w(hat) (yew) have (awl)ready done for my (bee)half, and t(hat)
... never again hap(pen) (to) (bee) in (yew)r way to (ass)ist my emmissaries
... (eye) (can?)not forb(ear) (lamb)enting (yew)r late mis(fort)une, (to) re(cap)itulate (awl)I like "ser(vice)s" and "the y(ear) (fort)y-6."

I can make out most of the... [more]
posted to Ask Metafilter by fantabulous timewaster at 7:04 PM on July 15, 2008 marked best answer

Google search for "dundass devil" brings up this, which you might be looking at a copy of?
posted to Ask Metafilter by fantabulous timewaster at 7:07 PM on July 15, 2008 marked best answer

Baro(ness), maybe? The mailing list suggests Dundas is a Scots name.

Oh, it could be a net. Good call on the hen.

Hmmm, Baronet Lawrence Dundas might have been a public figure subject to satire in the mid-1700s.
posted to Ask Metafilter by fantabulous timewaster at 7:28 PM on July 15, 2008 marked best answer

... Wikipedia says Dundas provided goods to the British army during the Jacobite Rising ending in 1746. That seems like who your letters are about.

If your artifacts look like imitations a historian interested in Britain during that period might recognize them.

Whee! This was fun.
posted to Ask Metafilter by fantabulous timewaster at 7:50 PM on July 15, 2008 marked best answer

aburd, I didn't mean to suggest you've found Priceless Yard Sale Antiques. But if they pique your interest and they are copies of something well-known, a historian might say "oh! that's the blah" and give you some more context.
posted to Ask Metafilter by fantabulous timewaster at 8:10 PM on July 15, 2008

To work on articulating your thoughts, write. Use the active voice and full paragraphs (as you have here). When you have something that pleases you, read it out loud. Your speech will always be less formal than your writing, but that sounds like what you want.
posted to Ask Metafilter by fantabulous timewaster at 12:25 PM on July 14, 2008

The default behavior in TeX^† is to superscript the footnote marker both in the text and in the footnote itself.
_________
^†TeX isn't authoritative but tends to be well thought out.
posted to Ask Metafilter by fantabulous timewaster at 8:31 AM on July 14, 2008

My copy of "Classical Dynamics" by Marion & Thornton (4th ed., 1995) uses unnumbered footnotes, but has a single well-footnoted page that uses all of the symbols *, †, ‡, #, ##, §, §§. Superscripted symbols also lead the footnotes themselves at the bottom of the page. This is also the style in Jackson's "Classical Electrodynamics." The other books I have in arm's reach use numbered footnotes.1,2

In the absence of... [more]
posted to Ask Metafilter by fantabulous timewaster at 12:00 PM on July 14, 2008 marked best answer

Related question:

If you are travelling in a moving car and stomp on the brakes, all of the loose items in the car (that book on the passenger seat, and the unbelted passenger holding it) continue to move forward at the original velocity until they are stopped by hitting the dashboard. This is equivalent to what would happen if you tilted the car forward, which is how those motion simulator rides work.

If you were in a motion simulator holding... [more]
posted to Ask Metafilter by fantabulous timewaster at 8:56 AM on July 10, 2008 marked best answer

knave, that was a question from my advisor (on a car trip, after a sudden stop). Not original to me.

Krampf seems like an entertaining guy. It's probably cheaper to drive to the store and get my own balloon, though. Plus I would have a balloon afterwards.
posted to Ask Metafilter by fantabulous timewaster at 9:32 AM on July 10, 2008

Wet Spot, that's a fantastically interesting paper.
posted to Ask Metafilter by fantabulous timewaster at 9:12 AM on July 10, 2008

I have been having this same issue but haven't gotten as far as you yet --- on days when my stomach complains I drink tea instead of coffee. I have mostly switched to constant comment, a milder black tea than most other things labelled "black tea."

When I do have coffee I have started taking it with cream. Not milk or half-and-half, but the stuff my grocery calls "heavy whipping cream." The milkfat cuts the acid back and also keeps me from... [more]
posted to Ask Metafilter by fantabulous timewaster at 7:56 PM on July 6, 2008

Florida's approach to this has been in the news lately. This story had an answer to your question, but doesn't have a transcript, bummer.
posted to Ask Metafilter by fantabulous timewaster at 5:23 AM on July 5, 2008

I think if you worked very hard at this you could make a tool to make mileage predictions accurate to ten or fifteen percent --- the estimate is that the 300 mile trip will take ten gallons of gas but it takes nine or eleven. That isn't much different from a typical time estimate ("four-and-a-half or five hours depending on how long lunch takes"), and it's probably about the same uncertainty as your tank-to-tank estimates of your gas mileage. So doing it carefully would be hard and... [more]
posted to Ask Metafilter by fantabulous timewaster at 1:14 PM on July 2, 2008

You have asked two separate but related questions.

A sine wave sounds like a "pure" tone because, as Class Goat has already said above, it stimulates a small number of nerve cells in the ear. Similarly a point of light (or "pixel") stimulates a small number of nerve cells in the eye. These choices have to do with the geometry and physics involved in the ear and eye.

Fourier analysis suggests that you could go back and... [more]
posted to Ask Metafilter by fantabulous timewaster at 10:05 AM on July 1, 2008

When you buy a battery, you are buying an object with an electron-friendly side and an electron-unfriendly side. One way to make an electron-unfriendly side is to put some extra electrons there: this is what happens to you when you shuffle across a carpet and zap the doorknob. One way is to wave a magnet around. Generators usually use falling water or steam or exploding gasoline to turn a wheel with a magnet tied to it, which makes charge move around in some conductor. Batteries use... [more]
posted to Ask Metafilter by fantabulous timewaster at 3:50 PM on June 25, 2008

An interesting calculation to do would be the relative power released by lightning (per acre per month or whatever) compared the the power released by falling rainwater. I would think that, even neglecting engineering and material costs, you could get much more energy from a system of roofs and gutters draining to waterwheels.
posted to Ask Metafilter by fantabulous timewaster at 7:02 PM on June 24, 2008

My wife's business is a lot like yours. She gets a lot of business from the "contact us" form on her web site --- much more than she ever did over random emails. Having little boxes labelled "name" "phone" "email" makes a big difference.
posted to Ask Metafilter by fantabulous timewaster at 10:43 PM on June 21, 2008 marked best answer

If your daughter is a student she may qualify for the educational price. Some school systems or universities have negotiated better deals, too.
posted to Ask Metafilter by fantabulous timewaster at 3:08 PM on June 21, 2008

"Squick" might appeal as a portmanteau of "squeak" and "ick." "Gride" doesn't suggest anything to me.
posted to Ask Metafilter by fantabulous timewaster at 10:37 AM on June 20, 2008

You can never trust the last digit on a digital display: there is always some Schmitt triggering that makes it round off incorrectly rather than flicker. (Or it flickers, in which case you have to know something about the noise anyway.) The fact that your scale has more digits than its claimed accuracy is promising. You may find that the last digit only shows 0 and 5, or only even final digits, or suchlike.

How you would calibrate your scale (or determine that it... [more]
posted to Ask Metafilter by fantabulous timewaster at 6:44 PM on June 19, 2008 marked best answer

I have yet to encounter a tax deduction large enough to justify a dubious financial proposition.
posted to Ask Metafilter by fantabulous timewaster at 7:58 AM on June 19, 2008

My (altered, female, black & white shorthair) cat makes this noise when birds use the feeder suction-cupped to the window. It seems to mean THEY ARE INCHES AWAY I AM UNCONTROLLABLY EXCITED. YMMV.
posted to Ask Metafilter by fantabulous timewaster at 9:51 PM on June 14, 2008

Shower drains, like other household drains, have water-filled U sections to keep the sewer gas out of your house. If you see water but no mouse, he is either drowned in the elbow or trapped between one wet place and another. If he's alive, a rapid water flow out to your sewer or septic system or whatever will probably give him a better chance than a few days to starve in the air gaps in your plumbing.

Probably your bathtub, toilet, and sink plumbing all join into a... [more]
posted to Ask Metafilter by fantabulous timewaster at 9:41 PM on June 14, 2008

The focus isn't on software, but I have learned lots from Michael Alley's "The Craft of Scientific Writing."
posted to Ask Metafilter by fantabulous timewaster at 2:34 PM on June 14, 2008

You should ask the police department that will arrest your shoplifters.
posted to Ask Metafilter by fantabulous timewaster at 4:51 PM on June 12, 2008

If above-ground nuclear explosions make the earth uninhabitable for people, it won't be due to 14C activity. I'll assume your question is about the welfare of people who don't die when the bombs knock their houses over.

People in the region around the Chernobyl reactor meltdown had a substantially increased risk of thyroid cancer. The thyroid contains lots of iodine, and one common fission product is 131I, which has an eight day half life. Apparently a few weeks of... [more]
posted to Ask Metafilter by fantabulous timewaster at 1:08 PM on June 12, 2008 marked best answer

The essential difference between batteries and capacitors is that batteries store energy in chemical bonds, while capacitors store energy in electric fields.

Capacitors can discharge quickly because miniscule changes in the geometry of a distribution of charges can dramatically change the electric field. A one foot signal cable will delay the edge of a pulse by a few nanoseconds, pretty close to the fundamental limit, but the actual speed with which electrons drift... [more]
posted to Ask Metafilter by fantabulous timewaster at 8:35 PM on June 10, 2008

I scratch my "what's wrong with this snippet" itch here.
posted to Ask Metafilter by fantabulous timewaster at 6:23 PM on June 10, 2008

I have heard the term "male sexual hair" used to describe the hair men have that women don't, especially in places where it evolves throughout life: on the chin, in the nose, in the ears. But wow, what a worthless search phrase.
posted to Ask Metafilter by fantabulous timewaster at 8:07 PM on June 7, 2008

If an analog phone works in another jack in your house, but not in your bedroom, then it's the jack.

If no phone jacks in your house work, take your analog phone outside where the telephone cable comes into your house. Some have a jack out there for testing. You may need a screwdriver to get in, or possibly a "security wrench." I got a box of security wrenches from a supplier of low-voltage electronics for $35 for exactly this reason when I moved into my... [more]
posted to Ask Metafilter by fantabulous timewaster at 12:20 PM on June 6, 2008 marked best answer

Seconding source control. I have been switching from subversion to git, and I love! how easy importing a project is:$ git init
Initialized empty Git repository in .git/
$ git add file*
$ git status
# perfectly sensible status message
$ git commit -m"added first three files"
$ git log
commit 4fa331e0bbd8987ab88fb0c340f64ebcd6c196af
Author:... [more]
posted to Ask Metafilter by fantabulous timewaster at 11:08 AM on June 5, 2008

ssh host -t screen -xRe^oo will connect you to a persistent session, creating one if it doesn't exist, not knocking you off if you're connected from elsewhere.

I add the e^oo because screen's default command key is something really annoying.
posted to Ask Metafilter by fantabulous timewaster at 10:45 AM on June 5, 2008

Mine do mostly, but not entirely.

Storytimefilter: in 1957, just after the discovery of parity nonconservation, Norman Ramsey and some other giant of physics happened to drive past a farm with a full pigpen. They exchanged a look and got out of the car. There were twenty pigs in the pen. They agreed that Ramsey would count all the pigs with left-handed tails, and the other all the pigs with right-handed tails. After a bit they compared notes: twelve left and nine... [more]
posted to Ask Metafilter by fantabulous timewaster at 6:57 AM on June 5, 2008

delmoi, I think you have the geometry wrong. The relevant directions are the direction the hair grows ("normal to the skin" or so) and the direction of the twist, which most people relate using the "right-hand rule." If the hair from both temples curls towards the face, the hair coming from the right temple is left-handed and the hair coming from the left temple is right-handed. You can see this if you put your fists on your ears so your thumbs stick out: the fingers on... [more]
posted to Ask Metafilter by fantabulous timewaster at 8:41 AM on June 5, 2008

Several people have pointed out that tides extract energy from the rotation of the earth relative to the moon (and, to a lesser extent), the sun. Where's the energy differential there?

Currently the earth rotates once every 24 hours, while the moon rotates once every 29 days: the same as the earth-moon orbital period. This is an intermediate condition: it has less energy than a system (with the same total angular momentum) where the earth and the moon both rotate... [more]
posted to Ask Metafilter by fantabulous timewaster at 4:46 PM on June 4, 2008

Put a cup of water on the palm of your hand. Rotate the cup 360o about the vertical by bringing your hand towards your stomach, under your armpit, back out to where you started. The cup is unchanged by this rotation, but your arm is crazy twisted. (The cup is just there so you don't forget which axis is the vertical. You can just keep your hand palm up if you don't want to walk to the kitchen or you aren't thirsty or don't trust yourself not to spill.)

Now rotate the... [more]
posted to Ask Metafilter by fantabulous timewaster at 9:05 AM on June 4, 2008 marked best answer

I have

# Let myself connect back in:

RemoteForward 2217 localhost:22

in my laptop's .ssh/config, and

Host mylaptop

User ft

HostName localhost

Port 2217

in the .ssh/config of machines I use regularly. This lets me just rsync file mylaptop: on the remote machine.
posted to Ask Metafilter by fantabulous timewaster at 10:24 AM on June 2, 2008

jepler, you've helped me to finally understand the proxycommand syntax. Thanks! I have several machines that I access through one tunnel, and now that I've added Host outer
LocalForward 2244 inner1:22
LocalForward 2245 inner2:22
...

Host inner1
HostName localhost
Port 2244
ProxyCommand /bin/bash -c ' echo | nc -w1 %h %p >& /dev/null || ssh outer -f exit && nc -w1 %h %p 'to my .... [more]
posted to Ask Metafilter by fantabulous timewaster at 11:26 AM on June 3, 2008

Whenever you get confused about entropy, go back to what entropy means: it's the number of microscopic states your system has that look the same to your experiment. (More strictly, it's how many digits that number has, multiplied by some dimensionful constant. That definition has nice mathematical properties, but from a conceptual standpoint it doesn't add much.) You have lots of good examples in your previous question, but it's easier for me to add another one than find the one in my head... [more]
posted to Ask Metafilter by fantabulous timewaster at 7:08 PM on May 31, 2008

Book recommendation: "Warmth Disperses and Time Passes" by Hans Christian von Baeyer
posted to Ask Metafilter by fantabulous timewaster at 5:00 AM on June 1, 2008 marked best answer

This thread reads like a red reed I once read about. I dread that the thread will come to a head if everyone reads and heeds these screeds. I might as well head to bed.

Interesting case where the use of punctuation to represent inflection introduces ambiguity.
posted to Ask Metafilter by fantabulous timewaster at 7:42 AM on May 30, 2008

Edward Tufte. Buy all four books.

So far, everyone I have loaned these books to has come back after devouring them over the weekend to show me the nifty and insightful visualization they've made that has solved some longstanding problem of theirs.

He runs an interesting forum, too.
posted to Ask Metafilter by fantabulous timewaster at 9:09 AM on May 29, 2008