PRIME NUMBERS

VERBATIM - 'It is not a simple life to be a single cell, although I have no right to say so, having been a single cell so long ago myself that I have no memory at all of that stage of my life. -- American Physician and Essayist Lewis Thomas (1913-1993) CNS Photo.

OLD JOKES - Researchers suggest that age-related cognitive decline is at least partly the reason why older adults seem to have a tougher time understanding jokes than younger people. CNS Photo.

PRIME NUMBERS - A hard popcorn kernel must contain at least 13.5 percent water to properly pop CNS Photo.

WHAT IS IT? - This is a picture of the recurve-billed bushbird, among the rarest birds in the world. CNS Photo.

237 - Number of identified motivations for why people have sex, according to a new study

40 - Percent more likely to survive a crash if sitting in the rear of a plane

13.5 - Minimum water content, as a percentage, that a hard popcorn kernel must contain to properly pop

Sources: David Buss and Cindy Meston, University of Texas, Austin; Popular Mechanics; "Random Kinds of Factness" by Erin Barrett and Jack Mingo (2005)

BRAIN SWEAT

Can you decipher these phrases?

1. timing ti ming

2. cotaxme

3. 1D 2R 3A 4C 5U 6L 7A

VERBATIM

It is not a simple life to be a single cell, although I have no right to say so, having been a single cell so long ago myself that I have no memory at all of that stage of my life.

- American Physician and Essayist Lewis Thomas (1913-1993)

POETRY FOR SCIENTISTS

Some aliens landed nearby

And borrowed our neighbor, old Sy.

They returned him intact,

But tattooed with exact

Instructions for shipping by sky.

- Jane Auerbach

BRAIN SWEAT ANSWER

1. split second timing

2. income tax

3. Count Dracula

OLD JOKES

The news is bound to make grumpy old men (and women)grumpier: Researchers at Washington University in St. Louis suggest that age-related cognitive decline is at least partly the reason why older adults seem to have a tougher time understanding jokes than younger people.

The researchers tested a pool of older adults and undergraduate students at the university, giving each of them a standardized exam called the Joke and Story Completion Test, then other tests that measured cognitive abilities such as abstract reasoning, short-term memory and mental flexibility. Older adults performed less well on tests of both humor comprehension and cognitive ability. The findings support an existing theory that cognitive decline over time affects people's ability to process and understand humor.

If you want to see someone (or something) who is truly humor-impaired, check out your nearest robot. Artificial intelligence scientists have avoided trying to duplicate human humor in robots because it's too subjective, too complex and probably way too hard to program.

Until now. A pair of researchers at the University of Cincinnati has written a basic computer program that "understands" at least one kind of joke: Puns, such as "A man walks in to a bar. Ouch!"

To create the program, researchers compiled a database of words derived from a children's dictionary, to keep things simple, then supplied examples how words can relate to each other in various ways to create different meanings.

Presented with a phrase, the program analyzes the meanings of the words involved and how they relate. If it finds an incongruity, it looks for similar-sounding words. If any of those words fits in better with the rest of the sentence, it deems the phrase to be a pun.

Whether it's actually funny is an entirely different matter.

JUST ASKING

How do you know when you're out of invisible ink?

'TRUE FACTS'

Frisbees were originally called Pluto Platters.

WHAT IS IT? ANSWER

If you answered "a bird," obviously you're right. But not just any bird.

The recurve-billed bushbird is among the rarest in the world and this is one of the first photos ever taken of it, courtesy of the Colombian bird preservation group ProAves.