Why does water spill out of our faces?

And where does the water come from?  I mean, obviously I know that tears come out of tear ducts, but where is the water before that?  Do we have little reservoirs of salty water that wait for the next moment where we feel sad enough to involuntarily open the dam for a while?  And when we do feel that way, why is it our bodies' natural response (but for some people more than others) to just... leak?

It makes sense that we should have a biological mechanism to wash particles out of our eyes when dust blows or small insects demonstrate their lack of intelligent flight patterns, and it also makes sense that babies need a nonverbal method of communicating their needs while developing the language processing parts of their brains.  The part that gets me, though, is why we continue to have the crying reflex as adults in those moments when we are physically hurt, or deeply sad, or angry, or even overjoyed.  By adulthood, we have full capability to express our thoughts, feelings, and needs verbally (or at least, theoretically we do -- some people seem to be severely lacking in effective communication skills, but I think that's a different issue... As my sister and I frequently quip each other in the most high-pitched, fakely sweet, condescending voice possible:  "Use your words...").

Anyway, the point is, why does my freaking face have to leak whenever I feel even remotely sad or frustrated or too happy?

During my first attempts to solve these mysteries, I thought, Let's Google "anatomy of a tear duct" and see what happens.  Maybe we'll find the hidden saltwater reservoirs.  

Well, the first image I clicked was this one:  

Thank you, Will, for that amusing but entirely uninformative diagram.  

Let's try this one instead:  

Now, I can study this image while murmuring some ahhhs and mmhmms of outstanding intellect and instantaneous understanding, but let's be honest.  This tells me nothing (other than that the picture suggests we do, indeed, have tear reservoirs).

Time for some further investigation...

Apparently, the lacrimal ducts and glands (a.k.a. the tear ducts and glands) "produce and distribute the watery component of the tear film.  Tears consist of a complex and usually clear fluid that is diffused between the eye and the eyelid.  Further components of the tear film include an inner mucous layer produced by specialized conjunctival cells and an outer lipid layer produced by meibomian glands along the eyelid margin" (Encyclopaedia Brittanica).

Some thoughts:  Tear film??  Usually clear??  Mucous??  Gross.

Well I'm glad that my tears are there to keep my eyeballs from drying out and stuff, but I still don't know why the water has to pour out in excesses at such vulnerable and inconvenient times.

More Googling...

Aha!  Google always knows the answers.  There are three types of tears:  basal (which are always there keeping your eyeballs appropriately moist), reflex (which are there to clean out the bad stuff), and emotional.  The elusive emotional tears are the ones I'm interested in.  HowStuffWorks tells me:

"It all starts in the cerebrum where sadness is registered. The endocrine system is then triggered to release hormones to the ocular area, which then causes tears to form. Emotional tears are common among people who see Bambi's mother die or who suffer personal losses."

But whyyy?

"Chemicals build up in the body during times of elevated stress.  [Some] researchers believe that emotional crying is the body's way of ridding itself of these toxins and waste products.  In fact, one study collected both reflex tears and emotional tears (after peeling an onion and watching a sad movie, respectively). When scientists analyzed the content of the tears, they found each type was very different. Reflex tears are generally found to be about 98 percent water, whereas several chemicals are commonly present in emotional tears [Source: The Daily Journal]. First is a protein called prolactin, which is also known to control breast milk production. Adrenocorticotropic hormones are also common and indicate high stress levels. The other chemical found in emotional tears is leucine-enkephalin, an endorphin that reduces pain and works to improve mood. Of course, many scientists point out that research in this area is very limited and should be further studied before any conclusion can be made."

Keep reading...

"After babyhood ends, researchers believe that girls and boys do equal amounts of crying until they reach the hormone-fraught adolescent years. As levels of testosterone skyrocket in boys, their amount of crying plummets. The opposite is true for girls, whose estrogen levels begin to rise substantially during the early teenage years. This is especially interesting, considering the relationship between the protein prolactin and breast milk production, which only happens in women. Perhaps this is why women cry roughly four times as much as men, according to biochemist and researcher William Frey and co-author Muriel Langseth, who wrote Crying: The Mystery of Tears.'  Frey estimates that women have about 60 percent more prolactin in their bodies at any given time than men [source: Women's Health]. He also believes that these elevated levels cause women to cry more because the protein revs up the endocrine system, which makes people more likely to cry."

Thank you, HowStuffWorks.  I now understand (however superficially) that there are biochemical processes involved and that crying actually serves a purpose.  For more details, click on the previous link.  Or Google it yourself.  I'm gonna go read the last Harry Potter book and cry my eyes out now.

Who invented bread?

Was it an accidental discovery?
If so, how did someone accidentally mix all these random ingredients and then unintentionally expose them to 300+ degree temperatures for approximately 25 minutes?
If not, how did someone come up with the idea to mix flour, eggs, yeast, etc. and just see what happens if they put it in the oven for a while?
When and where did this take place?

According to the infallible wisdom of the Internet, "bread is prehistoric - every ancient culture known used some form of bread, and stone-age tools often include implements for grinding grains into flour" (http://wiki.answers.com/Q/When_was_bread_invented_and_who_created_it).  Hmm, okay, so now the scenario in my mind has shifted from a 17th-Century French dude in a tall white hat throwing random ingredients all over the place like a mad scientist... to a caveman accidentally baking a loaf of perfectly baked golden-brown bread in his stone cave-oven...?  Actually, several cavemen and several cave-ovens in several different parts of the world.  I'm guessing the first guy didn't just tweet his new discovery to share it with the rest of the world, so how did various people in prehistoric societies across the world all accidentally discover bread?

Google Answers offers a more comprehensive explanation here, but the basic consensus seems to be that humans have been harvesting wheat since before recorded history, discovered they could grind it and make it into a paste, and then heated this paste over a fire to make a flat bread.  Then somewhere along the way, yeast was accidentally added and they discovered bread that rises!

Prehistoric humans and their ingenuity.

Why is Z the letter of sleep?

Where did the phrase "catch some zzz's" come from?  Who decided the letter Z sounds like people sleeping?  I've heard some weird snores, but I've never heard anyone who sounded like a buzzing bee while sleeping...

When I Googled it, the most interesting theory I came across was this:

"I've been looking into this, and as far as I can tell, it entered common use through a comic in the 50's, though I haven't found which one. Recently, though, I've been reading a book called Mao, in which there is some discussion about a spy who played a critical role in the Battle of Shanghai in 1937. What's interesting about him is that he was a sleeper spy who had been planted by the Russians in the CCP army years before he was stationed in Shanghai--and his initials were ZZZ. Whether he is related to the use of "zzz" to mean sleep, I don't know, but I found it very interesting."

Read more here.

Also, BullyH's answer on Yahoo! Answers just made me chuckle:

"If most were like me at school, by the time I got through reciting the alphabet, I would have been asleep. So I guess when I got to the letter Z, I would have been catching up with my sleep. How much quicker would it be to say, I'm going to catch some Zs. Three words actually."

So the common consensus seems to be that "catch some zzz's" became popular slang over 50 years ago when it started to appear in cartoons, but I'm still curious as to why the letter Z was chosen.  In my opinion, snoring sounds more like ffffrghhgghhhnntthhgghfff...

Why can't I look at the sun?

I distinctly remember my grandmother nagging me from her driver seat while I sit in the backseat staring out the window at dusk, "Don't stare at the sun; you'll go blind!"  I hear this time and time again, but no one ever tells me why it'll make me go blind...

Will the UV rays overwhelm my sensory neurons and cause them to go on the fritz and then stop working?  Will the intensity of the sun penetrate my occipital lobe like a laser?  Will it melt my eyeballs?  Will it just cause so many dots in my vision that they'll never go away and I'll never be able to see normally again?

As I desperately try to look at the solar eclipse tonight, these are the questions that run around inside my brain.

The best answer I found when I googled my question was posted by Elizabeth H. on Yahoo! Answers:

"The solar radiation that reaches the surface of the Earth ranges from ultraviolet (UV) radiation at wavelengths longer than 290 nm, to radio waves in the meter range. The tissues in the eye transmit a substantial part of the radiation between 380–400 nm to the light-sensitive retina at the back of the eye. While environmental exposure to UV radiation is known to contribute to the accelerated aging of the outer layers of the eye and the development of cataracts, the primary concern over improper viewing of the Sun is the development of retinal burns.

Exposure of the retina to intense visible light causes damage to its light-sensitive rod and cone cells. The light triggers a series of complex chemical reactions within the cells which damages their ability to respond to a visual stimulus, and in extreme cases, can destroy them. The result is a loss of visual function, which may be either temporary or permanent depending on the severity of the damage. When a person looks repeatedly, or for a long time, at the Sun without proper eye protection, this photochemical retinal damage may be accompanied by a thermal injury—the high level of visible and near-infrared radiation causes heating that literally cooks the exposed tissue. This thermal injury or photocoagulation destroys the rods and cones, creating a small blind area. The danger to vision is significant because photic retinal injuries occur without any feeling of pain (the retina has no pain receptors), and the visual effects do not become apparent for at least several hours after the damage is done (Pitts 1993). Viewing the Sun through binoculars, a telescope, or other optical devices without proper protective filters can result in immediate thermal retinal injury because of the high irradiance level in the magnified image.

The only time that the Sun can be viewed safely with the naked eye is during a total eclipse, when the Moon completely covers the disk of the Sun.
Source(s):
NASA"

Thank you, Elizabeth H.  Now I understand the seriousness of the situation, and I really won't stare at the sun anymore.