Urinal 101 (for boys and mothers)

[elestat]

http://www.straightdope.com/columns/030509.html

Maybe the question was not about public urinal types, but simply home toilet bowls.

When a boy, I had this quarrel with my mother.
I used to aim the porcelain side or back, because (a) I thought it was less noisy than to splash the water (especially if I woke up early and the family was still sleeping) (b) I also thought it would make less drops outside the bowl.
(And Cecil seems to have made my point. Thirty years later ! Thank you Cecil.)

My mother insisted that I should aim the water: she considered piss would bounce on porcelain but be absorbed by water. And she accused me of splashing all around the toilet.

Experimentation (yes, a scientific mind begins young) lead me to no clear-cut conclusion. I seemed to do not much harm to the floor, whatever the method.
In the end I found out it was my father who had some aiming problem. Seems my mother had it more natural to educate her boy than her husband...

[sawatzky]

I consider it extremely bad form to stand up at a toilet period. Especially in a private home. There may be ways to minimize splashes... (at filthy gas station rest rooms I flush FIRST, creating a vortex and bubbles out of which no splash can escape)... but there is NO WAY to control those periodic accidents when a sticky penis first squirts pee sideways or in two streams before settling into a strong downward flow. I don't stand up in other people's houses, and I get 'pissed off' when they stand up at MY toilet and soak my floor [and magazines and towels and walls ...]

[Mr. Moto]

Standing's fine. Most incidents can be discreetly solved by mopping up the affected area with TP.

[sawatzky]

Isn't that like discreetly mopping up a Cola spill with paper towel? Half an hour later people will be wondering what that smell is, or why the floor is so sticky!

[pierre72]

A propos of not very much, but following on from the "give fellers something to aim for" idea, I've recently notived an ingenious development in urinal enhancement technology and marketing.

At a football stadium I frequent in London, the urinals have stickers on them. These stickers, naturally become targets. When the higher temperature, er, let's just call it liquid, hits the heat sensitive stickers, they change and reveal the advertising slogan.

Genius. Minimising splashback, while getting your message across. Hats off to the bloke who invented that.

Now wash your hands.

[Pablito]

I, too, am thinking that Cecil bailed out on a complete answer by failing to address the appropriate methodology for approaching traditional toilets.
Years of experience and thoughtful deliberation have taught me to aim near the back of the water, just short of the porcelain. This seems to avoid the deep-water splashing and noisiness phenomenon while also mitigating the splash-back of a direct hit on the porcelain.

And so far as having something to aim for in urinals, I'm especially fond of the ones that have those little fans, which enable the user to try to make them spin as fast as possible. In a man's world, everything's a game.

[fool4jesus]

When I was in college, the fraternity house had a small "Virginia Tech" sticker in the back of the urinal (I went to Va. Tech). Now THAT gave you something to aim for. Maybe nowadays people are putting little pictures of Saddam Hussein, or President Bush, or whoever. (I'd personally aim for Tom Daschle.)

[blahedo]

Fascinating.

I've actually thought about this before, and my conclusion was that aiming anywhere on the back wall of the urinal will cause some of it to bounce back at you. Yuck. But (and Cecil mentions this in his column) if you can get the right angle on the porcelain the stream will just run straight down the urinal with no splash. How? Stand slightly off center and aim at the sides. Some urinals just aren't shaped right for this, but most have a flat side at about 90 degrees from the back---and approximately parallel to the direction of the stream, making it easier to get a sufficiently oblique angle.

As for private toilets, that's more of a dilemma. For auditory reasons I don't like aiming for the water (hadn't even really thought about splash in that case; I just don't like the sound); so I aim for the porcelain just above the water line. But then, no matter how, er, tightly-controlled the stream is, I feel like there is always a tiny bit that goes astray and lands on the edge of the bowl. The seat's up, so it's not unsanitarily gross, but it's still gross. (Honestly, even if we aimed for the water, I think there'd still be some making it to the edge.)

I think more private homes need urinals. Not only would it be more sanitary, it'd save a lot of water on flushing. :P

[alewbail]

A few (more-or-less) related observations from the international scene:

I recently visited Japan and noticed a trend in some public restrooms. The urinals have a shallow "auxilliary" trough on the floor, below the lip of the urinal, to contain the results of splashing. I found this deeply disturbing. It draws attention to a problem that we all know exists, but never talk about (except on SD). The trough makes you confront the fact that you're incompetent at an activity you've been engaged in since you were born.

Also in Japan, on many of the trains they have urinal-only restrooms the size of a phone booth. The door has a window whereby any passers-by can see your full frontal backside. (The urinal is arranged so that you face away from the door.) Of course, when peeing you wouldn't normally be showing any backside, but still, any "gyrations" are clearly noticeable.

In France, I once used a portable roadside multi-urinal. Instead of port-a-johns, they have these multi-urinals. From the top, it looks like a big plastic asterisk. You stand in one of the "V's", facing toward the center, and pee into a hole in the plastic. There's no backside coverage at all, with or without a window. Again, the "arms" of the asterisk hide the naughty bits, but the "dance of urination" is clearly visible.

On the other hand, visitors from Japan or Europe to the U.S. are appalled that our stall doors/walls don't go all the way to the floor. In those countries the stalls are completely enclosed, and may even be separate rooms.

On the other (third) hand, at public restrooms in Japan and Europe, female attendants come in to clean at all hours and everyone just goes about their business.

Interesting what different people see as disgusting in different places.

[fool4jesus]

Originally posted by alewbail
I recently visited Japan and noticed a trend in some public restrooms. The urinals have a shallow "auxilliary" trough on the floor, below the lip of the urinal, to contain the results of splashing. I found this deeply disturbing.

Speaking of disturbing parts of toilets, has anybody ever used one of those "water closets" (you know, a "sit-down" toilet) with the shelf that sticks up out of the water? The one like this that I used was in Belgium, but I understand that they are common in the Netherlands. For those unfamiliar, a column of porcelain rises up from the bottom maybe 8 inches out of the water to form a shelf maybe 4-5 inches wide.

Now, I never got the opportunity to use this toilet for a number two, but I wonder: is this shelf so you can admire your handiwork after you've deposited it? If not, what is its purpose?

[sawatzky]

The Germans hit the nail on the head with their public roadside toilets. I used a few that only had a vortex shaped floor with a covered hole in the middle and two pedestal foot-shaped protrusions on either side of the hole. No instructions necessary. You stand in the only possible place you CAN stand, and either stand upright and pee, or squat like a cave man and make your deposit to the covered hole. TP was in a lidded enclosure. When you leave, and the door clicks shut -- the hole opens and the entire room flushes! No worrys about splashes there.

I've never in my travels seen a porcelain platform sticking out of a toilet. THAT is creepy.

[fool4jesus]

"the entire room flushes". That's great. Sort of like the traditional toilets in China, where you put your feet on little treads and then do your business into the slot-shaped hole beneath you. My (7-year-old at the time) son looked at one of them and said "Er... I can hold it." :-)

[Maximum Blob]

http://www.peeball.com


That is all.

[CuriousCanuck]

Cecil, I just asked about urinals! :)

See the very recent thread here, where perhaps you can help with the question I had about drain holes. (http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=181802)

I knew thet one day one of my questions would be addressed by you, Cecil. I guess I should have gotten pissy about it sooner. :)

[Happy_Booker]

Is there a reason (and, no, good taste doesn't count) that no one has commented on the "Please don't gush!" instruction that precedes Cecil's forum?

[Flyfisher]

One sure cure for the problem is to go out doors to "check" something like the AC compressor, termite detectors, or etc. Or just hike a leg and "mark your territory". Of course this is best done at night and in poorly lighted areas since daylight, whether natural or artifical, would likely draw unwanted attention. But, what the hell, there won't be any shiney tile or porcelin fixtures to splash with pee. And if it happens to be winter with snow on the ground as you can practice your "penmanship".

[fool4jesus]

To prove I'm not crazy (including to myself):

http://www.expatica.com/index.asp?pad=32,39,&item_id=26

http://www.americanvlaai.com/toilets.htm

http://www.scallen.com/2001_10_28_archive.html

(look up the word "shelf" in the third one)

The dreaded shelf toilets appear to be found in at least Belgium, the Netherlands, and Germany. The best quote: "The odd shape of the toilet incorporates a shelf that rests above the waterline and acts as an examination table, as it would appear the Dutch pay more attention to their meals after they eat them than when making them."

[ahansen]

Um, why don't you guys just sit down like normal people?

[bohrer]

Waterless urinals are one way to avoid the issue of splashing in the water. Also a new water-conservation trend, I suppose. Here's a US manufacturer: http://www.waterless.com/

Don't know about splash-back, though, because from the photo it looks like the rear wall is flat, not parabolic. However, they claim that the waterless design will "improve restroom hygiene":

"No-FlushTM urinals improve rest room hygiene: Urine itself is normally sterile, 0% bacterial. Fecal matter is 95% bacterial, and may include pathogens.

Microbes, bacteria and viruses thrive in moisture, but they die when dried. There are surface areas in water flush urinals that are constantly damp where bacterial growths appear. These growth colonies are seeded by fecal material carried in air-borne droplets and aerosols that were produced by the turbulence in flushing the rest room's toilets. When the rest room urinals are themselves flushed they in turn create aerosols containing the new-growth bacteria, and inject still more microbes into the rest room atmosphere.

Installing No-FlushTM urinals with predominantly dry surfaces and no flushing actions lessen rest room visitor exposures to airborne bacteria."

Perhaps more than I cared to know.

[lets_not_listen]

everybody knows the best urinals are those with ice in the bottom.

[fool4jesus]

Originally posted by lets_not_listen
everybody knows the best urinals are those with ice in the bottom.

Somebody once told me a joke about putting somebody bread in the bottom of a urinal - I forget how the joke goes, but I've never been able to get the image out of my mind. Something to think about next time nature calls. :-(

And according to the http://www.waterless.com/SaveEval.pdf, the average male uses the facility 3 times a day. It's good to know I'm not some kind of freak of nature.

[sford]

I can attest to Cecil's recommendation not to use plastic piping for toilets. My g/f house has plastic. When somebody upstairs flushes, the dining room gets treated to a rather loud rushing and tinkling sound. AND, it also led to my cutting a hole in the wall to find the "leak".

Sometimes (but not all the time) when somebody upstairs flushed or drained the tub, you would hear in the dining room a very distinct tapping sound. It came from near the floor, and was obviously water dripping between the walls. But opening it up showed the area to be bone dry.

Turned out to be thermal expansion - when the water flowing in the pipe was a different temp than the pipe itself, the pipe would expand or contract, with the largest movement being near the floor. The sides of the pipe were rubbing against the wall board, with friction causing the "tap-tap-tap" sound.

[fool4jesus]

Originally posted by sford
...with the largest movement being near the floor...

No pun intended, of course ...

[li'l Dickie Dirtz]

Originally posted by bohrer
Waterless urinals are one way to avoid the issue of splashing in the water. Also a new water-conservation trend, I suppose. Here's a US manufacturer: http://www.waterless.com/
And they suck. And they are definitely not odorless. And urine starts out sterile, but by the time it hits the porcelain it sure ain't anymore (http://www.straightdope.com/classics/a4_220.html). It picks up a lot of nastiness along the way out.

[Latino Yoshi]

Originally posted by ahansen
Um, why don't you guys just sit down like normal people?

I do sit down, in the morning. I'm just not coherent enough at the early hour to trust my aiming ability.

Every other time, though, I stand up because there's no fun in sitting down. I dream of the days when I will be able to play video games every time I visit the urinal. See the link below:
You're In Control (Urine Control) (http://web.media.mit.edu/%7Ehayes/mas863/urinecontrol.html) [/B][/QUOTE]

However, I only see the above leading to higher splash rate than the absymal rate that there is now.

[hermann]

All I can say is..........ewwwwwwwwwwww, I'm glad I don't live in Amsterdam

[Thursday]

Something I've noticed, is that no one has commented on the physiology of the, ah, "originating source". Aiming can actually be a little tricky for men.

Imagine, women, if you will: a sausage with a vertical slit running through the centre (no, the hole isn't round) attached to a water balloon. Now, if anything else had been in the passage that the water was about to travel the water is going to be thrown off-course. This is especially true if the previous substance was sticky at all. Which (guess what?) it is.

Most guys have erections throughout the night, and some are "early risers" who take care of business by themselves or with some helpful assistance, and this definitely "gums up the works" a little bit. This causes some odd directions, or even two directions at once, which is always a surprise and really tough to aim.

Just thought you'd like to know!

[tcdaniel]

Methinks modern urinals are poorly designed. Remember the tall ones back when? What happened to those?
And about the placement - well the average inseam is 30" - why do they put them at 32-34" I need a damn stool or go to the little boys urinal. Just place them where men won't make a mess on themselves and the floor.
My own water experiments have concluded if sitting is not an option, make noise at the waters edge pissing downward. I don't think much of screens - they were designed to keep out cigarette butts.

A necessary function discussion might lead to some changes here.

[Irishman]

To add to Thursday's remarks, note that the opening has two flaps of skin from the slit. Sometimes they do not seperate properly, causing the same effect of putting your thumb over the opening of a hose. Aiming isn't always as easy as it seems. No matter how precise you are with the pointing, the stream exits at whatever angle it desires. The dreaded split stream is a killer (two streams diverging at approx 30 - 45 deg angles, neither one hitting the bowl).

[schizmaticism]

Hate to say it, but I completely disagree with Cecil. I pee in the water, because every time I try to pee on the back wall it splashes on me. I've never been splashed on by peeing in the water. Not once.

On a related note, there is a seemingly large growth in the use of flat rubber mats with holes in them to hold the urinal cakes. If I am forced to pee in a urinal that has one, the splash rate goes up by a large amount. I have no idea why janitorial staff thinks this is a good idea.

[brucemac]

I came across a different problem than tcdaniel. I am six feet tall, and many of the urinals in department stores are too low for me. If I don't do knee-bends, the only direction the stream can go is straight down, thereby causing a splash at about the shin level.

[brucemac]

I forgot to mention that I am living in Malaysia. There aren't a whole lot of six-footers here.:smack:

[sford]

Originally posted by schizmaticism
On a related note, there is a seemingly large growth in the use of flat rubber mats with holes in them to hold the urinal cakes. ... I have no idea why janitorial staff thinks this is a good idea.

As was mentioned earlier, it prevents clogs and makes it easier to clean after inconsiderate smokers have used it.

[dwc1970]

Originally posted by Mr. Moto
Standing's fine. Most incidents can be discreetly solved by mopping up the affected area with TP.

Not if the bathroom has a carpeted floor.

[wilbert]

Not to pick on American Standard (I think all urinals are poorly designed), but the parabolic shape is exactly the WRONG shape for the back wall of the urinal.

Anybody who studied physics, math, engineering, or life knows that if you're standing at the focus of the parabola, the splash will be focused directly back at you (duh). :smack:

Those directors of design obviously never use their own products, because if they did, then they'd know that blahedo above is right in aiming for the side. Only an acute angle will produce laminar flow and reduce splashing. That's why aiming for the waterline along the back wall, as pablito suggests, also works.

-- wilbert (former mechanical engineer and eternal student of life)

[friedo]

Originally posted by dwc1970
Not if the bathroom has a carpeted floor.

Well, if you put carpet in your bathroom you deserve what you get. It's a simple fact of life that sometimes bodily fluids get the best of us. Not just urine either, but also sudden diarhea or vomit can lead to aiming disasters. (With vomit, being room-spinning drunk doesn't help much either).

[C K Dexter Haven]

I just knew that the Teeming Millions would keep this discussion at the high level of fluid dynamics and angles of refraction...

[QuasiQubit]

I've heard the orgin of the phrase "to take a piss" comes from the subject of urinals. The original urinals had a target built in, in the form of a butterfly. And the latin for butterfly is Apis, which if you horrible mutate it into english sounds like a piss.

anyway just though I'd throw that out there

[Thursday]

I believe that you mean a bee, not a butterfly.

[Blalron]

What the heck are you all talking about? I haven't been "splashed" by a urinal once in my entire life. Not once. Either I have superb urination skills that some of you don't possess, or you are doing something seriously wrong.

I always aim for the porcelin part of the urinal, not the water.

[TBG]

I never use urinals. Not enough privacy. Now if only they'd get the stalls with the doors that go all the way to the floor.

And I'm so glad to hear it's not uncommon to have the "bi-directional peeing" thing going on once in a while.:)

[alewbail]

Here's Cecil's quote regarding the parabolic shape of the American Standard urinals:
The rear wall of the typical urinal is parabolic in cross section when viewed from above, and the porcelain finish is conducive to laminar flow. The principles of fluid dynamics tell us that a fluid striking a smooth surface at an oblique angle will tend to flow along that surface. Assuming the source of the fluid is near the focal point of the parabola--and modesty makes it unlikely he'll stray too far--the fluid will run straight down the urinal wall with little or no splashing.
I think he's mis-interpreted things a bit (or the American Standard guy mis-explained it a bit). If the shape is a parabola, and if you are standing at the focus, and if you happen to be peeing ball bearings, then if you pivot and pee in any direction, each ball bearing should fly straight out of the urinal, on a trajectory perpendicular to the wall.

Think of the urinal as the reflector of a flashlight, and your business is the lightbulb, and the ball bearings are the beams of light. The lightbulb throws light in all directions, but the parabolic mirror aligns it so it's all shooting straight out of the flashlight.

So I think it's more likely that the focus of the urinal is inside the urinal, within the bowl. That way, it works like a flashlight in reverse (or like a satellite dish). It doesn't matter how you "pan" right or left (not pivoting, but just moving laterally), as long as you pee straight into the urinal. When the ball bearings hit the wall of the urinal they're deflected toward the focus in the bowl of the urinal.

(I just took a look at the A.S. urinal in the restroom at my workplace, and I'm not really sure where the focus is. Someone also asked me who I was talking to.)

Of course, all of this is sort-of moot, since only the manliest of men pee ball bearings. The more important point (see Cecil's quote above) is to pee at an oblique angle (the more oblique the better, I'd guess), to get the laminar effect, which minimizes splash-back.

[Nightime]

A lot of women always complain about guys not sitting down. One of the reasons is that if a guy has an erection, for instance when he first gets up in the morning, it becomes impossible to pee sitting down. Especially since, unlike public toilets, home toilets have seats that go all the way around, including in front. Why do the seats go all the way around? All toilets should have U-shaped seats.

[Askance]

One variable here is the different toilet designs for domestic fittings. In Australia at least the bowl is deep with a minimum of water at the bottom. There is plenty of porcelain to aim at, at the rear, and no-one ever spashes (except for the split-stream effect mentioned earlier).

In the US they seem to be low and shallow with the water alarmingly close to the rim; one's fingers dip into the water (et al) appallingly often while wiping. Then when you flush the whole mess spins round several times before being sucked down, far worse a view than the European step phenomenon. There is precious little porcelain above the water to hit.

[sawatzky]

Originally posted by Nightime
...One of the reasons is that if a guy has an erection, for instance when he first gets up in the morning, it becomes impossible to pee sitting down. ...

Not impossible, but certainly awkward. That particular pee, first in the morning with full erection is usually so powerful it is the only one guaranteed to splash back.

Originally posted by Nightime
... Why do the seats go all the way around? All toilets should have U-shaped seats...
This would be nice at home, BUT, I have noticed that my 5 and 7 yr old daughters get cold porcelain under at least one cheek, the little one, both cheeks. They just don't GET that you shouldn't be touching dirty porcelain toilet bowls.

[Chronos]

I think he's mis-interpreted things a bit (or the American Standard guy mis-explained it a bit). If the shape is a parabola, and if you are standing at the focus, and if you happen to be peeing ball bearings, then if you pivot and pee in any direction, each ball bearing should fly straight out of the urinal, on a trajectory perpendicular to the wall.No. If the source of fluid is at the focus, then the resulting streams will all be parallel to the axis of the paraboloid. Everyone here is assuming that the axis is perpendicular to the wall, which would indeed be phenomenally stupid. But if you make the axis vertical, or nearly so, then all splashes will be straight down, into the urinal.

Amusing annecdote, by the way: Last summer, I, my mother, and a female cousin all flew through JFK airport, and had occasion to use the facilities. I noticed the fly painted in each urinal, and being a guy, of course, immediately divined its purpose, and admired the genius in putting them there. When I came out and told the other two about this marvelous idea I had just seen implemented, they hadn't a clue what I was talking about. It took about five minutes to explain to them why putting a fly in the urinals was such a stroke of genius.

And QuasiQubit, why would an old German word have a Latin origin? There's nothing wrong with the obvious explanation that "piss" is an onomotopaea. When you make water, what does it sound like? Especially if you're aiming into a clump of underbrush under a tree, which is a lot older "urinal" than hypothetical ones with decorative butterflies.

[alewbail]

Chronos sed:
Everyone here is assuming that the axis is perpendicular to the wall, which would indeed be phenomenally stupid. But if you make the axis vertical, or nearly so, then all splashes will be straight down, into the urinal.
In that case, "everyone" must include Cecil. Again, from the column:
The rear wall of the typical urinal is parabolic in cross section when viewed from above
Under your "vertical axis" theory, it would not look like a parabola when viewed from above (along the axis). The cross-sections would be circular for a "paraboloid" (revolved about the axis) or just straight lines if the parabola was "extruded" along or perpendicular to the wall.

Furthermore, if the axis is vertical, and the apex of the parabola is the bottom of the bowl, then anything hitting the sides would tend to bounce up. Unless you're trying to suggest that all the urinals in the world are installed upside-down.

If I'm still being dense, then please draw a more detailed mental picture, or an actual picture.

Back when I thought I knew what the parabola looked like, I really didn't care. But now that I'm confused, I find that I simply must know.

[spinky]

I opened this thread specifically to make the same point as wilbert, which is that a parabola is a lousy shape to use, and that most urinals were designed by people who never ever wore shorts. With a parabola, your stream isn't always going to be perpendicular to the porcelain surface, but it's going to be pretty close to it. And I think we can all agree that perpendicular or close to it is the worst angle for your stream to hit.

Some observations that need to be made:
1) A stream of urine is not an idealized billiard ball. The angle of incidence does not equal the angle of reflection. In fact, if you hit perpendicular, the splatter seems to go in every direction except straight back at you. The argument that a parabolic reflector can be used to focus a stream of liquid to its focal point is, as far as I can tell, pure bullshit. (and same goes for the claim that a parabolic reflector is a particularly good shape for causing an "oblique" angle of incidence -- a simple plane does a better job)

2) You want your stream to hit as close to parallel to the surface of the porcelain as possible. This allows the stream to flow along the surface of the porcelain with as little change in its direction as possible. Ideally, you could pee almost straight down while standing really close to the wall. The obvious downside is that you'd be standing in the urinal, possibly touching porcelain with Willy. Luckily, you can get pretty far from the "ideal" angle (say at least 30 degrees) and still cause no splashback.

The best urinals for reducing splashback (in my experience as a frequent bare-legged urinator) are ones with a perfectly flat surface which is parallel to the wall they're mounted on. Some bars have the multi-player implementation which is a flat stainless steel wall about 5 feet high with a trough at the bottom at floor level. You pee on the wall and it flows quietly down into the trough. My second-best nomination goes to the tall single-player porcelain ones that are sunk into the floor. I remember these from elementary school, and I think they're what tcdaniel is talking about. I assume the reason a lot of places don't use them is that garbage on the floor gets kicked into them and clogs them up. Leave the design the same and raise them a foot off the floor, I say.

And if the American Standard urinal designers are so confident that they're reducing splashback, they won't mind if I come "beta test" their new designs and then ask them to kiss my knees. :)

[privard]

alewbail--close but no cigar. The trough along the base of the wall under the urinals is not to catch whatever misses the toilet. It's not a nod to bad hygeine but a sign of cleanliness. The trough and drain are for the buckets of water they dump on the floor to clean it--and frequently, too (you might have noticed that bathroom floors in Japan are often suspiciously wet, and yet they don't smell like pee).

ntucker--thank you. I was hoping someone else would notice that urine isn't made of ball bearings or billiard balls. Liquids don't behave like solids--would someone who knows more about these things than I (and than all these people who expect urine to bounce elastically) care to confirm my suspicion that the difference is partly due to surface tension? Or is that guess way off?

[OxyMoron]

Originally posted by ahansen
Um, why don't you guys just sit down like normal people? Two reasons:

1) We don't have to. Many, many women I know are envious of men's ability to pee standing up (or, I should say, comfortably pee standing up).

2) Toilets are too short. This is a Raging Annoyance of mine - I'm 6'2", which is not that tall for guys in countries at first-world nutrition levels. But we're stuck with industrial standards left over from when everyone was about five feet. For my own apartment, I bought a "handicap" toilet that's 14" high instead of 12" - makes a huge difference in my comfort (although if I had my druthers, it'd be another inch or two taller still).

My favorite solution is simply to install urinals in home bathrooms - a family I knew in Japan had this and I thought, "why don't more people do that?" Houses and bathrooms keep getting huger anyway.

[alewbail]

First, to "privard", you must be thinking of a different Japanese restroom than I am. The troughs I'm talking about are about 1/4" deep and rectangular, and they have no drain and no outlet and don't go anywhere. Of course they get swabbed out whenever the floor gets mopped, but the rest of the time they're clearly just a receptacle for spillage.

And of course I don't imagine that pee acts like billiard balls. That was sort-of my point in introducing the ball bearings. The parabola shape as far as I know only makes sense if you _are_ peeing ball bearings (or beams of light, cool!), which few of us do. Unless the parabola has more magical powers that we didn't learn about in Algebra II. Any fluid dynamics types out there?

[spinky]

For what it's worth, my favorite anti-splashback strategy is to pee full-force directly into the water, which is kind of counterintuitive. The water foams up, and the foam acts as a pretty good splash arrestor.

[monterey86]

Here's my million-dollar product idea for accuracy and entertainment for the urinal industry:

You know that carnival game where you line up with 4 or 5 competitors to shoot a water pistol at a target that inflates a balloon? Winner gets a prize.

Combine that with a men's room in a Las Vegas casino and you've got something.