A bucket of water

[mummymonkey]

When I'm changing water in my fish tanks I carry it around in a 3 gallon bucket. Often, a few seconds after I set it down, the water slops over the side.
How is that the water can increase in "aggitation" enough to spill over the top, after any movement has stopped?
Something to do with waves I'm thinking.

[MRC_Hans]

Probably there are several wave motions in the water at the same time. For instance on from carrying the bucket, and another started by the impact whan you put it down. These cause interference patterns, sometimes cancelling each other out sometime intensifying, so at the peak, it spills over.

Just set it down a little more carefully, especially, make sure sideways motion has stopped, so you lower it straight down to the floor.

Hans

[phildonnia]

It's a square bucket, no? In my experience with changing fish water, a wave will hit the corner of the bucket, which seems to sort of "focus" it into spilling over.

[TeaBag420]

Make sure you set it down with the water facing upward.

[roger]

If it is an ordinary plastic bucket, then it changes shape when you sit it down due to pressure on the bottom. This can induce a wave, causing it to spill a short time after the bucket it set down.

[Just thinking]

Originally posted by mummymonkey
How is that the water can increase in "aggitation" enough to spill over the top, after any movement has stopped?
Something to do with waves I'm thinking.

Have you ever heard of rouge (freak) waves??

http://www.math.uio.no/~karstent/waves/index_en.html

Calm seas, no big winds -- all of a sudden out of nowhere the sea builds in intensity and sloshes around a series of large dangerous waves that basically bob up and down in place. Then all is again calm in moments.

It has to do with the constructive/destructive interferrence properties of waves.

Similar things are going on in the disturbed bucket. After it is placed back down, the wave energy is somewhat random, but given some time (and the fact that the bucket's shape helps focus the energy) some waves may concentrate in one spot, producing a collective wave of much larger size than any of the others. That wave has enough energy to spill over the side.

[mummymonkey]

Ooooooh!
All this in a wee (round) bucket. Good info folks, many thanks.

[roger]

I'm having trouble with the rogue wave theory. I've *never* seen this happen with a cup of coffee, milk, etc., yet the bucket scenerio has happened to me plenty of times.

[jj]

http://www.pythonproducts.com/nospill.htm

Just fyi :)

No idea what the deal with the bucket is. If it always goes over a square edge, there could be some focusing effects.

[jj]

Originally posted by roger
If it is an ordinary plastic bucket, then it changes shape when you sit it down due to pressure on the bottom. This can induce a wave, causing it to spill a short time after the bucket it set down.

Now THAT is an interesting theory. The bucket gets smaller, because the bottom bows.

Could be, could be.

[Soapy Sam]

Resonance?

There must be enough kinetic energy in there to move the stuff. Walk softer and carry a bigger bucket.

[The Don]

By placing the bucket down, you are in effect succussing a large volume of water which, necessarily because it's tap water rather than nuclear water, contains quite a lot of imupurities. This succussion transfers an enormous amount of energy (or entropy) into the water because of quantum mechanics and string theory. The water slopping out of the bucket is merely a side effect of having so much essential energy being transferred into the water at one time. The energy is converted into Kinetic energy.

I think you could prove this by putting much less water in the bucket. If the bucket were only 1/4 full then the water wouldn't slop out due to the fact that there would be so much less energy being transferred by succussion.

[Iconoclast]

Originally posted by Just thinking
Have you ever heard of rouge (freak) waves??
Not until now. In any case, you should never judge a wave by it's colour.

[Mercutio]

Originally posted by Soapy Sam
Resonance?
That's what I was thinking, sorta. If setting the bucket down creates a cacaphonous mix of wavelengths in the water, some of those wavelengths will eventually combine, in a hydrofourier synthesis, if you will. It would be like combining the sound of two tuning forks; if they are only off by a few cycles per second, you will get a "beat" or wobbling sound, as they combine additively then subtractively...(I don't think I am explaining this well). With the water, if such waves combine at the right place, then smaller waves will essentially climb on one another's backs to slosh out of the bucket and onto your shoes.

[Hellbound]

Well, here's my theory:

With a plastic bucket, the bucket will deform, more so when carrying weight. When carried by a handle, the sides of the bucket where the handle attaches pull inward. The sides without the handles bow outward. When the bucket is set down, that pressure is released...the handle sides spring out and the non-handle sides spring inward. This creates four large waves...two waves moving from the inside to the outside along the handle axis, and two waves from outside to inside starting at the non-handle sides. Seems to me that this would create enough disturbance to cause the effect. I've attached a diagram to illustrate a bit better :)

http://us.f1.yahoofs.com/bc/3f9a25cf_c483/bc/Public/Bucket.jpg?BCXk_bBBcBd.Qo8u

[Deetee]

Now its quite obvious when its laid out on a plate for us -
three cheers for the arachnid!

[Hellbound]

Originally posted by Deetee
Now its quite obvious when its laid out on a plate for us -
three cheers for the arachnid!

Gee, it was nothing. Any stunningly handsome, charming, athletic, Adonis-like genius could have done the same.










Or a skinny geek like me :D

[Just thinking]

Originally posted by roger
I'm having trouble with the rogue wave theory. I've *never* seen this happen with a cup of coffee, milk, etc., yet the bucket scenerio has happened to me plenty of times.

Waves in a cup of coffee (or similar liquid) are too small due to the confines of the cup -- hence they do not have enough crest height to spill over. I'll bet though that if you tried it with the liquid very close to the brim you will get some to spill over; it's just that normally one does not fill a coffee cup right to the top. Also, in a coffee cup there is going to be relatively more surface interfacing in damping the liquid -- it has to due with scaling up the effect. Although you can have the same ratio of contact surface area to liquid volume in a cup to a bucket to a swimming pool, the time it takes for all 3 to settle down from equivalently scaled sloshing will not be the same. The longer the time the liquid is allowed to slosh, the greater chance for a collective wave to occur that will spill over.

PS: I have a swimming pool and have noticed this effect. After the water is sufficiently disturbed (from swimmers) and they exit the water, the disturbed water will slosh around for some time with no large waves. And every so often, enough energy will collect in a corner and spill out from a large wave. It isn't huge, but it is clearly much bigger than the average waves still sloshing around. I don't think the pool's shape is changing (as suggested for the bucket) to cause this.

[Ladewig]

Water is alive and this water is trying to escape the bucket and return to its mother, the sea.

[Zep]

1) Leave the water in the fish-tank.
2) Add less than one molecule of fish-tank cleaning agent.
3) Succuss tank twice on a leather-bound bible.
4) BINGO! Tank is clean in a fraction of the time! No need for bucket-carrying caper at all!

[bows to forum homeopaths for showing him the answer]