Ok ok! You guys were right! …now what?

One Dumm Hikk;604032 wrote: Quote from that article:


What that article says, unless I read it wrong, is that the coarseness of the grains doesn't determine what floats or doesn't. And that the bigger particles don't always rise to the top. "if they are six times heavier and twice the diamerter, they sink" (bolded by me).

Did I mis-read the article?

LilRobb;604156 wrote: It doesn't - ignore the temperature part as it applies to gases and other molecular setups only.

This might be easier:

http://en.wikipedia.org/wiki/Granular_convection">http://en.wikipedia.org/wiki/Granular_convection</a>[/QUOTE]

I wasn't referring to anything about temperature. The article says that if they are six times heavier and twice the diameter, they sink. You are saying they won't sink, they will float. That is a disagreement to me. But, if the larger rocks will float and the sand settles, why are beaches (and the ocean bottom) sand and not boulders? Something to think about.

Either way, unless the sand is agitated, whatever you put on top in a tank will stay on top. With agitation, you get different results.
 
One Dumm Hikk;604160 wrote: I wasn't referring to anything about temperature. The article says that if they are six times heavier and twice the diameter, they sink. You are saying they won't sink, they will float. That is a disagreement to me. But, if the larger rocks will float and the sand settles, why are beaches (and the ocean bottom) sand and not boulders? Something to think about.

Either way, unless the sand is agitated, whatever you put on top in a tank will stay on top. With agitation, you get different results.

Because Beaches per se are not agitated, they settle...

And of course somewhere is an end to that rule, a 1000lbs lead ball will sink in styrofoam beads - no doubt...
 
LilRobb;604085 wrote: Guys, do me an easy favor.
Take a glass with a lid, fill it with sugar, salt, sand (whatever you find with small grain sizes) and add peas, lentils, marbles (or anything else with a large diameter (regardless of weight!!!).
Close the lid and shake vigorously - if you get it to sink to the bottom, I'll suggest you for the nobel prize!

The effect has nothing to do with weight, only with surface friction
in the interest of a healthy discussion...

I've already done your science project.. only I used a 90 gallon reef aquarium (Oceanic, if that matters), using Seachem Meridian Sand and about 50 shells ranging in size from the average turbo snail shell to the "new blue leg hermit" shell...

oh, and I added about 3000gph flow in the form of Tunze Turbelle Stream Powerheads..

:)
 
Rbredding;604167 wrote: in the interest of a healthy discussion...

I've already done your science project.. only I used a 90 gallon reef aquarium (Oceanic, if that matters), using Seachem Meridian Sand and about 50 shells ranging in size from the average turbo snail shell to the "new blue leg hermit" shell...

oh, and I added about 3000gph flow in the form of Tunze Turbelle Stream Powerheads..

:)

And you have no sandsifting animals, right?
That would chew the fine sand and spit on top of the bigger shells...?

If that is the case, you're a true outlaw - you don't obey any law, not even that of physics...
 
I tried a little experiment... but its hard to duplicate our scenario.
I took a pail and put in serveral inches of sand, filled it with water and added some blue gravel like for a fresh water tank. I jiggled it around a bit, tapped on the bottom, and swirled the water around. It got covered with the sand but not because it "sank". The sand just got blown over it. I should have used more gravel. I think if I had the surface of the sand completely covered with gravel...like an inch or more to prevent the sand from blowing around it would stay in place. I dont think its gonna sink to the bottom.

I do not anticipate a Nobel prize nomination but if I come up with some more gravel I will try again.
 
LilRobb;604170 wrote: And you have no sandsifting animals, right?
That would chew the fine sand and spit on top of the bigger shells...?

If that is the case, you're a true outlaw - you don't obey any law, not even that of physics...

I do...

but then again.. don't WE ALL ?


and yes, I break all the laws.. even physics'
 
Back
Top