Out of the mouth of babes?

Question

At the beach one day, my son was building a sandcastle. He kept trying to fill the moat but no luck.
He then asked me this: if the water sinks in the sand when I try to fill my moat, why doesn't the ocean sink into the sand???????????

Answer 1

Congratulations, you've got yourself a scientists there.

(Actually, most kids are scientists, but he's on his way to being a good one.)

If you put some sand in a container, like a bucket or cup, and put water in it, at some point, the water wouldn't keep sinking into the sand, the sand would have all the water it can hold.

Suggest next time you're at the beach, he test this idea.

So the ocean is just WAYYYYYY to much water, and there isn't enough sand for all the water to sink into the sand.

He's putting a relatively small amount of water on a whole beach-worth of sand -- the water trickles down and out through all that sand, which is a lot.

If he used sand that was already soaked, some water would stay in the moat for a little while.

But it would keep trickling away, between the grains.

Do encourage him to test the idea next chance you get by putting sand somewhere that will hold it and the water.

Edit: oh, yeah. Under the ocean, the sand doesn't go down forever and ever, but it a layer on top of rock.

Answer 2

The ocean has many many layers of sediment on it as the ocean floor. As you get deeper the particle get closer to together and towards the centre of the earth it is very hot and very hard rock. In the sand the particles fit together but have lots of gaps. Which is why water can seep into it. The ocean is also alot deeper so there is more rock and fossils. :D

Answer 3

Kids can say some of the cutest things!

Answer 4

because the ocean sits on bed rock.

Answer 5

isnt it amazing what kids say these days...hes a smart cookie.

Answer 6

good question i will have to think about that x