Q & A: simple questions

Q:
i HAVE A SON AGED 5 YEARS. HE ASKS ME MANY SCIENTIFIC QUESTIONS.

1) WHY LOG FLOATS ON WATER AND STONE DOESNOT?
2) WHY WATER MAKES US WET?
3) WHY THINGS LOOK SMALL WHEN FAR AWAY?

CAN U PLEASE ANSWER THEM IN A WAY HE CAN UNDERSTAND BECAUSE HE IS ONLY FIVE YEARS. HE DOESNOT UNDERSTAND WHAT IS ATOM, OR MOLECULE OR ANY SUCH THING OR ANY PRINCIPLES.

I TRIED TO ANSWER BUT HE IS NOT ABLE TO UNDERSTAND. SO I SEND YOU THESE QUESTIONS.

THANKS
SHIVANI
- shivani (age 35)
PALATINE,IL,USA
A:
Shivani- You're lucky to have a son with such a lively mind. We can try to give some answers, but they can't take the place of a real back-and-forth conversation.

1. A piece of wood is not as heavy as a stone of the same size. The wood is (usually) not as heavy as some water of the same size. The water is heavier, so it sinks below the wood. The stone is heavier the the same size of water, so it sinks below the water.

2. Water sticks to us. We can feel things that are stuck to us. We give the name 'wet' to the feeling we get when water is ticking to us.  (OK, that's not even as good an answer as #1.)

3. When we see things it's because light comes into our eyes from those things. Light traveles (pretty much) in straight lines. Take a piece of paper and draw a person on it and draw the lines representing light from parts of that person to a little eye. Now draw a big elephant. You can see  that if the elephant is far enough away, the lines from it come in over the same range of directions as the lines from the person. It looks the same size to your eye, which just senses that light.

Mike W.

(published on 10/22/2007)