0:03:50 > 0:03:57.
0:04:04 > 0:04:08It's great to relax after a hard week's work.
0:04:08 > 0:04:11- What time is it, Bob? - Oh, I've forgotten my watch!
0:04:11 > 0:04:13Hm, now let's see.
0:04:13 > 0:04:16I think it's about midday.
0:04:16 > 0:04:17How do you know?
0:04:17 > 0:04:22- I used the sun, Lofty.- I didn't know the sun could tell you the time.
0:04:22 > 0:04:25Mister Sun! What's the time?
0:04:25 > 0:04:29The sun can't talk, Dizzy. I can tell it's the middle of the day,
0:04:29 > 0:04:33cos it's right above me and my shadow is very short.
0:04:33 > 0:04:35Look! My shadow's short, too.
0:04:35 > 0:04:38Everyone's is. In the morning, when the sun's low,
0:04:38 > 0:04:40it makes your shadow long.
0:04:40 > 0:04:43How does that work, Bob?
0:04:43 > 0:04:47Imagine this apple is the earth and this orange is the sun.
0:04:47 > 0:04:51- The sun is like a great big light. - It's really bright.
0:04:51 > 0:04:55Never look straight at the sun, cos it can hurt your eyes.
0:04:55 > 0:04:56Oh, erm... OK.
0:04:56 > 0:05:00The earth spins around each day, like this.
0:05:00 > 0:05:04When the earth is facing away from the sun, it's night.
0:05:04 > 0:05:06When we're facing towards it, it's day.
0:05:06 > 0:05:11So if you stood in the same place all day, the earth would turn
0:05:11 > 0:05:14and you'd see your shadow move around you.
0:05:14 > 0:05:16Rock and roll!
0:05:16 > 0:05:21We could build a sun dial. It's what they used in the old days.
0:05:26 > 0:05:30The sun is behind me, so I'm facing north. This is twelve noon.
0:05:30 > 0:05:34We'll use my watch to mark where the shadow falls every hour.
0:05:42 > 0:05:44Now, who can tell me the time?
0:05:44 > 0:05:45Oh, me! Me!
0:05:45 > 0:05:49I think it's six o'clock, Bob.
0:05:49 > 0:05:51That's right, Dizzy.
0:05:51 > 0:05:55BOB'S TUMMY RUMBLES
0:05:52 > 0:05:55My tummy doesn't need a sun dial.
0:05:55 > 0:05:58It knows exactly when it's time for dinner!