0:00:02 > 0:00:04- HOWLING AND MOANING - Day five - I can barely remember
0:00:04 > 0:00:06the last time I spoke to another human being.
0:00:06 > 0:00:10Wow, Colin is really embracing this wilderness survival thing.
0:00:10 > 0:00:15I'm so impressed. Confronting your fears is never an easy thing to do.
0:00:15 > 0:00:19Out here in the wild, there could be snakes, mountain lions,
0:00:19 > 0:00:22- flies, dogs, rabbits... - HE GASPS
0:00:22 > 0:00:24What was that?
0:00:24 > 0:00:26Be brave, Jonathan. Be brave.
0:00:26 > 0:00:29- BELL RINGS - Well, the show must go on.
0:00:29 > 0:00:31We are going live, Professor.
0:00:31 > 0:00:33Hey, wait for me!
0:00:33 > 0:00:35ANNOUNCER: This is...
0:00:35 > 0:00:37With...
0:00:41 > 0:00:44..the floor manager.
0:00:44 > 0:00:46And...
0:00:46 > 0:00:48Stand by!
0:00:48 > 0:00:50Come on, everybody!
0:00:53 > 0:00:55- BOTH:- It's time for...
0:00:57 > 0:00:59Today, we are asking...
0:01:01 > 0:01:04Did you know that the Earth isn't perfectly round?
0:01:04 > 0:01:08In fact, its circumference is around 67km less measured vertically,
0:01:08 > 0:01:12going through the poles, than it is around the equator.
0:01:12 > 0:01:14I always thought it was flat.
0:01:14 > 0:01:18So tell us, Dr Knowles, how long would it take to walk around
0:01:18 > 0:01:20this not-quite-round Earth of yours?
0:01:20 > 0:01:22If we allow for eight hours' rest per day,
0:01:22 > 0:01:24walk only in a straight line
0:01:24 > 0:01:27and assume a constant speed of about 5km per hour,
0:01:27 > 0:01:30it would take a person about 500 days to walk the distance of
0:01:30 > 0:01:32the Earth's equator.
0:01:32 > 0:01:35Hmm. But that doesn't take into account mountains,
0:01:35 > 0:01:37deserts, oceans, jungles...
0:01:37 > 0:01:39I'm not sure if it's possible to
0:01:39 > 0:01:41accurately calculate this one, Professor.
0:01:41 > 0:01:42Here's an idea.
0:01:42 > 0:01:45Why don't we take a quick break while Dr Knowles figures out
0:01:45 > 0:01:48a better way of answering the question? Heh!
0:01:51 > 0:01:53HOWLING
0:01:53 > 0:01:56Whatever is out there, whatever is making that noise,
0:01:56 > 0:01:58it's planning to have me for dinner.
0:01:58 > 0:02:00- Oooooh!- Owwwww!
0:02:00 > 0:02:02- Oogie-boogie-boogie-boogie.- Ow-owww!
0:02:02 > 0:02:05Ms Hucklebuck, can we stop doing this now?
0:02:05 > 0:02:07My arms are really tired.
0:02:07 > 0:02:11Yes, I think that just about covers frights and terrors in the wild.
0:02:11 > 0:02:13You can stop now.
0:02:13 > 0:02:15- Yes, nailed it. - BELL RINGS
0:02:15 > 0:02:16Ooh! Positions, everyone!
0:02:22 > 0:02:24So tell us, Dr Knowles, if there were
0:02:24 > 0:02:27no mountains or barriers or anything, and if you never
0:02:27 > 0:02:30needed to take a rest, how long would it take to walk the Earth?
0:02:30 > 0:02:33Well, in this hypothetical situation,
0:02:33 > 0:02:37and assuming a constant speed, it would take an average human
0:02:37 > 0:02:39around 335 days to walk
0:02:39 > 0:02:41the Earth's equator. Just under a year.
0:02:41 > 0:02:43At the speed of a crawling baby,
0:02:43 > 0:02:46it would take two years and four months.
0:02:46 > 0:02:49But that seems fast compared to the giant tortoise,
0:02:49 > 0:02:53which would take over 76 years to complete the journey.
0:02:58 > 0:03:00Dr Knowles, I wonder what
0:03:00 > 0:03:02the fastest way to go around the Earth would be.
0:03:02 > 0:03:05Based on top speed alone, the fastest way to travel around
0:03:05 > 0:03:08the Earth would be in a North American X-15 rocket plane
0:03:08 > 0:03:11in just over five-and-a-half hours.
0:03:11 > 0:03:12PLANE ENGINE ROARS
0:03:12 > 0:03:14See you next time!
0:03:14 > 0:03:17And we are clear.
0:03:17 > 0:03:19OK, Colin. Training's over.
0:03:19 > 0:03:20You can come out now.
0:03:20 > 0:03:23Yes! Civilisation at last!
0:03:23 > 0:03:25Well done, Jonathan.
0:03:25 > 0:03:26You scored full marks
0:03:26 > 0:03:29on wilderness survival training level one.
0:03:29 > 0:03:31Level one?
0:03:31 > 0:03:33Oh, Colin, you are going to love level two -
0:03:33 > 0:03:36a three-day hike to Monster Mountain.
0:03:36 > 0:03:38- Raaaaar!- Ahhh!
0:03:38 > 0:03:41I-I-I-I think I've reached my desired wilderness level for now,
0:03:41 > 0:03:44thank you very much. B-B-Bye-bye.
0:03:44 > 0:03:47Oh, dear, I hope we didn't scare him too much.
0:03:47 > 0:03:50Maybe level two could just be camping in the back garden.
0:03:50 > 0:03:52Or sleeping with the lights off.
0:03:52 > 0:03:55Good idea. One step at a time.