WEBVTT - How does a Dippy Bird work?

0:00:00.680 --> 0:00:03.960
<v Speaker 1>Welcome to Brainstoff front House, stuff works dot Com where

0:00:03.960 --> 0:00:15.400
<v Speaker 1>smart happens. Hi. I'm Marshall Brain with today's question, how

0:00:15.440 --> 0:00:19.040
<v Speaker 1>does a dippy bird work? A dippy bird is a

0:00:19.079 --> 0:00:23.040
<v Speaker 1>toy that you'll frequently find it toy shops or novelty shops.

0:00:23.360 --> 0:00:26.760
<v Speaker 1>They cost about five dollars and they look a little bizarre.

0:00:27.320 --> 0:00:31.680
<v Speaker 1>A dippy bird has the following parts. First, two equal

0:00:31.800 --> 0:00:36.599
<v Speaker 1>size hollow glass bulbs, a long glass tube that connects

0:00:36.640 --> 0:00:41.200
<v Speaker 1>the bulbs, a fuzzy water absorbent material covering the head,

0:00:41.400 --> 0:00:44.040
<v Speaker 1>and often some kind of little top hat on the

0:00:44.080 --> 0:00:47.720
<v Speaker 1>head as well. Two plastic legs with a pivot connection,

0:00:48.440 --> 0:00:52.800
<v Speaker 1>and then some methylene chloride in the abdomen. This is

0:00:52.880 --> 0:00:57.200
<v Speaker 1>usually a reddish liquid In real life. Methylene chloride is

0:00:57.240 --> 0:01:00.680
<v Speaker 1>an industrial paint stripper and a solvent one thing that

0:01:00.800 --> 0:01:04.360
<v Speaker 1>dissolves easily. A methylene chloride is caffeine, so you'll often

0:01:04.400 --> 0:01:08.600
<v Speaker 1>see it used to decaffeinate things. Methylene Chloride helps make

0:01:08.640 --> 0:01:12.399
<v Speaker 1>a dippy bird work because it evaporates very easily. It

0:01:12.520 --> 0:01:16.400
<v Speaker 1>boils it just a hundred degrees fahrenheit or forty degrees celsius.

0:01:17.040 --> 0:01:20.120
<v Speaker 1>To operate a dippy bird, you get its head wet.

0:01:20.480 --> 0:01:24.440
<v Speaker 1>As the water evaporates off the head, fluid moves up

0:01:24.480 --> 0:01:27.520
<v Speaker 1>into the head, causing the bird to become top heavy

0:01:27.640 --> 0:01:31.440
<v Speaker 1>and dip forward. Once the bird dips forward, fluid moves

0:01:31.600 --> 0:01:34.600
<v Speaker 1>back into the abdomen, causing the bird to become bottom

0:01:34.640 --> 0:01:38.479
<v Speaker 1>heavy and tip back up. It'll tip up, and back

0:01:38.640 --> 0:01:41.600
<v Speaker 1>up and back essentially forever, as long as there's water

0:01:41.720 --> 0:01:44.120
<v Speaker 1>that can cool its head and the room is at

0:01:44.200 --> 0:01:48.560
<v Speaker 1>room temperature. Here's how a dippy bird works. When water

0:01:48.680 --> 0:01:51.960
<v Speaker 1>evaporates from the fuzz on the dippy bird's head, the

0:01:52.000 --> 0:01:56.080
<v Speaker 1>head is cooled. The temperature decrease in the head condenses

0:01:56.200 --> 0:01:59.920
<v Speaker 1>the methylene chloride vapor that's floating around in the tube anyway,

0:02:00.360 --> 0:02:03.440
<v Speaker 1>decreasing the vapor pressure in the head relative to the

0:02:03.520 --> 0:02:07.120
<v Speaker 1>vapor pressure in the abdomen. The greater vapor pressure in

0:02:07.120 --> 0:02:10.400
<v Speaker 1>the abdomen forces fluid up through the neck and into

0:02:10.400 --> 0:02:13.600
<v Speaker 1>the head. As the fluid enters the head, it makes

0:02:13.639 --> 0:02:18.120
<v Speaker 1>the dippy bird top heavy. The bird then tips, liquid

0:02:18.200 --> 0:02:21.080
<v Speaker 1>travels to the head and the bottom of the tube

0:02:21.200 --> 0:02:24.400
<v Speaker 1>is no longer submerged in the liquid. In the lower bulb.

0:02:25.120 --> 0:02:28.320
<v Speaker 1>Vapor bubbles travel through the tube and into the head.

0:02:28.720 --> 0:02:32.160
<v Speaker 1>Liquid drains from the head displaced by the bubbles, and

0:02:32.240 --> 0:02:35.800
<v Speaker 1>the fluid drains back into the abdomen, making the bird

0:02:35.840 --> 0:02:39.640
<v Speaker 1>bottom heavy. Then the bird tips back up and starts

0:02:39.639 --> 0:02:42.520
<v Speaker 1>the cycle over again. If the bird dips into a

0:02:42.560 --> 0:02:45.640
<v Speaker 1>cup of water so it's heads stays wet, the fuzzy

0:02:45.720 --> 0:02:49.000
<v Speaker 1>material absorbs water over and over again, and the cycle

0:02:49.120 --> 0:02:53.440
<v Speaker 1>just keeps repeating. Your warm hand can cause fluid in

0:02:53.440 --> 0:02:56.280
<v Speaker 1>the dippy bird to rise as well. If you hold

0:02:56.280 --> 0:02:59.440
<v Speaker 1>a dippy bird upright in your hand touching the abdomen,

0:02:59.480 --> 0:03:03.079
<v Speaker 1>the following happens. Your body heat warms the fluid in

0:03:03.160 --> 0:03:07.000
<v Speaker 1>the abdomen. The heat increases the vapor pressure in the

0:03:07.040 --> 0:03:10.040
<v Speaker 1>abdomen relative to the head, the reverse of what happens

0:03:10.080 --> 0:03:13.200
<v Speaker 1>when you get the head wet. The fluid rises into

0:03:13.200 --> 0:03:15.760
<v Speaker 1>the head in response to the pressure difference, moving from

0:03:15.880 --> 0:03:18.919
<v Speaker 1>high pressure to low pressure. The bird becomes top heavy

0:03:19.000 --> 0:03:23.079
<v Speaker 1>and it tips forward. Either way, you've created a little

0:03:23.200 --> 0:03:26.120
<v Speaker 1>heat engine when you look at a dippy bird that's

0:03:26.240 --> 0:03:31.160
<v Speaker 1>using the evaporation and condensation of a liquid to cause motion.

0:03:32.520 --> 0:03:34.960
<v Speaker 1>For more on this and thousands of other topics. Because

0:03:34.960 --> 0:03:41.400
<v Speaker 1>it has staff works dot Com Audible dot Com is

0:03:41.440 --> 0:03:44.880
<v Speaker 1>the leading provider of downloadable digital audio books and spoken

0:03:44.920 --> 0:03:48.600
<v Speaker 1>word entertainment. Audible has over one hundred thousand titles to

0:03:48.680 --> 0:03:51.440
<v Speaker 1>choose from to be downloaded to your iPod or MP

0:03:51.600 --> 0:03:55.040
<v Speaker 1>three player. Go to audible podcast dot com slash brain

0:03:55.080 --> 0:03:57.200
<v Speaker 1>stuff to get a free audio book download of your

0:03:57.280 --> 0:03:58.720
<v Speaker 1>choice when you sign up today