1
00:00:00,200 --> 00:00:03,640
Speaker 1: Jack Threads is the online shopping destination for dudes. Everything

2
00:00:03,640 --> 00:00:06,000
Speaker 1: on the side is up to eight off. All styles

3
00:00:06,000 --> 00:00:09,120
Speaker 1: are curated, so buyer's remorse just doesn't happen. What's more

4
00:00:09,200 --> 00:00:11,000
Speaker 1: is if you were brain stuff, you can skip the

5
00:00:11,039 --> 00:00:13,880
Speaker 1: membership wait list and get instant access at jack threads

6
00:00:13,920 --> 00:00:17,440
Speaker 1: dot com slash stuff. Welcome to brain Stuff from how

7
00:00:17,480 --> 00:00:28,440
Speaker 1: Stuff works dot com where smart Happens. Hi, I'm Marshall

8
00:00:28,440 --> 00:00:33,120
Speaker 1: Brand with today's question, how does a Crooks radiometer work?

9
00:00:33,800 --> 00:00:38,839
Speaker 1: A Crooks radiometer has four veins suspended inside a glass bulb.

10
00:00:39,320 --> 00:00:42,120
Speaker 1: The veins are black on one side and silver on

11
00:00:42,200 --> 00:00:45,960
Speaker 1: the other. Inside the bulb, there's a good vacuum. When

12
00:00:45,960 --> 00:00:48,800
Speaker 1: you shine a bright light on the veins in a radiometer,

13
00:00:49,000 --> 00:00:52,680
Speaker 1: they spin. In bright sunlight, they can spin at several

14
00:00:52,720 --> 00:00:56,480
Speaker 1: thousand rotations per minute. The vacuum is important to the

15
00:00:56,560 --> 00:01:00,760
Speaker 1: radiometer's success. If there's no vacuum, that is, if the

16
00:01:00,800 --> 00:01:03,960
Speaker 1: bulb is full of air, the veins don't spin because

17
00:01:04,000 --> 00:01:07,920
Speaker 1: there's too much drag. If there's a near perfect vacuum,

18
00:01:07,959 --> 00:01:10,840
Speaker 1: the veins do not spin unless they are held in

19
00:01:10,880 --> 00:01:15,319
Speaker 1: an absolutely frictionless way. If the veins have a frictionless

20
00:01:15,360 --> 00:01:19,720
Speaker 1: support and the vacuum is complete, then photons bouncing off

21
00:01:19,720 --> 00:01:22,520
Speaker 1: the silver side of the veins push the veins, causing

22
00:01:22,560 --> 00:01:28,080
Speaker 1: them to rotate. However, this force is exceedingly small. If

23
00:01:28,120 --> 00:01:31,800
Speaker 1: there's a good but incomplete vacuum, then a different effect

24
00:01:31,880 --> 00:01:36,080
Speaker 1: called thermal transporation occurs along the edges of the veins.

25
00:01:36,120 --> 00:01:39,080
Speaker 1: The effect looks as though the light is pushing against

26
00:01:39,080 --> 00:01:42,600
Speaker 1: the black faces. The black side of the veins moves

27
00:01:42,640 --> 00:01:46,280
Speaker 1: away from the light. For more on this and thousands

28
00:01:46,319 --> 00:01:52,720
Speaker 1: of other topics, Is it how staff works dot com.

29
00:01:52,800 --> 00:01:56,280
Speaker 1: Jack Dreads is the online shopping destination for dudes. Everything

30
00:01:56,280 --> 00:01:58,640
Speaker 1: on the side is up to eight off. All styles

31
00:01:58,640 --> 00:02:01,040
Speaker 1: are curated so buyers are more. It just doesn't happen.

32
00:02:01,320 --> 00:02:03,200
Speaker 1: What's more is if you were brain stuff, you can

33
00:02:03,240 --> 00:02:06,160
Speaker 1: skip the membership waitlist and get instant access at jack

34
00:02:06,200 --> 00:02:07,800
Speaker 1: threads dot com. Slash stuff