1 00:00:00,000 --> 00:00:04,000 There is a lot of hustle and bustle because the integration is in full process. 2 00:00:04,000 --> 00:00:08,000 music 3 00:00:08,000 --> 00:00:12,000 Just look at NASA's James Webb space telescope. 4 00:00:12,000 --> 00:00:16,000 Its gold mirrors are definitely 5 00:00:16,000 --> 00:00:20,000 its most stunning feature. And yeah, that's real gold. 6 00:00:20,000 --> 00:00:24,000 Humans have long history of searching for gold 7 00:00:24,000 --> 00:00:28,000 and using it in their most prized possessions. These mirrors weren't gilded 8 00:00:28,000 --> 00:00:32,000 to make them pretty. There isn’t’ even all that much gold 9 00:00:32,000 --> 00:00:36,000 about 5 men's wedding rings-worth over the 18 mirrors. 10 00:00:36,000 --> 00:00:40,000 So I wanted to see for myself, why does it make sense to use a 11 00:00:40,000 --> 00:00:44,000 microscopic layer of gold on these mirrors? 12 00:00:44,000 --> 00:00:48,000 Why Does Webb have Gold Mirrors? 13 00:00:48,000 --> 00:00:52,000 So our everyday mirrors tend to use silver or aluminum 14 00:00:52,000 --> 00:00:56,000 as their reflective material. One of the major differences 15 00:00:56,000 --> 00:01:00,000 between our earthly mirrors and these fancy optical mirrors is the position 16 00:01:00,000 --> 00:01:04,000 of the reflective material. Look at the side of this this small mirror. 17 00:01:04,000 --> 00:01:08,000 It has the glass on the front, and the metal 18 00:01:08,000 --> 00:01:12,000 coating behind it. That glass actually traps a tiny amount of light 19 00:01:12,000 --> 00:01:16,000 and creates what we call a ghosting effect. So the clearest reflection 20 00:01:16,000 --> 00:01:20,000 we can get actually have that metal coating on the front. 21 00:01:20,000 --> 00:01:24,000 Dentists and hygienists also front-surface mirrors 22 00:01:24,000 --> 00:01:28,000 to get an accurate look at your teeth. 23 00:01:28,000 --> 00:01:32,000 The position of the reflective coating might make a sharp observation, but the kind of metal also matters too. 24 00:01:32,000 --> 00:01:36,000 There are a couple of reflective materials that really excel at reflecting 25 00:01:36,000 --> 00:01:40,000 infrared light, which is how Webb will observe. 26 00:01:40,000 --> 00:01:44,000 Aluminum reflects 85% of that wavelength of light 27 00:01:44,000 --> 00:01:48,000 , silver up to 95% and gold up 28 00:01:48,000 --> 00:01:52,000 up to 99% of all the infrared light that it encounters. 29 00:01:52,000 --> 00:01:56,000 But gold is special, and I can show you using 30 00:01:56,000 --> 00:02:00,000 the rings that I typically wear. This one is gold. 31 00:02:00,000 --> 00:02:04,000 And this one is made out of silver. 32 00:02:04,000 --> 00:02:08,000 And in the presence of the right chemicals, these two chemicals react differently. 33 00:02:08,000 --> 00:02:12,000 I think, actually, it's a little easier to 34 00:02:12,000 --> 00:02:16,000 show you, all of this with this spoon. My mom 35 00:02:16,000 --> 00:02:20,000 surprised me by pulling out this whole tub of silver! Not tub, it came out of a box 36 00:02:20,000 --> 00:02:24,000 so I'm able to demonstrate sort of on a bigger surface, how silver can react 37 00:02:24,000 --> 00:02:28,000 differently using an egg. 38 00:02:28,000 --> 00:02:32,000 music 39 00:02:32,000 --> 00:02:36,000 Smoosh that in. 40 00:02:36,000 --> 00:02:40,000 We've got nothing. We've got nothing. 41 00:02:40,000 --> 00:02:44,000 So what we have is a really fast reaction between the sulfur in the egg 42 00:02:44,000 --> 00:02:48,000 and the silver, and it creates a new thin layer 43 00:02:48,000 --> 00:02:52,000 on the spoon of silver sulfide. 44 00:02:52,000 --> 00:02:55,000 Silver might be great at reflecting infrared light, but it tarnishes so easily. 45 00:02:55,000 --> 00:02:59,000 Not only does gold reflect more infrared light, 46 00:02:59,000 --> 00:03:03,000 but it is also one of the most unreactive metals. 47 00:03:03,000 --> 00:03:07,000 It is too durable to oxidize and decay in space. 48 00:03:07,000 --> 00:03:11,000 And it is certainly 49 00:03:11,000 --> 00:03:15,499 Webb's best chance at seeing the cosmos!