Previous: 305: No Manholes Allowed
Next: (None)



View count:9
Last sync:
What is indigo? Do you study for your books or rely on past knowledge? Would we notice if everything in the universe got bigger? If I fell through a cloud, would I get wet? Why can't I melt wood? Who do you have so many publishers? Hank Green and John Green have answers!

If you're in need of dubious advice, email us at
Join us for monthly livestreams and an exclusive weekly podcast at
Follow us on Twitter!

 (00:00) to (02:00)

*awesome socks club advertisement on spotify version*

Hank: Hello and welcome to dear Hank and John. 

John: Or as I prefer to think of it: dear JOHN and Hank 

Hank: It's a podcast where two brothers answer your questions, give you dubious advice and bring all the news from both Mars and AFC Wimbledon. John it's October, which means that I'm officially carrying around the Pebble that I throw at people who sing Christmas songs before November. It's called my Jingle Bell rock. 

John: [chuckle] I- I enjoyed that. 

Hank:I think like there's like a 40/50% chance that I've said that one on the podcast before. 

John: I liked that one because I didn't see it coming but at the same time it was a punchline- which are my only two requests of your jokes. Hank, before we answer questions from our listeners, there's something that we really need to get to- very, very rarely in the history of dear Hank and John has anything elicited the kind of responses that we got-

Hank: yeah

John: -to the question of what happens if a person made out of lemons standing on a scale puts one of their lemon hands into a bucket of water that's on a different scale. Goodness gracious, our producer Rosiana had to create a separate document called “Lemon people bucket problem”

[both laugh]

John: Which I'd like to think-

Hank: Which is how long? It's 23 pages long, John and I'm sure that we've both read all of it. 

John: I have read it, it is amazing. Y'all are wonderful. Some of you are wrong. Most of you are right. 

[Hank laughs]

Hank: There's still a little bit of debate out. 

John: Umm, there's not a lot of debate. 

Hank: Yeah.

John: If you are a lemon person standing on a scale and you put one of your lemon hands into a bucket full of water, that's on a different scale. The scale gets heavier. That scale shows a heavier weight and you get lighter-

Hank: Yes.

John: -on your scale. 

Hank: Which is not what I expected Like it's not- it’s definitely not intuitive. I saw somebody who I follow on Tiktok, Tom Lum was like, oh, this is great. I'll do it. I'll do it. I’ve got a scale I'll put my hand in and it won't change, right? And it changed and he was like “Oh no”. And this is the outcome in science that you want. Where you're like, I had a hypothesis and I've proven it to be non intuitive. 

John: Yeah, although it is intuitive apparently if you understand Newton's third law-

Hank: of buoyancy, yes. And Archimedes. 

John: Because all the explanations that made sense to me were- And this the easiest one for me was from somebody named Michael who wrote too long, didn't read Newton's third law, means the bucket scale must go up by the same amount that the person scale goes down since the forces between the person and the bucket must be equal and opposite

Hank: Yes. 

 (02:00) to (04:00)

John: And I was like “I think I have it”

Hank: Well, yeah I get that, but it but that doesn't. They couldn't stay the same and that would not violate Newton's third law. But yeah, then there's the other piece. 

John: There is the other piece, which is that Archimedes Principle tells us that the amount is equal to the weight of the water displaced. It’s displacement. 

Hank: So it's not about it's not about the weight of the thing that gets put in, it's about how much of the water gets displaced, so it's just a volume thing. 

John: Oh goodness, it was extremely complicated, but we got there. If you are a lemon person, I have good news and bad news. The good news is that I now know what happens to you if you put your hand in a bucket of water that's on a scale. The bad news is that you're made out of lemons.

Hank: Yeah, the bad news is that we have a saying here, on Earth, among the humans, that when life gives us you we squeeze you and put sugar into you. 

John: Wait, whoa, whoa, whoa. You were imagining the lemon people as aliens? Cause I was definitely imagining the lemon people as like a- here's what I imagined, Hank

Hank: OK

John: Cause I was kinda thinking about a lemon person movie. And what I was imagining is there's a lemon in a landfill somewhere that's rotting away, and it's like rotting away, but then it encounters some sort of DNA. 

[Hank laughs]

John: And it encounters an- no I got it: It encounters an MRNA vaccine, and in that moment the lemon like starts to become more like a lemon and then it sniffs out other lemons and suddenly there's like a lemon magnet kind of thing happening where all these lemons are coming together inside of the landfill and then once they become a lemon person, that's the moment when they like emerge out of the landfill. They like emerge out of the garbage and like stand up to their full lemon height and are like: “I need to put my hand into a bucket of water.”

Hank: It’s what the vaccine told me to do!

[both laugh]

 (04:00) to (06:00)

Hank: There's so many auto injectors that don't get used. For people who have like epinephrine auto injectors so maybe it was one of those *and* an MRNA vaccine at the same time I got back and then it's like “injecting noise.” And it’s like “transforming noise” I’M ALIVE!

John: Yeah, I don't know if you've ever actually injected somebody with an EpiPen, but I have and it is, uh, it's intense. 

Hank: Uh, for the person doing the injection? 

John: No, for the other person. 

Hank: Yes, well they do get that bad epinephrine in which-

John: I could totally see how that could make a lemon person just want to stick their hand in a bucket. 

[both laugh]  

Hank: It's a good origin story John, I hadn't really thought of it. 

John: I do really want us to use more lateral thinking in this podcast, Hank when we're trying to think of solutions to problems. 

Hank: [overlapping] Well and and also just as the species, all of us together on Earth, yes.

John: Almost every day I think about my favorite example of lateral thinking, which was when Edmund Halley determined the size of England. Like the government or whatever was like: “hey Haley, we don't know how Big England is'' and Haley was like: “oh, I got an idea. Here's what I'm going to do: we got a good map of England. I'm going to cut out the largest circle that I can cut out of England in this map. 

And what I'm going to do is, I'm going to weigh the circle and then I'm going to cut out the rest of England and I'm going to weigh the rest of England. And because I can figure out the area of a circle pretty easily. I can therefore figure out what percentage of the weight the circle is, which in turn will tell me how Big England is.”

Hank: Yeah, that's pretty great. That's a smarty pants move. You can't fault that one. 

John: Very impressive lad. 

Hank: Now that's a man who could tell you about a lemon bucket situation. 

 (06:00) to (08:00)

John: Oh man, he would have had no doubt. Oh man, you should hear Dear Redmond and Isaac, Edmund Halley, and Isaac Newtons podcast. Those guys, they got it figured out. 

Hank: John Speaking of Isaac Newton, I want to ask our first question, it's from Angela who asks: 

Dear Hank and John, my 5 year old is fascinated by rainbows frankly, so am I. However, after reviewing the color wheel and kindergarten level color theory and comparing it to the weather phenomenon, that is a rainbow, I have a question for you. What is indigo? 

John: Oh boy

Hank: [continuing] It's not a primary color. It's not a secondary color. What is it doing in the rainbow? Why doesn't the rainbow have six colors? Red, orange, yellow, green, blue and purple?

Hank: This makes sense. These are the colors that we talk about. This is me adding to the question, not Angela talking 'cause I agree with you 

-and if indigo is a blueish purple. Don't all the colors bleed into each other anyway? Why don't we distinguish a reddish orange then as well? Perception precipitation in pots of gold, Angela.

Hank: Do you know why Angela? Do you want to know why? It's because Isaac Newton said so. 

John: Are you serious? 

Hank: Yeah yeah he was working with prisms and he was like here are the colors, there are seven of them. Maybe to be complementary because like 7 is a nice number. Or if it's like complementary with I don't know other things that there are seven of. 

John: Right, it maybe felt a little bit like a proof of God's plan or whatever. 

Hank: Maybe, maybe some of that? 

John: I have always felt when I actually see a rainbow, most of the time that there are like: three colors you know? Like I think because I was told that a rainbow had seven colors, I'm always a little underwhelmed by actual rainbows. I'm always like, oh I mean. I guess yeah, it has- I'll tell you what it has: color which is incredible.

Hank: Which is very strange. 

John: Wild and wonderful. 

 (08:00) to (10:00)

Hank: Yeah, if you look at a rainbow, like a really vivid rainbow, really closely here are the colors I see: brown, orange, green, kind of purple and then kind of blue and then kind of purple and then kind of blue and then kind of purple and then kind of blue. Because there's like this thing happening that isn't like the just the rainbow. It's like an additional like Rainbow upon Rainbow sometimes. Where you get like multiple rainbows but like next to each other so you'll see the latter part of the spectrum over and over again. So you see, like this like blue Band, purple band, blue band, purple band, blue band purple band which is really cool, but not what you think of when you think of a rainbow. 

John: Yeah, I mean honestly, Hank, I don't really remember what rainbows look like. I don't know what that says about my imagination, like and its lack of visual acuity, but when I close my eyes and try to picture a rainbow, I mostly see the letters that spell the word rainbow. 

Hank: Hmm yeah, well I Google image searched them which made it easier for me and having looked at them for a little while, I'm realizing that when you look at a rainbow you might just be seeing a bunch of rainbows all stacked on top of each other. And they like go back, but you can't see them 'cause they're all in a direction, but I'm just guessing right now. I don't know this. Here's the other thing I want to talk about rainbow stuff. So like this, this color wheel thing that Angela brings up. We think about colors in the way that we experience them, which is that they all bleed into each other. And when you get to purple, like you've got blue and then purple and then red and purple is a mix between blue and red. We know this. This is definitely the case. We can functionally do it. But then there's this other way of like physically understanding rainbows where red and purple are opposites, they are as far apart in terms of electromagnetic spectra as they can be before you get out of visual light and you get into the infrared and the ultraviolet.

 (10:00) to (12:00)

 (12:00) to (14:00)

 (14:00) to (16:00)

 (16:00) to (18:00)

 (18:00) to (20:00)

 (20:00) to (22:00)

 (22:00) to (24:00)

 (24:00) to (26:00)

 (26:00) to (28:00)

 (28:00) to (30:00)

 (30:00) to (32:00)

 (32:00) to (34:00)

 (34:00) to (36:00)

 (36:00) to (38:00)

 (38:00) to (40:00)

 (40:00) to (42:00)

 (42:00) to (44:00)

 (44:00) to (46:00)

 (46:00) to (48:00)

 (48:00) to (50:00)

 (50:00) to (52:00)

 (52:00) to (52:15)