Daniel and Kelly give our US-based listeners some things to gobble about over Thanksgiving dinner other than politics.
Happy Thanksgiving friends, or happy Thanksgiving to our US based friends at least, and happy November twenty eighth to the rest of you.
On today's episode, we're going to give you.
Some things to gobble about at the Thanksgiving dinner table other than politics.
You're welcome.
First up, we have an expert on to talk about whether or not the trip to fan in Turkey actually makes you.
Sleepy after Thanksgiving dinner.
Then we're moving on to talking about a vegetable that comes in a variety of forms, all of which are improved by lots and lots of cheese. And finally we're talking about why it takes so stink and long to cook a turkey and some probably bad ideas for how you could speed this process up. Welcome to Daniel and Kelly's Extraordinary universe.
Hi. I'm Daniel. I'm a particle physicist and Thanksgiving is my favorite holiday.
Ooh. I'm Kelly Weener Smith. I'm a parasitologist and I really like Thanksgiving. I don't know if it's my favorite holiday, but I do love the food.
It's food, it's family, and crucially for me, it's not commercialized. It's not all about shopping and expensive presence. It's really just about spending time with your family eating good food, and like, hey, what's better than that?
Right, that's pure, that is that's beautiful. I love that.
So has the commercialization of Halloween ruined Halloween for you?
Because that's a top contender for rey.
Yeah, it's crazy. We all just go out and buy a bunch of candy and give it to each other. It's hilarious. Although I do like the community aspect that everybody comes out. My neighborhood goes crazy for Halloween. We get hundreds and hundreds of trigger treaters. We give away like a full garbage can full of candy. It's incredible.
Wow, that is incredible.
This Halloween, we ran out of candy. We started giving away stuff from our pantry and people were excited. They were like, ooh, canned corn, sweet potatoes, Are you serious? Yeah? Absolutely. We gave away dried beans, we gave away summer sausage. People were very excited to get anything but candy. Actually, maybe next year we're just going to give away sweet potatoes.
That's amazing. I love that.
I remember there were, like, you know, some neighbors who would do the king size candy bars. And some would give you a dollar, and then we had a neighbor who gave a penny and we were all like, what, No, it's not okay, you fail.
My Thanksgiving questions for you are what are your most and least favorite items on the Thanksgiving table?
Oh man?
So you know, I often have Thanksgiving up my parents' house, and like, literally everything my father makes is amazing. Everything is like my favorite thing. And every year he tries a new pie or cake, which is incredible. He makes these fantastic like almond cookies for me every year and then sends me home with so many that I I put on like fifty pounds. So I have no least favorite. Anything with mushrooms I don't really like. And sometimes when I don't have Thanksgiving with my dad, mushrooms sneak into the meal and that's disappointing.
But all right, so what about you?
My favorite thing on the table is probably turkey wings. Not a big fan of turkey, but the wings. Love the wings, so crunchy, so good. Though I gross out my daughter by like audibly crunching them at the table, and she's a vegetarian, so that's not so funny for her. And my least favorite are people who put marshmallows on sweet potatoes. I just don't get it. Like, to me, that combination makes no sense. It's like snickers bars on a hamburger or something like, what is going on here?
Not sure I have a problem with snickers bar on hamburger either, but that would be a little weird. I can't say I'm bothered by the marshmallows on the sweet potatoes, but it's not one of the first things I go to. But I think I'm with your daughter. I'd probably sit on the other side of the table. I'm not a big fan of the sounds of crunching on bones.
Personally audible carnivores.
I mean, I feel like if I were a better person, I would be more at peace with what it takes to put the food on my table. But I like to bury my head a little bit when I can.
But you live on a farm, right, You're very connected to where your food comes from.
Yeah, but they're all friends on my farm. They don't end up on the table. Their eggs do.
But not them.
Yeah.
Just their children, well.
They're not children, yeah, just their proto children. I mean, even our nasty roosters didn't end up on the table, even though that was at tempting.
Sometimes. All right, well, we're not just here to debate when life begins for chickens. We're here to talk about the science of Thanksgiving, what it means, how it works. As you all sit there and enjoy your Thanksgiving meal, we want to inject a little bit of science into your sleepy afternoon.
We do.
And one of the scientific factoids that I feel like I hear every year is that trip to a fan in the Turkey makes you sleepy. And I believe the history of the word factoid is that it used to be a little piece of information that's wrong.
It's an anti fact I see exactly.
Yeah, these days it means a tiny fact, but I think it used to mean this is not correct. And that is the story with tript to fan making you sleepy. And we got lucky because your wife knew an expert that we could talk to about this topic.
Katrina knows a lot of fun, smart people, so I often ask her for help in finding an expert. So we were very lucky to get to talk to doctor Mark Mapstone here at UC Irvine. But whether or not trypto fan actually makes you sleepy or if it's all just a huge nation wide placebo effect.
And he was a fun guy to talk to, so none of us are going to have trouble staying awake, even if we ate a lot of turkey.
Here's our chat with Mark.
Okay, So the first topic we're tackling for the Thanksgiving episode is whether or not the trip to Fan in Turkey actually makes you sleepy. And we have an expert on the show today to help us with that. We invited doctor Mark Mapstone's chief of the Neuropsychology Division in the Department of Neurology at UC Irvine.
Welcome to the show, Mark, Thank you for having me. It's great to be here.
We're excited to have you to debunk this. So when I was an undergrad, I remember sitting in an anatomy and physiology class and having my professor say, Okay, Thanksgiving is coming, You're gonna eat turkey, You're gonna be tired, and that's because of the trip to Fan.
Is that true? Is that how it works?
Well?
Probably not.
This is a myth that's been going around for decades, if not centuries, This idea that this essential amino acid called trip to fan that's present in Turkey, which it is causing you to become sleepy, and there's a.
Background for that. There's a nugget of truth.
Specifically, tryp to fan is an amino acid that we need. It's an essential amino acid that we need for protein construction in our bodies, and we don't get it. We can't make it ourselves. We can't make all that we need by ourselves, so we have to get it from our diets. And there are nine essential amino acids that we get from our diet, and.
The trip to fan is one of them.
However, it turns out that Turkey isn't the only place you can find trip to fan, and as a matter of fact, Turkey isn't the highest density of trip to fan as far as other foods as well, So it's found in dairy eggs, other poultry, meat, even beef. There's nothing special about the amount of trip to fan in Turkey. However, trip to fan is very important in the synthesis of a number of other chemicals that affect the brain and behavior which might lead you to feel sleepy, and those chemicals are serotonin and melatonin. So there's a nugget of truth. But probably you have to eat like ten pounds of turkey to get enough trip to fan to really make that direct effect to make you sleepy.
I'm up for that challenge getting but I've done it before.
Anything for the science.
Exactly, I have a lot of friends and kids who take melotone into sleep. How good is the science showing that orally consuming melatonin actually results in better sleep or more sleep?
Probably not so strong.
A lot of it is metabolized in the gut before it even gets out to get to the brain. So it turns out that most of the serotonin that's produced in our bodies is produced in the gut. The epithelial lining of the gut produces the serotonin, probably ninety percent. Although serotonin is widely used throughout the body, we think of it mostly in the brain. And serotonin is the feel good drug. It's the chemical that, similar to dopamine, kind of can make you feel It's a mood altering or mood regulating neurochemical that our bodies produce in states that we require for making our mood good. So serotonin is produced in the gut and it's also produced in the brain. So most of the brain relevant serotonin is produced in the raphae nucleus. So this is a chemical that's produced within the brain, but it's also very important and produced largely in the gut.
Ninety percent of it comes from the gut.
Can I step in with totally naive skepticism about how much we understand any of this stuff? I mean, can we identify an individual chemical and said, this one makes you feel good, this one makes you feel X like. Isn't it a whole symphony of complex chemistry that few people understand maybe a little bit.
Yeah, No, you're You're absolutely right. When people start saying this particular neurochemical does this, you have to realize that all of this is happening in this complex miilu. You know, the brain is more than just a big bag of chemicals. There are specificity for certain networks and certain areas of the brain for each of these chemicals. They don't just all float around. But you're absolutely right. You can't really just take one neurochemical in isolation and say this gives you this. It's really a combination of many things.
And do we understand the sort of microphysical process like this chemical least to this, which does this? Or is it all just sort of like correlational studies, where like, hey, we gave rats a bunch of serotonin and they looked happy.
Yeah, well, you know, that's kind of how science go. We can only start with reductionists sort of questions, and we can test those, and then we have to extrapolate to bigger issues and bigger concepts and make bigger inferences. So we do have to start with very tightly controlled sorts of things like that, Like you move one neurochemical a little bit, you feed them some trip to fan and they get sleepy. Although Givens isn't really strong for that, there's lots of foods that do that. There's probably bigger contributions to feeling sleepy after Thanksgiving dinner than trip to fan, and we can review those if you'd like, But let's review those.
So I think a lot of people out there are probably thinking, but after I eat turkey dinner.
I do feel sleepy. So what is happening there?
So you're also doing a lot of other things.
So Thanksgiving dinner traditionally, at least at my house, I mean, we've got mashed potatoes, you've got stuffing, you've got pumpkin pie. I mean all of the carbs that you're eating is going to make you feel sleepy to begin with this post prandial effect. And we know this every day after you eat lunch, righted an hour to an hour a half after you eat lunch, you tend to get sleepy. It's that why you need that cup of coffee in the early afternoon. The same thing happens at Thanksgiving, but we tend to do it like crazy ten times even more than the eating. So we do tend to overindulge in Thanksgiving dinner and it's usually on carbs that are going to make you very sleepy. These are things that divert your blood flow from brain from muscles to the guts so that you can deal with all of the stuff that you just smacked in your gob So it's all part of like overeating. It's what you're overeating. It's carbs and sugars and things like this. Maybe very minor effects of the trip to fan in the turkeys is probably what's going on. And you're probably having a glass of wine with that or more who knows or even you know, while you're watching the football game before Thanksgiving dinner. So there's the potential effects of alcohol, which of course is a depressant in the CNS, it tends to make you sleepy, It tends to make you groggy and dope e. So alcohol carbs overeating. So I think if you put all those in a line, trip to fan is like all way down at the.
Bottom relatives football, political conversations, politics.
I mean that could make you want to go take a.
Nap, right amen?
Absolutely So when we were talking about trip to fan, you mentioned that it comes from turkey and chicken and eggs, and it all sounded like it came from meat products. Do vegans never get sleepy? Does it also come from plants?
So we have what we call protein dens, are perfect foods that have all nine essential amino acids, and those tend to be meats. So I think the protein dense foods, vegetables, beans, that sort of thing does not contain all nine Many of them do contain trip to fans. So do vegans get post Thanksgiving sleepiness?
That sounds like a study right there. You should be doing that work.
We need money first.
Cacina tells me about the three sisters, Like if you have squash and beans and maybe a corn together, then you get all the amino acids.
Yeah, there are combinations obviously of the vegetables that you can pull together to make sure you get all nine. And then obviously there's supplements which are not as good, but I mean you'd rather get them directly through the diet rather than take supplements. But people supplement with these as well.
Right, But we don't want people to get the impression that you can't get a complete diet as.
A vegan, right, right, right? Oh, yeah, I didn't mean to say that at all. You can definitely take vegetarianism and veganism very seriously and get everything you need.
So you had said that this idea that trip to fan is what makes us sleepy after Thanksgiving meal has been around for maybe centuries.
Do you happen to know.
What's the earliest evidence we have of this sort of meme taking flight?
Oh?
Good question. I wish I had a source for you.
It may be when I was in elementary school or high school biology or something, and I first heard this.
Myth was that centuries ago, centuries ago.
Getting up there, we can talk decades.
I may be attributing this to my high school biology teacher who gave that evidence but did not quote a source, so don't quote.
Me on that.
Okay, got it.
How much do we understand about what makes you feel sleepy? I mean, I know neurobiology is really complicated, but this is a very subjective thing, like to feel sleepy. Do we understand the mechanism for that at all? I mean, do you feel sleepy because you need sleep? Is it really just diverting the blood from the brain to the gut.
We know that there are certain processes that are involved in regulation of sleep and wake. We refer to these as circadian rhythms, and these are ways that organisms kind of move through the sleep and wake estates and then they're in between states as well. Sleep plays a really important role. We need to sleep. I mean, it's very clear that if you deprive animals or humans of sleep, things go wrong really quickly. You can go for a couple of days, perhaps at the most, without sleep, but you start getting beyond that and you start having derangement of thinking and eventually it can be fatal. This is something that's really critical and for the brain processes sleep. It turns out there's been a new system described as called the glymphatic system, and this is a network that allows for the metabolic and cellular detritis that's produced during waking hours to be removed from the brain. You kind of want the garbage trucks to come around and clean up after you've had a hard day working as a brain cell. So we do this as sleep, and it's really critical to get good sleep because it allows for these clearance mechanisms to proceed and your brain is able to clean up after itself and it kind of shuts down a little bit and allows for these things to happen. So sleep is really important, and we've got to do this in a cyclical way. We go through sleep and wake cycles. And one of the main neurochemicals or neuro hormones frankly as melatonin, which is produced by the pineal gland in the brain, and this is a hormone that regulates the movement between wake and sleep. So this is a very complex system and most organisms, you know, from multicellular organisms to humans, have to go through these cycles to produce meaningful activity, to feed, to reproduce, to do the things that an organism needs.
And then you need the downtime.
Why do you need to be asleep for the garbage trucks to come in and clean up the mess. What is it that they're doing that you can't be awake for.
Oh, that's a good question. I'm not sure that I know the answer to that. I can say that the brain goes into a state, an electrical state where there's oscillations that promote the movement, and that's not compatible with being awake. So it kind of means that when your brain is in this state, it's drowsy, and that allows for these metabolic byproducts to be taken away as garbage.
On the topic of understanding sleep, what do you think are things we will understand about sleep in the next ten or fifty or one hundred years that we don't understand today.
One thing that I'd love to have us get to the point of is really understanding how these clearance mechanisms work, because there are a number of diseases and disorders of particularly older adulthood, that are probably strongly related to failure of clearance of this cellular stuff. And I'm speaking specifically of Alzheimer's disease, where the build up of proteins in the brain that are normal, they should be there, but they're allowed to build up to a much higher level in people who eventually develop Alzheimer's disease, and the current thinking is that this may be a failure of clearance in the sense that if you're not getting good sleep, then your brain is not taking out the garbage, and it's allowed to build up in a bad way. So a normal, healthy brain and aging brain would allow for that to get out, the garbage to be taken out, but in an Alzheimer's brain, it's not being allowed to We don't clearly understand the mechanisms behind that, but certainly sleep is playing a role. There's a strong correlation between impaired sleep and risk for Alzheimer's disease as we get older, and unfortunately that's probably starting in midlife, probably in our fifties and sixties, when we start having problems with sleep, that's when this is probably happening. So I'd love for us as a scientific field to be able to understand more about that so that we can promote good sleep and promote clearance of these abnormal proteins.
Sometimes when I'm having trouble sleeping at night, I panic because I feel like I should be sleeping more, and that keeps me up more and I feel like you've just exacerbated that problem for me.
Now I'm going to be like, oh, here comes Alzheimer's.
Well, you know a lot of people listen to the podcast to fall asleep. So would you say, Mark, as a medical doctor, that you're prescribing listening to the podcast, this podcast is actually good for your body?
It could be. However, I am not a physician.
I'm a PhD Clinical psychologist, so I can't write scripts anyways, I give recommendations and yeah, this.
Sounds like a great thing to fall asleep too.
Well, I'm going to go ahead and prescribe our podcast to our listeners. I medically shouldn't do that either, but I'm doing it all right.
Thanks so much Mark for being on the show.
Yeah, you're welcome, Thanks for having.
Me, and we're back and we're ready to tackle topic number two. All right, So let's move on to another staple of the Thanksgiving dinner table, which are veggies. And for Daniel's sake, we're not going to put any marshmallows on them.
Thank you. I know veggies don't need marshmallows. They're delicious by themselves.
I think they could use cheese most of the time. But we can agree to disagree there.
So a few years ago I was surprised to learn that a bunch of the veggies that I smother with cheese are all from exactly the same species of plant. What Yeah, So, just like dogs, whose scientific name is Canus lupus familiaris, we've used artificial selection to sort of change the way that they look so that they can have different traits that we appreciate for different reasons.
So we have everything from tiny.
Little chihuahuas that you could fit in your bag and they're super cute all the way up to great Danes, which my husband is afraid of.
But you don't have dogs in your Thanksgiving table. That's not where this is going.
Where this is going. No, no, no no.
But another species that we have artificially selected to produce very varied forms that humans like for different reasons is a plant called Brassica olerasia. And this is the plant that produces kale, coole, robbie cabbage, broccoli, cauliflower, Brussels sprouts.
Brussels sprouts too. This is like a monopoly on the Thanksgiving table.
I know they're all the same species, and that kind of blew my mind.
They look really different.
So you're saying Brussels sprouts are to cauliflower like chihuahuas are to cocker spaniels exactly.
And I think that if podcasting doesn't work out for us, you have a future writing SAT questions, which I hated taking when I was younger.
Then I'm not taking that as a compliment, Kelly, that was a backhanded insu.
Okay, it wasn't meant to be.
I would have enjoyed taking the SAT much more if you had written questions, Oh.
Nice, save, nice, save, all right, I am smooth. Well, I'm a fan of all those vegetables you suggested, but they all seem so different. I mean there's a green sort of leafiness, like a crunchiness to them all. But you know, like cabbage you can eat totally raw, and kale you definitely shouldn't. How can all these really be the same kind of vegetable?
Okay, So there was this wild plant that we think came from the Mediterranean, and it was domesticated, and this happened a really long time ago, right, So a lot of this information has been lost to history, but here's what we think happened. So initially, people found versions of this plant that looked different, and some of them had bigger leaves, and so we like preferentially planted the ones that had bigger leaves, and over time, by picking the ones that have the biggest leaves and then helping those have plant babies over and over again, we ended up getting big leafed plants like kale.
So that's where kale came from. That's when you get a lot of leaves.
So this is just artificial selection. It's like greeting your donks to have certain traits by setting up the matches, yes, or the way that we like took korn from having these tiny little kernels to this enormous, monstrous deliciousness. It's the same sort of effect, but it takes a long time, right, This is not something you can do in a lab in ten years. It's like hundreds of years or thousands of years of work.
So a lot of the answers to this stuff have been lost to history. So, like we know there were Greeks around three hundred years BCE who would write about kley kinds of plants, and so we think that, you know, thousands of years ago this was like starting to happen. But you know, over time, like when someone uses whatever the Greek word was for, like cabbage or kale, It's possible they were referring to a different plant, but we think they were referring to this one. And so we don't know exactly when all of these different forms popped out, but we think that we started with big leafy things like kale, and that was maybe a few thousand years ago.
Incredible that we don't know the history of our own foods. It's fascinating, I know. You know, whenever there's a gap in our knowledge, you always find some core order the Internet where there's conspiracy theories about it, you know, like how did the Egyptians build the Pyramids? So I wonder if there's some corner of the Internet where people like have some conspiracy about how, like Cole Robbie is actually an alien plant that came on an asteroid or something.
I mean, that would be really fun.
Let's start it. Let's start it.
Yeah, So Robbie was brought to us by the Enceladusians, and we should thank them every Thanksgiving for this contribution.
No, no, no, We're not going to join the ranks of other quote unquote natural science podcasts that just deal in speculation and nonsense. We are hard hitting science here, so no, this is fascinating, actual science. So you're telling us that all of these things have what the same common ancestor, or there's still technically the same species, Like I know that great Dane and the chihuahua can mix. I know, for example, because my dog is a mixture of German shepherd in chihuahua, which is a fascinating combination. Could you today take like Brussels sprouse and mate them with cole robbie?
Yes, what I think?
I was sure you were going to say, you can.
Get like broccolini, which is a mix between.
Broccoli and Chinese broccoli, and it's just like it's a leafier sort of thing. And so yes, you can cross these different brasca Oleracea species. They still are fertile together, so they are still the same species. And there's some closely related species that also make some other foody things that we eat. So this is like a genus of plants that were you know, really happy about. I guess, depending on how much you like your vegetables. A difficult question that scientists were trying to answer is like where did this originally come from? And it was more difficult to solve than you might expect. So, like, if you go to lots of different places like the UK, you find what looks like the original version of this plant, so like, you know, it doesn't look like a cabbage, It like looks like the original wild version that we then did all this selection on.
And what they think happened was.
That actually it started from the Mediterranean and then we domesticated it, and then we had it in gardens like throughout the world, and then it escaped from our gardens. And so there's a bunch of lineages that they say went feral, which was like a thing I only thought happened to animals, but apparently plants can also go feral. And when you're not regularly doing this selection and trying to pick the ones that make the best cabbages every single time, I guess over time it goes back to looking like the wild version did.
Because now natural selection is applying its own influence. Yeah.
Fascinating, Yeah exactly, and so it goes back to looking like the wild version. And so through like a number of different genetic things, and also by trying to look at like historical records for when we were first talking about things that were called cabbages. The current theory is that it's probably from the Mediterranean initially and then it went feral everywhere else.
Do we have examples of that in animals where we domesticated them and then they went feral again and sort of returned to their natural shape. I always wonder that about like coyotes. You know, our coyotes like domesticated dogs that escaped and became wild again.
A good question.
I don't think coyotes are domesticated dogs that went wild again. Pigeons were really popular animals for artificial selection for a really long time. They were like all these fancy pigeons, And anyone who's interested in that should read Rosemary Moscow's book about pigeons because she's amazing book. Maybe we should have her on the show to talk about pigeons at some point, definitely should. It wouldn't surprise me if a lot of pigeons that were domesticated went feral subsequently.
Oh what about bores?
Aren't there like pigs that were domesticated and then got released and now they're like in Texas.
This like thirty to fifty wild hogs rampaging around Texas somewhere.
I think that actually bores that were domesticated and then got out are a problem in some areas.
I could be wrong about that.
You know, and I think it's dingoes. I think it was not coyotes, but I think dingos in Australia might have once been domesticated. Really, we'll dig into that and look into it. But back to the topic of the Thanksgiving table. Were these things selected to be eaten with cheese or were people in doing these things even pre cheese. I mean, cheese is pretty ancient as well, right, Matt.
You are asking all the questions I didn't prepare for. So you said that your family is all about fermenting and stuff, So maybe you know when was the first instance of cheese coming on a scene for humanity?
I think they have records of cheese from like Mesopotamia. You know, people have been eating cheese basically since cattle have been domesticated, because you know, you take that milk and you've got to make it last a little longer. So yeah, cheese has been with us for a long long time. I think maybe ten thousand years. But tell us a little bit more about how you take this plant and make the different varieties, like how do you take this crazy chewy kale like small leaf thing and make cabbage?
So I was interested in this question, and to be honest, plant parts, I kind of fell asleep during a lot of the plant physiology stuff. And I've got some plant friends who are just like, we're taking your ecologist card away, and that's totally reasonable.
I just remember stamen and that's the only thing I learned in ninth grade biology, and that was the last biology class I took.
Yeah, there's also pistols and that's exciting. But I found this website called Botanist in the Kitchen and it's botanists who are also interested about like telling you about how to cook all these cool plants. And so they were saying that the way you get from kale to cabbage, so kale is like leafy, and so if you take the leaves that are like growing along the stem and you lessen the distance between them, so now you've got lots of leaves that are very close to each other, and you start getting like the stem a little bit thicker, and what's called like the marra stem at the top also gets a little bit thicker.
Then now you've got something that looks like cabbage.
So now you've got those leaves, you got more of them, the closer together in a bigger stem, and now you've got cabbage.
That's fascinating because the way you describe it, you sort of have to have cabbage in your mind to understand where you're going. It's like this is somebody's target, but with somebody, just like I wonder what happens if you do this to this plant, Like this is just random exploration of like changing this plant and other stuff and seeing if it gets crunchy and delicious. That's incredible.
I don't think we know.
I can imagine someone being like, oh man, this one has a lot more stems with leaves on it that I can eat.
That's great.
And they just happened to be like shorter distances between the stems. I don't know that the goal was we want cabbage. I think the goal was just like more leaves closer together. That's great, and then it kind of became cabbage.
Or maybe some of these things were accidental, right, You had a weird mutation and weird mixture of two things accidentally and created something like ooh, this is good. Looks called cabbage, yeah, could be, Yeah, fascinating.
So broccoli and cauliflower are about sort of modifying what's happening with the inflorescences, which are flowers that grow together. And so if you've ever left broccoli or cauliflower in your refrigerator for too long, you might see these like yellow flowers opening up. So what you try to do is, like you get a lot of these flowering parts, you get them to grow really close together, and then you cut it before it starts to actually flower. And that's broccoli and cauliflower as far as I know, this one, I think started in Italy around the sixteenth century. It's like a little bit newer, and it required some complicated genetic mutations. Maybe we have a little bit of a better handle on what happened here with broccoli. But I think broccoli is probably my favorite of all of these. I just feel like that's an important thing to mention.
What about you, how much cheese does it take before you enjoy broccoli? Will you eat broccoli pure without cheese?
I will eat broccoli with some soy sauce and without cheese, And the same for Brussels sprouts with some spices. But you know, everything is better with cheese. Let's be honest. What about you, what's your favorite of these?
I will eat broccoli raw. You know, chopped broccoli is delicious and a salad. It's crunchy, it's got a little bit of a bite to it, as long as the chunks aren't too big. It's really fantastic. Raw kale. I'm still learning to love, you know. My wife's a big fan of kale. I know kale is supposed to be really good for you, but there's just no way in which kale becomes delicious. Actually, no, I take that back. Somebody once made kale chips. Put them in the oven, roast them at high temperature. They get really crunchy, but not very oily. Kale chips are good. But I'm a fan of all these things. Brussels sprouts, I think are probably my favorite, which is funny because I remember my dad cooking Brussels sprouts when I was a kid, and my memory is that it was the most disgusting aroma I could imagine, Like when he cooked Brussels sprouts, I had to leave the house. It was revolting. And now I totally love them. And so it's bizarre how you developed these tastes, like why did it take decades to learn to love Brussels sprouse?
Actually I was talking to Zach about this this morning, and I didn't go and verify this by finding a scientific paper, but he was saying that part of why people our age like Brussels sprouts now but we hated it when we're kids, is that actually there has been some artificial selection for flavor, and it has gotten less bitter and stuff over time, and so part of it maybe is that where adults are, we're cooking it better blah blah blah, but it might actually just taste better, which I feel like also happened to apples in our lifetime.
But that's terrible because I've been congratulating myself for learning to love my dad's Brussels sprouts for a long time, and now you're saying I haven't even accomplished that. I'm just eating like baby version of Brussels sprouts, like candy version.
I'm sorry I took that away from you, but you know, I feel like, in general, you know, maybe you should give your dad some more credit, like call him and be like, I'm sorry, your Brussels sprouts were probably as good as they could have been.
No, actually, he's British and he cooked them the British way of like boiling them to death, and so that probably also contributed to their disgustingness.
No, no, yeah, you should have emancipated yourself at age seventeen.
That's unacceptable.
But I agree almost all of these are better with cheese. Cauliflower incredible with cheese, absolutely broccoli. It's all the dishes. And I hope everybody out there had a really good helping of healthy vegetables to go along with all their pie.
I think that's important.
And now I think we should return to Turkey, but now take a physics turn on things, and so we're going to take a break, and then I'm kicking the control of the conversation over to you.
All right, all right, we are back, and I hope you've had a good full meal. You're done crunching on your turkey wings and slathering your broccoli with geese, because we're going to take this conversation away from the biology of Thanksgiving and talk about the physics of turkey.
Hope you haven't had too much trip to fan.
A big part of the Thanksgiving experience is cooking a turkey, and most people don't cook turkeys throughout the year, and so when Thanksgiving comes along, you look up that turkey recipe and you invariably do it around two in the afternoon. You're like, Okay, what do I need to do to this turkey? And then you look at the recipe and it says cook for six hours and you're like, oh, no, I've started too late, or my turkey is still frozen.
I think I've had three or four instances in my life where the plan was to eat it for and then we ate it like nine because it was like the turkey the center was still frozen exactly.
And you can blame that on people's planning skills, but really the problem is physics. Physics is the reason that turkeys take so long to cook.
What are the electrons doing wrong?
Blame the electrons, they're so negative they are, so to think about cooking a turkey from a physics point of view, of course, first thing we do is we assume the turkey is just a sphere. Right to naturally simplify the problem, assume a spherical turkey.
This is the go to joke with ecologists was that physicals will like assume a spherical cat anyway, So all right, we're spherical turkey.
But here it's actually useful because you can't think about all the wiggles and weird shapes of a turkey because the crucial thing to think about when you're thinking about the physics of cooking a turkey is how to get the core of the turkey above a certain temperature, because that's what cook means. Like, you don't want to eat the turkey when the core temperature is below about one hundred and sixty five fahrenheit because and this is a little bit of biology, what happens when you cook is you're raising the temperature, you're denaturing the proteins. You're also killing all the microbes, etc. But really what's happening is the transformation of those proteins. That's why it goes from like gouy and translucent to like white and opaque, because you've transformed these molecules, have broken them down. Did I get the biology right there, Kelly?
Yeah, that sounds good and delicious and delicious.
So you have this object. The whole thing is cold. It starts at like fifty degrees fahrenheit or whatever. The temperature is of your fridge, and you have to raise the whole thing up to one hundred and sixty five degrees fahrenheit. But the problem is you can't inject heat into the center of it. I mean, you could microwave your turkey, but I don't recommend it. If you're roasting in an oven, you apply heat only to the outside. Right, Your oven is like a big bath of hot air. You put the turkey in the oven, The oven heats the outside of the turkey. It doesn't directly heat the inside of the turkey. So from a physics point of view, the reason that it takes so long to cook your turkey is that it takes a while for the heat to propagate from the outside of the turkey to the center of the turkey.
So this is where we reveal to our listeners that I don't go in the kitchen excepting eat the food that Zack has been cooking. And you can't speed that process up by turning the heat up too much, because then you're going to burn the outside.
Is that right?
Yeah, that's right. What you want is an evenly cooked turkey. You want the center to be one sixty five, You want the outside to be one sixty five. Now, the oven temperature is like three P fifty or so, and so when the core is one sixty five, the surface is going to be hotter. And so if you make the temperature of the oven hotter nine hundred degrees or whatever, then you're going to cook the outside faster. The inside will get to one sixty five and it will get there faster. But when it does, the outside is going to be even hotter. It's going to be totally burned. And so the best way to cook a turkey slowly. This is why, like a souved, you put the thing in a water bath like whatever the target temperature is, and you just wait forever until the whole thing comes up to that temperature. And so what's happening here is diffusion of heat. The energy is spreading out from the oven to the turkey, or from the water bath in the case of a souved into the object. And that's physics. It's really basic, simple core physics that we see actually in lots of places in the universe.
So does a tur ducan take longer to cook because it's more packed in the center and there's more you need to heat through.
Yes, you're violating my spherical turkey assumption here, Kelly. But yes, it's helpful when you cook a turkey not to stuff it either with stuffing or other birds, or even cauliflower or cheese, because you're creating more mass that needs to cook and you're making it more of a sphere. If the air can get into the inside, into the chest cavity, that they can directly heat the inside of the turkey and it goes faster.
Okay, So if you've got that like chest cavity, that's how the air gets in, you can start heating from the inside. Could you make the chest cavity even bigger or like cut the turkey in half?
Why do I have to wait so long?
Exactly? So if we understand the details the physics here, that will help us think about how to organize our turkey to make it cook faster. And so the way I think about the physics is you have this layer of hot air that's touching the surface of the turkey, and microscopically, what's happening is that the air particles are hitting the turkey. Right, the air particles are moving fast. That's what it means for air to be hot, right, those particles have a lot of energy. They bounce off the turkey, and they deposit some of that energy. They hit the turkey at high speed, they come off with less speed, and that speed has now gone to like the vibration energy of the molecules of turkey. So you have this layer of hot air that's heating the outside layer of the turkey. So then how does the inside of the turkey get hot? Well, that now hot layer the outside of the turkey is heating up the next layer, and that warms up and that layer heats up the next layer. So the air actually only cooks the most outside layer of the turkey. The rest of the turkey is cooked by the rest of the turkey. So you have like layer N is cooked by layer N minus one. Like imagine your turkey is a series of layers. Each layer is heated up by the layer outside of it that's a little bit.
Hotter than it unless you have nothing in the center of the turkey, and then you're getting a little heating from the inside going out.
That's right. And in the case of a spherical turkey, it's simplest because all these layers are just spheres, and you're only cooked by the one outside of it. But even in a non spherical turkey, still you have a layer of the turkey and the outside that's touching the air, and then an inner layer, and another layer and another layers, just that each of these layers is no longer a sphere, and that takes time, Like you can't instantly take energy from the air and put it into your turkey or from the turkey into the next layer of turkey. There's a mathematical equation that describes this. It's called the heat equation, and it's fascinating because you see this equation everywhere in physics. This is one of the things I love about physics is that there are only a few equations and they describe so many different things. We talk in this podcast a lot about waves, how waves describe the motion of the ocean and ripples in the electromagnetic field and ont and field theory, like wave equation is everywhere. That's because it's very mathematically simple. It's a second time derivative related to a second spatial derivative, and that's it. Any condition you have where those two things are coupled, the time derivative and the spatial derivative, meaning how fast things are changing over time and how fast things are changing over space, then you're going to get a wave equation, and you're going to wave like behavior. The heat equation is very similar to the wave equation. It's just a different derivative. It's one time derivative instead of two, and so you see this everywhere. The heat equation describes how heat flows through a turkey. It also describes how water will soak through cloth, or any time you have diffusion or osmosis. It describes like how salt will spread through something, or how your cream will spread through your coffee. The heat equation describes anytime something is spreading through something else. The physics of turkeys is actually like the physics of the universe. It's really kind of incredible, and.
I think that you should definitely push the conversation at the family dinner table away from politics and towards more philosophical topics like this.
And so the reason a turkey takes so much longer to cook than a chicken, sort of surprisingly longer, is also because of the dimensionality of space itself, right, Like, we live in three dimensional space, and that means that as your turkey or your bird gets larger, the volume of the bird goes up by the radius cubed Right, the area for the volume of a sphere hasn't R cubed in it, but the surface area, the way you get heat into it, only goes up by R squared. So as your turkey gets bigger and bigger and bigger, the ratio of surface area to volume gets smaller, and so it's harder to heat that turkey. This is why, for example, elephants get so hot because they're huge, have a lot of volume in a relatively little surface area. And I don't know if it's a myth or a factoid, and that's why elephants have such big ears to increase their surface area. I have to dig into that. But it's definitely true that as something gets larger, it's volume increases faster than its surface area, and so it's harder to cool or harder to heat. That's core physics.
So if you have a bigger family, you've got to get up earlier in the day to start.
Your turkey exactly, And that's why a turkey takes much longer to cook than like the equivalent mass of chickens. If you took like five chickens and you cook them, you could cook them a lot faster because there's a lot more surface area for the same amount of meat. And that's why people invented techniques like spatchcocking your turkey. This is where you basically break your turkey in half and flatten it. You remove the backbone and you break the chest cavity because this just allows the air more access. It increases the surface area of your turkey, which cooks it faster.
So why doesn't everybody do that? Is it because it doesn't look as nice in the pictures.
It doesn't look as nice. Yeah, okay when it comes out, it doesn't have that like holiday turkey kind of sheen to it. I think it's much tastier. It cooks faster, and it keeps the breast to thine, the ring all at good temperature. So I'm a big fan of spatchcocking. We do it every year.
I think every family needs eye they're a sower or a surgeon, so that after you spatchcock it, you can like stitch it back together for the photos and then it's faster and it looks nice.
Well, plastic turkey surgery, huh, you think we would do that in Orange County. We're big fans of a parents down here.
Yeah, well maybe that's where it'll start.
So sometimes people put turkeys in oil, and that is a big cause of fires around Thanksgiving, I believe, so do that carefully, very dangerous, and that makes it faster.
Right, Why is that faster?
That's right? If you deep fry your turkey, it takes like five minutes per pound as opposed to like fifteen minutes per pound. And the reason is just that oil transmits heat better than air, and so heat flows faster into the turkey and the oil gets in all the crevices and stuff like that.
Ooh, and so as an efficient person, I should start deep frying everything.
Yeah, I suppose. So if you really want to gain some weight on Thanksgiving and you want to do it fast, that's a way to do it.
Yes, all right, maybe we'll spashcock instead.
But to double down on the physics of Thanksgiving, I was thinking about whether there is a nuclear connection here. Nuclear power is physics, and you know, we use a lot of energy on Thanksgiving. We're cooking our turkey, it's in the oven for hours. I was thinking about, like, where does that energy come from? And what is the physics that provides the energy we use to cook our turkey?
All right?
So usually when you get excited about an idea, it means my kids are probably in some sort of trouble.
How are you going to be cooking the turkey this time?
So I wanted to start from a fairly safe direction, which is nuclear reactors. And I was thinking how many turkeys could you cook with a nuclear reactor? So I did a little calculation here, and your oven it's on for like three and a half hours, but your oven pretty much uses around two hundred and forty watts. That's like how much energy it takes to heat of that air to keep it hot. And that doesn't actually depend on like what you put in it. You just turn your oven on, it's going to use around two hundred and forty watts. I mean, you put like an ice sculpture in there, it's going to take a little bit more energy, but in general, you just have it on. That's how much energy it costs. So then you can think about how many ovens a nuclear reactor could run simultaneously. Okay, and a modern nuclear reactor runs at about a gigawatt, so a billion watts. A wat is jeweles per second. So this is a rate of energy, which means that you can calculate fairly easily that a single nuclear power plant can run around four hundred and twenty thousand ovens simultaneously. Wow. So if you took a nuclear power plant and you wired it directly to people's ovens, that's all you did with it for three and a half hours on Thanksgiving afternoon, you could cook almost a half million turkeys with a single power plant, which is kind of incredible.
Sorry, turkey population, that's true.
Really turning off our turkey listeners. Huh yeah, but you know we're sacrificing some turkeys. But you know, one turkey feeds like twelve people or so overall, this is like five million people can have turkey cooked by a single nuclear power plant. It's incredible how productive these plants are.
All Right, I am pro nuclear power, and so I'm feeling good about this. Are you going to amp things up to something I'm less excited about?
Well, then I was thinking nuclear power plants. Okay, that's kind of vanilla. What if we try to cook our turkeys with nuclear bombs instead?
There you go, uh huh, and This.
Is actually a homework problem I assigned in one of my thermal physics class to think about like the energy required to cook a turkey and the energy released by a nuclear mom So I did another calculation which was to think not just how much energy does it require to run an oven, but what about the actual energy it takes to raise the temperature of the turkey. So you can think about the turkey as a combination of water and protein. And I found some measurements online that said that the specific heat of a turkey, that's how much energy it takes to raise a gram of turkey by one degree, is about two point eight jewels per gram centigrade. And so from that you can calculate like how much energy it takes to take a whole turkey and raise it about one hundred degrees And that's like one point six gigajewels. So if you could take that energy and just sort of like inject it into your turkey somehow, you would raise it up about one hundred degrees, which is what you need to do to cook it.
How big is this turkey?
This is a fifteen pounder, So yeah, you're making a meal for the neighborhood.
Okay, all right, well it depends on your family. I think my daughter and I could put down a fifteen pounder. My husband's a vegetarian. My son doesn't eat meat.
Wait, so Zack's a vegetarian, but he makes the turkey on Thanksgiving.
Oh heck no, no, no, no no. He cooked meat once and turned green. This is when I was pregnant and.
I was like, oh, can you please make me a euro?
And I've never asked him since in are like almost twenty years together now. But no, my sister in law is amazing and makes the turkey, or my dad.
So one point six giga jewels, it's not like a number we think about a lot, so I tried to translate it into something more practical. If you had like one hundred and fifty D cell batteries and you ran them for an hour, that's about one point six giga jewels, So you could like cook a turkey with about one hundred and fifty d segn matteries, which I don't know. Maybe that'd be useful information for somebody in the end times when they're trying to have a Thanksgiving of yesteryear.
If you raid the Amazon warehouse and find a big store of D batteries like we're on for Thanksgiving.
Yeah, you made your turkey like a resistor in some crazy circuit or whatever. But the other alternative if you're in the end times and there are nuclear bombs going off, is you could try to use the energy released by those nuclear bomb drops to cook your turkey. And so a nuclear blast has a few million gigajewels of energy released. Wow, So that means that there's enough energy in one nuclear bomb dropping to cook about a million turkeys.
That would feed millions of people, right, so that you could be like president of like a community with all of these turkeys that you're passing out.
You can be the queen of the end times or the king of the end times.
That's right now. One thing we have in factored in here is like how you get the energy from the nuclear blast into your turkey. We talked year about like slowly cooking your turkey. You know, put your turkey on a stick and hold it up to the nuclear bomb drop, and it's gonna get fried, like it's going to get blasted. Probably you're gonna end up with like a cold core and a totally crisp outside, so there's a challenge there and finding the right distance, and you know, to really be efficient and to cook like all those millions of turkeys, you really need to like build a spherical shell of turkeys that's around the bomb blast so they all capture that energy. Imagine like a dice and sphere around the sun, but now you have like a turkey sphere around the nuclear bombing.
I'm starting to feel like maybe even during the apocalypse, there's better things you could do with your time. Also, i feel like you're a strategy of holding it on a stick and it fries the front but doesn't cook. That's probably not good for the people either. I think maybe you shouldn't be king in the end times.
I've never claimed to have any useful skills for the end times. You know, particle physicists. They're the kind of thing you see in society when times are good, you know, not in the lean times. So we don't spend energy on particle physics in a lean time. So I'm hoping the civilization crashes after I pass off from this mortal coil.
And I'm hoping none of your kids decide to take on the family profession. And because if they're microbiologists, they might be okay.
But well, you know, when my dad retired from the lab, he took up blacksmithing, came Annville and a forge and in the garage and he like made his own tools and weapons, and so he would definitely be a useful guy to know in the end times. But not me.
Well, I mean, maybe when you retire he can teach you some of that stuff.
That would be good.
He probably forced me to choke down. He's discussing Brussels sprouts first.
Oh yep, no, no, good, forget it. It's not worth it. It's not worth it.
Just call it quick, no amount of cheese.
All right.
Well, we have conveyed lots of not useful information today that will hopefully be fun to talk about.
But there's science everywhere, and science in everyday life. There's even science in Thanksgiving. So thanks very much everybody for sharing your Thanksgiving with.
Us, and we appreciate you, and weppreciate the questions and the input that we get from all of you, So please feel free to reach out to us at questions at Daniel and Kelly dot org.
We are very thankful for all of you.
I have agree. Thanksgiving everyone.
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