Listener Questions #13 - podcast episode cover

Listener Questions #13

Jul 03, 202549 min
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Episode description

Daniel and Kelly talk about warty comb jellies, white holes, and humpback whale navigation.

See omnystudio.com/listener for privacy information.

Transcript

Speaker 1

What on Earth is a wardy comb jelly? And why does it sound like it's probably very smelly?

Speaker 2

If the Sun were replaced with a white hole, would it be very bright or dark as coal?

Speaker 1

How do willes navigate the seas? Magnetics gravity or mysteries of chemistry?

Speaker 2

Whatever question keeps you up at night, Daniel and Kelly's answer will make it all right.

Speaker 1

Welcome to another Listener's Questions episode on Daniel and Kelly's Extraordinary Universe.

Speaker 2

Hi. I'm Daniel. I'm a particle physicist, and I've never been tempted to eat a warty comb jelly.

Speaker 1

Hello. I am Kelly Weener Smith. I also have never been tempted to eat a warty comb jelly, But I feel like the existence of the name wharty comb jelly reveals that biologists have a much more fun time of naming things than physicists do. What is your favorite species name?

Speaker 2

Daniel wait, I can't get over warty comb jelly, and I'm not gonna let it slide that you're somehow congratulating yourself for this name. This name is a mess. I'm like, is it a wart is it a comb? Is it a kind of jelly? Is it a jelly made of warts? Can I comb my hair with it? What is going on with this name? It sounds like just three random words. It sounds like a password recommended by XKCD.

Speaker 1

All right, well, so one, I think you must lack imagination because I imagine a jellyfish that is sort of warty with some like comy projections. I think they did a great job.

Speaker 2

I don't know. I've heard this thing is also described as a sea walnut, So I'm not sure anything in our vocabulary can really capture the weirdness of this creature. Maybe biology has gone beyond naming.

Speaker 1

You know, it has two different life stages, and sea walnut describes one of the stages very well, and warty comb jelly describes the other very well. So maybe if you just knew a little more natural history, you'd follow along.

Speaker 2

So it needs five words in its name, not just three. Oh it's oh that fabulous.

Speaker 1

It's pretty fabulous. But I think my favorite species, or my favorite common name for a species, is the humped trash line weaver. It's a spider that has like sort of a humpy shape, but also it puts trash in the middle of its web. And I don't remember why should have looked that up before the show. But it's got a line of trash and it's got a hump, and it's a humped trash line. Orb Weaver and I love them. They live on my farm in Virginia and they are permanent residents.

Speaker 2

Well, there's a well known spider that I think could use a better name, And I once heard an episode of This American Life where they were speculating about a better name for the black widow spider. And my favorite suggestion is not family friendly. It has to do with the fact that until we had running water, most of the bites were on guys using outhouses because of little swinging bits that the spiders bit onto.

Speaker 1

Yeah. So I was reading a journal of parasitology and there were men who were purposefully letting themselves get bit by black widows to try to get a handle on how bad the bites are. And the story starts with how he was like doing experiments on rodents and ends with how many days he was stuck in the hospital

after he did it to himself. But the doctor treating him said, yeah, I've seen someone else with a black widow bite, and it was in the same location, but alcohol was involved, and so I have since found myself wondering if men is like, oh, it's because of the outhouse, I just but it was really just other shenanigans.

Speaker 2

Well, there are so many wonderful questions to ask about that story and where people get bitten by black widows and other things about the universe. And today we're going to be celebrating those kinds of questions because we're here today not to talk about the things that we wonder about the universe, but the things that you wonder about the universe. Our podcast is a conversation between us and you,

and we want to hear from you. We want to know what you want explained about this extraordinary universe.

Speaker 1

So let's go ahead and jump into our first question about the wardy comb jelly.

Speaker 3

Hi, Kelly, Hi Daniel wanted to see if you could discuss the wordy comb jelly things.

Speaker 1

Well. I was excited about this question because honestly, I've never heard of the wardy comb jelly, and it turns out and has a number of really fascinating features.

Speaker 2

Well, first of all, what do you think inspired this question? Is it just the craziness of the name, or is it some incredible biological magic that's happening in this critter.

Speaker 1

If I had to guess, I would guess that this listener sent us the question because this species has a transient anus.

Speaker 2

Another pair of words I never thought would go together.

Speaker 1

Biology is amazing, And.

Speaker 2

I'm hoping that that means exactly what I think it means.

Speaker 1

Yeah. Probably, So let's back up and let's clarify the appearance and the diet of this thing. And so we're gonna do the inputs and when we get to the outputs, we'll talk about the transientanus. So, all right, the warty comb jelly you know, if you imagine it, it has sort of like a jellyfish shape, okay, but has two different stages of its life. When it's small, it's called

a sidipid. And at this point it looks like it's clear, but it has sort of a walnut shape with two long, feathery tentacles that come out from the back.

Speaker 2

So why isn't it called a wardycomb jellyfish instead of a wardycomb jelly Because when I hear wardcomb jelly, I think of a pot of jam.

Speaker 1

Uh. It was probably not named with you in mind.

Speaker 2

And why not is the real question.

Speaker 1

Well, you know, I think jelly so jellyfish might be slightly distantly related. There's probably a lot of diversity in jelly like things out there. These are some very ancient creatures. And also, you know, jellyfish is sort of confusing because they're not really fish, and so maybe someone was like, let's drop the fish because these aren't.

Speaker 2

Really fish, and also it's pretty good on toast.

Speaker 1

I wouldn't suggest eating these, although I think they're mostly water and I don't think they could sting you, so maybe it would be fine. Why not? But as they transition to adults, they lose those long, feathery tentacles and instead they grow these lobes. So I kind of imagine like a glass paper weight, but with like ribbons coming off of the sides kind of, So it has these lobes, and the lobes have these like iridescent spots on them that attract little like tiny fish so that they can eat them.

Speaker 2

This sounds really cute.

Speaker 1

No, it is really cute. You should look up a photos. It's cute and it has beautiful iridescent colors. I can imagine having it as a pet, and I've seen it at some aquarium.

Speaker 2

Because again the name wardicomb jelly doesn't conjure up cute images in my mind. But your description was beautiful.

Speaker 1

Well thank you. I mean, biologists have a sense of humor, and that's that's what you need to know. And so when they're young, they use those feathery tentacles to capture very tiny creatures living in the water column. As they get older and they get into the low bait stage where they have those lobes, I agree, this is not a very pretty name for the stage when they have

those like ribbons coming off the side. Then they're eating things like eggs and tiny fish and crustaceans, so they start eating bigger things, so they have a transition.

Speaker 2

So does this mean they're up near the surface where they can eat those things or do they go much deeper.

Speaker 1

They're swimming around the surface and they can move throughout the water column, so you can find them at different depths. They also will eat each other. So like for the Daniel and Kelly checklist, we've hit cannibalism. So this species has a lot of things that you and I love. So next we're ar at least that I love. So next we're going to talk about poop. That's point two for dKu.

Speaker 2

I hope we get to aliens eventually.

Speaker 1

I was gonna say aliens are white chocolate. That's where we got to get this kind of station two.

Speaker 2

So tell us about how these things spend their time on the body.

Speaker 1

Okay, So as they eat and they accumulate waste, their gut expands, and as it expands and kind of balloons out. At some point it touches the outside of the body. And as it touches the outside of the body, it fuses and an anus is formed. So like the gut and the outside of the body are only like one cell thick, and so they fuse form a hole through which waste is expelled, and this happens like every ten minutes to every hour, depending on how big they are.

And then once the waste has been expelled, the gut starts shrinking and it pulls away from the outside of the body, and that hole is completely covered up. It goes away, it totally fuses, and the anis disappears. What I know, and it's thought that this is an intermediate stage between the permanent anuses so many of us know and love, and this early stage of the anus, and maybe we should put a warning at the beginning of the show. But you could talk about butts with kids, right, yeah, And.

Speaker 2

We could just pretend that permanent Anus is the name of a punk band we both enjoy.

Speaker 1

That's right, That's right, yeah, from the nineties.

Speaker 2

I love their second album, Oh my God, so good? Are you saying that this is a transition stage sort of evolutionarily like that there are some critters that didn't have an anus, and then there were critters with a temporary anis, and then their critters with a permanent anis.

Speaker 1

So I'm imagining the PhD student who will one day have the job of working on the phylogenetic tree studying the evolution of anuses. But I did find a paper that was hypothesizing that this is a step in the evolution of the anus that early on, when you've got very primitive species, they have this transient anis that kind of comes and goes. But as you move down the evolutionary tree, we sort of settle on a better method, because why recreate the wheel every ten minutes if you

don't have to do that? So anyway, yes, this could have been a step in the evolutionary path that brought us to where we.

Speaker 2

Are today, and does that allow us to extrapolate into the future, like go from non to temporary to permanent. What's beyond that double triple extra permanent. I can't even imagine.

Speaker 1

I don't know, man, we might need like AI and artificial tech to give us, you know, additional new ones. I know sometimes you have to move them around following surgeries and stuff, but I can't imagine that we're going to end up with too many more of them. I feel like we've maybe hit the fitness peak on anus and we're good where we are.

Speaker 2

So I just heard a talk by Brian Mallow, the science comedian who actually lives near you, and he was telling me that there's a critter that lives on our face that doesn't have an anus. It's called a face mite, and it like walks around your face chomping on stuff, doesn't have an anus, and events you just explodes all over your face. And I was like, wow, that's so many gross details.

Speaker 1

It is one of gross details in one story. I do feel like there's life stages of insects and stuff where they don't have an anus. They just kind of accumulated, and then when they move to the next stage or when they transition to a different body plan and they leave the feces behind. I gotta say, it's convenient to be able to, you know, remove your waste as you need without yeah, without too much trouble.

Speaker 2

Well, what are the disadvantages of this.

Speaker 1

Of needing to recreate an anus every ten minutes? I didn't imagine i'd get asked that today. But here we are, Yeah, I but here we are. I don't know. I mean, I have not seen reports on, for example, how often it fails. Needing to create a new sphincter over and

over and over again. Seems less efficient than just having one that works when you need it, And so I imagine the downside is that it's a fail point if it needs to be created so regularly, and it's better to just I can't say I've thought too hard about this, all.

Speaker 2

Right, Well, then I'm going to connect us to the last dot and ask you an alien anus question, which is, if we're landing on an alien planet, do you expect that aliens are going to have a permanent anus or where they have a transient one? What do you think are there permanent anuses all over the universe, is my question, Kelly.

Speaker 1

I would say, uh it, you know, it depends. You can never know for sure, but if I had to guess, I would put my money on Yes. It seems like a very convenient feature. And uh, you know, they maybe they would have. I'm gonna say, yes, what do you think, Daniel, I agree with you.

Speaker 2

I think the universe is probably filled with butts?

Speaker 1

Good. Yeah, all right, Well, I'm guessing that's what the listener wanted us to talk about. But this species is well known for two other things. One, it lives on the east coast of the US, and it's been introduced in Europe into like the Caspi and c the Black Sea and the Baltic Sea, and it's caused a lot

of problems there. Part of why it causes a lot of problems is because when it is in the water, it's consuming a lot of crustaceans and eggs and tiny fish, and so it's been a problem for the native fish because it's eating the baby stages of the native fish, and it's eating the food that those baby stages of the native fish eat, so it's competing.

Speaker 2

That's not so nice.

Speaker 1

Not so nice, so people have been trying to get rid of them. But the other thing that they're well known for is a result that was just published last year, twenty twenty four. It is one of the few species we know of that is able to turn back the clock and transition back to an earlier life stage. So let me give you some details. So we talked about how it has that sidipid stage where it's a walnut with feathery tentacles, and then it has a low bait

stage where it's a paperweight with some ribbons. And if you've got it in the low bait stage and you starve it or give it a lob back to me where you remove one of the lobes, which is not very nice to no. No, Essentially, if you stress it out, it's able to essentially go back in time and it absorbs the rest of its lobes and it goes back to the sidippid stage, So it goes from having those ribbons, it absorbs those ribbons, it goes back to looking like

a walnut with feathery appendages. So it can like go back in time and reverse its development, which not a lot of species can do. We don't know that that like extends its life span. But if they go back in time and then they grow back, they can grow

back that other lobe. So it would be like if you lost an arm and you can be like, no, not cool, you like absorb a bunch of body parts, go back to just being like a ball of cells, and then you sort of go through the development again and now you've got both arms or something like that.

Speaker 2

Well, maybe there's a great advantage to having transient bits is that you can generate bits at will, and so if you lose one boom, you can grow an arm or like, hey, I could use a second head today, let me grow another one.

Speaker 1

Yeah, I don't know that they grow like twice as many of the ribbons and they usually come back with the same number of ribbons. But another thought for the benefit of this reverse development is that if you're going around and you're trying to eat babyfish and there's like just no baby fish, it's not the right time of

year and you're starting to starve. When you go back to that tentacle phase, you can now access a lot of the much smaller food stuff, and so it could be a way to like open up the kinds of foods that you're able to eat at a time when the foods that you are really well shaped to eat are no longer available. So they've got this interesting reverse development that we don't understand very well.

Speaker 2

Fascinating.

Speaker 1

Well that is all I have to say on the wardy comb jelly.

Speaker 2

And wait, this is the last question, which we teased in the intro. Oh do you think the wardy comb jelly is very smelly?

Speaker 1

Oh? No, no, it's mostly water. I'm guessing it. I don't think it smells bad, but I agree it's got a kind of stinky name.

Speaker 2

What do you think I think probably if you put it on toast and left it, it would smell pretty bad, as basically everything from the sea does.

Speaker 1

I mean, I think just about any organism, if you let it die and you left it on your toast for a while, you're going to regret that decision.

Speaker 2

Well, that's just fermentation. And sometimes fermentation is delicious, you know, you get marmite or whatever, or cheese, and sometimes it's not.

Speaker 1

Yeah. Well, you know our conversation went from transient anisis to cheese. And let's see what the listener has to say.

Speaker 3

Hi Kelly, Hi Daniel, Thanks for talking about the wordy comb jelly. Maybe one day we'll all be able to regrow our parts inside or out, or even flip them around. Thanks.

Speaker 2

All right, we're back from talking about the transient holes in wordy comb jellies to talking about a very different kind of hypothetical cosmic hole.

Speaker 4

I'm Sammy, I'm ten, and I want to know what would happen if this sun was aplace with a white hole?

Speaker 2

All right? I love this question, and I that young people are thinking about the universe and asking questions. And thanks to all the parents out there who listen to the pod with their kids.

Speaker 1

So, Daniel, what are white holes? And do they come and go depending on how recently youth consumed a meal?

Speaker 2

You know, when we started this episode, I was like, well, there are no connections between these topics. Now I'm seeing them more and more. Yes, maybe aliens with transient anuses are going to use cosmic white holes to come and visit us and tell us about it and learn all about our permanent ones.

Speaker 1

We can hope, but hopefully they don't eat us. I guess that wouldn't be cannibalism. So I'm not really connecting the dots there, But anyway.

Speaker 2

Yes, So Sam is asking a great question. Basically, he's wondering what does a white hole look like? And could his serve as an alternate sun, etc. So let's talk about what a white hole is. Number one. A white hole is a hypothetical thing. We don't know that white holes exist in the universe, and we're not even really clear on what a white hole is, you know, like a black hole, we have a very crisp concept for

what it is. It's a prediction of general relativity. We talk about it, we understand about it, we can calculate about everybody agrees what a black hole is a white hole, and we'll get into what it is exactly. Is the sort of a fuzzy set of concepts that are closely related. And so if you read about white holes and you listen to this episode and you might think, on, that's not what I heard, and then you go read another article and you're like, that's not what I understood to

be a white hole. That's because there is nothing that it is to be a white hole. It's like a set of ideas that people are still sort of developing that all go by the same name, which can be.

Speaker 1

Confusing, sort of like our study of the anus, you've got multiple stages. We're not really sure how to define it, but all right, go.

Speaker 2

On, yeah, yeah, So most commonly, a white hole is thought as something like the opposite of a black hole. So a black hole is a region in space, an event horizon, which nothing can escape. Right. Remember that gravity is the bending of space time in the presence of mass and energy. So the Earth and bends the space around it, which affects the way things move around it. And if you have enough mass and enough energy, you bend space so much that you change its shape so

that nothing can escape. It's not that black holes have intense gravity to pull on things, even light. It's just that the shape of space is such that nothing can escape. Space only points in one direction past the event horizon, towards the center. So no matter how fast you go or how you wiggle or struggle, you're always going towards the center. That's the black hole, a region of space where nothing can escape because of the shape of space itself.

Speaker 1

Okay, so if I were to just guess a white hole, so you'd imagine it would be exactly the opposite. So is it is everything running to escape from a white hole. Nothing can you get pushed away from it if you get too close.

Speaker 2

A white hole is a region of space that nothing can enter, so things can escape it, but nothing can enter it. And the opposite of a black hole. A black hole things can enter but nothing can escape. A white hole is a place where nothing can enter, but things can escape.

Speaker 1

How is that made?

Speaker 2

Yeah, and that's a different question, right, Like what is it? And could it exist? It's a different question from how do you make it? That's an important subtlety, right, Like, for example, a wormhole, which we'll talk about in a minute, is something which can exist in general relativity, and a white hole can exist in general relativity. But that doesn't mean that there are any or that we know how to go from a universe without one to a universe

with one. It's like the difference between saying, oh, I know how to eat a soufle. I know soufles exist, and I know how to make a soupfle from ingredients.

Speaker 1

Right, it's hard to make a soufle, yes, exactly.

Speaker 2

The recipe is a challenge. So those are actually two different questions, Right, is it possible for them to exist in the universe? And is there a series of actions you can take to create one.

Speaker 1

Two different questions are we going to answer either.

Speaker 2

H we have no idea about the second one. We are going to talk about the first one, right oka, like, can general relativity accommodate this? What does it even mean? What are we talking about here? And so the first concept of a white hole, and I think the most generally discussed one, is a sort of mathematical extension of

space time. Roger Penrose is famous for thinking about black holes and the structure of space time, and he came up with a cute little diagram to draw the whole universe and like a little square where infinities are like squeezed down into the corners, so you can draw things nicely. And they're called Penrose diagrams. You can google them and see them. They're a little hard to wrap your mind around, and we're not going to try to explain them today.

But these diagrams do inspire the concept of white holes, because if you look at the diagram, the whole universe is like a diamond and black holes are on one side, and you can ask, hmm, what could be on the other side, And so it's just sort of like, hey, let's ask questions about this diagram and is it possible there's something there we hadn't considered the way you might be like, oh, there are positive numbers, could there be

negative numbers? There are particles, could there be antiparticles. It's just like this search for symmetry in the universe and wondering, and then people realized, well, there's really nothing preventing that. Like in print, Well you could have a region of space that nothing could enter, but things could escape from. And the way to think about it in terms of these Penrose diagrams is just some region of space where you can get messages from but you could never reach.

And that seems really weird. I have two sort of ways to think about it for you. Number one is to just reverse the black hole. Like if you think about black holes not as a big blob of stuff pulling in on you really really hard with its gravity, but literally a rearrangement of space so that space only points in so that no matter what you do, you are moving towards the center. Remember that black holes and gravity are all about the shape of space itself, not

forces on stuff within space. Now just reverse that. Imagine a points in space where space points outwards, and the only way you can go is out. There is no in, right, there's only motion outwards. So if you accept that black holes are space pointed in, then white holes are just space pointed out.

Speaker 1

So for white holes, nothing can get in, but stuff can come out. Where is the stuff that comes out coming from?

Speaker 2

Great questions?

Speaker 1

Did the gut gets filled into the white hole?

Speaker 2

And great question? And in general general relativity has no answer to that, right, It doesn't predict anything that could come out it nothing comes out, could be that green eggs and ham comes out, right, General relativity is no idea what could come out. In general. However, there are some theories that connect white holes and black holes via

a wormhole. And say, for example, if you have a black hole where things go in, and then you have like basically a tube that connects it to a white hole, things come out the white hole after they've gone in the black hole. And so in that sense, a black hole and a white hole are two ends of a one directional wormhole transit, and so things come out the white hole that fell in the black hole. But you can't go the other.

Speaker 1

Direction, right, So I'm tempted to ask how many anuses. That means the universe has for Sammy, well.

Speaker 2

That would be one, right, because you can think about your digestive system as a tube. There's an in in and out and usually one direction always.

Speaker 1

But there's more than one black hole in the universe, right, So there's more than one anis that's true.

Speaker 2

And we don't think that all black holes are connected to white holes, right. Some of them just eat stuff. There's no anus there at all. It just gets bigger and bigger and maybe eventually explodes like a face mite on your face.

Speaker 1

I don't know, mmm, love these connections.

Speaker 2

Yeah, So that's sort of the concept of white holes. Another way to think about white holes that's maybe easier to grapple with is try to imagine a region of the universe where you can get messages from, but you could never send messages too, And that seems contradictory, like how could you do that? But actually that exists in our universe already. It's our cosmic horizon. Like there are galaxies out there that sent us photons, but they are now past our cosmic horizon because of the expansion of

the universe. If we shout a photon at them, it would never reach them. So there's a whole region of the universe where photons have escaped. They've come from there, but they can't go to there. So I'm not saying that everything outside the observable universe is a white hole, but it's just sort of a way for you to get a handle on what are we talking about.

Speaker 1

Okay, so I've absorbed a lot of information and the you know, my brain is a box and it's overflown and some has started to fall out. So I think you've already said this, but just to confirm, white holes are not anything that's really supported by physics theory. It's more of a thought experiment that arose out of a way that we decided to portray the way the universe could look. But that could have just been a result of our artistic way of trying to explain things.

Speaker 2

It could be, yes, it could also be that we're exploring the true nature of the universe and discovering it in our minds before we discover it in the universe, the same way we did with black holes. People thought exactly the same thing about black holes before we found them. They were like, well, that's cute, but it's just a mathematical oddity. I'm sure that doesn't actually exist out there in the universe. That would be bonkers, And then of

course we found them. And so sometimes mathematically exploring the corners of our minds can reveal the true nature of the universe, which is amazing and philosophically deep and incredible and really kind of a as close as you get to a spiritual moment, I think in cosmology.

Speaker 1

Yeah, yeah, I'll give you that. That's incredible.

Speaker 2

So everything you said is true, But I think the implication that therefore is probably not really out there, I think is a question mark.

Speaker 1

All right, So can you remind me what was Sammy's question in particular?

Speaker 2

So Samy was like, if you replace the sun with a white hole, what would it look like? Oh, and before we get to that, we had to consider one more idea about white holes, because white holes, again a broad topic. So we've talked about white holes is sort of like inverse black holes region of space time that you can escape and not enter, or maybe the back end of a wormhole. But there's one more version, which is the quantum version of a white hole.

Speaker 1

What's that?

Speaker 2

And this suggests that there are no black holes actually that the things we see out there in the universe that look like black holes are actually just slowly collapsing stars because in regions of very high mass, time slows down. Talked about time dilation many times, and so perhaps what's happening is stars are collapsing, but time has slowed down so much that it looks like a black hole. It's

just a very very slowly collapsing star. And there are folks out there like Carlo Ravelli who thinks that it's not actually going to collapse all the way to a singularity. Quantum mechanics will somehow prevent that from happening, push it back and invert it, and eventually a black hole sort of bounce back and turn into something which emits all of its mass.

Speaker 1

Wow.

Speaker 2

So this is Carlo Ravelli's concept of a white hole.

Speaker 1

Ah okay, all right, very cool. And so we've talked about three different ways to get white holes, or three different ways of thinking about it. Does each one of them give a different answer to Sammy's question?

Speaker 2

Yeah, absolutely it does. So you know, if white holes are just some region of space that you can't escape, and you replace the Sun with a white hole, then like maybe nothing would come out right, there's no prediction for anything to come out. It just depends on what happened to be in that regional space in the deep deep past before it formed, right, and so probably nothing.

If the white hole that we put in the center of our solar system is the back end of a wormhole, then what comes out depends on what's going in that black hole. If there are aliens out there and they're

treating that black hole as like a cosmic dumpster. They're like making really dangerous elements in their crazy experiments and they're dumping it in a black hole for their safety, then you know we're going to be the cosmic dumping yard of some alien physicists, which could be amazing, like wow, you could see some cool stuff come out of that white hole though, or it could be really bright, you know, like what if that black hole eats a star or

something like an enormous amount of radiation could come out of it. Or it could be just like weird alien leftovers. Who knows, I.

Speaker 1

Would eat weird alien leftovers, give it a shot.

Speaker 2

If I had to choose between weird alien leftovers and wardycomb jelly on toe, I'm not sure what I would choose.

Speaker 1

Yeah, it'd be a tough decision. So what about Carlo Ravelli's vision of a white hole.

Speaker 2

Yeah, so if white holes are actually slowly collapsing black holes that then reverse, then you're gonna get something with an enormous amount of radition. It's going to be very, very bright. And one of the inspirations for white hole research is that there are things in the universe that are very bright that we don't understand, things like gamma ray bursts, these very short lived, incredibly bright waves of

gamma rays, very high energy photons. Nothing in the universe we know about can make them, and yet we see them and people wonder like, oh, maybe those are white holes. People also talk about, you know, the Big Bang maybe being the result of a white hole in the early universe, because people like thinking about cyclical universes, like the whole universe turns into a singularity and then bounces back into

a big white hole. Anyway, Sammy, the answer is, we don't know if white holes are real, and if they are, it depends on which flavor of white hole you get.

Speaker 1

Do you think that Sammy wanted to know what would happen to Earth if the Sun was replaced by a white hole, or what would it be like if the Sun was replaced by a white hole? I think in all of these situations, Earth is toast.

Speaker 2

Earth is not in a great shape in any of these situations. Yeah, and in many cases the white hole has mass also, so you could continue to orbit it while you're getting fried with alien cosmic junk.

Speaker 1

Thumbs down. All right, what do you think, Sammy?

Speaker 4

I prefer if the sun was not a plate to a white home, although that that end of a wom hole idea does sound pretty cool.

Speaker 1

All right. Our last question comes from Rhonda and is about humpback whales.

Speaker 5

Hey, Daniel and Kelly, it's Ronda and I live in North Alabama. I was recently scrolling through the Internet and saw a whale of a tail about how whales migrate. They were saying that whales migrate because the bacteria in the bumps in their back aligned with magnetic north. I was just wondering if you might be able to clarify that a little bit. Let me know if it's true. Huge fan of the show, Love you guys, and thank you so much for feeding my curiosity.

Speaker 1

Well, this is a great question, Ronda. I was super excited to have the opportunity to dig into navigation for humpback whales. A little bit of background, There are humpback whales at both of the poles. They tend to feed in polar regions, and for example, Antarctica has loads of this crustacean called krill that they eat, and you find it in really high densities there. So they go to the polar regions to feed, and then when it comes time to have babies, they head up to the tropics

where the is warmer and shallower. We think maybe those are better baby nursery conditions, so they head up there to breed, and then when the babies are old enough, they head back down to the cold areas where their food is found in high abundances.

Speaker 2

So this is similar to how birds migrate, but it's just much more massive in underwater.

Speaker 1

Yes exactly, and I mean incredibly long distances. Imagine going from you know, Antarctica to the tropics, like that's a huge distance, and they often make very straight line paths, and so it's been for a long time a question how do they remember, you know, when they're very young, when they make this journey for the first time, how do they remember where they've gone, and how they go back to the same place, and how do they go there without Like, you know, I get lost when I

go to the grocery store sometimes, like how do they not get lost?

Speaker 2

And it's a super fascinating question. I heard that these whales move in a straight line relative to the earth rather than relative to the water, right, which requires some kind of navigation because you know, no matter what the currents are, they find a way to follow the path, which suggests that maybe they know where they are on the earth, which is amazing.

Speaker 1

It's crazy. But let me just take a step back to talk about why it's so hard to answer this question in humpback whales. So if you were asking this question in pigeons, for example, you could take a pigeon from one place and if you thought that maybe they were paying attention to some queue in the northern hemisphere, you could transport them to the southern hemisphere and then

see how they change their behavior. If they thought they were paying attention to magnetic fields, you could, like I don't know, stick a giant magnet on their back that confused them and then look to see do they get lost? If you thought they were looking for visual cues. You could you know, put them in a giant arena and move the cues around and see how that messed things up.

And then you could do other things, like you know, could put blindfolds on them and if you think that they're just you know, responding to magnetic fields or something. But with humpback whales, they're endangered, or at least they're threatened. I can't remember what their status is right now. But you can't do any of those things to them. Yeah, you can't move them to the other hemis. You can't poke their eyes out. You shouldn't poke their eyes out.

You can't do the kinds of manipulative experiments that you'd

need to really try to nail this stuff down. So the best that we can do at the moment, as we can look at old records for where humpback whales were killed in the era where whaling was popular, and now that we have technology for tracking animals, you can put trackers on them and you can follow their movements over time and then you can collect data on how their movements are correlated to things that you think might be important for navigation.

Speaker 2

So we basically have to wait for natural experiments like if the magnetic poles flip, or if the currents change, or if the visual conditions change, we can look to see how it affects the whales, but we can't induce those changes ourselves.

Speaker 1

Right, And unfortunately humans are doing some of those experiments now. So one of the things we think they queue into is water temperatures or following certain currents or certain salinities. And as global climate change is happening, that's impacting water temperatures and that's impacting where currents go. And I guess the good news is that for humpback whales these changes are relevant to their smaller movements, so it's relevant to

where their food sources are. As their food sources, for example, maybe track certain water temperatures. But even as all of this stuff is changing, they are still taking pretty straight line paths up to their breeding ground, which suggests that that's not the main cue that they're using. So even as this changes, they're still getting to where they need

to go. So one of the leading hypotheses is that the Earth's magnetic fields are being used by these giant whales to try to figure out where they're going to go. And Daniel I should tell you that while I was writing this outline, I just assumed that you would be able to explain these to us, and I didn't give you the heads up or research it ahead of time. Was I right?

Speaker 2

You actually were right. I'm really fascinated by this. Okay, and the folks in my department here at UC Irvine biophysicists who study this question of how birds migrate, for example, which is a very similar question and one of the leading hypotheses has to do with quantum mechanics. Actually, there's like a protein inside bird's eyeballs which has two different states, and it flips back and forth between these two states, and the rate at which it flips depends on the

magnetic field. So this is a thing which actually does happen. And so in principle, is a mechanism by which an animal could sense a magnetic field Because like we don't think humpback whales or Canadian geese are like building little compasses and strapping them to their bodies, as cute as that would be, they need some sort of biological mechanism. What we don't know is if that's really the mechanism. You know, this is like something inside their body that's happening.

We don't know if it's connected to their sensory organs or somehow to their brain to allow them to somehow like see or experience these fields, or actually even use them in their navigation.

Speaker 1

There's a newer hypothesis that there are bacteria that also respond to magnetic fields, and they sort of align themselves with magnetic north And the idea here is that you'd have these bacteria and then the animals would have some way of sensing what the bacteria are doing. And this is what the listener was referring to. But actually what I had imagined you would explain was why does Earth have magnetic fields in the first place.

Speaker 2

Yeah, oh that's awesome. It's a little bit of a mystery. I mean, we know that magnetic fields are generated by charges in motion, right, Like, give an electron, it just generates an electric field. You move the electron, you give it a velocity, you get a magnetic field, which is already kind of mind bending because it means that like whether the electron has a magnetic field around it is frame dependent. You know, Like I'm holding an electron, I

see it as an electric field. You whiz, buy me in a car, you see that electron having a magnetic field, So we like disagree about whether there's a magnetic field there, which is crazy. Yeah, that's a whole fascinating story about the development of special relativity. But anyway, charges in motion generate magnetic fields. There are no magnetic charges in the universe that we know about that could just generate magnetic

field while sitting there. So most of the magnetic fields are generated either by like electrons spinning that quantum version of motion can generate a little magnetic field, or you have the electron itself is like flowing in a current, And so what's flowing underneath our feet when there's lots of rock and metal in motion underneath our feet, and we think that that motion is probably generating the magnetic field, but we don't totally understand it. The magnetic field is

weird and not reliable. The poles flip and flip it in a irregular way, like sometimes every fifty thousand years, sometimes once a million years. The poles are always migrating a little bit, and sometimes they're like, you know, north and south will flip, which is weird. Meanwhile, like in the sun, it's super regular every eleven years, the Sun flips its magnetic field, and this has to do with like currents of plasma going through the Sun. Again not

totally understood. So roughly we think it's flowing currents within the Earth, but there's lots of detailed questions we don't know the answers to all right.

Speaker 1

Well, so the idea here is that, either through the bacteria that live with the whales or different senses that there are organs that they have in their body that have not yet been identified, they're able to sense these magnetic fields and follow them from one place to another,

and there's some good evidence that this has happened. For example, whales tend to get stranded more often during solar storms, and what they think is happening here is that when there's a solar storm, it's messing with the whale's ability to sense the Earth's magnetic fields. So it's not that it's messing with the Earth's magnetic fields, it's just sort of giving the wrong information to whatever the whale is using to figure out where the magnetic fields are, and

so whales are more likely to get stranded. Essentially, the idea here is that they're not able to read the Earth's magnetic lines anymore, and so they end up in places where they're not supposed to be.

Speaker 2

So that's really interesting, and it sort of suggests that whales are using the magnetic field or that something else about these solar storms might be affecting their senses. Do we know anything about the history of whale migration as the magnetic field shift.

Speaker 1

I did find a paper that tracked humpback whales over a fifteen year period, and during that period there were pretty significant shifts in the magnetic fields. And even in years where there were shifts, the whales were going on the same paths and essentially a straight line. So these shifts didn't seem to move them off course, which suggests that it's not just the electric field. Maybe it's the electric field plus some other things that they're using to

correct themselves. But it does make it look like this is not the whole story.

Speaker 2

Could they be using just visual cues, like hey, turn left at this canyon and then go around this underwater mountain cause they just have like amazing memories.

Speaker 1

They could They could have amazing memories. They also often travel with other individuals, so you know, like sometimes when I think I'm lost. I'll never ask that because that would just make it worse. But like if i'm you know, if I'm in the car with a friend, I'll be like, you know, oh, do you remember Chase Bank being on that side of us last time? Or should it be on the other side? Are we going the wrong way? And so, you know, whales travel with friends might use

each other. And additionally, whale calls can be heard over very great distances, and so it could be that they can, you know, hear that, like Frank is way up ahead, and they're just following the noises that Frank makes or Fran And so it could be a combination of noticing landmarks, you know, sharing information with each other, and then listening to the sounds of the seas to get to where they're going.

Speaker 2

Is there any chance that they're like popping up to the surface and opening their eyeballs and like using the stars to navigate.

Speaker 1

There have been some folks who have proposed that they think it's more likely that they might be using cues from the sun than cues from the stars. We don't know that whale vision would allow them to see the stars with the level of detail that you would need to navigate by it. And so there are folks who are interested in that question. But I'd say at the moment that's a pretty hotly debated topic in the field,

and there's not a clear consensus. Although I do absolutely love the idea of the humpback whales navigating by the stars.

Speaker 2

That's beautiful, that would be gorgeous. Well what if they're just really good good at dead reckoning. You know, what if they don't need navigational cues, they're just like, I know, I swim in this direction for forty five minutes and then I turn, I swim in that direction. It's hard to conceive of. I mean, imagine like driving to your friend's house, like across country with your eyes closed. Yea, right, just like knowing when to turn. That would be crazy.

But hey, maybe whales are just good at that.

Speaker 1

Yeah, I mean, this could be an example where my personal experience limits my ability to imagine an answer. It is hard for me to imagine that. But you know, they've got giant brains. Maybe they're putting some of that giant mass to like incredible processing abilities to navigate incredible distances.

Speaker 2

All right, So what's the answer then, to the listener's question, I would say.

Speaker 1

The answer is, we don't completely know. It probably has something to do with landmarks, something to do with sharing information. They might be using the magnetic fields to some extent. They're paying attention to currents and temperature, but even when those change is not throwing them off course. So it's probably a what we would call like multimodal signals like it. They probably making lots of different kinds of information and

integrating it. But at the end of the day, we can't do the sort of manipulative experiments we'd need to lock it in, So we're just gonna have to keep waiting to see what sort of experiments nature throws at us so that we can collect data as we go.

Speaker 2

Amazing.

Speaker 1

Oh and I forgot. There was one other queue that has been getting a lot of attention in the papers that I read, and that's gravity as a sort of landmark. And so I think the idea here is that there are like mountain ridges that are made of dense materials, and so they pull on these giant whales a little bit more, and so you can use these as sort of cues as you move around their environment, because these

don't change much you know those mountains. If they're there one year, they're probably going to be there one hundred years from now. And so there's some thought that those are cues that are being used. What do you think as a I mean, I know, we don't know what particle makes gravity, but does this make sense?

Speaker 2

It makes sense sort of from a physics point of view. I mean, we all feel gravity, and gravity mostly points down, but gravity would points straight down if the Earth was a perfect sphere. If you're standing next to like a huge blob of stuff, then you're gonna feel it's gravity also, and so the net gravity is gonna point like a

little bit to the side. And so if there are like dense deposits of iron under the ocean floor or something, and whales are super sensitive to the direction of gravity, they have some like internal biological pendulum, then in principle they could detect those and I guess in principle you could use that to navigate. To me, I'm not sure how much of a navigation a help it is because it doesn't provide you like longitude latitude information the way the stars do, right, It just tells you that you're

near a landmark. To me, it seems like about as useful as eyeballs, not as useful as celestial navigation.

Speaker 1

Well, but if you can't see the stars, then you know that doesn't help so much. And we don't know that the whales can see the stars. Does it matter that they are so like many orders of magnitude bigger than we are. Does that make it easier for them to detect differences in gravity along the Earth's surface.

Speaker 2

You definitely have a larger force on larger masses, right, But of course they also have larger mass, so it is the same acceleration which they sense in their stomachs probably, so like maybe they're sensing shifts in how their stomachs move or something. I mean, And what I mean by like as good as eyeballs is that you know, if you could see underwater features like oh, there's a mountain underwater, or there's this cliff underwater, that seems to me as

good as this gravitational stuff. It's not like it tells you where you are on the planet. It's still local information in that way. But yeah, maybe whales are doing that.

Speaker 1

And that would give a whole different meaning to like, I've got this gut feeling the mountain is actually pulling your gut to the right, and you're like, we should go right.

Speaker 2

I mean, you're joking, But your gut is an accelerometer, right. That's why on a roller coaster you feel like you're leaving your stomach behind or it's in your mouth. There's something. It's for exactly that reason. You are measuring a change in the local acceleration away from the normal Earth's gravity. And so, for example, if you walked by some super dense deposit of material, you would feel the same way. You would feel a force pulling in a weird direction, and yeah, it'd be a gut feeling.

Speaker 1

Well, usually it pass out on roller coasters before I get that feeling. So but maybe if I was slowly walking along the ocean floor, I'd be able to sense it better. But all right, so I think the summary point here is that we don't really have it all figured out yet. It's probably more than one thing. They're probably integrating cues from a variety of different sources, but one way or another, they make these amazing migrations.

Speaker 2

Well, you might be wondering, how is Daniel going to connect this question of whales back to the aliens and their auses.

Speaker 1

I'm dying to now.

Speaker 2

It's a lot easier than you might imagine. Any fan of Star Trek knows that in Star Trek four the aliens were interested in the humpback whales because it turns out they're the smartest critters on Earth, and so maybe aliens will come to Earth to talk to not just about their navigation, but you know, to get advice about whether or not they should promote their transient aeuses to permanent ones.

Speaker 1

Oh my gosh, I am so proud of the way you tied it all together. It's only missing cannibalism and a dig on white chocolate. Bravo.

Speaker 2

You know, we try to end these episodes about inspiring humanity, and I'm not sure that accomplished that, but I did find some connective tissue.

Speaker 1

I'm impressed. And on that note, let's see if Ron does impressed. Wow.

Speaker 5

Thank you so much Daniel and Kelly for digging into that question about humpback whales and how they migrate. I found it was really fascinating and I've never heard some of those theories before. I really can't wait until the aliens get here to interpret the answer for us too. Thank you again.

Speaker 2

All right, Well, we had a lot of fun talking about jelly and white holes and whales and tying it all together in surprising ways. And we also had fun because we're answering your questions, and we'd like to think that we're scratching your curiosity inch because there's so many incredible things to be curious about in this universe. So please share your curiosity with us and with the other listeners. Write to us to questions at Daniel and Kelly dot org.

Speaker 1

We can't wait to hear from you. Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio. We would love to hear from you.

Speaker 2

We really would. We want to know what questions you have about this Extraordinary universe.

Speaker 1

We want to know your thoughts on recent shows, suggestions for future shows. If you contact us, we will get back to you.

Speaker 2

We really mean it. We answer every message. Email us at Questions at Danielankelly.

Speaker 1

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Speaker 2

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