Rachel Feltman: Hey listeners! Rachel here. Today we’re sharing another episode of Vox’s podcast Unexplainable. On September 16, you heard me chat with host Noam Hassenfeld about some of science’s most difficult to answer questions. Today we’re sharing part two of that series. In it, Noam talks with Scientific American’s Joseph Howlett, a senior reporter who covers physics, math, astronomy, and more. Joe actually used to study dark matter—and the unanswerable nature of that scientific quest is what pushed him to leave the research world behind. Here’s their conversation now.
Noam Hassenfeld: Take a look around you, wherever you are. The table, the TV, your own body. At a basic level, it's the same stuff as everything else, and everything you see if you look out the window, or even further out. The ocean, the rest of the planet, the sun, the stars. It's all matter. We can see it, we can feel it, but all of that stuff is just 15% of all the matter in the universe.
The other 85%, 85%, is something called dark matter. This kind of invisible, untouchable matter. But we don't know what it's actually made of. Scientists have been trying all kinds of things for decades to try and figure out what it is, but so far they've got nothing. So what does it mean for science if we can't find it?
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If we can't answer arguably the biggest mystery in the universe? Today on Unexplainable, I'm gonna talk to a physicist who spent years looking for this stuff and then realized he couldn't do it anymore, so he quit because he started asking questions that went way beyond what he initially thought science was for.
And stick around to the end of the episode for an update on some dark matter news.
Joseph Howlett, thanks for coming on the show.
Joseph Howlett: Thanks for having me.
Hassenfeld: So, uh, you are, you are a science writer now. You used to be a physicist What made you wanna be a physicist? Like, what got you so excited about it in the first place?
Howlett: Yeah, I mean, I always liked these kind of big questions.
Hassenfeld: Mm-hmm.
Howlett: Like, um, the questions humans have always asked.
Hassenfeld: Mm-hmm.
Howlett: Like, how'd we get here? What is stuff made of? I had that instinct always to go deeper, right? Like, if you're in chemistry class, you hear that everything's made of atoms.
Hassenfeld: Mm-hmm.
Howlett: And then you hear that atoms are made of electrons swirling around a nucleus. Then you hear that the nucleus is made of protons and neutrons.
Hassenfeld: Mm-hmm.
Howlett: And then you ask, "Well, what are those made of?" They say, "You have to take physics."
Hassenfeld: Right.
Howlett: So if you do this enough times, you end up with a PhD in physics.
Hassenfeld: Uh-huh.
Howlett: And then you very quickly learn that there's a lot of things that we don't know.
Hassenfeld: Mm-hmm.
Howlett: And you run up against that. My favorite stuff.
Hassenfeld: Exactly. The unexplainable.
Howlett: And when you actually become a working scientist, that's the stuff you work on, right?
Hassenfeld: Mm-hmm.
Howlett: Um, so the decision I had to make is which of those questions to work on. Yeah, yeah. And for me, it was obvious that it was gonna be dark matter, at least, like, when I heard that everything I had been learning about is only one-sixth of everything…
Hassenfeld: Huh.
Howlett: At least for the picture I had of what science is supposed to do, uh, that came as a real shock.
Hassenfeld: So it's been a while since we've talked about it on the show. We had our first episode of the show on dark matter, but what is dark matter and, and why did you get so excited about it?
Howlett: Yeah, so dark matter is a thing that we know is there but we don't know what it's made of.
Um, really, it's thanks to Vera Rubin. In the '70s and '80s, she cataloged how fast stars are moving around their galaxies. Mm-hmm. So she looked at all the stars. They're orbiting the center, the same way we're orbiting our sun, right?
Hassenfeld: Uh-huh.
Howlett: But the problem with every galaxy is that all the stars are moving way too fast, especially the stars on the outside.
Uh, compare it to, like, a race car on a racetrack, right? If a car is going around the track and it speeds up and speeds up and speeds up, eventually, the tires won't be able to hold it on anymore- Right ... and it'll fly off the track.
Hassenfeld: Yeah.
Howlett: And when Vera Rubin looked at all the stars and all the galaxies, she was like, "They're all going way too fast." Like, there's not-they should all fly off into space or something like that?
Hassenfeld: They should...
Howlett:Everything, including our sun, should be flying off into space because there's not enough stuff inside to be holding it at the speed that it's going at.
Hassenfeld: Uh-huh. Right?
Howlett: Um, so either we don't understand gravity-
Hassenfeld: Mm-hmm ...
Howlett: And all the laws of how much stuff it takes to hold a thing in going that fast, we're wrong about, or there's stuff we're not seeing that's gravitating, that's extra glue, like, holding that thing in.
Hassenfeld: Mm-hmm.
Howlett: So you, you, if you imagine a race car, it can go way faster if you, like, stick a stake in the middle of the track and…
Hassenfeld: Yeah ... tie a rope to it, right?
Howlett: Right. And it's like there's some additional thing we're not seeing that's holding everything in, that's holding all the stars in. And
Hassenfeld: That's dark matter.
Howlett: That's what we call dark matter, just because we can't see it and we have no idea what it is. It's just a blanket term for this missing stuff.
Hassenfeld: So, so it's matter that interacts with stuff via gravity, right? It can pull in these fast-moving stars at the edges of galaxies via gravity, but we can't see it.
Why can't we see it?
Howlett: We don't know that. I mean, we just know that whatever this stuff is, it doesn't interact with light. It's somehow invisible.
Hassenfeld: And, and when astronomers, physicists do calculations, the only way to have enough of this stuff to make sense of the way galaxies move, that's how they get to 85% of all matter is dark matter, or five-sixths of all the matter is dark matter, right?
Howlett: Yeah, that's where this number comes from, this, why I say five-sixths of the universe is missing. It's because that's how much stuff you would need to add, how big that cloud would have to be to explain how fast the stars are moving.
Hassenfeld: Mm-hmm.
Howlett: And since Vera Rubin, we've established it in all kinds of other ways. Like, you can make maps of the mass distribution of faraway things…
Hassenfeld: Mm-hmm.
Howlett: By looking at how they bend light around them.
Hassenfeld: Mm.
Howlett: Our earliest picture of the universe, which is called the cosmic microwave background, it's, like, the light that was released very shortly after the Big Bang when the universe began to cool.
That light tells us what matter there was then…
Hassenfeld:Mm-hmm.
Howlett: And it's very clear that there was five times more of some stuff we don't understand.
Hassenfeld: Right, okay.
Howlett: Like, there's all of this additional evidence, and all of it aligns with this five-sixth number.
Hassenfeld: Huh. So why is it still such a mystery to us?
Howlett: Yeah, it's 'cause we don't know what it is. I mean, like I- It's a big, it's a big thing not to know. Especially if you're like me, right?
Hassenfeld: Yeah.
Howlett: If you're asking these questions, like, "Okay, what's an atom? What's in that? What's in that?"
Hassenfeld: Mm-hmm.
Howlett: If you keep doing that, like, you wanna know what stuff is at a fundamental level. Dark matter, if you picture some galaxy, it's like this shadow realm that's on top of the galaxy.
Hassenfeld: Mm-hmm.
Howlett: You can't see it, and it's only, like, interacting with it through the way it tugs on things, right, all together.
Hassenfeld: Through gravity.
Howlett: But what is that a cloud of, right?
Hassenfeld: Right.
Howlett: I'm not satisfied that we know what dark matter is if we don't know what that cloud is.
Hassenfeld: But scientists are trying to figure out what it is, right?
They've been researching this for decades.
Howlett: Yeah, so one thing to say is that, like, shortly after Vera Rubin, there were these two explanations. Mm-hmm. There's either we're wrong about gravity, or there's this missing stuff. Over the decades, that first hypothesis has kind of fallen apart. It's very hard to adjust gravity in a way that makes everything make sense.
Hassenfeld: Right.
Howlett: All of this evidence we have. We're pretty sure we understand gravity pretty well. It's a good theory.
Hassenfeld: Yeah.
Howlett: Uh, so there's this missing stuff.
Hassenfeld: Uh-huh.
Howlett: And there was this kind of arms race. There was people trying to build detectors on Earth to detect this stuff that we know is going through us all the time, but we don't know what it is, right?
Hassenfeld: Mm-hmm.
Howlett: So the next question is, like, "Okay, let's figure out what it's made of by trapping it in a lab," right? That's how science works, right? Like, you- you, there's this missing part of the universe, so you develop a theory that can explain it and that gives you a testable hypothesis that you go build in a lab.
And what's great for us is that theoretical physicists in the '80s already had an idea for a type of particle that might exist in the universe that exactly explained all the dark matter.
Hassenfeld: Yeah. They were trying to map all potential particles, right? Yeah. This is the standard model of physics?
Howlett: Yeah, the standard model of physics is the 17 building blocks, the Lego pieces that everything we know about is made of, right? Yeah. So it's the quarks that make up protons and neutrons. Electrons are one of these particles, and together, these 17 particles build everything that we can see, right? Mm-hmm. It only explains one-sixth of everything, right?
Hassenfeld: Right.
Howlett: Like, we know that it doesn't account for this extra stuff, so we know that it's incomplete.
Hassenfeld: And we had some kind of predictions, like there may be empty spots on the standard model, and what you're saying is that one of those empty spots would be the dark matter particle.
Howlett: Yeah, it was really convenient, and physicists like convenience, right?It's Occam's razor, like the simplest explanation is…
Hassenfeld: Mm-hmm.
Howlett: is the one you go for first.
Hassenfeld: Mm-hmm. Right?
Howlett: And this is what's great about this theory they had in their, in their desk drawer…
Hassenfeld: Mm-hmm
Howlett: Is that it's, it interacts gravitationally.
Hassenfeld: Mm-hmm.
Howlett: It goes through us like a ghost, right? Mm-hmm. Like, we knew about dark matter.
But very, very rarely, on rare occasions, the ghost becomes corporeal for just a second…
Hassenfeld: Okay.
Howlett: And smashes into one of our atoms.
Hassenfeld: Wait, that's the theory?
Howlett: That's the theory. Okay?
Hassenfeld: Okay.
Howlett: Their, this particle that they had in their desk drawer, it was, it explains all the dark matter, but in addition to its gravitational pull, there's a very, very, very weak coupling to the normal stuff in the universe.
So dark matter's going through us all the time. Very, very rarely, imperceptibly rarely, one of those particles smashes into one of our atoms. We don't feel it.
Hassenfeld: Got it.
Howlett: But that means that you can build a detector of regular matter to detect that, and that was key, right? Okay. 'Cause that meant that, okay, we can on Earth look for this particle.
Hassenfeld: And this is where your research enters into the picture, right? This is when you became a physicist. What kind of experiments were you working on? What kind of experiments are out there to find the dark matter particle?
Howlett: I mean, the way things went down is- Vera Rubin and others convinced us that there's this missing stuff.
And then theoretical physicists said, "Oh, we have an idea for what this missing stuff might be made of, and you can’t- you can build a big detector". A detector is just a tank of atoms that they light-the tank lights up when one of the atoms gets hit, right?
I said when..
Hassenfeld: Gets hit by a dark matter particle.
Howlett: By anything.
Hassenfeld: Oh, by... Okay.
Howlett: So when we get hit by a dark matter particle, you don't notice.
Hassenfeld: Mm-hmm.
Howlett: You have a tank of liquid xenon, for instance, which is a cryogenic liquid. It's kind of like liquid nitrogen that you play with in a lab.
Hassenfeld: Okay.
Howlett: When a xenon atom gets hit by a particle, it lights up.
Hassenfeld: Mm-hmm.
Howlett: So that's all a detector is.
So they said, "Okay, if I put a detector on this table, it would see stuff all the time 'cause there's particles coming from space".
Hassenfeld: Got it.
Howlett: So you would never see the dark matter particle that interacts once in a year or something.
Hassenfeld: Right.
Howlett: So it wouldn't work here…
Hassenfeld: Mm-hmm.
Howlett: But it would work underground. So I was working to build this big dark matter detector underneath a mountain, one of Italy's biggest mountains.
Hassenfeld: Okay.
Howlett: Yeah.
Hassenfeld: So dark matter would go through the surface. It would go all the way into this underground lab or wherever.
Howlett: Yep.
Hassenfeld: And the idea would be that maybe there we could see dark matter hitting…
Howlett: It would go through...
Hassenfeld: Some other atom...
Howlett: It would go through this whole mountain in Italy. It would go deep under, in, into the center of the mountain.
It would go into the lab, it would go into the detector, and 99.99999% of the time it would go through the detector without doing anything. But the idea is, once in a blue moon, if you wait long enough and you make the detector quiet enough…
Hassenfeld: Mm-hmm.
Howlett: One of those dark matter particles will become corporeal just at the right moment, smash into a xenon atom, light the detector up, and then we say, "Okay, we found dark matter".
Hassenfeld: Okay.
Howlett: "We know it's made of these particles". And then the problem's solved, right?
Hassenfeld: Yeah, tell me about the-the mountain…
Howlett: Yeah.
Hassenfeld: The lab. Like, what did, what does this look like in Italy?
Howlett: It's an interesting commute. Like, you you pile into, like, a little Fiat and you, you, you, you drive down these mountain roads, you go on the highway, and the highway has a tunnel that goes through this mountain.
Hassenfeld: Mm-hmm.
Howlett: But we don't go all the way through the tunnel. We go halfway through the tunnel, and then there's this turnout for the scientists.
Hassenfeld: It's like a little secret…
Howlett: There's a little secret…
Hassenfeld: Oh my God. Okay ...
Howlett: Entrance with these Italian guards who mispronounce your name. And Olet, they called me, yeah.
Hassenfeld: Okay.
Howlett: Uh, and…
Hassenfeld: Amazing.
Howlett : And, you know, you, you show them your badge, you go through, and then-
Hassenfeld: Mm-hmm.
Howlett: You're in this cavern. It's like a big underground cavern. It's kind of chilly. It's, uh, expansive.
Hassenfeld: It, i- is the ceiling like cave?
Howlett: It's cave.
Hassenfeld: Oh my gosh.
Howlett: Yeah, yeah, yeah, yeah. It's cave. I mean, it's i- finished in different places-
Hassenfeld: Mm-hmm
Howlett: But you, you know that you're underground. Uh, it's a little claustrophobic if you're someone like me, but we never see the sun basically 'cause you'd stay there most of the day…
Hassenfeld: Mm-hmm ...
Howlett: When you're really working at it, yeah.
Hassenfeld: Wow. I think I have a photo of you. Uh, is this you-
Howlett: Yeah
Hassenfeld: In, uh, Italy?
Howlett: Yeah. This was, I think, 2019, something like that.
Hassenfeld: Mm-hmm.
Howlett: Underneath the mountain-
Hassenfeld: Okay.
Howlett: Closing the giant detector. So you can see it's kind of a size of a very small sedan.
Hassenfeld: This is the actual ... But so, like, this is full of xenon?
Howlett: It, it will be full of xenon.
Hassenfeld: Okay.
Howlett: So where I'm standing will be water, basically.
Hassenfeld: Mm-hmm.
Howlett: And, and this thing will be contained in vacuum 'cause it has to be very cold, right?
Hassenfeld: Mm-hmm.
Howlett: Um, but first you have to build it and close it up, and that's, that's what we're doing in this picture.
Hassenfeld: What do you think 2019 Joe is, uh, is, is feeling at that point, looking at that detector?
Howlett: I mean, it was really invigorating-
Hassenfeld: Mm-hmm.
Howlett: To be, like, building the thing. Our experiments were working really well. They were getting very sensitive, and we were about to make that jump to cover the region of, of predictions…
Hassenfeld: Mm-hmm.
Howlett: That was exactly what the theorists predicted. It, it, it felt not probable, like, I don't know that I would've put money on it, but there was optimism around.
Hassenfeld: Mm-hmm.
Howlett: Yeah, definitely.
Hassenfeld: Then tell me when you started to feel differently.
Howlett: Yeah, so we ran this big detector, and I was working on the analysis. So you have all this data. You have, like, whatever, uh, many months of this thing sitting quietly and looking for the light. And there was this one big Zoom call…
Hassenfeld: Okay ...
Howlett: With my entire collaboration, people all over the world, hundreds of people on one video screen, uh, in all their different universities.
And it was this moment where we were gonna find out if the experiment worked or not. It had already run for a long time. We had already built out this big method for analyzing whether or not the data contained dark matter, and all at once, we were gonna push a button, and the experiment was gonna tell us whether, yes, you discovered dark matter, or no, you didn't.
Hassenfeld: Mm-hmm.
Howlett: And I remember that moment when we pushed the button. We watched it churn through all this data and say, "No, you didn't find it."
Hassenfeld: Okay.
Howlett: And I remember watching- what seemed like despair wash over everybody's face. I watched, like, the stages of grief in fast motion. Yeah. It…
Hassenfeld: What, what did you see on people's faces?
Howlett: At first, like, a kind of denial. Like, I think, I think everybody was like, "It's okay. It's okay." Like, they're... Instantly they went from, from, I think, a sincere belief that we had a good chance of seeing it to, like, "Okay, well, it's not the end. We can build more. Like, dark matter could just be a little more ghostly than we thought before."
Hassenfeld: Mm-hmm, yeah.
Howlett: Build a bigger detector. And we immediately started doing that. That was most of my PhD, was building bigger and bigger detectors, and waiting longer and longer. The bigger you, the detector you build, the longer you wait, the more sensitive you become to this rare dark matter interaction. But the, that day had an impact.
Hassenfeld: Hmm.
Howlett: Like, especially when I talked to young people who I was working with. So, you know, I was in Italy, I was going underground, and you would have these conversations over lunch, over dinner, and you would get the sense that, like, nobody actually thought the thing was gonna work anymore.
Hassenfeld: Huh.
Howlett: Like, the disillusionment, at least among young people, was pretty universal.
The professors who had spent their whole career working on dark matter, they showed more optimism. They showed more, like, "Okay, well, maybe the next one."
Hassenfeld: Mm-hmm.
Howlett: But especially all those young people who had seen that first failure, I think they were shaken. Their faith was shaken.
Hassenfeld: Do, do you remember any of those conversations?
Howlett: Yeah, I mean, I started taking, like, an informal poll, right?
Hassenfeld: Mm-hmm.
Howlett: I would ask people, so, like, "What do you think are the chances that this detector we're building," the next one, the bigger one, "will find dark matter?" And they would say, "Zero." They would say, "No, it's not gonna happen."
Hassenfeld: So what does it mean for science if we never crack what might be the biggest mystery out there?
We'll get into all that after a quick break.
[AD BREAK]
Hassenfeld: So it seems like there's two possibilities here. Either we are failing as a scientific community, or, or struggling, I don't wanna say failing, to detect the particle, we're not building big enough or quiet enough detectors, or there's something about the nature of dark matter that makes it, like, impossible to detect.
Howlett: Yeah, I mean, it could be that it's just this shadow realm that only interacts with our world through its gravitational pull. If that's the case, we'll always be in this place where we know it's there, and we don't know what it's made of.
Hassenfeld: Yeah. I mean, I, y- you sent me a, a conversation you had with Siska De Baerdemaeker. She's a philosopher, and she said something that really stuck out to me.
Siska De Baerdemaeker: It is entirely possible that dark matter only interacts gravitationally.
Howlett: Yeah.
De Baerdemaeker: And that would be worst case scenario for physics.
Howlett: Mm-hmm.
De Baerdemaeker: But, like, nature doesn't have to play nice.
Hassenfeld: What do you think about that line, "Nature doesn't have to play nice"?
Howlett: Unfortunately, what Siska's saying is that nature doesn't have to have made a dark matter particle that you can ever know what it's made of, right? Like, we can only know what something's made of if we can trap it in a detector on Earth.
Hassenfeld: Right.
Howlett: That's how we answered all the questions I asked in high school and college, right?
Hassenfeld: Mm-hmm.
Howlett: We can never answer those questions for dark matter if it only interacts gravitationally.
Hassenfeld: Right.
Howlett: Because you can never trap it in a detector. Gravity's too weak of a force.
Hassenfeld: It just seems like such a tantalizing situation, that we can see it doing all of this stuff, we see it holding galaxies together and, and spinning them faster than they should be, and we can't capture it, we can't detect it.
Howlett: It's horrible. Billions of them are going through us all the time.
Hassenfeld: Yeah.
Howlett: But we'll never know what they are. That's what I'm saying.
Hassenfeld: Mm-hmm.
Howlett: For me, that's...that runs up against my entire picture of what science is supposed to do.
Hassenfeld: Yeah, so, so you've talked to a bunch of scientists and philosophers of science.
Did anyone disagree with your perspective that science can't tell us the secrets of the universe? That, that maybe it's unreasonable to expect science to reveal itself in the ways we want it to reveal it?
Howlett: You know, when you put it that way, when you ask a scientist, "Does the universe owe us explicability…
Hassenfeld: Mm-hmm.
Howlett: Comprehensibility?" They'll say, "Of course not." But if you ask them in any one situation, "What do you think is gonna happen with dark matter?" including my former peers, the people who said 0%, that our experiments would work.
Hassenfeld: Mm-hmm.
Howlett: All of them, to a one- felt that at some point we'll figure it out. I don't know what's gonna happen, but some genius will come along, some Einstein, and change the paradigm, and we'll learn that we were wrong about everything and everything will suddenly make sense.
All the physicists I talked to had this faith that I used to have, and there's good reason for that. There's reason for optimism. It has done a lot of things. We've overcome a lot of mysteries.
Hassenfeld: Mm-hmm.
Howlett: Um, but even if I'm wrong, and I might eat my words tomorrow, I'd love us to find dark matter. There's a wall somewhere is what I've learned.
Hassenfeld: Yeah.
Howlett: Maybe this isn't it, but it could be this.
Hassenfeld: You used the word faith.
Howlett: Sorry.
Hassenfeld: Uh, no, it's fine. It... See, it, it makes sense to me. Uh, is that what this feels like to you? Does it feel like-some of the scientists you talk to have faith that you no longer have in, in what science is and how it's supposed to work?
Howlett: Yeah. I mean, I threw that word at some of them. Uh, my advisor, Elena Aprile, she threw it back at me. She said, "How are you so certain, Joe, that we will never find this thing?" And it's true, I think I've been so disillusioned that I've maybe l- lurched into pessimism.
Hassenfeld: Mm-hmm.
Howlett: Uh, another philosopher I talked to told me to lighten up.Uh, that was his professional advice. Uh…
Hassenfeld: [Laughs] Ugh.
Howlett: I've become convinced that even if dark matter gets discovered tomorrow, which could happen, I could eat my words, right? Uh, I would love to. But even, even if dark matter gets discovered tomorrow, I now feel that there will be another wall down the road.
Hassenfeld: Hmm.
Howlett: If the wall we can't penetrate in our understanding isn't dark matter, it will be something else.
We'll never understand everything. It's something that sounds obvious once you say it, but, like, the fact that there is means that I was asking the wrong thing of science.
Hassenfeld: Ah, I see.
Howlett: Means that I was wrong about what science is. And maybe that means that there's other people who are misunderstanding the purpose of science.
Maybe science is the thing that tells us that we can't know everything.
Hassenfeld: Mm-hmm.
Howlett: And, like, maybe that's the point of science.
Hassenfeld: Maybe we're verging, verging a bit into religion here, but it kinda feels okay. Uh, you know, I think about Maimonides, the, the medieval Jewish philosopher. He, he, his conception of God is that God is unknowable and, and the reason God is anthropomorphized in the Bible is because God is fully unexplainable.
And I, I feel like for him that was meaning, right? And, and you're telling us that science maybe has gotten us to a point where it's shown us that the universe is at some deep level unexplainable or mysterious or out of reach, and maybe that is... That's it. Maybe that's, like, a reminder to us that we need to be humble, and we are not the kind of, like, conquerors marching over the universe explaining everything.
Like, maybe that actually is the meaning. I don't know.
Howlett: I'll go there 'cause you invited me-
Hassenfeld: Okay. ...
Howlett: To go there. Uh, I think in medieval times, right, in the Christian Dark Ages, for example, there was all these weird mystics saying that God is unknowable and, and the universe is unknowable and that is God and all this stuff, right?
They were really comfortable, not only comfortable with unknowing, they worshiped unknowing, right?
Hassenfeld: Mm-hmm.
Howlett: I- in that era. And then- the Enlightenment happened and we were kinda like, "Well, never mind, actually. We can kinda know everything." Like, and it…
Hassenfeld: It w- it was working pretty well ...
Howlett: It was working for a while.
Hassenfeld: Yeah.
Howlett: And I think we might have over-adjusted-
Hassenfeld: Huh ...
Howlett: To now we're in this time where we could raise an idiot like I used to be, who thinks that eventually we'll figure out everything. And, like, I think we could learn some lessons from those weird medieval mystics…
Hassenfeld: Hmm ...
Howlett: Who, of course, like, it's great, everything we've gotten from science, but we shouldn't mistake that for meaning, and I, I think there's a lot of meaning in this wall, in, in the unknowable. Yeah.
Hassenfeld: Hmm. One thing I wanna be clear about, though, I think there's a, there's a way that someone might hear this conversation and say, "Joe is saying that scientific research, specifically physics research, is pointless or, uh, not gonna go anywhere." When you're looking at these experiments to find dark matter particles or building a bigger particle collider than CERN, are you saying that those experiments shouldn't keep going on, or are you saying that, like, your personal motivation doesn't necessarily line up with those experiments?
Howlett: Yeah, I'm, I'm really glad you brought this up, actually, Noam, 'cause, like, I think- You know, science funding is in crisis right now.
Hassenfeld: Yeah.
Howlett: Uh, including fundamental science funding.
Hassenfeld: Right.
Howlett: And, like, it's important to say that the reason we had this discussion is because of science, right?
Hassenfeld: Mm-hmm.
Howlett: Like, because of Vera Rubin's work and everybody that followed her, and the 40 years we just had of failure of trying to find dark matter, it's-
Hassenfeld: Right.
Howlett: It's how we're able to have this conversation, and the next 40 years of basic science will enable better, more informed conversations about the limits of knowledge, and, like, what we can learn from them. Like, I love science research, and it, not enough of it is happening. That's the problem. I mean, I'm not saying we shouldn't build the next thing.
I, I don't know what the next thing will find. It might find something crazy. We should build more next things so that we can get more questions, and, and, and prove me wrong, right? Like, I would love for us to find dark matter. I would love to be wrong. I just think we should spend some fraction of our time stepping back and saying, "Well, we might not ever know everything."
Hassenfeld: Mm-hmm.
Howlett: You know?
Hassenfeld: I guess I wanna bring this back to you. Well, you're no longer a physicist. I mean, once a physicist, always a physicist, right? But at a certain point you decided to stop doing research and become a science writer. Do you remember the moment you decided to stop being a researcher?
Howlett: I mean, there was a bit of an identity crisis, right?
Hassenfeld: Mm-hmm.
Howlett: Like, I had decided that this is how you make meaning.
Hassenfeld: Mm-hmm.
Howlett: And I was learning that it just isn't. I'm not an Einstein. I can't go step back and reframe all of physics, but maybe I could talk about people who are. I, I-
Hassenfeld: Mm-hmm.
Howlett: Like, I knew I would never be able to leave science behind.
Hassenfeld: Mm-hmm.
Howlett: Um…
Hassenfeld: I mean, you love it.
Howlett: I love it- Yeah ... and I especially love this, these, this edge of what we can know.
Hassenfeld: Mm-hmm.
Howlett: Right? Um, but yeah, I had to give up on the idea that I was gonna penetrate the wall, right? That I was part of this grand program that was chipping away slowly, marching along human knowledge until we figure out everything.
And that made the world way scarier to me.
Hassenfeld: Mm-hmm.
Howlett: Um, but I think it also ultimately made it more beautiful.
Hassenfeld: This feels like a, a very personal journey you've been on of what you wanted from science to find out about the universe. What do you think you've found out about yourself?
Howlett: That I'm deeply uncomfortable with not knowing things. And maybe that all of us are.
Hassenfeld: Mm-hmm.
Howlett: Um, and I think I've learned that that's the thing I should be engaging with, right? That discomfort, what it means about me. Um, and now that's what I spend, like, all my time thinking about.
Hassenfeld: Mm-hmm.
Howlett: What we don't know, what we can and what we can't, and it still makes me uncomfortable, but I think it also makes me better because of humility.
It also makes me appreciate people more. Like- I'm not looking out there or down there or at the fundamental reality anymore for meaning. I'm looking around me.
Hassenfeld: Are you still searching for meaning? I, I feel like you, you've searched for meaning in this one way.
Howlett: Yeah.
Hassenfeld: Now you're saying like, "Oh, I, I can't chip away at the wall, maybe admire the wall," but do, do you still feel like you're searching?
Howlett: Yeah. I think this is a weird place we've been thrown down.
Hassenfeld: Mm-hmm.
Howlett: Right? And left to figure it out. And, like, yeah, I'm still looking for it. I, I, I don't know that I've found it, but, like, I feel like I scratch the surface every now and then.
Hassenfeld: Mm-hmm.
Howlett: Like, when you hear an amazing story, when you think about dark matter, like, it's the closest I feel to, yeah, like a deep, real meaning.
Hassenfeld: Hmm. Well, maybe someday we'll figure it out.
Howlett: Yeah, that'd be great.
Hassenfeld: We'll have, we'll have you back on the show.
Howlett: I would love to come eat my
Hassenfeld: words. We can, we can just say, "Hey, we, we know the meaning of life, everybody." Yes. Uh, until then, though, Joe, thanks so much for coming on the show.
Howlett: Thanks so much. It was so fun.
Hassenfeld: All right, Joe. Thank you for, uh, coming back to talk with me. Uh, we, we taped the episode a couple weeks ago, and then researchers at this huge underground dark matter experiment in South Dakota just made this big announcement about something that they discovered a few years ago. Uh, they noticed that this particle hit another particle in a way that they can't really explain, so, uh, did we just discover dark matter?
Howlett: I think when we talked I told you I might eat my words tomorrow. I didn't, like- Yeah ... literally mean tomorrow.
Hassenfeld: Are you eating your words?
Howlett: Um, no. We definitely... I mean, we definitely don't know that we found dark matter, and unfortunately…
Hassenfeld: Okay ...
Howlett: I'm pretty sure, and I think most experts are, would tell you if they're being honest, that they're pretty sure we didn't. Um-
Hassenfeld: Hm ...
Howlett: Like, I would bet $1,000 against this being dark matter. It's a bet I would love to lose. Like, I would love...
Hassenfeld: Okay.
Howlett: To be wrong about that, but I, I, I just think it's very unlikely. But it is still the most interesting thing to happen in one of these experiments for a long time.
Hassenfeld: So, so are people so excited just because this is the first time in a long time anything interesting has been found?
Howlett: These experiments have been looking for literal decades for this thing that we know is everywhere, but we can't find, and they've…
Hassenfeld: Right ...
Howlett: Come up with nothing. So it's very easy to get excited about any little thing that you see.
Hassenfeld: Right.
Howlett: It doesn't mean that it's dark matter, and that's not how science works, right?
Like, you learn in elementary school the scientific method. You make a hypothesis, then you go build an experiment to confirm or disconfirm that hypothesis. That's not what ha- what happened here, right? Like, the dark matter this experiment was looking for, it didn't find. It found something else unusual, but that, that's not confirming or disconfirming its original hypothesis, right?
If you build an experiment that's sensitive enough, deep enough, run it for long enough, eventually you are guaranteed to see something you don't understand. It doesn't mean you've found-
Hassenfeld: Hm ...
Howlett: Dark matter.
Hassenfeld: Does this make you rethink your feelings at all with the search in general? Like, maybe this is that ray of hope we needed in order to build bigger and deeper and more sensitive detectors so that we will find dark matter.
Howlett: I mean, I'm excited about this event, right? It's the most exciting thing to happen in the dark matter detector in a long time. But also, I know what's gonna happen to this field, right? It's gonna take us five years to figure out what actually happened, and it's not the first time we've seen something unexplained.
It's been a long time, but it's not the first time, and it always turns out to be nothing. Whether or not this is the wall, I think there is one, and I think…
Hassenfeld: Mm-hmm ...
Howlett: We still need to be grappling with the questions about science that that raises, whether or not we found dark matter, and I hope we have.
Hassenfeld: Well, Joe, thanks for, uh, getting back on the line for the update.
Uh, I do hope at some time in the near future you do eat your words and we get you back on the show, uh, and we, we do actually discover dark matter.
Howlett: I'm absolutely down to come do my mea culpa on your podcast. I'd love to.
Hassenfeld: All right, till next time.
Howlett: Thanks Noam.
Hassenfeld: If you wanna see this episode on video, head over to Netflix. This was our second episode of our series with Scientific American. If you wanna read more about this and other impossible questions, go check out their special issue. You can find it in print or on their site at scientificamerican.com, and check out their excellent podcast, Science Quickly.
This episode was produced by Valerie Shenkman and me, Noam Hassenfeld. It was edited by Joanna Solotaroff with help from Meradith Hoddinott, who runs the show. Our video editor is Jacob Reynolds. Our animator is Karyim Carreia. Our fact checker is Melissa Hersh. Our studio engineers are Ibrahim Ochic and Joe Nebres.
Mixing and sound design by Christian Ayala. Music from me. And Byrd Pinkerton leaned against a wall in the passageway. She wasn't sure which path she should take. She lay down, and then she heard it faintly in the darkness
Special thanks as always to Brian Resnick for co-creating the show with me and Byrd. If you have thoughts about the show, we would love to hear from you. You can email us at unexplainable@vox.com. Or if you wanna support the show, join Vox. Become a member. Just go to vox.com/members. And if you signed up 'cause of us, let us know.
It would make us very happy. Unexplainable is part of the Vox Media Podcast Network, and we'll see you right back here next time
