In Scott Snyder and Greg Capullo's Dark Nights: Metal, readers are learning about a fictional Dark Multiverse that is connected to the real-world scientific concept of "dark matter."
"What they've discovered is that there's dark matter and dark energy which we literally cannot perceive around us," Snyder told Newsarama, describing the genesis of the idea for Metal. "We don't know what it is, but we can see its effects in holding galaxies and star clusters together and all these kinds of strange things.
"So I started thinking, what if the Multiverse is that way?" the writer said. "What if the Multiverse essentially has these 52 universes, but has almost this ocean of possibility, this ocean of almost reactive matter beneath it that's like a Dark Multiverse."
As Newsarama continues a series of articles we've titled "Dark Nights 101," examining the concepts in Dark Nights: Metal, we went to an expert for the exploration of dark matter and other scientific aspects of the series.
A comic book fan and scientist, James Kakalios is a professor in the School of Physics and Astronomy at the University of Minnesota. He wrote the book The Physics of Superheroes and consulted on the Watchmen film.
More recently, Kakalios released a new book titled The Physics of Everyday Things: The Extraordinary Science Behind an Ordinary Day, which he describes by saying: "You're the superhero and just as you go through your normal day and interact with smart phones or go through TSA at the airport, I explain the physics behind it."
Although Kakalios is aware of DC's Metal event, he hasn't been reading the series yet. However, after briefly examining some of the concepts introduced in the first issue of Metal, the professor took a few moments out of his day to discuss the ideas with Newsarama for our latest "Dark Nights: Metal 101."
Newsarama: Jim, let's start with the concept that inspired Scott Snyder to writer this story in the first place. What is dark matter?
James Kakalios: Dark matter is essentially a placeholder as a solution to a real problem, but we don't know what the solution is.
OK, so what am I talking about?
Going back as far as the 1930s, and getting more confirmed in the '50s, was the observation that all of the light that we could see in the universe, which is coming from all the stars and everything else, that there had to be some extra gravity around there that we could not account for.
One of the simplest examples of this is that we observe other galaxies. And some of these galaxies are rotating. You know, they're in the shape of a disc, say, like a record or a CD. And they're rotating.
By looking at shifts in the wavelength of light, we can figure out how fast they're rotating. And we can see how big the galaxy is. And we can estimate how many stars are there and how massive the stars are.
And the galaxy is rotating too fast to be held to be held together, just by the gravity due to the stars. The thing should just fly apart.
And yet, it doesn't.
And so the question is, what is holding them there? We can see the starlight. So there has to be some extra gravity that's there that we can't see.
We can see stars because they emit light. But there has to be something that we can't see.
Nrama: Thus the "dark."
Kakalios: Right. It's "dark." It's most likely matter of some sort that exhibits gravity.
Nrama: Thus the "matter."
Kakalios: This is why it has been described as "dark matter."
The name "dark matter" is easier to say than "some strange extra source of gravity that we can't account for."
Nrama: And we're not even sure what it is?
Kakalios: Well, there are basically three options that are still on the table:
- It could be something very big and dim. There's the possibility that maybe there are extra black holes and neutron stars and things that aren't particularly bright that are accounting for that.
- It could be something very tiny, but a lot of it, that interacts in a strange way with matter. There's the idea that there's a new type of fundamental particle — you know, we discovered a new particle a few years ago with the Higgs boson. Maybe there's some new particle that permeates the galaxy. It doesn't emit light. It doesn't then interact with many other things, otherwise we might have seen it in a laboratory here. But it could account for that.
- The third possibility is that maybe gravity just is weird on the level of galaxies and has to be modified.
They're still searching for an answer.
Nrama: OK, Snyder's story had Lady Blackhawk saying dark matter makes up the "great majority" of our universe. True?
Kakalios: Well, we know there's much more of this dark matter than there is normal matter that we can see.
Nrama: OK, so I can see similarities in your "galaxy" example and the description of the story's "Dark Multiverse" as it relates to the known Multiverse — Snyder has used the word "floating," but the implication is that it's an unseen part of the Multiverse. It sounds like dark matter is that part of this galaxy (in your example) that can't be seen, but it has a function within the physics of that galaxy?
Kakalios: Yes, that would be a correct way to paraphrase what I said, a correct way to describe it.
But I must stress that the dark matter exists within the galaxy. Dark matter is here with us. It exists within our universe. It interacts with the matter in our universe.
Nrama: So you're contrasting it with the idea of a Multiverse. However, the Dark Multiverse takes the concept of dark matter a step further: Instead of being matter you can't see, it's like a Multiverse you can't see — one with an ocean of possibilities beyond the 52 we "can see." You're familiar with Grant Morrison's Multiversity? Can you talk about the science of that?
Kakalios: Yes. Grant Morrison's Multiverse is talking about — it goes back to a theory in quasi-mechanics called the "many worlds interpretation," where there are parallel earths. That idea goes back to the original DC Comics — Earth-1, Earth-2, Earth-X, Earth-S — all these different parallel earths that you can get to if you're the Flash and you can change your vibrational frequency. And they all exist, occupying the same space, but in different dimensionalities.
But these ideas of parallel universes, of many other worlds, bubble universes — these are all in the realm, in physics, of speculation.
It's not like there's any observation or data that says, oh, this could only be accounted for if there are parallel worlds or distant bubble universes or things like that.
Nrama: What about dark matter? Speculation as well?
Kakalios: There are experiments that say there has to be something like dark matter.
Whether you consider dark matter to be maybe black holes leftover from having formed early in the universe, whether they're some new particle we've never discovered, whether it's some change in the nature of gravity we don't understand — there has to be something there, because there definitely are observations.
There definitely are things that cannot be accounted for with non-dark matter.
So that we know is real.
It's real. We just don't know what it is.
Nrama: Another concept the series is playing with is "Nth Metal," which you're probably familiar with?
Kakalios: Yes, from Hawkman's days. It was basically anti-gravity metal that allowed the Hawks to fly.
Nrama: Well, there are various approaches to the Hawkman and Hawkgirl mythos. This approach has Nth Metal contributing to their ability to reincarnate — their immortality.
Kakalios: Oh really?
Nrama: It's even been implied that in the DCU, there's an additional part of the periodic table connected to these immortality metals. Let's talk about that — can you explain the periodic table and address the idea of new metals being discovered in the DCU?
Kakalios: Well, the periodic table says, let's start with the simplest atom — one proton, one electron; that's hydrogen. Now let's have two protons, two electrons; that's helium. You keep going up.
As you keep going up from one to about 92, and you get to uranium, it's not like there's a whole column that's missing.
Maybe you could get another row in there, like super-heavy ones, but they tend to decay quickly. So the fact that they would be so stable that I could make a belt out of one….um….who knows?
Nrama: Or a dagger?
Maybe once you get past there, you have an island of stability in the periodic table.
Nrama: In the periodic table of the DCU, at least.
Nrama: OK, I just looked up the description of Nth Metal from Metal #1…let's see… "Nth metal connects us to a realm much older and vaster than ours — an oceanic, subconscious realm our tiny multiverse floats on." Well, I assume there's no "our-world physics" in that sentence.
Kakalios: No, not really.
Nrama: But this is the science of the DCU, and Nth Metal is just one of the unknown metals being explored in this series. How about this — do different metals interact with matter in different ways?
Kakalios: Yes. Metals do interact with matter in different ways. You know, iron rusts and gold does not. So to some extent, the metals are interacting differently with oxygen. You could have a metal like sodium and you throw it in water and it explodes. It undergoes a chemical reaction and releases a tremendous amount of heat energy. You throw a paper clip into water and nothing happens.
So different metals interact with matter in different ways. That's normal.
Nrama: So I think the idea here is that Nth Metal, this fictional metal that exists in the DCU, interacts with dark matter in a specific way. Or dark energy.
Nrama: Well, it sounds like the concepts they're using in this series have their roots in real science, but what they're doing with them — that's where fiction comes into play.
Kakalios: Right. They're using some of these ideas in a more metaphorical sense. That's comic books.