Astrophysicist Hakeem Olusheyi walks through three layers of reality that make your existence possible — the quantum realm, the cosmological realm, and the multiverse. From the scale of the observable universe to the behavior of a single electron, Olusheyi has a rare ability to make all of it feel within reach.
In our interview, he breaks down the strongest experimental evidence we have for the multiverse and why physicists still argue over whether it’s conclusive. He digs through the actual nature of electrons, why you're moving through spacetime at the speed of light right now, and why the Andromeda Galaxy is visible to the naked eye, yet almost no one has looked for it.
About the speaker: Hakeem Oluseyi is an astrophysicist, cosmologist, inventor, STEM educator, and science communicator known for his work in “hacking stars” to understand the universe. Oluseyi’s work has resulted in 11 patents and more than 100 publications covering contributions to astrophysics, cosmology, and plasma physics and the development of space missions, observatories, focal plane instruments, detectors, semiconductor manufacturing, and ion propulsion.
Timestamps
00:00:21 Chapter 1: The strange world of quantum physics
00:06:25 Why quantum math defies intuition
00:13:31 Entanglement, spacetime, and the deepest unsolved questions in physics
00:21:12 Chapter 2: The cosmological realm
00:26:38 You’re moving at the speed of light right now
00:46:00 The universe Is disappearing
00:52:08 Chapter 3: The two multiverses we might live in
01:00:51 The evidence for the multiverse
01:07:08 Why the equations deserve our trust
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Transcript
Below is a transcript of the first five minutes of this video interview. This is a true verbatim transcript that captures the conversation exactly as it happened. If you’d like to read the full transcript while following along with the video, click here.
I am Hakeem Oluseyi. I am an astrophysicist and author of the new book, Why Do We Exist? The Nine Realms of the Universe That Make You Possible. Today on Big Think, we’re going to discuss three of these realms. The quantum realm, the cosmological realm, and the multiverse realm.
Chapter 1: The strange world of quantum physics
Quantum physics is weird because it breaks every intuition of the physics that we normally experience in our regular world. The rules break, certainty breaks, things become probabilistic, things come into existence, out of existence, objects pass through walls. It is strange.
How should we think about quantum particles? They are not things. They are not things like the world around us. Quantum particles are the fundamental constituents of matter that come together to build up the world around us. So protons and neutrons are made up of fundamental quantum particles called quarks. Light is made up of fundamental quantum particles called photons. Electrons are a fundamental quantum particle. And so they come together in ways that cause new properties to emerge that give us a reality that is fundamentally different from the reality that created them.
When we look at an artist’s description of what an atom is, you typically see something that looks like Solar System in three dimensions, right? You have these lines of electrons orbiting a nucleus. But that is not what’s happening, right? Planets that are orbiting the sun, they’re basically falling around the sun, just like an object falls here in Earth’s atmosphere. It’s the same process. Electrons are not falling around the nucleus of the atom. And the other thing is that they’re not these little tiny spheres that we imagine. When you look at them at their fundamental basis, they have a particular property and that is that every electron is identical. For example, you can’t tell one from the other.
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So what that tells me is that gives us a hint of what they are. So I like to make the analogy that they’re kind of like musical notes. If I hear a musical note, a C, every C is a C. They’re identical. But is the C a real thing? What the real thing is, is the instrument or the voice that vibrated and created this vibration in the air. That vibration in the air is a real thing. But that perception of the C is, you know, comes out of that vibration.
And so how do you create a vibration? You add energy to the string or to the instrument that you’re blowing. Well, reality does the same thing. At the most foundational level, there is this concept of quantum fields. And these quantum fields permeate all of spacetime. And what we call a particle is energy injected into one of those quantum fields. We call electrons excitations in the quantum electron field, and you know so in essence we are a symphony of musical notes in quantum fields. And what’s really interesting is, is that if you take that analogy to its extremes, right? If I have a musical instrument like a guitar that has a string that vibrates, if I don’t pluck the string, the string isn’t vibrating right?
Well, not right. It turns out that if I zoom in and look at that string really closely, you’ll see that it’s always vibrating. And in the same way, those quantum fields are always fluctuating. And that means that there’s two types of vibrations. The ones where you insert energy and get an excitation that results in a note, but then it still vibrates at the same frequency, but really tiny. Those are what we call virtual particles in quantum mechanics. So they both can exist on these quantum fields.
So, the thing about quantum fields that makes them really uncomfortable for me — and I thought, you know, maybe this is just a mathematical analogy — is that they don’t have some source like a magnetic field. You think, oh, here’s a star. Here’s a planet. That’s the source of the field. If you have the electric field, you think, oh, here’s an amount of electric charge. That electric charge creates that electric field. And, you know, most of the fields that we’re normally concerned with, electric, magnetic, gravity, they’re associated with matter. These quantum fields have no source. They’re not necessarily associated with matter in the same way as far as they generate, you know, some matter with some property generates a quantum field. They just seem to be there, just exist throughout all space, right?
And so I thought for, you know, I’m like, man, this just can’t be real. This just can’t be. And then in 2012, we discover the Higgs field, this scalar field that permeates all space and imbues mass to these quantum particles. And at that point, it’s undeniable now. The quantum fields are real.
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