Across the long span of cosmic history, there is a quiet stretch in which the universe was dark, filled with gas that had not yet been lit by anything of its own. A team at MIT and Harvard has now built Lumina, a vast computer model that replays those first two billion years, from the birth of the first stars and galaxies to the moment their light began to burn away the old gloom. It is less a picture than a kind of time machine, offering scientists a way to test their stories about how the cosmos began against the faint evidence that telescopes gather from the distant past.
MIT and Harvard's Lumina Simulation Recreates the Universe's First 2 Billion Years
A cosmic time machine, built from half a trillion tracked pieces
Mark
So what is Lumina, in plain terms?
Mimi
A simulation of the universe's first 2 billion years, built by researchers at MIT and Harvard. It covers star and galaxy formation and the re-ionization of hydrogen and helium.
Mark
Why does the size matter?
Mimi
It's reported as about 100 times larger in volume and 30 times sharper than older models. That means one model can cover big regions of space and still zoom into a single galaxy.
Mark
What did it take to run?
Mimi
The Frontier supercomputer, with more than 100,000 processors and 15,000 graphics chips, tracking half a trillion pieces of gas, dark matter and light.
Luke
Let me flag something. The 100 times and 30 times figures come from the research team and its news release. The reporting doesn't say how they were measured or which earlier simulations were the comparison.
Mimi
Fair. Vogelsberger's quote is the source for the volume claim, and he's one of the study's authors.
Mark
So how do we know it's right?
Luke
We don't yet. A simulation produces predictions, not proof. The test is matching it against telescope images, and the article says that comparison is only now beginning.
Mimi
Right, and the team has shared Lumina with astronomers worldwide so others can run that test.
Luke
Which mysteries it might solve is also unspecified. The article says only that scientists hope to address some of the biggest remaining ones.
Mark
So the thing to watch is the comparison with the telescopes.
Mimi
Yes. That's where the model either holds up or doesn't.
Le Pouls
- A dark, unlit early universe waits to be understood, and the question of how its first lights emerged remains unresolved.
- Lumina, run across more than 100,000 processors on the Frontier supercomputer, churns through half a trillion simulated particles of gas, dark matter and light.
- Researchers move from the zoomed-out sweep of cosmic scale to the close-up of single growing galaxies, all within one model.
- The simulation is now shared with astronomers worldwide, who will hold its predictions up against images from modern space telescopes to see whether it holds.
Across the long span of cosmic history, there is a quiet stretch in which the universe was dark, filled with gas that had not yet been lit by anything of its own. A team at MIT and Harvard has now built Lumina, a vast computer model that replays those first two billion years, from the birth of the first stars and galaxies to the moment their light began to burn away the old gloom. It is less a picture than a kind of time machine, offering scientists a way to test their stories about how the cosmos began against the faint evidence that telescopes gather from the distant past.
A team of researchers at MIT and Harvard University has built a computer simulation that lets viewers watch the universe during its first 2 billion years. They call it Lumina, and in effect it works as a cosmic time machine, rewinding to an era when the universe was still shrouded in darkness.
The model follows the birth of individual stars and galaxies, and it also traces the re-ionization of hydrogen and helium, the large-scale process by which the first luminous objects ended the universe's dark ages. Lumina shows how those early lights gradually filled the cosmos.
Its builders say it is about 100 times larger than older models and about 30 times sharper. Mark Vogelsberger, an MIT physics professor and co-author of the study, explained that the simulation handles both small-scale star formation and large-scale re-ionization across a volume 100 times bigger than the best previous efforts. It ran on Frontier, one of the world's fastest supercomputers, tracking half a trillion tiny pieces of gas, dark matter and light.
The team has now shared Lumina with astronomers around the world. The next step is comparison: placing the model's predictions beside real images from modern space telescopes. Those results will reveal how well the simulation holds up, and whether it can help settle some of the biggest open questions about how the universe came to be.
A team of researchers at MIT and Harvard University has built a computer simulation that lets viewers watch the universe during its first 2 billion years. The program is called Lumina, and its builders describe it, in effect, as a cosmic time machine.
The simulation covers a wide range of scales. It follows the formation of individual stars and galaxies, and it also tracks the re-ionization of hydrogen and helium, the large-scale process by which the first luminous objects helped bring the universe's dark ages to an end. Lumina shows how those first stars and galaxies lit up the cosmos.
The size of the project is the central claim. According to the report, Lumina is about 100 times larger than older models and about 30 times sharper. Mark Vogelsberger, a professor of physics at MIT and an author of the study, put it this way in a news release: Lumina handles everything from small-scale star and galaxy formation to large-scale re-ionization of hydrogen and helium, in a volume 100 times larger than the best previous simulations.
The computing behind it is substantial. The team ran Lumina on Frontier, one of the fastest supercomputers in the world, linking more than 100,000 computer processors with 15,000 graphics chips. The machine tracked half a trillion tiny pieces representing gas, dark matter and light.
That resolution is what allows the model to change perspective. Researchers can zoom out to look at huge stretches of space, or zoom in on a single growing galaxy, all within the same simulation.
The work is now being handed off. The team has shared Lumina with astronomers around the world so they can study it. The next step is comparison: researchers can set the computer's predictions beside real images captured by modern space telescopes.
That comparison is where the model will be tested. By checking what Lumina predicts against what the telescopes see, scientists hope to resolve some of the biggest remaining questions about how the universe came to be. The results of those comparisons will show how well the simulation holds up.
Citations marquantes
Lumina handles everything from small-scale star and galaxy formation to large-scale re-ionization of hydrogen and helium, in a volume 100 times larger than previous best simulations.— Mark Vogelsberger, professor of physics at MIT (paraphrased from news release)
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