1087: It’s incredible how the universe is just so much weirder than we thought it was
Day 1087: Wednesday, March 8, 2023
It’s incredible how the universe is just so much weirder than we thought it was
Humans have long found meaning in the stars, but only recently have we begun to understand whole clusters of them—galaxies, way out in the depths of space. After the Hubble Telescope, astronomers felt pretty confident that they understood galaxies and how nature makes them. But some new, startling developments have recently popped up, courtesy of a space telescope far more powerful than Hubble. The James Webb Space Telescope, in full operation since last summer, has shown that galaxies formed much sooner after the Big Bang than scientists previously thought—and that some of them are unexpectedly large, absolutely brimming with stars.
The findings have thrown scientists into a new reality in which their existing theories no longer apply.
Everyone in the astronomy community knew that the Webb telescope was going to be revolutionary. “And we had a very clear list of things that we thought Webb would totally blow our socks off about,” Joel Leja, an astronomer at Penn State University, told me. But the discovery of cosmically chunky galaxies where there shouldn’t be any? “This was nowhere on it. No one was looking for this.”
Instruments like Hubble and Webb are something like time machines. When the observatories look out into the depths, they’re basking in starlight that left its source eons ago, and has been traveling across the universe toward us ever since; in other words,
to understand the cosmic beginning, astronomers must look for the most distant galaxies.
Before Webb, scientists believed that those early, distant galaxies emerged at a leisurely pace. In Webb’s first weeks, as astronomers raced to find the most distant galaxies ever detected, they wondered whether the data were actually wrong. The ancient galaxies were just too big and bright. A recalibration of Webb’s instruments soon showed that some measurements were off, making some galaxies appear more distant than they actually were, and some claims were revised. But the big-picture findings stuck.
The early universe was, somehow, bold and brash and remarkably luminous. “The objects we’re finding are as massive or larger than the Milky Way, which is astounding." One of these galaxies may have a mass 100 billion times that of our sun. Our own galaxy similarly contains many billions of stars, but it has had 13 billion years to reach its size.
The first island universes are not what we expected. Even accounting for some weird new phenomena; everything’s too big, and it’s too big, too soon. Researchers are in the thick of it now, with fresh spectroscopic data expected to come this spring. The effort verges on soul-searching. Primordial starlight has never been so in demand, and astronomers and theorists—those who observe cosmic wonders, and those who explain them, respectively—don’t know exactly what they’ll find once they’re finished. “It’s probably going to be something like five years until we’ve totally settled into our new universe that we’ve gotten from The Webb Telescope" - Wren Suess, an astronomer at UC Santa Cruz and Stanford,
In one sense, these new discoveries have injected drama, even anxiety, into a field that was quite stable. “It’s incredible how the universe is just so much weirder than we thought it was,” Erica Nelson, an astronomer at the University of Colorado at Boulder, told me. But in another sense, it’s just fun. When I asked Kirkpatrick whether she feels stressed about the uncertainty her profession is navigating, she cackled with glee. “It’s the beginning of the universe!” she said. “It’s not going to affect my life, so it’s really fun to think about this kind of stuff.”
As I’ve talked with astronomers about what Webb has found so far, one word keeps coming up: shouldn’t. Galaxies shouldn’t be this way; the cosmic dawn shouldn’t be that way. I find these shouldn’ts delightful. They hint at the well-intentioned hubris of humans, especially the most curious ones, those who wish to determine exactly how something works and why.
But of course the universe says, speaking to us by way of a giant telescope floating a million miles from Earth, This is how it is. This is, apparently, how it has always been. We’re just discovering the wonder of it now.
- By Marina Koren