This artist’s impression pinpoints many cosmic voids –– relatively empty bubbles of space.
The universe is home to trillions of galaxies, each chock full of smaller cosmic objects like stars and planets. Since galaxies gravitate together in a web-like pattern, there are also immense open spaces called cosmic voids in between. In those growing, gloomy places, dark energy dominates.
Galaxies in this animation are structured a bit like a Hoberman sphere (a lattice-like toy ball that expands and collapses), growing farther apart as the universe expands.
Zoomed out maps of the universe show that galaxies often cluster together in bright city-like regions. Each cosmic metropolis is connected to others by interstate highways – vast filaments of dark matter, gas, and dust, along which additional galaxies can be found. This large-scale structure is called the cosmic web.
Way out in the boondocks – far from the galaxies and filaments – are the cosmic voids. They’ve been growing larger for billions of years, emptying out as gravity pulls matter elsewhere.
This animation visualizes the early universe, when the cosmic was full of a hot plasma soup.
Cosmic voids were born when the universe looked extremely different than it does today. Instead of being speckled with stars and galaxies, the cosmos was filled with a sea of plasma (charged particles) that formed a dense, almost uniform fluid.
There were slightly denser kernels of matter, like a single ounce of cinnamon sprinkled into about 13,000 cups of cookie dough! Since the clumps had more mass, their gravity attracted additional material. Those areas grew and grew, drawing more matter together to form stars, galaxies, and galaxy clusters as the universe expanded over billions of years. Meanwhile, the spaces in between became ever emptier.
A simulation of large-scale structure forming under the influence of gravity.
Cosmic voids aren’t completely empty, though. They do have sparse galaxies, though they seem to have delayed development. Since there’s less matter, there’s weaker gravity pulling things together so stars and galaxies form more slowly. And those galaxies are isolated so they’re less likely to interact with others, which fuels growth in denser places like galaxy clusters.
But voids are mostly filled with things we can’t see. They contain a thin mist of dark matter along with a relatively larger amount of WIMPS (weakly interacting massive particles) like ghostly neutrinos than we find elsewhere in the universe. Since there’s not very much stuff in voids to create gravity, a different force reigns supreme: dark energy, the mysterious cosmic pressure that seems to be speeding up the universe’s expansion. Since cosmic voids are influenced primarily by dark energy, they offer clues about its behavior.
Astronomers haven’t thoroughly studied cosmic voids yet, but our upcoming Nancy Grace Roman Space Telescope will be wide-eyed enough to reveal those desert patches of space like we’ve never seen them before. Studying them will show how the universe is put together and how dark energy is pushing galaxies apart.
If you could fly through the cosmic web at hyperspeed, you might see a view like this simulated one!
So far, scientists have found around 1,000 cosmic voids. Roman’s 3D surveys should find tens of thousands more, both large and small, scattered throughout earlier cosmic eras than previous large sky surveys could see. That means we’ll be able to watch how the most vacant places get even emptier over billions of years. And astronomers can trace any changes in dark energy’s might by seeing how it stretches voids, where dark energy dominates, across cosmic time.
Follow along with Roman’s journey to launch at nasa.gov/roman.
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BREAKING: Journalist and college professor Stacey Patton goes viral by penning a stunningly powerful statement about how she was on Charlie Kirk’s “digital hit list” and recounting the horror that he inflicted on her.
We cannot allow this tragic assassination to whitewash Kirk’s legacy…
“I am on Charlie Kirk’s hit list,” Patton wrote to her 215,000 followers on Facebook. “His so-called ‘Professor Watchlist,’ run under the umbrella of Turning Point USA, is nothing more than a digital hit list for academics who dare to speak truth to power. I landed there in 2024 after writing commentary that inflamed the MAGA faithful. And once my name went up, the harassment machine roared to life.”
“For weeks my inbox and voicemail were deluged. Mostly white men spat venom through the phone: ‘bitch,’ ‘c*nt,’ ‘n****r.’ They threatened all manner of violence,” she continued.
“They overwhelmed the university’s PR lines and the president’s office with calls demanding that I be fired,” Patton wrote. “The flood was so relentless that the head of campus security reached out to offer me an escort, because they feared one of these keyboard soldiers might step out of his basement and come do me harm.”
“And I am not unique,” she added.
“Kirk’s Watchlist has terrorized legions of professors across this country. Women, Black faculty, queer scholars, basically anyone who challenged white supremacy, gun culture, or Christian nationalism suddenly found themselves targets of coordinated abuse,” Patton wrote.
“Some received death threats. Some had their jobs threatened. Some left academia entirely. Kirk sent the loud message to us: speak the truth and we will unleash the mob!” she continued.
“That is the culture of violence Charlie Kirk built. He normalized violence. He curated it, monetized it, and sicced it on anyone who dared to puncture his movement’s lies,” she wrote.
“And now, in the wake of his shooting, there’s all this national outpouring of mourning, moments of silence, yellow prayer hands, and tributes painting him as a civil debater,” Patton continued. “But the truth is that Kirk and his foot soldiers spent years terrorizing educators, trying to silence us with harassment and fear!”
“And now the same violence he unleashed on others has come full circle.”
“But what i find especially jarring is the dissonance in public mourning for a smug white man whose life work was actively hostile to certain groups,” she continued. “Kirk spent years demonizing LGBTQ people, mocking gun survivors, spewing racism about Black folks, and pushing policies that literally shorten lives.”
“It is so revolting to watch a bipartisan wave of grief sweep over this hateful racist as if he was a neutral community servant,” she concluded.
This is pure unvarnished truth from Patton. Charlie Kirk did not deserve what happened to him, but nor did his victims deserve the hell that he unleashed on them. If Americans are going to build a more peaceful future for ourselves we must condemn political violence while also condemning the hateful, bigoted rhetoric that made Kirk a multimillionaire.
