In science, it is often said that data doesn't care what you think. This is especially true when it comes to cutting-edge new instruments like the James Webb Space Telescope (JWST). So it was no surprise that some of the data from the James Webb Space Telescope wasn't exactly what scientists expected.
In the 2024 Isaac Asimov Memorial Debate, astrophysicist and science communicator Neil deGrasse Tyson moderated a discussion at the National Museum of Natural History in New York. The conversation was between scientists and revolved around the topic of how data from the telescope could change our fundamental understanding of our universe. Of discrepancies in age Universe Because of the unexpected brightness of early galaxies, the James Webb Space Telescope has already prompted scientists to reconsider how the early universe worked, leading to discoveries that could lead to major shifts in our models of the universe over the next decade or more of the James Webb Space Telescope's lifetime. .
One committee member said the data from the telescope “paints a consistent and constantly new picture” of the early universe Mike Boylan Colchina theoretical astrophysicist at the University of Texas at Austin.
Related: The universe may be younger than we think, as the movement of galaxies suggests
But just because it was impossible to know what the James Webb Space Telescope might see, doesn't mean scientists didn't try. However, it was difficult. The most difficult part, panelists said, was coming up with basic criteria to base their forecasts on. As Tyson puts it, variable parameters are like “knobs you turn” in computer simulations of the universe that aim to predict outcomes based on hypotheses. Let's take an example, committee member Rachel SomervilleA senior research scientist at the Flatiron Institute's Center for Computational Astrophysics in New York City, she described a study she worked on that tried to predict what the James Webb Space Telescope would see.
“We turned all the knobs in our models to fit the nearby universe,” Somerville said. But something wasn't right. “We disagreed with the remarks,” she said. After looking at the data, Somerville and her team discovered that their predictions would be more accurate if they took into account the increasing density of the early universe, which was smaller than our current more expanded universe, yet contained the same amount of mass.
Other problems were not solved so easily. For example, several observations made by the James Webb Space Telescope have revealed that the early universe was a surprisingly vibrant place, with galaxies that were much larger and brighter than scientists expected.
“I don't think anyone's models really predicted the amount of activity that was there at that time,” Boylan-Kolchin said. It seems that “everything happens faster than we thought in the early universe.”
The case of the surprisingly active early universe may be related to another known paradox in the universe Astrophysics – the age Universe.
the Hubble Space Telescope It was a big factor in helping narrow the scientific consensus on Age of the universe — In fact, telescope mirrors were made specifically for observation stars The committee member said that “Cepheid stars” can be used by astronomers to calculate this age Wendy Friedman, a cosmologist at the University of Chicago. The resulting measurement of the age of the universe, about 13.7 billion years, has remained constant ever since.
But let's not forget that there is another way to measure the age of the universe, Boylan-Kolchin said.
“This is with Cosmic microwave background“Light is from the earliest stages of the universe,” he said. Using this method, scientists arrived at a slightly larger number, 13.8 billion years. Although this difference may not seem like much, some estimates using Cepheid stars go as far back as 12.8 billion years, Boylan-Kolchin said. What's worse is that no one knows where the difference comes from. “It's as if we were tunneling on opposite sides of the mountain, and we missed it,” Friedman said.
Unfortunately, the surprisingly luminous early galaxies discovered by the James Webb Space Telescope have done nothing to solve this mystery.
In fact, the telescope's findings prompted Rajendra Gupta, an astrophysicist at the University of Ottawa, to publish research suggesting that, based on the new data, the universe could be 26.8 billion years old, about twice the age of current estimates. . While participants agreed that Gupta's proposal is highly unlikely, the discrepancy in the age of the universe overall points to the standard cosmological model and our understanding of the effect. Dark matter And Dark energy In our world, it may need some renovation.
“There could be something fundamental missing from our current picture,” Friedman said.
On the bright side, it appears that data from the James Webb Space Telescope can do more than point out inconsistencies; it may be able to help scientists answer some fundamental questions in… Astronomy That lasted for decades. The telescope will not be the only technology that helps solve these problems. New tools such as artificial intelligence and increasingly powerful supercomputers may help; Other telescopes, such as the Giant Magellan Telescope, a massive optical telescope under construction in Chile whose development Friedman led, will add to the high-quality data available to scientists as well. One panelist said that with so many new tools, the quantity and quality of data will be unprecedented Priya Natarajana theoretical astrophysicist at Yale University.
“We are in the midst of a data revolution,” she said. “Soon it will begin to tightly constrain models and thus our theoretical understanding.”
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