"It wasn't supposed to happen." How did James Webb prove scientists' beliefs about the dawn of the universe wrong?

Translation Introduction

A galaxy is, to a very simplified degree, a gathering of billions of stars orbiting a single center, sometimes appearing in space as scattered islands and sometimes as clusters. Because of the importance of this topic, scientists have long been preoccupied with the history of these galaxies — which starts from the cosmic dawn period of about 50 million years to about a billion years after the Big Bang — assuming that galaxies at that time began small, submerged in a state of weakness and fading, and then coalesced together to build larger and larger galaxies.

But the recent observations of the James Webb telescope have caught scientists by surprise: The ancient galaxies Webb observed seemed so large and bright and not as small or weak as they thought. The universe seems to have taken an astonishingly bold and vocal approach, obliterating astronomers' most solid theories about its origins and structure, so what exactly happened?

Translation text

Humans have always tried to make sense to the stars that adorn the sky, yet it took us a long time to understand recently that it was an entire crowd of them that formed galaxies making their way deep into space. Looking at the sky in crystal clear, we could see with our naked eyes some galaxies close to us, such as the Andromeda galaxy, known as the "serial woman", which appears as a dark spot in the night sky, unlike the structures of other glittering galaxies that we did not know until after the invention of the telescope in the seventeenth century. At the time, scientists argued about the nature of these galaxies, wondering: Were these galaxies clouds of cosmic dust in our Milky Way? Or are they isolated cosmic islands in their own worlds far from our galaxy?

Hubble continued his quest to find his way in space to finally observe thousands of galaxies shining as cosmic islands floating in a vast cosmic sea. (Shutterstock)

Until the twenties, humanity was unaware that these glowing clouds were galaxies separate from us until astronomer Edwin Hubble (relying on the work of the then lesser-known American astronomer Henrietta Levitt) discovered that some stars were too far away to belong to our Milky Way galaxy. By the mid-nineties, a space telescope called Hubble had taken off long distances to explore depths that no telescope had ever reached. Hubble continued his quest to find his way in space to finally observe thousands of galaxies shining as cosmic islands floating in a vast cosmic sea.

After the images conveyed to us by Hubble, astronomers are confident in their understanding of galaxies and how they form, but some amazing new developments have recently begun to take place on the scene thanks to a much more powerful space telescope than Hubble's, James Webb, which has been fully operational since last summer. Webb showed that galaxies formed much earlier than astronomers previously thought, and some of them turned out to be unexpectedly larger and starry. (That is, these galaxies weren't as young or young as scientists thought, but looked as mature as our galaxy today at the time it was supposed to have dawned the universe.) Scientists have a new wind blowing over their stable atmosphere to throw them into a new reality in which their current theories cannot be applied.

Everyone in astronomical circles understood that the Webb telescope would produce revolutionary results. Astronomer Joel Lega of Pennsylvania State University said: "We had a very clear list of things that we thought Webb would absolutely amaze us with, but it resulted in things that had never happened before in our minds, such as his discovery of those star-filled cosmic galaxies when none of these galaxies were supposed to appear like this. The idea seemed so remote that no one thought of looking for it."

The telescope as a time machine

In the first weeks of James Webb's launch into space, astronomers raced to find the most remote galaxies in the universe. Meanwhile, the results went on to go on to go awkwardly. (Shutterstock)

Space instruments like the Hubble Telescope and James Webb are like time machines: when these space observatories take a look into the depths of the universe, the starlight they receive is the light that left its source eons ago and has since made its way into space (meaning that the stars and galaxies that telescopes have observed and now have shape like they were eons ago, not their current form). Before James Webb's invention, for example, scientists believed that these early, distant galaxies traveled at a slow pace until they were formed by the collapse of hydrogen gas clouds on themselves to explode, causing a very strong ignition, after which stars were formed, and then gravity began to group ancient celestial bodies together to form galaxies.

All of these disparate materials were supposed to take at least a billion years to gather in a huge cosmic ocean and form galaxies, but what scientists overlooked at the time was that the farthest galaxy ever observed by the Hubble telescope was certainly too bright for cosmic conditions at the time, suggesting a much larger constellation of stars than expected. form the first galaxies in the universe). Instead, they predicted that the Webb telescope, with its super-powerful infrared vision, would detect the first galaxies they predicted that Hubble could not observe.

In the first weeks of James Webb's launch into space, astronomers raced to find the most remote galaxies in the universe. Meanwhile, the results went on to go on to get weird, and scientists were confused and wondering if the data was really wrong, because the ancient galaxies observed by Webb looked so large and bright. The results soon proved that the early universe somehow took a bold, noisy and amazingly bright approach.

Amazing galaxies

Astronomer Joel Lega co-published a new study in February (2023) indicating that there are six massive galaxies that probably formed between 500-700 million years after the Big Bang, and one of these galaxies may be a hundred billion times the mass of our sun. Our galaxy similarly contains billions of stars that may roughly match the number of stars in these early massive galaxies, but the difference is that it took about 13 billion years for our galaxy to reach its current size.

For a moment, this new reality seems to threaten scientists' fundamental way of understanding the entire universe, hence the most important question: "If the starting point of the universe seems like this, can the standard model of cosmology, which is our most solid theory of the origins and structure of the universe, be wrong?" Astronomers now believe that the theory can still absorb the surprises of the new telescope, as recent computer simulations guided by the Standard Model have shown that there is a possibility that the universe may actually be able to form such early galaxies that Webb found. "At a time when the data seems inconsistent with cosmic models, I have a feeling that the crises we face will not be about cosmology, but about the way we really understand how galaxies form," says Lija.

James Webb telescope is able to penetrate dust clouds in the Orion Nebula (French)

Possible explanations for how astronomers misunderstood early galaxies are partly because the first stars may have formed much more efficiently than we thought by mechanisms scientists had never thought before. Alison Kirkpatrick, an astronomer at the University of Kansas who studies the evolution of galaxies, wonders whether the cosmic dust in these galaxies tricked Webb and gave stars a certain aura to look older than they actually are, or perhaps the cosmic dust at the time was completely different.

Ivo Labby, an astronomer at Swinburne University of Technology in Australia, believes that black holes may also have played a role in the brightness of early galaxies, because they become one of the brightest objects when they feed on cosmic matter, which glows once absorbed by black holes. "If you throw a lot of gas into a black hole, the latter will start to shine so hard that it may shine more than the entire galaxy, so early galaxies may look bright and full of stars," Labby said. But none of these possibilities will invalidate the fact that the first cosmic islands were not what we expected. To confirm this, Kirkpatrick says, "Even taking into account some new and strange phenomena, everything seemed too big so early in the universe."

Ivo Labby, an astronomer at Swinburne University of Technology in Australia, thinks that black holes may also have played a role in the brightness of early galaxies. (Shutterstock)

Studying these problems will require further observations collected from the James Webb Telescope, particularly those that may result in more detailed measurements of starlight, known as spectroscopy (this technique helps scientists determine the chemistry of the celestial body from which this light was emitted).

For scientists to put an end to their turbulence, they need to analyze more data to make sure that the very strange galaxies they discovered reflect the true features of galaxies at the time. If they realize that they were as old and large as they seem, understanding their structure will help them know the circumstances in which they were formed. The researchers are currently working to study these findings, awaiting new spectroscopic data expected this spring.

A bold new world

According to these surprising developments, astronomers and theorists — those who observe and interpret cosmic wonders — don't know what will await them once the data is analyzed. Ren Suisse, an astronomer at the University of California, Santa Cruz and Stanford University, says, "It could take almost five years for us to fully settle into our new world that James Webb unveiled." If we look at it on the other hand, these new discoveries have added some drama and anxiety to a field that has been quite stable.

Erica Nelson, an astronomer at the University of Colorado Boulder in the US, says: "It's amazing! One can hardly believe how the universe looked so much weirder than we thought." But on the other hand, we can follow what's happening as just fun! When astronomer Alison Kirkpatrick was asked if she was nervous about the uncertainty of her profession, she giggled, "It's the beginning of the universe! Knowing what happened at that time is not a risk that would disturb my life, so it's really fun to think about things like that."

Talking to astronomers about Webb's findings so far, everyone agreed on one phrase that has been on their tongues: "It wasn't supposed to happen." Galaxies were not supposed to form like this, and the cosmic dawn was not supposed to manifest itself this way. On the other hand, I feel pleasure whenever I reflect on these objections, which shed light on some of the arrogance of well-intentioned human beings, especially those who are very curious about how things work, and did not work that way. But of course, the universe has a different opinion: it communicates with us via a giant telescope floating a million miles from Earth, telling us: "That's how it works." It seems that this is what the universe has always been, and everything we do now is nothing more than our attempts to discover its wonders.

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Translation: Somaya Zaher

This report translated from The Atlantic does not necessarily reflect Meydan's location.