The best card in the early universe is the double -edged sword for cosmologists

Our last and best card in the early universe is five times more detailed than anything we have had before, but although it precisely supports the main model of the universe, it is also a double -edged sword because the new data also offers no clues to resolve some of the greatest mysteries of cosmology.

The map shows the cosmic microwave (CMB), a low radiation residing in the first stages of the universe. It started as the first light only 380,000 years later Big BangBut billions of years from the expansion universe have moved its frequency of the visible spectrum in the microwave.

Now, the new data in the Atacama cosmology telescope (ACT) have given us a clearer image of the CMB – but only half of the sky which can be imagined of the location of the observatory in Chile.

Jo Dunkley At Princeton University, who worked on the project, says that the data has nailed with better precision the ingredients of the universe, its size, its age and its expansion rate. But the really key discovery was that nothing contradicts the current leading model of the universe, known as Lambda-CDM.

Previous data have aged the universe at 13.8 billion years and the rate at which it develops – known as the Constant Hubble – between 67 and 68 kilometers per second per distance from Mégaparsec de la Terre. ACT data confirms this essentially, but increases accuracy and confidence in these results.

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The CMB was first mapped by Cosmic Background Explorer (Cobe) of NASA in the 1980s and 90s, then by the NASA microwave anisotropy probe (WMAP) in the 2000s, then in even more details by the Spatial Planck from the European Space Agency From 2009 to 2013. Each mission provided successively more detailed cards from the CMB, making our knowledge of cosmology and understanding from the start of the universe progress.

A limitation of act is that it is a telescope on the ground, unlike these previous space missions, which is why it is limited to only half of the sky. Despite this, ACT not only gives better resolution and sensitivity than these previous cards, but it also measures the polarization of the CMB, or the orientation in which the light waves oscillate, revealing certain information on the way in which CMB light has evolved over time.

“Looking at the polarization of the CMB in detail, we could have seen something different. We could have seen the standard cosmological model break up, ”explains Dunkley. “Because every time you look at the universe in a different way, you cannot be sure that your original model will always work. We were quite ready to see something leaving this model, a subtlety. But we did not do it.”

This can be reassuring for those who work on Lambda-CDM, but it was not good news for all scientists. Colin Hill At the University of Columbia in New York, said he hoped to see evidence in the data of a phenomenon not yet explained-perhaps a new type of energy or particles-which could help explain the so-called Hubble tension: the divergence between the rate of expansion in the universe given by the standard Lambda-CDM model and what we measure directly.

“We were all stunned by consistency (ACT data) with the standard model. We all try to prick and walk the model from different aspects and look for a place where it will crack, and where nature will give us something to sink our teeth. And so far, nature has not given this crack, ”explains Hill.

He says that the most viable theories for the Hubble tension difference require phenomena that simply do not appear in ACT data, which is currently the best we have. This will force scientists to the drawing board to seek another explanation. “The new measures will put theorists, including myself, in an even tighter tank top,” explains Hill. “It deepens the mystery.”

ACT has collected the data that make up this new card between 2017 and 2022, but which has now been closed. Dunkley says it is unlikely that we get a higher resolution card for a few years, although a new telescope in Chile will start working later this year. As for the other half of the sky, only two locations on earth could be able to accommodate new telescopes that would give results: Greenland and Tibet. Dunkley says that, unfortunately, Greenland does not yet have the infrastructure necessary for such a project, and Tibet is politically sensitive.

A Jes club At the University of Manchester, in the United Kingdom, says that if the project scientists have already worked with the data, the open version of the Act card will now trigger a wave of activities.

“The entire cosmology community can get their hands on the data and do any kind of cross -analysis with their data sets,” explains Chluba. “It's super exciting and I'm almost sure that there will be an explosion of follow -up publications after that.”

Mysteries of the universe: Cheshire, England

Spend a weekend with some of the most brilliant spirits in science, while you explore the mysteries of the universe in an exciting program that includes an excursion to see the emblematic Lovell telescope.