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Science Weekly

Is our model of the universe wrong?

Dec 17, 2024
Catherine Heymans, the Astronomer Royal for Scotland and a professor of astrophysics at the University of Edinburgh, explores the perplexing Hubble tension—conflicting measurements impacting the universe's expansion rate. She discusses dark matter and energy's roles in this cosmological crisis and reflects on insights from the James Webb Space Telescope. The conversation also touches on the importance of observational accuracy and intriguing concepts like primordial magnetic fields and early dark energy that could reshape our understanding of the cosmos.
17:45

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Quick takeaways

  • The ongoing Hubble tension reveals a conflict in cosmic measurements that questions either the measurement methods or the entire model of the universe.
  • Emerging theories, like early dark energy, are being explored to reconcile the discrepancies in the expansion rate and observations from the James Webb Space Telescope.

Deep dives

The Hubble Constant and Cosmic Expansion

The Hubble constant is crucial for determining the age of the universe, indicating how fast it is expanding. Current measurements yield two conflicting values for this constant: approximately 72 kilometers per second per megaparsec from observations of the late universe and around 67 from the cosmic microwave background. This discrepancy raises a significant issue for cosmologists, leading to questions about the accuracy of measurements or the validity of the underlying cosmic model. Understanding these numbers is essential, as they also affect our calculations regarding the universe's age, estimated at 13.8 billion years versus a younger 12.6 billion years based on varying interpretations.

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