Universe Approaching Midpoint of 33-Billion-Year Lifespan, Cornell Physicist Calculates

Strategic Insights -

The Cornell University physicist Henry Tye has calculated that the universe is approaching the midpoint of its 33-billion-year lifespan. According to Tye's model, the universe will begin to contract after expanding to its peak size approximately 11 billion years from now, eventually collapsing to a single point at the end. This conclusion is based on new data from dark-energy observatories, which Tye incorporated into a model involving the cosmological constant.

Key Takeaways:

  • The universe is currently 13.8 billion years old and expanding.
  • According to current models, the universe's two simplest fates are either continued expansion forever or a big crunch, depending on the value of the cosmological constant.
  • The cosmological constant has been measured to be negative, indicating that the universe will reach a maximum size and then contract, eventually collapsing to zero.
  • The big crunch is expected to occur approximately 20 billion years from now.
  • The recent data from the Dark Energy Survey (DES) in Chile and the Dark Energy Spectroscopic Instrument (DESI) in Arizona support this conclusion, showing that dark energy has something else going on beyond a pure cosmological constant.
  • Researchers propose a hypothetical particle of very low mass that behaves like a cosmological constant early in the universe but does not anymore, which fits the data well and tips the underlying cosmological constant into negative territory.
  • Scientists are continuing to gather data to refine the model and confirm the prediction of the big crunch.
  • The model's prediction of the universe's end provides a greater understanding of the universe and the goal of cosmology, which is to understand the beginning and end of the universe.

Statistics:

  • The universe is 13.8 billion years old.
  • The universe's lifespan is 33 billion years.
  • The cosmological constant has been measured to be negative.
  • The big crunch is expected to occur approximately 20 billion years from now.
  • The Dark Energy Survey (DES) has made observations in Chile, and the Dark Energy Spectroscopic Instrument (DESI) has made observations in Arizona.
  • There are hundreds of scientists measuring dark energy by observing millions of galaxies and the distance between galaxies.
  • The DESI will continue observations for another year.

Sources:

  • Tye, H. (2025). "The Lifespan of Our Universe." Journal of Cosmology and Astroparticle Physics, 18, Sept.
  • Dark Energy Survey (DES).
  • Dark Energy Spectroscopic Instrument (DESI).
  • Zwicky Transient Facility in San Diego.
  • European Euclid space telescope.
  • NASA's recently launched SPHEREx mission.
  • Vera C. Rubin Observatory.