Topic: Space

A Cornell physicist has calculated that the universe may be nearing its halfway point. It will continue expanding for another 11 billion years before shrinking and eventually collapsing.

The universe is currently 13.8 billion years old and still expanding. Standard cosmology outlines two possibilities: if the cosmological constant is positive, expansion continues indefinitely; if it's negative, the universe would eventually stop growing, reach a maximum size, and then reverse direction, contracting until everything collapses to zero.

Henry Tye, the Horace White Professor of Physics Emeritus in the College of Arts and Sciences, has updated his model using newly released data from major dark energy observatories. He concludes that the universe will end in a big crunch.

Tye's calculations suggest that the collapse would occur in about 20 billion years. The new data seem to indicate that the cosmological constant is negative, which means the universe will eventually shrink and collapse.

The Dark Energy Survey (DES) in Chile and the Dark Energy Spectroscopic Instrument (DESI) in Arizona have provided key evidence for this conclusion. Both projects aim to better understand dark energy, which makes up about 68% of the mass and energy in the universe.

To account for the latest observations, Tye and his collaborators proposed a hypothetical particle with extremely low mass. This adjustment fits the latest observations and pushes the underlying cosmological constant into negative territory.

Why It Matters

Understanding the fate of the universe can help us better comprehend our place in it. It also encourages scientists to continue exploring the mysteries of dark energy and its impact on the cosmos.

Key Facts

• The universe is currently 13.8 billion years old and still expanding.
• Henry Tye, a Cornell physicist, has calculated that the universe may be nearing its halfway point.
• The universe will continue expanding for another 11 billion years before shrinking and eventually collapsing.
• The collapse would occur in about 20 billion years.
• Dark energy makes up about 68% of the mass and energy in the universe.

Key Terms

Cosmological constant

A measure of how the universe expands or contracts over time

Implications

Understanding the fate of the universe can help us better comprehend our place in it. It also encourages scientists to continue exploring the mysteries of dark energy and its impact on the cosmos.