IAS Gyan

Daily News Analysis


19th April, 2024 Science and Technology


Source: Space

Disclaimer: Copyright infringement not intended.


  • The universe may be dominated by particles that break causality and move faster than light, new paper suggests.


  • Physicists propose that tachyons, hypothetical particles moving faster than light and breaking causality, may dominate the universe.
  • The researchers suggest that tachyons could be the true identity of dark matter, which constitutes a significant portion of the mass in the universe.
  • Dark matter outweighs normal matter in galaxies by a ratio of 5 to 1.
  • The paper proposes a cosmological model where an expanding universe filled with tachyons initially slows down before reaccelerating, akin to the current accelerating phase driven by dark energy.
  • This model aims to explain both dark energy and dark matter simultaneously.
  • The researchers tested their tachyon cosmological model against observations of Type Ia supernovae, crucial for understanding the universe's expansion rate.
  • Surprisingly, the tachyon model performed comparably well to the standard model involving dark matter and dark energy.

About Tachyons

  • Unlike ordinary matter, which moves at speeds slower than light, tachyons are theorized to travel faster than the speed of light.


  • Tachyons were first proposed by physicist Gerald Feinberg in 1967 as a byproduct of his research into faster-than-light phenomena.
  • The name "tachyon" originates from the Greek word "tachys," meaning "swift" or "fast."


  • Imaginary Mass: Unlike ordinary particles, which have positive mass, tachyons are theorized to possess imaginary mass. This implies that as their energy decreases, their speed increases, leading to a phenomenon where they gain energy as they lose speed, defying the principles of relativity.
  • Faster-Than-Light Travel: Tachyons are postulated to travel faster than the speed of light, violating the fundamental tenets of Einstein's theory of special relativity. If real, this would have profound implications for our understanding of causality and the structure of the universe.

Theoretical Implications:

  • Causality Paradoxes: Tachyons could potentially lead to causality paradoxes, such as the famous "tachyonic antitelephone," where information could be sent back in time, violating causality as we understand it.
  • Quantum Field Theory: Tachyons are also a subject of interest in quantum field theory, where they arise in certain theoretical frameworks such as string theory and the Casimir effect.


  • Theoretical Consistency: Many physicists question the theoretical consistency of tachyons within the framework of modern physics, particularly their compatibility with relativity and the lack of experimental evidence.
  • Alternative Explanations: Some phenomena that were once attributed to tachyons, such as the Cherenkov radiation observed in certain mediums, have been explained through other means, casting further doubt on the existence of tachyons.




Q.  Awareness of the harmful effects of sugar and efforts to promote healthier dietary habits are crucial for addressing the global health challenges associated with excessive sugar consumption. Discuss.  (150 Words)