Study: Cosmic inflation no longer theory

The scientists from the Background Imaging of Cosmic Extragalactic Polarization 2 (BICEP2 )found out the primordial gravitational waves, the first direct evidence of cosmic inflation theory. The data represent the first images of gravitational waves, or ripples in space-time. These waves have been described as the “first tremors of the Big Bang”. The data highlights a deep connection between quantum mechanics and general relativity.

 Purpose: To find a residual marker for “inflation” – the idea that the cosmos experienced an exponential growth spurt in its first trillionth, of a trillionth of a trillionth of a second.

About the BICEP2 study on cosmic inflation

  • Experimental Location: South Pole’s dry atmosphere (one of the driest and clearest locations on Earth, perfect for observing the faint microwaves from the Big Bang).
  • Studied the 13.5 billion-year old residual energy of the Big Bang called the Cosmic Microwave Background (CMB).
  • Purpose: To detect gravitational waves, as these waves are of purely gravitational energy capable of stretching or squeezing the space-time continuum.
  • Gravitational waves squeeze space as they travel, and this squeezing produces a distinct pattern in the cosmic microwave background. Gravitational waves have a “handedness”, much like light waves, and can have left- and right-handed polarizations.
  • Detected a B-mode polarization signal i.e. considerably stronger than many cosmologists expected.
  • The swirly B-mode pattern is a unique signature of gravitational waves because of their handedness. This is the first direct image of gravitational waves across the primordial sky.
  • Scientists analyzed their data for more than three years in an effort to rule out any errors. They also considered whether dust in our galaxy could produce the observed pattern, but the data suggest this is highly unlikely.
  • Outcome: The study opened the door for physicists to explore a unified theory of nature in new light.

In other words, in theory, this swirling polarization pattern could only be created from gravitational waves. And that is what BICEP2 found.

Key terms:

  • Cosmic Microwave Background (CMB): A field of microwave radiation that permeates the universe. It consists of electric (E) and magnetic (B) fields, called modes.
  • B-mode: A twisting or ‘curl’ pattern in the polarized orientations of the ancient light
  • Cosmic inflation: The expansion of space in the early universe at a rate much faster than the speed of light.
  • Cosmic inflation indicates that the universe expanded at many times the speed of light a fraction of a second just after the Big Bang. These newly-discovered gravitational waves are ripples in space-time buried deep in the cosmic microwave background radiation, ancient light that permeated the known universe 380,000 years after the universe came into existence.

Note: BICEP2 is funded by the National Science Foundation (NSF). NSF also runs the South Pole Station where BICEP2 and the other telescopes used in this work are located.


Categories: Science and Technology Current Affairs - 2017