Scientists using NASA-NSF Telescope Discover Gravitational Waves from Big Bang – UPDATE
UPDATE, February 2, 2015: After further analysis, scientists involved in this “discovery” retracted it. The Associated Press quotes Brian Keating as saying “we’re essentially retracting the claim” in a new paper. “It’s disappointing … but it’s important to know the truth.
ORIGINAL STORY, March 20, 2014: Scientists using a telescope in Antarctica equipped with sensors developed by NASA announced on Monday that they discovered evidence of gravitational waves produced by the Big Bang that many believe created our universe.
Understanding the origin and evolution of the universe is a scientific quest dating back centuries. Today, most scientists believe an event called the Big Bang started it all, though what created the Big Bang is unknown and only theories exist about what happened in the first moments afterwards.
Based on observations from NASA’s Hubble Space Telescope, the universe is calculated to be 13.8 billion years old and NASA’s Hubble and Spitzer space telescopes have peered back through about 13.3 billion of those years. NASA’s COBE and WMAP satellites as well as the European Space Agency’s (ESA’s) Planck mission have studied light – the Cosmic Microwave Background (CMB) – that originated from an even younger universe and began to stream through space 380,000 years after the Big Bang.
What happened before that remains a mystery. One theory is that in the fractions of a second after the Big Bang, a period of “inflation” took place where theoretical particles called “inflatons” pushed space-time apart. Eventually stars, galaxies, planets and the other objects and phenomena observable today formed. Some scientists theorize that the inflatons continued to form new universes in a process dubbed “eternal inflation” with “infinite pocket universes” creating a multiverse. Andrei Linde of Stanford was quoted by New Scientist as saying that “[i]f inflation is there, the multiverse is there.”
The findings from the BICEP2 telescope in Antarctica announced this week by the Harvard-Smithsonian Center for Astrophysics (CfA) relate to an infinitesimal period of time – a trillionth of a trillionth of a trillionth of a second – after the Big Bang. Inflation theory posits that the events occurring at that time created gravitational waves that can still be detected today. The observations with BICEP2 support that theory.
BICEP2 found a characteristic swirly pattern in the polarization of the light left over from the Big Bang (the CMB) that could only be caused by gravitational waves. Waves of light are polarized when they tend to wiggle in one particular direction. Gravitational waves – ripples in space-time caused by the motion of massive objects like those being flung outward during the violent expansion of inflation – would polarize light as they swept through the universe. The Harvard-Smithsonian CfA announcement said the BICEP2 data “represent the first images of gravitational waves, or ripples in space-time.”
BICEP2 is a radio telescope funded by NSF, which also runs the South Pole Station where BICEP2 is located. NASA’s Jet Propulsion Laboratory (JPL) developed the superconductor-based BICEP2 detectors. Jamie Bock, who has joint appointments with JPL and Caltech, is co-director of the project and said that it already was known that the Big Bang produced density waves, but these observations are the first to show that gravitational waves were also produced.
The BICEP2 findings support inflation theory, but remain to be corroborated by subsequent studies, a sine qua non of the scientific process. Nonetheless, the astrophysics community is energized.
In the meantime, assuming the result holds, the implications are tantalizing: it solidifies the theory of inflation and greatly narrows the pool of inflation models that can be correct. Furthermore, it again proves Einstein’s prediction of gravitational waves.
BICEP2 is not the only telescope searching for signs of inflation. Among the others is NSF’s Laser Interferometer Gravitational Wave Observatory (LIGO), a large ground-based experiment designed to detect gravitational waves directly. Work is now being done to upgrade the detectors in the facility and “Advanced LIGO” should begin operations this year. The Laser Interferometer Space Antenna (LISA) is a potential NASA-ESA mission that would seek to detect gravitational waves directly using three separated spacecraft. It received a relatively low priority (priority 3) in the National Research Council’s most recent Decadal Survey for astrophysics because the technology is not mature. ESA plans to launch a technology demonstration for such a mission, LISA Pathfinder, next year.
BICEP2 is an international collaboration involving 11 institutions: Caltech, JPL, UC San Diego, Harvard, NIST Boulder, Stanford, University of British Columbia, University of Chicago, University of Minnesota, University of Toronto and University of Wales Cardiff. BICEP stands for Background Imaging of Cosmic Extragalactic Polarisation. This was the second phase of the BICEP experiment, hence the designation BICEP2.