Big Idea of 2017: Cosmic Discoveries in Space and Time

In October, the Nobel Prize in Physics was awarded to the scientists who discovered gravitational waves in 2015. It was an appropriate decision—not only because the merit of their work spanned light-years, but also because 2017, too, brought successive revelations in physics, from violent events millions of miles away to ancient, empty spaces illuminated by the tiniest of particles.

In April, hints of a new particle in the Standard Model originated from LHCb, a small companion detector to CERN’s Large Hadron Collider (LHC) accelerator. Physicists working with LHCb noticed a deviation in the decay rates and patterns of B mesons—particles that last only about a thousandth of a nanosecond. Aberrations in B meson decays suggest there might be a lost particle waiting to be found.

Then in October, physicists from LIGO (the Laser Interferometer Gravitational-Wave Observatory) and Virgo, a new gravitational wave observatory in Italy, announced that they’d detected an electromagnetic signature of a neutron star collision that occurred 130 million years ago. It seems like this would be an insignificant milestone in the timeline of our universe—but to researchers, it’s like a letter from the past, delivered in the form of light.

This artist’s illustration shows two tiny but very dense neutron stars at the point at which they merge and burst into a kilonova.

The merger of these neutron stars created pandemonium both out in space and here on Earth. The crash caused a bright explosion called a kilonova, sending light speeding toward our planet. Just two seconds before the light arrived at Earth, the gravitational waves that had emanated from the event also passed through our planet.

Excitement ensued in the physics community and amongst members of the general public—this example of “multi-messenger astrophysics” shows that physicists are now capable of analyzing gravitational wave data in conjunction with other types of information (in this case, light) to provide a mosaic of perspectives on a single cosmological event.

Now it’s clear that the 2015 gravitational wave discovery—groundbreaking at the time—was just the beginning of a “renaissance in astronomy,” according to astrophysicist Nergis Mavalvala, who is part of LIGO’s detection committee. Watch our video on the finding:

And while this wasn’t an shattering discovery in particle physics, a team of archaeologists reported in November that they’d found a “big void” inside Khufu’s pyramid. Again, it doesn’t sound like the most thrilling. What would be so exciting about a hole in a pyramid? First, it’s a proof of concept for muon technology—a modern technique of particle physics—which was instrumental in unearthing this void. Second, it gives Egyptologists another clue in their on-going investigation of the Great Pyramid’s mysteries. Check out our video to learn more: