Proving Gravitational Waves exist

abstract-wavesWe used to think space and time were two separate things … until Albert Einstein challenged our common sense with his Theories of Special Relativity and General Relativity. He declared space and time are inseparable, creating a four-dimensional “fabric” made from three dimensions of space, and a fourth dimension of time.

Einstein gave us his Theory of General Relativity in 1915, but it has taken decades to prove his theories about space-time. Back in 2007, NASA’s satellite Gravity Probe B showed that the Earth really does distort the fabric of space-time.

Imagine the Earth is a big marble, sitting on a rubber sheet (representing four dimensions of space-time). The Earth-marble’s mass makes the stretchy fabric sag in the middle. A smaller Moon-marble trundling by, gets drawn towards the lower parts of the space-time fabric. Instead of travelling straight past, it curves into an orbit round the Earth. But imagining is not the same as proving. That takes clever tests and measurements.

So what happens to this space-time fabric when the Earth is spinning? Einstein suggested this would cause GRAVITATIONAL WAVES, little ripples in the space-time fabric. Well, last September we found one! It’s only recently been announced as scientists had to carefully check their data first.

They discovered a series of eight gravity waves (caused by two huge black holes spinning around and into each other) by using lasers and mirrors at the Laser Interferometer Gravitational-Wave Observatory. LIGO is a system of two specialised telescopes. Instead of detecting light, they detect gravity waves. One of LIGO’s detectors is in Louisiana, the other in Washington USA.

Scientists and Einstein fans know that LIGO’s gravitational wave proof is a fantastic milestone for science. And will probably lead to new technologies, as well as enriching our understanding of the universe.

To celebrate poetically, here’s Gravity Waves and a link to The Gravity Poem by Cassy Lawrence with a video, courtesy of HSE Docs UK.

Gravity Waves by Celia Berrell
(Einstein’s right again)

Time and space
like warp and weft
of cosmic fabric set adrift
should bend for mass
by theory
of General Relativity.

Laser beams
at LIGO’s base
have captured
distance changing pace.
A travelled length
in altered time
means gravity gave us a sign!

So LIGO’s proved
how gravity
(that force of massive
can kink and ripple
space-time’s shawl.

A wave to Einstein’s know-it-all!