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aspaceinthecosmos · 10 months

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hello! i've got some GROUNDBREAKING space news for you!

scientists have uncovered evidence for a gravitational wave background (GWB) in our universe, and the way they went about it is fascinating.

To fully understand what's going on here, we need to go into a bit of background information.

First of all: what are gravitational waves? gravitational waves are often called 'ripples' in spacetime, often caused by extremely energetic processes such as black holes colliding, or two neutron stars orbiting each other closely.

So, how did scientists figure this out? They used 67 pulsars (known as the Pulsar Timing Array) throughout the Milky Way, practically creating a galaxy-sized telescope in order to study this.

Pulsars are the extremely dense cores of massive stars, left over after they go supernova. These are fascinating on their own, but for this project, they had an essential feature: Pulsars rapidly rotate (think up to hundreds of rotations per second), spewing radiation out in pulses from their magnetic poles. For some pulsars, these radiation jets cross Earth's line of sight, and we get incredibly constant bursts of radio signals, which can be catalogued and used as a sort of standard, universal clock.

Here is a link to a gif showing the rotation of a pulsar. Please be warned for flashing and eyestrain.

For 15 years, a team of astronomers working for the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), used radio telescopes around the globe to track minuscule changes in the signal patterns from pulsars. The changes they found are due to the slight movement of spacetime between us and the pulsars, stretching and compressing the paths of their radio waves as extremely low frequency gravitational waves pass through the universe (yes, that includes you. your atoms, as well as the atoms making up everything around you, are very slowly shifting position, dancing along to the heartbeat of the universe).

At the moment, scientists are still debating what could have caused this gravitational wave background, but some there are some leading theories: the GWB could be caused by trillions of binary black hole systems (black holes orbiting each other) throughout the universe. It could also be due to cosmic inflation, or even the big bang itself. Scientists just don't know yet, but the opportunities this discovery opens up are incredible.

The knowledge of the GWB could help us better understand the formation of early galaxies, or even help us understand the origin of the universe.

#aspaceinthecosmos #space #astronomy #outer space #just jupiter #astrophysics #gravity #gravitational waves #physics #pulsars #black holes #neutron stars #the universe #LIGO

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