Shedding Light on Gravitational Waves: Part One

NSF’s LIGO Has Detected Gravitational Waves (c)Charly W. KarlCC BY-ND 2.0

Since the beginning of time, people have been fascinated with the unknown. In our universe, the area that we know the least about is outer space. Scientists have studied space for centuries. Despite that, there are still many things we don’t know, such as the behavior of dark matter and until recently, the existence of gravitational waves.

Personally, outer space interests me. because it is where science can be observed at its extremes – from dark holes to supernovas. So when the 2017 Nobel Prize in physics was awarded to the first observation of gravitational waves, I was amazed. How could scientists provide evidence to a theory made by Einstein almost a century ago? How were these waves detected? I ended up researching this topic for my school’s science fair, but before we talk about that, there is an essential question to answer:

What are Gravitational Waves?

To understand this, we first need to understand what gravity is. The picture below illustrates gravity as a mass stretching the “fabric” of space-time.

GPB circling Earth (c)NASA, 
NASA material is not protected by copyright unless otherwise noted.

If a stretch in the fabric is gravity, gravitational waves are ripples in the fabric of time and space. They are caused by objects with mass that accelerate. To visualize gravitational waves, you can imagine the ripples that would move through the space-time fabric when the Earth is moving. You can also imagine the ripples that spread out when you drop a rock into a still pond.

Generally, gravitational waves are hard to detect because they are so faint. Interestingly enough, you and I give off gravitational waves too, but they are undetectable. The waves that can be detected by the Laser Interferometer Gravitational-Wave Observatory are caused by some of the biggest events in the universe: colliding black holes, neutron stars, and exploding supernovas.

Why are Gravitational Waves Important?

Before, scientists used electromagnetic radiation to observe phenomena in space. However, gravitational waves carry information that electromagnetic radiation cannot pick up. For example, black holes give off little to no electromagnetic radiation. This has made them very difficult to detect in the past. However, black holes can be easily detected by the gravitational waves that they emit.

Gravitational waves also interact weakly with matter. This means that they can travel the universe without being distorted, unlike light waves. Through gravitational waves, scientists can make observations in space that could not have been done in research labs on Earth. This includes investigating nuclear physics and thermodynamic changes in the cores of neutron stars.

Finally, gravitational waves are an aspect of Einstein’s general relativity theory that we still need to test and observe. Their existence and our newfound ability to observe them will allow us to understand Einstein’s theory better, and ultimately reveal if there is truth to support it.

But how are Gravitational Waves Detected?

Great question! I’m glad you’re interested in knowing. Unfortunately, the explanation behind the detection of gravitational waves is a bit long so it will have to wait until next time.

Until then,

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