The Discovery of Gravitational Waves and Its Consequences

The discovery of gravitational waves was actually last month. I didn't feel compelled to write about it until I saw a news story about it on the Quark Science Society's website. But yesterday, when I searched for "gravitational waves" on Uncle Gugle and saw that no one else had explained it properly, I felt compelled to write about it.

What Are Gravitational Waves?

Warping of space

First of all, what is a gravitational wave? When Einstein proposed his theory of special relativity, he realized it contradicted Newton's theory of gravity. I won't go into detail about this, but Einstein began working on his own theory of gravity, eventually creating the theory of general relativity. In this theory, as we know, space is curved and contracted by the influence of mass. You can see it in the image to the left.

When it comes to gravitational waves, I liken space to water. But I liken this to two-dimensional, stretching water. Think of it this way: The Sun, with its large mass, is 150 million kilometers away from us. Its mass curves space, but this curvature becomes standard. Later, when you enter its gravitational field with a rocket (a very heavy rocket), your rocket will also curve space, so the change in space will be a gravitational wave. Now, compare it to this: Just as a stone thrown into water creates a wave, so does this. Or imagine that the Sun is not stationary (actually, it's not stationary, but whatever) but is moving. In this case, space will constantly change and create waves. But what does this wave look like? We can actually compare it to a wave in water. Just as a wave in water (note: I searched for a picture, and it turned out to be a hairdo called a water wave, is it good? The wave is below for clarity), at normal water level, as we can see in the picture, there is a peak and a trough. Normally, hydrogen molecules in water move as a result of these movements, but when space ripples, space actually stretches and contracts. As an analogy, if these gravitational waves hit you, your height would increase by 2 meters, then 1 meter, then 2 meters again, and so on, due to the stretching and contraction of space (I'm exaggerating wildly here).

Fluctuation

But these gravitational waves don't occur with every moving object. They are created by extremely fast and massive objects. For example, a binary neutron star spinning and approaching each other. Each time they approach, they spin faster and faster, creating gravitational waves. Or supernova explosions. Another important point, and one important for this article, is the theory of inflation. After the Big Bang, the universe expanded 10 to the -32 power (I couldn't get it to the higher power :( ), for trillions of ...

Now you might be asking yourself: We know what it is, and we know the conditions under which it occurs, but why is it proven now? Even though we know all this, it's all information provided by mathematical equations. And these waves aren't large enough for us to observe. The magnitude of these waves is estimated to be close to the Planck length, which is billions of trillions of trillions of times the distance between an atom and countless trillions of times smaller than we can even imagine (which is why strings haven't been discovered :( ). Our technology is inadequate to detect such small values, and it won't be for a long time.

Gravitational fluctuations, also known as the Ripple effect, depict how a 3D space appears to ripple.

Discovery of Gravitational Waves

Now you might be asking: How was it proven at such low values? Even if the values are small, they can still leave traces, like sea waves on sand (more noticeable at shallow depths). What, you might ask, is the trace left here? It's the microwave cosmic background radiation itself, permeating every corner of the universe.

We've stated that if inflation theory is correct, gravitational waves must be responsible. Scientists, believing these gravitational waves might have left a mark in the microwave cosmic background radiation, launched a nine-year study with a telescope to examine this radiation in minute detail. The result of these nine years of work has finally emerged. We all know the microwave cosmic background radiation. In the first 300,000 years after the Big Bang, electrons and protons were very active, and due to the extreme heat of the universe, they couldn't combine with neutrons to form neutral atoms. After 300,000 years, when the temperature dropped to the appropriate level, neutral atoms were able to form. At that moment, light (photons), previously immobile in the chaos, began to scatter throughout the universe. This is the microwave cosmic background radiation. Scientists studying this radiation noticed that the gravitational waves formed after the universe's rapid expansion would leave distinct marks in the hot radiation of the universe's early moments. In other words, certain bends and rotations would occur in the radiation. While such a detailed assessment was very difficult, it was made. You can see an example below.

The Trace Left by Gravitational Waves

Results of the Discovery

With this discovery, the most difficult equation in general relativity has been proven. Furthermore, the theory of inflation has now been proven with great certainty. But it is certainly not irrefutable. Of course, a different theory could be developed that could explain gravitational waves and explain other things that inflationary theory can explain, but I don't think it's very likely.

On the other hand, the theory of the recurring universe collapsed. Frankly, this theory seemed quite beautiful, but in science, the beauty of the theory is irrelevant. This theory was developed in opposition to the theory of inflation, which posits that the universe constantly collapses and expands again as a Big Bang. Drawing strength from M-Theory, it claims that space is a three-dimensional membrane, and that two three-dimensional membranes collide every trillions of years, creating the Big Bang and extremely rapid inflation. However, this theory does not produce gravitational waves. Therefore, the proof of gravitational waves has demolished this theory. Of course, if the scientists who developed this theory develop it accordingly, the situation may change.

At the same time, Andrei Linde from Stanford University announced that this discovery opened a door to multiple universes.

Sources:
Nature – Telescope captures view of gravitational waves
Space – Cosmic Inflation & Gravitational Waves: Complete Coverage of Major Discovery
Universe Today – Rumors Flying Nearly as Fast as Their Subject: Have Gravitational Waves Been Detected?
Dailygalaxy – Epic Gravitational-Wave Discovery Points to Existence of Multiple Universes