Over time, as we studied photons, we have concluded that they are massless particles. This has kept us thinking that light is somehow different from all other components of the universe.
In reality, photons do have a mass. The only difference between photons and something we can easily measure the mass is just that: their mass is so small that we cannot easily measure it. Just because our experimental efforts to measure the mass of a photon, which is ultimately infinitesimal have come up inconclusive does not mean that their mass is actually zero.
To claim that their mass is actually zero is quite the bold claim. Gravitational lensing alone disproves this, as gravity is a function of the mass of the interacting particles. How could gravity lens the pathing of light if it were massless?
Einstein's equation E=mc2 proves that photons have a mass, as photons have energy. How could photons have energy if they were massless?
The simpler conclusion regarding light is that we have not been able to measure its mass because it is so small relative to atoms that we cannot tell the difference between zero and infinitesimal.
By thinking that photons have no mass, we have concluded complex, illogical details about light. Light does not have what we call wave-particle duality. This description pretends that light is different from all other things. What light has is many particles that travel together as a wave, just like a wave in the ocean. All things function the same.
Firstenberg et al. demonstrated that light can be shown to be massive. In their experiment, they stretched the limits of perception by using a vacuum and a highly interactive particle to see light demonstrate it's mass' influence. Within "normal" conditions, we cannot see these effects. However, in the right setting, we are able to expand how far out we can see the mass of particles so that even photons can be shown to have a mass.
Light doesn't just have one specific mass either. The entire electromagnetic spectrum is dependent on the relative mass of the particles that make up each wavelength of light. In a way, the wavelength is a measure of mass per volume. There are infinite layers of particles in light that make up the entire electromagnetic spectrum.
It is no accident that red light is red and blue light is blue and radio waves are radio waves and x-rays are x-rays, and so on. Each wavelength is due to the mass of the particles in the light. Since they are still infinitesimal, we do not see their relative mass difference since we cannot measure their mass. However, they show their mass difference by being different parts of the electromagnetic spectrum.
There is an entire universe in each wave of light. The only difference is the particles are so small relative to what we call "planets", "stars", "black holes" and so on that they function essentially instantaneously. Within every wave of light, all that is, was, and ever will be in infinite dimensions occurs with every moment in a given observer's perceived time.
In fact, our entire observable universe is alike to but one photon in a stream of light to an observer composed of such relatively large building blocks that we make up but a speck of their reality in both space and time. No details are missed, no approximation is made, when the universe functions. Approximations that are so far from reality that they are non-reality only occur when an observer interprets what is happening. That light is light and travels at the speed of light while we do not.
The so-called speed of light is the same mistake as the massless photon interpretation. In reality, the "speed of light" is not an inherent trait of the universe. Instead, the limit of motion of matter is. Light, since it is made of such small particles relative to our own, we see it as moving so close to this limit of motion of matter that we actually interpret that it does move at this limit of motion of matter. Then, due to this interpretation, we think of this limit of motion of matter as being specifically associated with light, just because it happens to be the best example of particles moving closest to this limit. And so we call this limit the speed of light. Even this is a misinterpretation stemming from lack of understanding that photons have a mass.
The universe is not complicated. Rather, it becomes complicated when we interpret it with approximations.
In reality, the universe is infinite. In terms of physics, this means that there are infinitely large and infinitely small masses, and the force of gravity then manipulates these masses into the universe as we see it. It is that simple. In fact, these masses themselves are held together by gravity, universes into themselves, divisible always into smaller components all held together by gravity. It's gravity all the way down. There is nothing but gravity. From one, all that is arises.