...However, the properties of light and its interactions with the vacuum can lead to intriguing effects, such as the bending of light around massive objects (gravitational lensing) and the phenomenon of vacuum polarization, where the presence of light alters the vacuum state.

In my opinion, I think the bending of light is due to the properties of photons interacting with the massive objects, because they’ve properties of mass. I don’t know if this has anything to do with the vacuum of space.

 In my opinion, vacuum doesn’t affect the speed of light, nor are photons part of the vacuum. Our understanding of existence is related to our perception of matter, and thus life as tangible components of the universe. We haven’t even touched the secrets of vacuum that exists in its own omnipresent state, facilitating every celestial motion, including that of light.

 Based on AI search:

“…while zero-point energy has not been measured directly in a straightforward manner, its existence and effects have been by experimental observations such as the Casimir effect and the Lamb shift, affirming its role in quantum mechanics.”

Just as we acknowledge the existence of an observable universe, there similarly exists an observable vacuum of space, beyond which we may attain a more precise understanding of the vacuum's nature - an infinite, intangible expanse devoid of any remnants of quantum fluctuations.

Why do I feel humans may very well be another complex form of virus with their capacity to destroy the planet 

in a long run.

Time is our making. If time was universal, we wouldn’t use light year to measure cosmic distances. Remember a year, whose origin is the complete revolution of earth around the Sun, is a local way of measuring time based on cyclical motions.

 For those who think the universe is not infinite.

I believe the vacuum of space is the only natural phenomenon parallel universes may have in common. For the limited imagination of our little minds, that concept qualifies the vacuum as infinite.

 Regarding unifying QM and GR:

To those who say what unites the GR and QM is the fact that the large is made up of the small, I say the small fundamentally never changes its shape and property but it flawlessly becomes orderly clustered to constitute the large, whose properties as a result can’t help but change. It means there stays two differing orders of magnitude until the bonding