It is very common for us to say that something exists if we see it, we also know if it exists even if we do not see it when we know that someone else has seen it. When we already locate the existence in something palpable it is because that something ends up being in the reality that surrounds our lives.
What we do not see can also exist, only that it has not been shown but sooner or later it can be shown, in other words what exists is because it is outside showing itself, but before it is shown it was internal and also existed, then the existence is left behind to something else that we can feel.
If for example for some circumstance the earth stopped rotating, some of us would be located on the planet on the side of the sun, and all the time the only thing we would see would be light, but that does not mean that the darkness of the universe does not exist, the darkness that shows us the stars of space are there, they just do not show themselves.
What exists in our present can mean an existential doubt to a future, since everything that we know today can die and cease to exist, or existence remains withdrawn to the times, perhaps what does not exist in the present and that not even the historical records speak of them, maybe in the past they existed but today they are not reality before our eyes.
Perhaps when we cease to exist as a human species, there will still be traces of existential elements that will gradually die, until nothingness arrives, but even nothingness will be something that exists for that moment.
Anything will exist forever, even when we feel that things are disappearing, there will always be something more than a sense of existence in the vast universe of the material and spiritual.
