Taking time as a fourth dimension is due to Einstein because of the speed of light being fixed. But why should such a finding have so important consequence on our philosophical contemplation of existence? I think philosophical questions are generally deeper than such scientific contingencies.
Let me explain my point: Suppose that we came to discover a new mean of communication other than light, and suppose we can detect it and make calculations about it by our devices, much as we do of light, etc... Suppose that this physical object travels at a very imaginary speed, like for example can traverse the whole width of our universe is a negligible fraction of a nanosecond. Would that brings us back to the older model of having absolute space and time? by then we can map all of what is existing NOW in the universe, which would be a very different map from what we are seeing depending on light.
On the other hand, if we depend on light for our information, then light having a fixed speed, would raise doubt of deficient information! Let me explain: for example what our devices are detecting is what reached us of electromagnetic radiation from the parts of the universe that are so near to us as to make this reach possible. But there still can be the case that there are some parts of the universe like stars light from which didn't yet reach us! Accordingly what we are seeing like the big bang, the expanding universe, etc.., could be just a pocket of the universe that is within our reach, and it might be just a small territory in a vastly bigger universe that we cannot visualize because light from it didn't reach us yet. I mean the domain of place and time would be bigger than the observed universe. Is there a scientific argument that falsifies the existence of such external universe? that could even be eternal? having fixed rules, in which change only occurs on matters inside it (like our observed universe).
My question is: is the observed information that science is speaking about the universe enough to settle old philosophical questions about eternity or non-eternity of existence as a whole? Or should metaphysics settle such a question?