Truth is similar to time in that in only exists when humans define it. There cannot be an absolute truth because there is no being that can perceive the world without bias. This, of course, is what I perceive to be true. In fact it would appear that the mere act of writing an essay on truth being conditional weakens your argument by mere principal. Whatever I write in this article, I am admitting that it may not be true, whereas whatever is written on absolute truth side may be claimed to be absolutely true.
People don't like to be told that there is no absolute truth, because doing so forces the person to admit that whatever they believe to be true may be false, and whatever principals or deities they believe in may not exist. If one were to attempt to live their life believing there is no absolute truth, it would prove to be quite difficult.
Now I'm not a quantum physicist, so you'll have to excuse any mislabeling or errors that occur henceforth, although who could be sure that the labellings or errors were absolutely correct in the first place? From what I understand the mere act of shining a light on a quark will cause it to move. Let me repeat that. The force from the beam of light will cause the quark to move. Now, it is thought that all matter is made up of these quarks. Since our primary way to observe matter is by looking at it, we usually have some form of light on an object we are inspecting. So, if the act of shining a light, on a quantum level, can change the position of the matter, than how can we know were the matter was before the light hit it. Scientists say that the quark is not in a specific place, but rather has a probability of being in a certain place.
Since all matter is made of quantums, and the act of observing a quantum will manipulate its existence in the space-time continuum, it follows that observing anything will cause it to be changed from its state before it was observed.
What happens if nothing is observed? What happens if there is no light on any of the quarks? Do they still exist or are they merely a probability? These questions could not be created or answered without perception which is flawed in that it does not exist separate from manipulation. If we cannot observe matter without changing it, there can be no absolute matter.
Some would argue that our ability to accurately perceive something has nothing to do with its existence. They may counter that this is an egotistical view of the universe. If there are no beings that can perceive a world then there is no way of knowing that it exists. Even if a world could exist without being perceived, we wouldn't know. Assuming that you agree with what scientists have shown in quantum physics, than for one to believe there is an absolute truth, one must also believe that there could exist a world that could not be perceived. If you believe this then I have an invisible bridge in Brooklyn to sell you.