It depends what you mean by "change". You may have heard of the issue of retrocausation in quantum mechanics. The way you perform a measurement on a particle actually seems to have a retroactive effect on the way that particle "travelled".UndercoverElephant wrote:Do you think the past is fixed? Or can it change?Ludwig wrote: I know about entanglement, and I undersand that "spacetime" was not really the right word. But I wanted to get the notion of time in there, because I think all moments in time are related to each other in ways other than mere sequence.
What we call time is, in fact, just a function of our perception. Get rid of the function of memory, for example, and your perception of time would surely be almost unimaginably different.
This is obviously highly speculative: but I think it may be possible to affect the past in the same way as the future - you can change it, as long as you don't know what you are changing it from. Just as Schroedinger argued that there is no objective resolution to the question of whether his cat is alive or dead until you look inside the box, so my speculation is that, in some bizarre way, the past is as indefinite as the future - until you start investigating it.
I'm not sure what the implications of this are... I'm not arguing that the World War 2 never happened... I suppose I'm arguing that "past" and "future" may actually be illusions; be just another way that our minds filter reality.
There are some Indians in America, the Tewa, who don't divide phenomena into past, present and future, but simply into categories of "the manifest" - things they observe to be the case - and "the manifesting" - things they don't know about yet, such as what's on the other side of a mountain. Their sole basis for categorising phenomena is their own knowledge. They have no developed conception of what we call time. I wonder if there is a profound truth in their way of viewing reality.
In his book "The Conscious Universe", Dean Radin describes experiments involving qm-based random number generators that appeared to show that retrocausative telekinetic effects may be real.