”Space-Time is Doomed”
Not just anyone could make such an outrageous statement as “Space-Time is Doomed” and actually provide a supporting argument. The point I want to make today, as quoted from Professor Nima Arkani-Hamed, physics is not at a “garden variety” point in its evolution.
My previous article gave a starting point for this path exploring new ideas in science and Arkani-Hamed is one with very new ideas. I wasn’t turning up much of any use for my pet “theory” for a mind-body connection until I found a lecture by Nima Arkani-Hamed on an “object resembling a multifaceted jewel in higher dimensions”, the Amplituhedron. As he explained in the lecture at the end of this article he and his colleagues developed a way to calculate particle interactions without needing to use time and space that has been intrinsic in our understanding of how things move and interact. It’s a revolutionary approach to reality and he makes it clear that physics is in revolution.
Articles appeared in 2013 on his ideas for doing particle physics in a new way. The first link, a Quanta Magazine article by Natalie Wolchover, is a well written introduction to the fundamentals of the new approach. The problem we lay people will have with even this well written article is the concepts leading to the doom of space time are not easy to grasp. I just think it’s wonderful that such new concepts are emerging.
I have extracted a few relevant quotes below to give a glimpse of the revolution that is starting:
“..The amplituhedron is not built out of space-time and probabilities; these properties merely arise as consequences of the jewel’s geometry. The usual picture of space and time, and particles moving around in them, is a construct.
…The amplituhedron itself does not describe gravity. But Arkani-Hamed and his collaborators think there might be a related geometric object that does. Its properties would make it clear why particles appear to exist, and why they appear to move in three dimensions of space and to change over time.”
“We can’t rely on the usual familiar quantum mechanical space-time pictures of describing physics,” Arkani-Hamed said. “We have to learn new ways of talking about it. This work is a baby step in that direction.”
The next link is the 2010 Cornelll Messenger Lecture he gave to describe the future of fundamental physics to a non specialist audience. It is the first of a five series lecture but I think that the first fourteen and a half minutes is all you need to get the point. You can continue with the whole series if you like since they are all available using a simple YouTube search such as “Nima Arkani Hamed five Messenger lectures”.
My understanding of his point that space-time does not exist as a fundamental component of reality is as an analogy to fire not being a fundamental element, as some historical philosophies had seen it. As we now know, fire isn’t its own thing, instead it is a construct produced from rapid oxidation and subsequent intense release of energy from the chemical reactions. The historical observer could be forgiven to see fire as existing in its own right since people don’t have the senses to see the molecular actions. Space-time, same thing, except now its other dimensions instead of molecules we don’t have the physical capacity to observe. Distinctions and interactions that we perceive as the orderly progression through space and time may well be a construct of multidimensional geometrical “jewels”. I like to visualize it that way but I am probably not being true to the physics.
The second link this week has Arkani-Hamed speaking to a young audience as he is interviewed on the advances in physics. At about thirteen minutes into it he is asked what questions keep him up at night and he comes back to the doom of space-time and also “why is the universe big.” Again, this is a very interesting view into the basic problems being tackled. It is here that he explains that we are not at “a garden variety” point in the development of the field of physics; the nature of the questions is now different, we are at a special time:
At about the twenty minute mark he gets to the problem of why is the universe big. This turns out to be a very interesting problem because it leads to the necessary solution called “fine tuning”. This is suspected as being a strong indicator that something fundamental is missing in the current theories for the “constants” of nature. He comes back to the space-time problem in answer to a question at the twenty six and a half minute point. His reply eventually gets to the crux of the problem in that if in principle something cannot be measured then the history of physics has taught us that the thing being measured has to have emerged from some more basic principles. The whole interview is very worthwhile and is a rare YouTube of Professor Arkani-Hamed outside of his usual highly technical presentations.
Just for the fun of seeing one of his physics lectures, try this one. It’s back to the Amplituhedron and I think it would give you insight into the genius of the man even if it isn’t helpful to the lay person to understand the material. I went to it after finding the magazine article on the Amplituhedron, but multiple viewings just left me with a big list of things I knew nothing about and a lot of Wiki searches.
Note: This video can be seen using the WEB Browser Chrome or FireFox
In my next article I will continue with gems that illustrate alternate aspects of time. Roger Penrose has a view of the entire evolution of the cosmos that does not depend on a Big Bang and the inevitable nothingness. The video is another interview that is directed to a general audience and aside from my interest in it because of the time aspect it is sure to be interesting to anyone not crazy about the universe eventually becoming a whole lot of nothing.