Tag Archives: spac-time

If Time Died Now, I Would Be Happy

I dream strange dreams. Thankfully, I don’t usually remember them. But at times, I do remember some, and they provide a lot of entertainment. One recent dream was of a TV interview, going on in a mall. The person being interviewed was a stranger, as the protagonists of my dreams tend to be. This guy was middle-eastern, either Iraqi or Iranian, and was talking about a kid who he was about to adopt. The kid turned out to be a child prodigy, and was flying away somewhere for specialized training. The interviewee, though a bit sad, was philosophical about it. At that moment, there was a background song in the mall that went like, “If time died now, I would be happy.” And the man says, “Yes, that is the way I feel!”

I remember feeling, in my dream, “Yeah, right! The right song just happened to be playing!” Way too skeptical even in my dreams. Not to mention that there is not such song (as far as I know). If you think this dream is weird, I once dreamed up an unknown (and non-existent) word while reading a book. I even tried looking up the word when I woke up, but in vain, of course.

One of my top dreams was when I was invited to the White House by President Bush (junior) right after his inauguration. As I stepped into what appeared to be a decent sized living room, the President was walking down a flight of stairs. And he asked me, “So. Do you still think I’m dumb?” Now, how did he know how I felt?

Coming back to my time-dying dream, there is something else that is a bit weird. I mean, one would normally say, “If I died now, I would die a happy man” or something to that effect. Why would “time” die? Is it my secret conviction that when one dies, one’s “time” also dies? That there is no common, universal time, but only our own, individual, personal times? Perhaps. I’m not talking about Newton’s universal times vs. Einstein’s relative time. There is something philosophical here that is just beyond my grasp. Like a name at the tip of your tongue. These are deep waters, and I really need to learn more. Back to school, some day…

The fanciest of my dreams? I was James Bond once. Complete with a bicycle that turned into a wooden canoe when I hit the local beach.

The Big Bang Theory – Part II

After reading a paper by Ashtekar on quantum gravity and thinking about it, I realized what my trouble with the Big Bang theory was. It is more on the fundamental assumptions than the details. I thought I would summarize my thoughts here, more for my own benefit than anybody else’s.

Classical theories (including SR and QM) treat space as continuous nothingness; hence the term space-time continuum. In this view, objects exist in continuous space and interact with each other in continuous time.

Although this notion of space time continuum is intuitively appealing, it is, at best, incomplete. Consider, for instance, a spinning body in empty space. It is expected to experience centrifugal force. Now imagine that the body is stationary and the whole space is rotating around it. Will it experience any centrifugal force?

It is hard to see why there would be any centrifugal force if space is empty nothingness.

GR introduced a paradigm shift by encoding gravity into space-time thereby making it dynamic in nature, rather than empty nothingness. Thus, mass gets enmeshed in space (and time), space becomes synonymous with the universe, and the spinning body question becomes easy to answer. Yes, it will experience centrifugal force if it is the universe that is rotating around it because it is equivalent to the body spinning. And, no, it won’t, if it is in just empty space. But “empty space” doesn’t exist. In the absence of mass, there is no space-time geometry.

So, naturally, before the Big Bang (if there was one), there couldn’t be any space, nor indeed could there be any “before.” Note, however, that the Ashtekar paper doesn’t clearly state why there had to be a big bang. The closest it gets is that the necessity of BB arises from the encoding of gravity in space-time in GR. Despite this encoding of gravity and thereby rendering space-time dynamic, GR still treats space-time as a smooth continuum — a flaw, according to Ashtekar, that QG will rectify.

Now, if we accept that the universe started out with a big bang (and from a small region), we have to account for quantum effects. Space-time has to be quantized and the only right way to do it would be through quantum gravity. Through QG, we expect to avoid the Big Bang singularity of GR, the same way QM solved the unbounded ground state energy problem in the hydrogen atom.

What I described above is what I understand to be the physical arguments behind modern cosmology. The rest is a mathematical edifice built on top of this physical (or indeed philosophical) foundation. If you have no strong views on the philosophical foundation (or if your views are consistent with it), you can accept BB with no difficulty. Unfortunately, I do have differing views.

My views revolve around the following questions.

These posts may sound like useless philosophical musings, but I do have some concrete (and in my opinion, important) results, listed below.

There is much more work to be done on this front. But for the next couple of years, with my new book contract and pressures from my quant career, I will not have enough time to study GR and cosmology with the seriousness they deserve. I hope to get back to them once the current phase of spreading myself too thin passes.