note: don't forget to check out the videos below

I can’t remember how many people have told me that when on my deathbed, I will want to believe in an afterlife. I haven’t crossed that road yet but Immortality is not something that I particularly feel is necessary for my existence, at least not in the same way that theists do. Sometimes I’m not even sure if I want immortality. The way my life is going right now, I don’t think I even want to make it past 30. But that’s a topic for another entry.

Whether I want immortality or not is irrelevant though. I don’t think that wanting immortality is sufficient reason to believe in an afterlife the same way that wanting to get a Canon 1Ds Mark III on Christmas is not sufficient reason to believe in Santa. So I don’t think I will want to believe in a spiritual afterlife when I’m on my deathbed. Besides if one’s rationale for belief should rest solely on one’s fear of death then wouldn’t it be more realistic to hope for drugs that would increase human lifespan indefinitely or future technology that could recreate the consciousness of people who have already died? Far fetched as they are, they still are a more realistic take on immortality than believing that you have a soul and it would detach itself from your body at the time of your death and go to a place called heaven where people get to live happily ever after. The concept to me seems childish and if I were dying and wanted false hope then I’d rather believe that I’ll be recreated someday in a computer. But as I always say, to each, his own. The comfort provided by religion to those who are grieving is undeniable. And who knows? I might need that kind of comfort someday when I’m faced with my own mortality or that of a loved one. Hoping to be recreated on a computer seems a bit unrealistic, going to heaven, even more so but one doesn’t necessarily have to resort to such notions to think of one's own permanence

Modern physics has fascinated me since I was 10 or 11. I didn’t really read too much fiction as a kid. What I read mostly were science journals like scientific American, discover, astronomy, nature etc. I’ve brought up modern physics in conversations more often than I would care to remember. Showboating used to be one of the reasons but now it’s mostly just to share my sense of awe for the cosmos. My awe of the cosmos is the closest thing I have to spirituality. When I look at people who don’t know about general relativity or quantum mechanics, it’s like I’m looking at people who are living in the matrix and not knowing or caring about it… And then I feel the strong urge to “evangelize” them.

General/special relativity, quantum mechanics, string theory etc bend common sense so much that if you talk about them to people who haven’t read about them before, they’d think you’re a loony. They describe the universe in a way that is so different from how we perceive it that, sans empirical data, one might as well believe that we are living in the matrix. The most astounding part is that they (at least relativity and quantum mechanics) are heavily supported by evidence and their predictions are extremely accurate down to the most mind boggling decimal places.

Some may be inclined to say that these are just theories, not laws and therefore should not be taken seriously. Theories and laws though are different concepts in science. One need not necessarily be more true than the other. Einstein’s “theory” of General relativity’s description of gravity is actually more accurate than newton’s “law” of gravitation. The latter’s description of gravity is actually now considered obsolete and has already been replaced by general relativity

Another thing I like about modern physics is that it makes philosophical discussions a lot more interesting. Few philosophers now would dare discuss free will without mentioning quantum mechanics. And few philosophers would dare tackle the concept of time without a basic grasp of general relativity
 “Time is an illusion” is a phrase that has been echoed by countless philosophers in history. In fact, Einstein himself said the exact same phrase. If we are to follow Einstein’s physics, time is not separate from space. It’s part of a 4 dimensional manifold called spacetime. Time is treated as just another vector, like the 3 other spatial vectors.
To give you a general idea of the real-world significance of the concept, what we perceive as gravity is actually not the invisible force that instantaneously pulls on objects described by Newton but is actually the movement of objects within curved 4d spacetime (massive objects like planets and stars distort the spacetime around them)

The concept of something that is 4 dimensional is something that is impossible to imagine. The 4th dimension is supposed to go perpendicular to the other 3 dimensions, how can one possibly imagine that? One may create 3 dimensional representations of what 4 dimensional objects look like but a true 4 dimensional object is impossible to conceive within 3 dimensional space. A good analogy would be to think of a 2 dimensional creature drawn on an impossibly thin piece of paper and how it would perceive the concept of up and down. For the creature, up and down don’t exist because it can only perceive objects within its 2d plane. It can conceive of 3d objects only as 2 dimensional slices. You can move his 2 dimensional piece of paper up or down but he wouldn’t perceive that he moved in space at all because up and down don’t exist in its space. If the 3rd imperceivable dimension for the 2d ant is height or up and down, the 4th dimension for us is time, the future and the past.

Relativity showed us that time and space aren’t absolute. And this has been experimentally verified. 5 seconds for one observer may not exactly be 5 sec for another observer. 5 meters for one observer may not exactly be 5 meters for another observer (The faster an object travels, the shorter it gets). The present for one may not exactly be the same present for another.
The passage of time is relative to the observer. Speed and gravity affect the passage of time. So it’s actually possible to travel to the future by traveling really fast or by being near a high gravitation body. In fact time travel to the future is not only possible, it’s already being done today. Highly accurate atomic clocks aboard satellites tick at a slower rate than clocks on earth. (Clocks on GPS satellites are actually adjusted to compensate for this). Russian cosmonaut, Sergei Avdeyev who spent 748 days in space has, in effect, traveled .02 seconds into the future.
Relativity also nullifies the concept of an absolute “present”. The exact state of the “present” at any given instant is relative. Two observers moving relative to each other will not measure the simultaneity of events the same way. (The disparity increases as the speed increases) From the perspective of one observer, event A may have happened before event B. From the perspective of the other observer, event B may have happened first. According to relativity both their perceptions of the order of events are correct, despite them being in conflict with each other. There is no absolute reference frame on which to base the present

So what is time? It seems like time isn’t completely illusory in the sense that it is imaginary or a mere human construct, as a lot of philosophers believed. It has a “structure” that can actually be stretched or deformed like most other things that are not imaginary. What may be the illusion is the way we perceive it –maybe even the perception that it actually flows.
Quantum mechanics complicates things a little bit and may require more than 4 dimensions to reconcile w/ general relativity but if we are to go by the mathematics of special/general relativity, as well as the views of some of the greatest minds in physics like penrose and Einstein, then time just exists. The present doesn’t cease to exist as it becomes the past. And the future doesn’t wait to exist until the present catches up with it. Spacetime is a 4 dimensional block made up of all future events and all past events, all at once! It may even be inaccurate to call any particular point in spacetime as the future or the past as there is no absolute reference point that can be called the present. Different slices of spacetime could be the present, depending on your perspective. The same way that earth and pluto exist in 3 dimensional space at different locations, the past, the future, and the present all exist within 4 dimensional spacetime. They’re just at different locations with respect to the time axis.

Let me go back to the subject of permanence. I don’t feel that our mortality makes our lives any less meaningful in fact I think it makes it even more special. But like others, I also see the appeal of permanence.
I’d like to think that something I did in my life would be able to outlive me –more than any other way, I’d like to be able to achieve permanence through that. It’d also be nice if technology that could extend my life for as long as I want could be made available within my lifetime. If there is such a thing as a spiritual afterlife then I would love to be greeted by 72 black-eyed virgins after I die. Such a place should be significantly more exciting than the Christian heaven, I would imagine (if you’re going to go with the extremely fantastic, why not go all the way) I’d also like to think that the people I know would achieve some sort of permanence.

Someone now dead once said “Our hope of immortality does not come from any religion, but nearly all religions come from that hope”. Science points to the conclusion that consciousness ceases to exist when the brain ceases to function. It’s a fact that the brain ceases to function at death and it’s unlikely that any brain could be made to function forever. It seems like most people are psychologically predisposed to thinking of their consciousness as everlasting and science seems to contradict that. That’s maybe why some people distrust science and would rather believe in completely baseless and fantastic concepts like divine creation rather than universally accepted facts like evolution.  But perhaps there are ways of imagining one’s permanence without necessarily delving into the spiritual realm

When Michele besso, a friend of einstein’s died, Einstein wrote to his wife saying that although Besso had died before him, it was of no consequence because: "...for us physicists who believe, the separation between past, present, and future is only an illusion, although a convincing one.". An implication of the block space-time model is that everyone who’s ever lived and will ever live are all contained within spacetime. Those who have already passed away may not exist in this particular “present” but they exist elsewhere in spacetime, in their own present. Saying that they exist in another point in time is no different from saying that they exist in another point in space, say somewhere on Pluto. Physics makes no distinction. They’d be unreachable either way but they’re there.

…too young to be thinking of death yet but I imagine it’s a thought that non-believers or doubters could find comfort in when facing their own mortality or that of a loved one. Maybe some believers could find comfort in it too… a scientifically palatable way of romanticizing one’s existence for a change

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Anyway, the main point of this entry is to introduce you, my obviously intellectual reader, to the world of general/special relativity and post classical physics. And i think videos do a better job at explaining the concepts than text. These are some videos that should get you more acquainted with the mind boggling world of modern physics. I suggest that you start from the top

Special relativity and relative time

general relativity, 4d spacetime and gravity


Quantum mechanics

think that 4 dimensions are too much? String theory suggests that there are up to 11 dimensions. Here’s a 4 part video on string theory. Here’s part I

Here's an artistic interpretation of how to imagine a universe with more than 3 dimensions