Photons too fall you know!

The universal theory of gravity, there wasn't any word better than "universal" to describe it. Till now that is.
Every one has heard of the law of gravity. It is a very popular and successful theory. One of Newton's best works you could say. We were truly wonder struck when we learnt of it. Such a simple and elegant solution to such an elegant but elusive problem. We were struck with awe at hearing the answer to the problem we, all of humanity, had pondered about for ages. We truly respect Newton's genius and his solution. But we are by habit and character forced to not stop there, and search for, maybe a better solution. To question the answer, so as to reach a better one.

Our doubt is not at all complicated. on the contrary it is very simple or perhaps even foolish as we will soon find out. Now let us get to the point: Now, every one knows what the law states. It states that the force, between any 2 given masses, of gravity is directly proportional to the product of their masses. But there is a slight problem. And before we get to it let me tell you of a certain phenomenon I came across during the prestigious and awfully fun-filled occasion, the Tech Fest. At the fest, I learnt of Gravitational Lensing. It, by definition, is a phenomenon by which a massive body acts like a convex lens and actually focuses the light that goes, near it. The body actually bend the light rays that go close by by means of gravity. You can learn more of this phenomenon using the internet. It is actually o f very much practical importance as dark matter too is located by this process.
I was very much fascinated after learning of it. But with it came a striking revelation. I mean, how can a beam of light be bent? It is supposed to have ZERO mass! Since the phenomenon was physically observed, the reality of the phenomenon could not be questioned. So, presumably, there was something wrong with the theory. After all, if the force of gravitation is supposed to be directly proportional to the product of their masses, the force should be zero. The mass of the photon(what a ray of light is made up of) is after all, nil. So the product is zero. (Though General Relativity could easily explain gravitational lensing, we are talking about just the law of gravity here.)

So please do think about this problem and send us answer soon. For our curiosity makes us more and more impatient. Do send us an answer soon. We do have certain inferences of this phenomenon of our own, but we would sure like to know what you think of this. Thank You for reading through our post with the kind of patience you have demonstrated now. Thank You.
A.B.G.D.