# Gravity

In the quantum theory of a particular physical system, the lowest energy attainable is higher than the minimum energy of the system predicted by the classical Newtonian theory. This difference in energy is called “zero point” energy.
For example, in the classical theory of the hydrogen atom, the electron orbiting the proton would gradually lose an infinite amount of energy in the form of electromagnetic radiation and fall onto the proton. In the classical theory, the hydrogen atom would therefore be the size of a single proton, or roughly 10-15 m. In the real world, the hydrogen atom is way bigger, with a size of about 10-10 m. The quantum theory, which gives a very good description of the properties of the hydrogen atom, only allows the electron to lose a finite amount of energy until it reaches an energy 13.6 eV below that of the ionised hydrogen atom. But no more. The zero point energy in that case is infinite. We also find that the electromagnetic zero point energy of empty space is infinite, or at least extremely large if we assume that there is a minimum wavelength (the Planck length) for electromagnetic radiation. But it is no cause for alarm, since in electromagnetism only energy differences matter, and not their absolute value. The zero point energy cancels out of the calculations.

Making someone levitate is relatively easy with Photoshop. Zero gravity without the space shuttle.

This is different in Einstein’s theory of gravitation, in that the absolute value of the density of matter determines the curvature of space-time. Einstein’s celebrated equation E = mc2 states that mass and energy are equivalent. Hence the very large (essentially infinite) zero point energy predicted by the quantum theory should be equivalent to a very large mass density that in turn would produce some enormous gravitational fields, which are not observed.

The development of a quantum theory of gravity is an important and yet unsolved problem that is occupying some of the best minds in theoretical physics.

Fortunately, the solution of problems caused by gravity is a lot easier in Photoshop. In the photograph above, I appear to float in zero gravity in my flat. A problem I was able to solve in relatively little time. Thank you Adobe!

# Digital is making it easier, but don’t lose your head over it!

These days you hear a lot of complaints about how the digital era has ruined professional photography, because it is now much easier to take pictures that are ‘good enough’.

When I got started in my previous career as a theoretical physicist, I realised it was essential to be good with computers, because most of the problems of current interest in physics weren’t solvable with pen and paper. Back in those days, there were no user friendly operating systems like Mac OS X. The tools available to check and correct one’s computer programs were very primitive by today’s standards, and so were the programming languages available for scientific computing. Never mind the fact that 256 MB of RAM was the most I had access to on the then state of the art Cray Y-MP supercomputer. The kind of computer that cost millions of dollars. Needless to say that a lot has changed in the field of computational science in the past two decades or so. The ease with which it is now possible to write and test complex computer programs coupled with the speed of today’s machines make it possible for novice programmers to carry out calculations experienced scientists couldn’t even dream of twenty-five years ago. Yet you don’t hear senior computational physicists complain that the new technology has totally ruined the field because it is now much easier to program computers. This is because the technology makes it easier for everyone, not just for the beginner. Provided you can be bothered to keep up with the times and learn the new tools.

The basic principles of good scientific programming and project management haven’t changed, and the experienced computational physicist has a great advantage over the novice who still has to learn those principles. Moreover, the advances in computer technology are opening new avenues for research. This is wonderful since you obviously don’t want to solve the same problems over and over again. I can think of no valid reason for anyone to complain about the changes brought about by the new technology.

Here’s an example of image that the digital technology makes possible, that hasn’t been done many times before, and isn’t within the reach of the novice digital photographer.

The similarities with the digital revolution in photography are striking to me. Sure, nowadays a novice can take the kind of picture that took quite a bit of technical skill twenty years ago. But then, why would you want to take the same kind of pictures you took eons ago? Isn’t it time to move on?

The basic principles of composition and lighting haven’t changed, and therefore the experienced photographer who masters those principles has the advantage over the novice who still has to learn them. And the digital revolution has opened up new avenues for image making. One of these is the use of compositing or image trickery with Photoshop. Another is low light or night photography. It is now possible to capture high quality photos and video with the same camera. Challenging time lapse sequences, like capturing the change from daytime to night, are now much easier to do. Just to give a few examples.

# The Calming Effect of Time in Life, Science and Photography

“Time makes more converts than reason” – Thomas Paine

Have you ever received a rude email or a negative comment on your work? I’m sure your first reaction is one of anger and the desire to strike back, and it is a normal emotion to have. It is your lizard brain at work, as Seth Godin would put it. But we have evolved higher cognitive functions, and we can use them to censor our inner lizard.  If you weren’t born yesterday, you know that lashing out back in anger is totally counter-productive. Let some time go by,  so your desire for revenge lessens. In the end you will calm down and realise it wasn’t such a big deal in the first place.

When my PhD supervisor and I published a paper about 20 years ago that went against the current common wisdom in the field, all hell broke lose and he was the subject of very strong criticism. Luckily, as the junior partner of the collaboration, I flew under the radar. Many years later, a review article in the scientific journal Nature described the theory once so unpopular as having “the most support in the community”.

Silverknowes beach, Edinburgh, sometime after sunset.

Last week, as I set my tripod on Silverknowes beach to take the picture above, the wind was blowing, creating many ripples on the water. The landscape looked quite agitated. But by using a long exposure time of about 90 seconds, the motion of the water ripples averaged out, and the overall landscape acquired a peaceful appearance. Time has a calming effect indeed.

# Nearly everything is interesting

“Nobody ever figures out what life is all about, and it doesn’t matter. Explore the world. Nearly everything is really interesting if you go into it deeply enough.” — Richard Feynman

Would you spend any time watching water freeze? Probably not. It’s not that interesting, you might think.

But if you look at the phenomenon deeply enough, the freezing of water has something to do with the quest by theoretical physicists to unify all the forces in Nature.

When water is liquid, its density is uniform throughout. No matter where you are in the liquid, the density is the same. This symmetry is referred to as ‘translation invariance’ by physicists. As the water cools and turns to solid ice, the water molecules form a regular array and no longer move at will. In a crystal such as ice, every molecule vibrates around a fixed equilibrium position. The density of matter is therefore high near the equilibrium positions of the water molecules and low in between. It is no longer uniform, and the complete translation invariance of liquid water is broken. In simple terms, ice (really cold water) is less symmetrical than room temperature water.

We live in a cold universe, and by analogy with the freezing of water, the universe today is likely less symmetrical than it used to be billions of years ago, when our universe was much hotter. Today we have four kinds of forces. The gravitational, electromagnetic, weak and strong forces. What if these forces used to be one and only one force when the universe was hot and that symmetry was broken into the four kinds of forces we observe today as the universe cooled down? This is a question at the forefront of current scientific research.

Now that I am a photographer, I still abide by Feynman’s quote. I strive to look at mundane objects and see if I can find a way to make them look interesting. How about a couple of forks and an aluminium container?

Two wet forks. Lit with a small torch and color gel, using the technique of light painting

Side of aluminium container reflecting an orange object (Seth Godin’s book Linchpin)

This is not simply an academic exercise. I believe that if I can find ways to make really simple objects like forks and aluminium containers look mildly interesting, I should definitely be able to serve my clients better by making them and their businesses look really interesting.