The physics behind Interstellar — Christopher Nolan’s space drama

As a man of physics, Interstellar is a film I would not miss for the world; if not for the physics, for the images — and director Chris Nolan’s images have always been powerful. Interstellar does not fall short on that. However, it helps for the layperson to learn a thing or two about physics before watching the film, which is why I wrote this article — and made sure there are no spoilers.

The film is really very small, but dressed as an operatic journey through space and time. The use of physics is interesting, almost exciting, and what holds the audience’s attention is (surprisingly) as much the science as the story of a parent-child relationship.

And yet, like so many films before it, Interstellar falls short merely because it was hyped far too much and it set itself an unrealistically high barrier.


On Physics and Hinduism

At the entrance to the Centre for European Nuclear Research (CERN) stands a 2 metre tall statue of the Hindu deity, Nataraja (see above). To the unaware, it looks like something out of place: something that does not belong in one of the world’s largest scientific research institutions. But it is only one instance of the compatibility between physics and Hinduism.


Understanding the Higgs Boson in under 10 minutes

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This is not a scientific article and should not be treated as such. As a work of popular science, this aims to introduce the Higgs boson (AKA the God Particle as the media call it) to the common man with a limited scientific background.

As of the time of writing this article, no papers had been published by CERN describing their results/discovery of the Higgs boson and hence no statistics or other data have been provided.

It is worth noting that CERN conducted multiple experiments at the LHC and two experiments, namely ALICE and CMS both independently discovered the Higgs boson simultaneously, thus strengthening the credibility of physicists’ claims.

BY 1915, EINSTEIN’S THEORY OF RELATIVITY had — even if it made absolutely no other point to the layman — certainly put the equation E=mc^2 on almost everybody’s tongue.

It all started with the big bang, er… Einstein

The equation has far-reaching implications even to this day, one of which is the equivalence of mass and energy.

The equation, as is obvious, says that energy (represented by E) is equal to mass (represented by m.) Precisely how they are equated is another matter altogether, but what we need to gather from this equation at the moment is that Einstein said showed that mass and energy are inter-convertible i.e. he showed that at some level they are pretty much the same!

Now this cropped up a new problem. If energy and mass are so easily converted into one another, what makes mass stay as mass? And what prevents it from just zipping around as energy? To understand that we will take a quick look at mass and energy.


Mass and energy and various attractions

Following Einstein’s work came that of Hawking et al. who proved that the story of the universe starting with a big bang was truer than we thought. So imagine this: the universe has just begun and the first particles have been created and anti-particles have disappeared (we do not really know where they went yet) and mass is clumping together to form bigger masses and bigger masses are becoming stars and planets and galaxies and so on; and all of these are in a state of continuous motion.


Albert Einstein, the man who started it all — in a way

Two important questions come to mind here: One, what makes these masses move? Two, what makes smaller masses clump together to form larger masses?

The first question is easily answered. Energy that was available to these masses just after the big bang is what makes them zip around. (Now that is a scientifically meaningless sentence because there was nothing before the big bang, but let us concentrate on getting the point across first.) So now we know how this works pretty well. Like salt in water or dirt in a pond, the particles just kept moving about in space. The only difference is that this movement was perhaps not as random, but the underlying principle is quite analogous.

So far we have masses moving about, which is all well and good. Now we come to our more fundamental second question, what makes masses clump together?

Higgs’ particle

The common understanding in physics is that the presence of mass creates attraction. This is why the earth and sun attract, why two stars attract and so on. They are all massive i.e. have mass. They all contain some substance that gives them the property of mass (whatever that substance is, we do not yet know, but we will come to that soon.)

Peter Higgs at the LHC tunnel

Physicist Peter Higgs at the LHC tunnel. Courtesy AFP

So now you realise that this thing called mass is important to keeps everything stable or else all the mass would have become energy and things would have just been zipping around the universe because the energy that is already present is not going anywhere. (Remember the saying, energy can neither be created nor be destroyed? It is actually a law of Physics.) We will now see how the Higgs boson — or the God Particle as the media call it for some reason which is beyond me — will actually help us answer this question.

Nothing in physics happens without reason. To be precise, we try to find a reason for everything and the next looming question was, what gives particles this property called mass? The answer is the Higgs particle.

The PRL Symmetry Breaking Papers and the Higgs boson

In 1964, three teams of two physicists each independently — within just a couple of months of each other — published papers now called the PRL Symmetry Breaking Papers. In a sentence, these papers all addressed different approaches to the same problem of mass could arise in the circumstance we have just talked about. Of these teams one consisted of American physicist Gerald Guralnik and British physicist Peter Higgs (hence Higgs boson.)

Their solution was simple: Higgs and Guralnik attributed the presence of mass to an as yet undiscovered particle. This was not all about building castles in the air. Their mathematical working had resulted in a strong conclusion that the presence (or addition) of a particle with certain characteristics would solve the mass problem. Further investigation revealed that the particle ought to have properties that put it under a certain category of particles called bosons (i.e. particles which obeyed the Bose-Einstein statistics. In relation, another category of particles, which obey Fermi-Dirac statistics are dubbed fermions.) And this boson came to me known as the Higgs boson.


But the problem (mathematically, again,) was that the Higgs boson appeared briefly (for a fraction of a second) seconds after the big bang and then disappeared. In other words, you do not find Higgs bosons floating around to detect them like you would an electron, or a proton or a car on the road. So the only solution that lay before physicists was to experimentally re-create the Higgs boson by re-creating the big bang, the very phenomenon that kick started our entire universe.

Thus began the LHC project at CERN: a 50-year long, trial and error experiment surpassing an entire generation of experimental physicists trying to get particles to reach 99.99% the unattainable speed of light (because Einstein said so,) and getting those terribly fast moving atoms to collide — much like two rocks colliding — and break up into a million fragments — much like two rock breaking — and look for the Higgs boson among those fragments — like looking for a needle in a haystack.

And we found the needle. That is physics.

On Physicists and the law: how society has misplaced its views of science and its community

While I have often said that the community of physicists works for the common gaining of knowledge and to derive infinite mental pleasure out of that, I have also asserted that little is done towards blindly implementing it—that is what engineers are for: the Engineering – this is where the semi-skilled workers realize the work of better minds… [The] Oompah-Loompahs of science, as Sheldon Cooper puts it.

But, fun apart, my argument has always been struck, perhaps even beheaded many a time in the past. And today, I learned the height of it all—although I was quite late in finding out. Perhaps the greatest opponent to my belief is social paradigm. Non-scientists (who are the ones supposed to understand this in the first place) fail to catch on to the fact that a scientist has so much on their hands that to conform to complicated social ways becomes terribly troublesome. And, needless to mention, it is quite meaningless to hold them legally responsible for it.

Dr Adlène Hicheur

Today I read the editorial on a recent issue of Nature (Oct. 13, 2011) about the singular case of the French-Algerian physicist Dr Hicheur, which reminded me of the villain from Iron Man 2 (he is a physicist.) As it happens, the French think that Dr Hicheur, a high-energy physicist from the Swiss Federal Institute of Technology, Laussane, was plotting terrorist attacks in France.

Whether his work was so alien to the (forgive me for saying this, but) incompetent authorities who captured him on this account, that it appeared to them like a diabolical plot to blow up France; or whether they just needed a reason to feel safe and so decided to catch somebody and call him a criminal, is beyond me. Either way, Dr Hicheur has been in jail since 2009. Yes, he missed the LHC experiments altogether.

As nature rightly put it, the continued imprisonment of the French-Algerian physicist highlights the need for scientists to defend the human rights of all colleagues.

Speaking of human rights, as the Nature Editorial rightly points out, although holding a person for so long without trial is legal under France’s anti-terror laws, it is a clear violation of the physicist’s human rights.

I seem to be borrowing heavily from Nature, but here is a small paragraph that says it best, that this is nothing new: “Persecution of scientists, and physicists in particular, is nothing new. During the cold war, researchers on both sides of the iron curtain suffered for their political views. In the United States, Robert Oppenheimer’s career was ruined by rumours of communist sympathies. And Soviet scientist and dissident Andrei Sakharov spent much of the 1980s in internal exile for his outspoken views on human rights and arms control.”

Apparently, Dr Hicheur—whose online exchanges are being blocked by authorities—has been quite forgotten until recently when his defenders helplessly confessed that he can be held another 12 months before the French courts come to a decision on whether to go ahead with his trial or not.

The L’Aquila Earthquake

What prompted me to write this article was not Dr Hicheur’s case alone. Just last month six Italian physicists were jailed and are now standing trial for the manslaughter of 300 citizens for failing to predict an earthquake in the town of L’Aquila.

While that sounds like a line right out of a fairy tale, it is, sadly, true. As ABC News reported it, back in March of 2009, the panel of scientists and a local official, Bernardo di Bernardinis (who is the seventh man charged,) had a meet and the scientists declared that there was no danger then. Six days later, the earthquake struck, understandably killing many (around 309) and making as many as 7,000 people homeless.

Stating that the community was misinformed and misled, the very able community, which can take care of itself, at L’Aquila, has lodged a case of manslaughter against the six scientists. And the naive court (which in an idealistic world is supposed to have a mind of its own) has now brought them to trial, successfully hindering scientific growth.

Who was to blame when Mt Vesuvius temporarily wiped out Sicily from the face of the earth? Who is to blame every time the San Andreas fault crack open? It is nature. Nature decides, nature goes ahead with it. And as people living in such places, they ought to expect such things and be prepared with it. One does not pull the trigger at the bidding of another’s mind. It is one’s own that rules our actions.

Why did the people not look to the gods they so deeply believe in? Do they then consider physicists worthy replacements? If physicists indeed could prevent such calamities and rightly predict it every time, why would they be on Earth? They would rather fancy exploring the remainder of the universe.

Why is the weatherman not blamed everyday he reports faulty weather (which is every other day)? Because people understand. But with dead kin on their hands, man’s logical reasoning centre seems to spontaneously shift from his head to his chest.

Looking on the brighter side, unlike hardly anybody coming to Dr Hicheur’s aid (and CERN even looking the other way,) the reaction to this outrageous incident has been rather good—although more ought to be done. Soon after this shocking incident (it quite sent me staggering backwards in disbelief) about 5,000 physicists have signed a petition condemning this unprecedented court action. This is well reflected in a Nature article from July this year (2011,) on human-rights issues among scientists and in scientific collaborations.

While Dr Hicheur stays hopeful of walking free soon, the seven Italians, if convicted, face 12 year jail terms. And physicists will expectedly cry havoc and let slip the dogs of war.

In the meanwhile, if you choose to do the right thing and support the physicists mentioned in this article and probably many others who are not, then speak out on your social networking profiles and like or +1 or share this article. You can also add your views as comments below.

Spotting New Horizons

NASA's New Horizons Space ProbeOn January the 19th 2006, NASA launched a celebrated robotic spacecraft at a whopping 16.25 km/s (Earth-relative) velocity towards what was then the very last member of our solar system, Pluto.

The spacecraft, quite aptly named New Horizons, is scheduled to fly by the dwarf planet by the 14th of July, 2015 and then continue towards the Kuiper belt. Some of you might recall that New Horizons flew by Jupiter back in February 2007, by Saturn around June 2008 and Uranus on March 18th this year.

The year before New Horizons lifted off, the Hubble Space Telescope Pluto Companion Search Team found two previously unknown natural satellites which they called Nix and Hydra. Incidentally, only a few months ago, on June the 28th this year, the same team spotted a third satellite which still goes by its scientific name of S/2011 P1 (or simply P1 for simplicity’s sake!)

Tonight, one can visualise New Horizons in the night sky, perhaps using the moon as a pivot.

No, you cannot see it!

If you got your hopes high, you might want to calm down because you cannot really see the spacecraft. Think about it, having crossed Uranus, New Horizons is about 8,000 times as far from us as the moon is! And, considering that even Pluto cannot be seen from here, how can a spacecraft not quarter its size be visible? And to top it off, Pluto outshines New Horizons by about 10 billion times.

But there is fun in it if one could take a moment to visualise how this little man-made thing carrying 4,34,738 names on a CD, Scaled Composites SpaceShipOne and an American flag, among other cultural artifacts—and, of course, scientific ones—is flying, right this instant, towards the edge of our solar system.

This is not the first spacecraft to leave our Sun and its companions: the Voyager duo have done that already, but this is the first to give us a clear fly-by of five planets and many natural satellites.

As it flies past Pluto, New Horizons will have a speed of about 13 km/s. Imagine the spacecraft (pictured alongside) royally skating past the dwarf planet and taking pictures, deploying scientific payloads, all in the cold dark of outer space. And then it flies beyond the Kuiper belt, into interstellar space—where good communication will remain till 2025 (no pun intended.)

Why wait for night?

Some may be asking themselves why, if we cannot see the spacecraft, should we wait for nightfall. The reason is simple: given that we are deriving joy out of picturing New Horizons at just the right point in space, it becomes important to have a good reference system. Not all of us are astronomers with access to motorised telescopes.

A map drawn by EarthSky team member Bruce McClure explains this nicely:

Look for the gibbous moon, then a little up and left as shown. To the naked eye, your mind’s eye is your best eye! To the telescope, if you have one powerful enough to give you Pluto at least as a faint gaze, you’ll have better time visualising.

Either way, experience the joy of theoretical physics through an experiment. Allow yourself to conclusively see things one can merely visualise!

And let me know your experience below.


Astronomy lecture-workshop — Day 3

I still do not know why somebody said ‘All good things end,’ but they did and they did.

Today was the last day of the Astronomy lecture-workshop hosted by Yuvaraja’s College, Mysore and convened by the Science Academies of India. If you have not read them already, you can see what happened on the first day, here; and go through my report of the events on the second day, here.

On the last day we had just two lectures signalling the end of eleven remarkable hours that stood for everything in this workshop. The two lectures were by Prof Uday Shankar of the Raman Research Institute and Dr Sreekumar from ISRO.

Questions galore

Prof Uday Shankar opened our eyes in one way—and nobody can deny that: the fact that we stop (or have already stopped, in some rare cases,) questioning the trivial things around us. In fact he made this clear by firing questions at us regularly and insisting that we must find the answers ourselves.

So let me take a little deviation here to state his questions and that I am still finding out the answers to some of them, so I will probably write an article or two explaining the stuff once I find out. In the meantime, if you get to it first, feel free to share below!

  • Why are only few frequencies of radiations allowed past the ionosphere?
  • How many different types of molecules have been discovered in Radio Astronomy?
  • What are some famous types of molecules that are also subjects of study in other disciplines of astronomy?
  • Which type, among translational, rotational etc. of these is actually dominant in Radio Astronomy?
  • How are parsecs and lightyears related?
  • What are the frequencies of Short Wave, Medium Wave and Frequency Modulated radio signals?

On I (?,?,?,P,t)

Prof Uday Shankar began his talk with a quick recap of yesterday’s lecture and continued with a detailed explanation of how a radio telescope works and how it uses Fourier transformation of wavefronts. As he explained the parabolic structure of the Radio telescope dish and the path of incident waves on it, I (and perhaps a few others) found it almost enlightening to understand a real-life example of a mathematical model, the real-life example of the use of what were, up to this point, merely theories although they were no less interesting.

It was one of those surges of enthusiasm to deal with science that every aspiring scientist feels—and needs—now and then.

Yesterday we had discussed a formula that went I (?,?,?,P,t) and today Prof Uday Shankar spent quite some time patiently explaining how we arrive at a determination of each of them and how they matter in the equation.

Having explained the continuums of thermal and synchrotron radiations and the spectral lines of spectral line emission, he moved on to explain the resolution properties of radio telescopes.

An interesting question he mentioned that he usually asked at interviews went thus: at what distance can you, as an observer, differentiate between a two-wheeler and a four-wheeler?

The point was that the human eye can resolve up to 1” (arc sec) and the maximum distance we could do so was about 3.6 kilometers if we took the resolution of either one (two-wheelers) or two (four-wheelers) headlights. This was analogous to a radio telescope resolving a bright speck in the sky either as a system/apparent alignment of two stars or just one.

And to meet the resolving power of the human eye, a radio telescope had to be a mighty 27 km in circumference! Clearly, this was impossible and he explained—as a solution to this—Ryle and Hewish’s Aperture Synthesis process using Young’s method to obtain a number of interferences that could later be added up to obtain a final image. He also parenthetically mentioned the Gauribidanur Radioheliograph near Bangalore and the Giant Metrewave Radio Telescope near Pune.

As he finished his talk, he gave us little details of the Raman Research Institute’s Visiting Student Programme. My friend, Subramanya Hegde, who shares my enthusiasm for physics (and is definitely better established at it, anyway!) has compiled this interesting list of such similar visiting student/summer/scholarship programmes for anybody who is interested.

Challenges in outer space

Like we do not have enough challenges down here on Earth, we have bigger ones in outer space (one major hinderance being the fact that one must wear a seven-layer suit for EVA even in low-earth orbit!)

The challenges space poses for X-ray astronomers and the troubles in detecting a neutral particle like the photon and how these brilliant astrophysicists overcame it was the topic of the last lecture of the workshop by Dr Sreekumar.

He spoke of how high vacuum outgassing, unchecked space radiations and trapped charged particles in the Van Allen Belts are problematic to X-ray astronomers. After a fleeting mention of the South Atlantic Anomaly over Brazil, Dr Sreekumar explained the payload of ISRO’s upcoming mission, Astrosat.

He then explained how it becomes difficult to catch X-rays owing to their sparse distribution and unpredictable occurrences (as opposed to Radio Waves) in the universe. Then he explored the Scanning Sky Monitor [SSM] and a simple photon detector and how it works.

He then ventured to examine what properties of the photon actually matter to us (energy, arrival direction, polarisation state, and arrival time.) He also briefly showed us the Geant 4, Garfield/ANSKS/Maxwell and Charge Transport simulations; and a very basic Bolometer.

He ended his talk with a look at Point Spread Function, and a comparison between a normal pin-hole camera and the process of Coded Mask Imaging. The last bit was a quick slideshow of perhaps previously unseen pictures of the various stages of developments and the various payloads of ISRO’s Astrosat on which project Dr Sreekumar is working presently.

And it all ends

The last part of the workshop saw Dr Sreekumar telling us aspiring scientists all about how one could get into ISRO, the qualifications they look for, the kind of posts available, when best to apply, how best to approach their interviews and how he believes the scales are tipping towards pursuers of the pure sciences.

A brief valedictory function later, the lot of us had lunch, interacted with each other, exchanged a few ideas and left the workshop, three days having been spent better than we could ever have hoped for!

And that is how it all ended.