Tag: universe

How is the distance to stars measured?

Ever since I started writing about my research period at the Indian Institute of Astrophysics, I have been getting questions about space from many of my readers. So, instead of blabbering on about the proceedings of day 3, I decided to answer one of their questions.

The most common question I got dealt with measurements, a la, just how do we know something is this big, this far, this heavy etc. when we cannot even approach it, let alone handle it, to measure such properties. So I decided to write a brief, mostly qualitative, answer to this question about distances: how exactly do we know how far a certain star or planet is from us?

Read more →

Have we crossed the Great Filter?

One of the biggest arguments regarding the existence of aliens are the famous Drake equation and the equally famous Fermi paradox. I wrote about them four years ago and debated that aliens may still exist in spite of these arguments against them, and I still stand by that belief.

I was reminded of this again recently when I read about a so-called Great Filter theory that attempts to explain the standard sceptic’s question: if aliens exist, where are they? why haven’t we seen or met them yet?

Stemming from astrobiology, the idea behind the great filter is that a civilisation or species reaches a developmental wall it cannot cross. But some — including myself — like to believe that we have already crossed this wall, or filter. And that leads to some interesting ideas.

Read more →

 The seven finest galaxies visible to amateur astronomers [Click on a picture to scroll through in h

 The seven finest galaxies visible to amateur astronomers

[Click on a picture to scroll through in high resolution.]

History or Physics?

Nobody can quite say which of these two men’s great words outdo the other. As Thomas Carlyle said, “History may be called, more generally still, the Message, verbal or written, which all Mankind delivers to everyman,” or, as Lord Kelvin himself put it, “When you can measure what you are talking about and express it in numbers, you know something about it.”

Although I knew the answer, I have been pondering over the need to study history ever since fifth grade when I first remember studying it. I still have no justification to study it except for the sake of entertainment. But a few learned men beg to differ.

While I have pondered over this question for quite a while now, it was not until I came upon a similar question on another website recently that I decided to write about it.

History or Physics? The website asked. And that set me thinking once again!

Why study history?

Apparently, there are many reasons to study/pursue the study of history. The American Historical Association has come up with an extensive list, from which I will pick the five most important of the lot:

  1. History helps us understand people and society. In the first place, history offers a storehouse of information about how people and societies behave. Understanding the operations of people and societies is difficult, though a number of disciplines make the attempt.
  2. History helps us understand change. The second reason history is inescapable as a subject of serious study follows closely on the first. The past causes the present, and so the future. Any time we try to know why something happened—whether a shift in political party dominance in the American Congress, a major change in the teenage suicide rate, or a war in the Balkans or the Middle East—we have to look for factors that took shape earlier.
  3. History contributes to moral understanding. History also provides a terrain for moral contemplation. Studying the stories of individuals and situations in the past allows a student of history to test his or her own moral sense, to hone it against some of the real complexities individuals have faced in difficult settings.
  4. History provides identity. History also helps provide identity, and this is unquestionably one of the reasons all modern nations encourage its teaching in some form. Historical data include evidence about how families, groups, institutions and whole countries were formed and about how they have evolved while retaining cohesion.
  5. History lays foundations for good citizenship. This is the most common justification for the place of history in school curricula. Sometimes advocates of citizenship history hope merely to promote national identity and loyalty through a history spiced by vivid stories and lessons in individual success and morality. But the importance of history for citizenship goes beyond this narrow goal and can even challenge it at some points.

Why study physics?

As I have said already, I side with physics. The reasons, most as stated by the University of Saskatchewan, are more than just convincing; I have, however, contained my enthusiasm and picked five:

  1. Physics is the most fundamental of the sciences. It is concerned with the most basic building blocks of all things in existence. It explores the very fabric of nature and is the foundation on which other sciences stand. In a strict, true sense, every other scientific discipline is basically a form of applied physics.
  2. Physics is beautifulPhysicists love simplicity and elegance. They are constantly striving to find the most fundamental ideas that can be used to describe even the most complex of phenomena. For example Newton found that only a very small  number of concepts could be used to describe just about all of the mechanical world – from steam engines to the motion of the planets. Not only is this beautiful, it’s downright amazing!
  3. Physics encourages one to think and question. This might seem like a strange statement. The study of all subjects teach you to think. But because physics deals with the most basic concepts, the application of such techniques as “Separation of Variables” and “The Scientific Method” are never more clear than they are in the study of physics. Once mastered you will find that these methods can be applied to all subjects, including the business world and just coping with everyday life.
  4. Physics gives one a new appreciation of the world. You can look a rainbow and say “Wow, pretty colours!”, or you can marvel at the amazing interactions between photons and electrons that come together in that particular way when light from the sun strikes spherical water droplets in the sky, and that you perceive as a multicolored arc suspended in the air. Now that’s awe!
  5. Physics gives good earning. I ought to have put an exclamation mark at the end of that sentence, but I will let the latest international job trend statistics speak for itself: an engineer earns a starting salary of $30,000, and an average of $60,000; a historian earns a starting salary of $25,000 and an average of $50,000; and a physicist earns a starting salary of $60,000 and goes up to $95,000! Adding to that, a Physics Bachelor’s degree alone will leave you with an average salary of $52,000.

The Verdict

While history would be most promising in shaping a man in his responsibilities and character, physics would hardly allow one to develop questionable attributes. While history can be useful as a good afternoon pass time, it would only make sense to study physics to attempt to answer those questions far deeper within our universe which would make the questions tackled by history—no offense here, but—shallow.

But opinions differ, and I would like to hear your side of the debate. Share it below.

The supreme arrogance of religious thinking: that a carbon-based bag of mostly water on a speck of iron-silicate dust around a boring dwarf star in a minor galaxy in an underpopulated local group of galaxies in an unfashionable suburb of a supercluster would look up at the sky and declare, ‘It was all made so that I could exist!’

Our Universe: marble or wood?

“Maybe nature is fundamentally ugly, chaotic and complicated. But if it’s like that, then I want out.”

—Steven Weinberg

If there is any fundamental quality of nature that has eluded physicists and sparked debates of a fearful scale, it is the question as to whether the universe has a simple (beautiful) underlying principle that runs quite everything in existence.

Undoubtedly, the dream of every physicist is, as Leonard Lederman creatively summed it up, ‘…to live to see all of physics reduced to a formula so elegant and simple that it will fit easily on the front of a T-shirt.” On a serious note, this highlights the strong belief in most physicists that nature is elegance and simplicity bundled into one.

Einstein’s world of marble

Physicist Albert Einstein likened this world to marble. In the pith his idea was that the world as we first see it would appear to the observer like wood. Various observations would seem vastly different, unpredictable and complicated.

It was his strong belief that we could, on further investigation, chop off these wooden structures to reveal an inside made of marble. Marble he likened to an elegant and simple universe with predictability.

Apart from the fact that wood and marble seemed, for some reason, to represent chaos and cosmos to Einstein, it was also an idea that would hold true for almost all discoveries in physics preceding, and including, relativity.

From Newton’s laws to Maxwell’s equations to Einstein’s relativity, with every passing discovery we seemed to have united another chunk of our universe to form a whole; and it was as if we either found new explanations for phenomena or found that new, unexplained phenomena happened to be in coherence with previously explained processes/laws.

It was like a work of fiction where everything, right up to the climax, would remain perfectly alright, going without a hitch and then, out of the blue, the whole idea of a world of marble collapses.

Quantum theory backs wood

Einstein was one of the founders of Quantum theory through his explanation of the photoelectric effect wherein he said that light—much like was predicted for other forms of energy, by Max Planck—was really made up of discrete packets of energy he dubbed photons.

At first the idea appeared perfectly alright (and Einstein went on to win the Nobel prize for this many years later.) To physicists, by and large, the idea seemed to boil down to one phrase: waves could, at times, act as particles.

The problem arose when Erwin Schrödinger took it upon himself—under the belief that the vice versa could also be true—to theorise how particles could convert into waves. After a year-long vacation, he returned to the physics society with his magnum opus, what is called the Schrödinger equation. Einstein and Schrödinger both believed then that this would descirbe the wave equation of a solid particle; but the reality was—as other quantum physicists like Max Planck, Wolfgang Pauli and Werner Heisenberg were quick to point out—this did not completely make sense.

At first both Einstein and Schrödinger were pleased with the resulting equation, but they had made a fatal flaw: they had failed to fully analyse the implications of the equation as soon as they realised it satisfied all properties they originally expected of it. And when the others studied it completely, they realised that it allowed for almost fantastic occurrences. Quantum physics was predicting that we needed to crack the marble to reveal a world of wood—and nothing could prove it wrong.

The debate rages

Einstein rejected the theory almost in its entirety simply because it went head-on against his personal belief of a world made of marble. When chance was introduced to the very core of physics; when we realised that these new developments allowed for the mathematical possibility of the unthinkable and the presence of a chance, however small, of contradictory occurrences, Einstein and Schrödinger shared the idea that this was outrageous. This even prompted Einstein to write,

Quantum mechanics calls for a great deal of respect. But some inner voice tells me that this is not the true Jacob. The theory offers a lot, but it hardly brings us any closer to the Old Man’s secret. For my part, at least, I am convinced that He doesn’t throw dice.

The Old Man was how Einstein referred to God in most of his writings. This debate rages to this day, even if subtly. While quantum theory, siding with wood, has not found a phenomenon that can prove it wrong, neither has relativity, which sides with marble.

Perhaps the most powerful analogy we have to date is that of Schrödinger’s Cat. Quantum theory tells us that an observation depends entirely on the observer—literally. Let us have Schrödinger’s Cat clarify this: imagine you had a box with a cat in it. It was alive when you put it.

You keep it closed for a while (that is to say, you are not making any observation of it as yet.) Then you open the box and find the cat happily playing, or sleeping sound. But what quantum theory suggests is that the only reason the cat is doing any of that is because you are observing it.

To go a step further, when you are not observing it, the cat may be doing something else. While this may seem all to commonplace, what is startling is that quantum theory defines the clause something else very differently: the theory, in fact, allows for the possibility that the cat may be dead when you are not making an observation of it!

In conclusion

A further complication is that neither of these two major theories, Quantum or Relativity, come in the other’s way. While quantum physics laws rule the smallest of particles, atoms, electrons and the like, relativity seems to apply to the largest of them, like our Earth or even our whole massive galaxy. To clarify this further, quantum theory actually breaks down at relativistic dimensions and relativistic laws break down at atomic levels.

It therefore seems to me at times that there is a possibility of these two theories themselves being manifestations of the same fundamental principle; that our race to uncover the basic law that runs the universe really lies in our ability to see through these theories at the point where they appear to contradict. Perhaps, like atoms making up galaxies, the quantum theory is really a microscopic view of relativity.

Perhaps the reason why quantum theory backs wood and relativity backs marble is because quantum theory really makes up relativity so long as we are able to take ten steps aside and view it from a different angle. Perhaps, in the end, wood is what observation suggests to us and marble is what investigation does. Perhaps the world is really made of marble. We are just not seeing it with a perspective that is broad enough.

You may not have anything to do with physics, or you may be a physicist yourself, but do share your views below. What do you think our universe is made of? Does it have an underlying principle? Is it predictable, or does chance really rule it? Or will we just have to excuse ourselves, ultimately, like Schrödinger who said, ‘I don’t like it. I’m sorry I ever had anything to do with it.’?

To commemorate my short tryst with the study of our Universe, I decided to compile a set of seven of

To commemorate my short tryst with the study of our Universe, I decided to compile a set of seven of the best photographs available, each describing one of seven phenomenon/bodies that have eluded physicists or struck them as remarkable.

In order, we have,

  1. Neutrinos (Super-K Neutrino Observatory)
  2. Wormholes
  3. Black Holes (‘Black Holes ain’t so black!’ courtesy Hawking, Stephen, A Brief History of Time)
  4. Supernovae (Eye Supernova)
  5. Saturn’s Rings
  6. Nebulae (Horse Head Nebula)
  7. Galaxies