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NASA’s Kepler mission

May 29, 2011 1 comment

NASA is searching for Earth-like planets in a specific area of the Milky Way galaxy, the galaxy to which we belong. This is being done by putting a spacecraft outside the atmosphere of the Earth. Even as you are reading this, the Kepler spacecraft is collecting brightness information from about 100,000 stars. This information will then be analysed to find out if there are any planets orbiting it.

The technique used is explained in this animation. What they do is essentially this. They continuously observe the brightness of the stars. If a planet moves across a star (called a transit) then the planet will block some of the light that comes out from the star and hence the brightness will go down. After the planet has passed, the brightness will come back to its normal level. It is these drops in brightness that will tell us that some planet is rotating the star being observed.

Of course a solitary drop in brightness does not suggest a planet. A planet is confirmed only if there are multiple transits, each having the same amount of drop in brightness, the same duration of drop, and a constant interval between the drops.

But the reason why I am writing this post is to show you the picture below. Click on it. The enlarged picture is worth spending some time looking at.

Planets discovered by Kepler Spacecraft

These are the 1235 candidate planets that were identified till March 2011. The second row gives a picture of the Earth so that the rest can be seen relatively. But if you thought that the picture was the Earth, then join the club. No, the picture is that of the Sun. As discussed above planets are observed in transit against the background of their stars. Here, the bright disk is the Sun. Do you see a dark dot in that disk? If it is not very clearly visible click on that picture and look at the full size pic. Now the dot is visible, right? That dot is…

No, neither is that the Earth. That is Jupiter, the biggest planet of our solar system. If you really want to see the Earth, download this full resolution picture that NASA has uploaded to flickr. It is 9.3 MB in size. But me being the large hearted soul, I have downloaded it and cut out that part alone for you to see it below.

Earth, Jupiter and the Sun

Do you see the Earth now? I still recommend that you download that full resolution picture. It is fun.

Now, coming back to the Kepler mission. One interesting point about this is that the drop in brightness can be observed only if the orbit of that planet is aligned along our line of sight. If not the planet will not obstruct our view of that star and hence no drop in brightness will be observed.

I will let the Kepler FAQ take over here.

For Kepler to detect a transiting planet, its orbit plane must be lined up with our line of sight. Most of the time, the extrasolar planets’ orbital planes do not line up. For Earth-size planets around Sun-like stars, the chances of randomly oriented orbital planes being in the correct orientation for Kepler to see a transit is about 0.5%. That is why the design of Kepler called for a very wide field telescope to be able to observe more than 100,000 stars. If all those stars had Earth-size planets, about 500 (100,000 x .005) would be in the correct orientation to transit. Statistically, we can infer that every planet Kepler detects represents hundreds more planets that are out there but not detectable due to inopportune orbital orientation.

Thus, if we have discovered 1235 planets, then there must, about 245,675 undetected planets out there. There are many more such interesting pieces of information on their FAQ page. Spend some time there to see what humankind is trying to do.

But if any of you reading this is thinking of moving to one of these planets once we exhaust our energy supplies here and pollute it sufficiently enough to render it useless for human habitation I am sorry to say that there is bad news.

The stars that Kepler is observing are in the range of a few hundred to a few thousand light-years away. One light year is about 6 trillion (6,000,000,000,000) miles.

In plain English, the theoretical minimum to reach even the closest of these stars is a few hundred years. There you go (pun half intended).

Categories: Physics, Uncategorized Tags: , ,

Are we two or one?

May 1, 2011 10 comments

I just finished reading Daniel Dennet’s Consciousness Explained (see proof at the end of this post). I bought this book for Rs.750. It is definitely beyond my usual budget for a single book, but I could not resist Daniel Dennett promising to explain Consciousness to me. Read this article, and you will understand why I could not resist. This was my fourth or fifth attempt. Let me clarify here that the need for repeated attempts speaks only of my own lack of capability and not about the author’s writing skills. There were many parts in the book that went over my head, and I still am not able to get the complete picture of the book in mind, but I learnt some very interesting things.

But reading the initial chapters of this book, made me (re)realise the mysteriousness of Consciousness. Consciousness is a curious thing. Try thinking about it on these lines. Which part of you is it, that really feels the beauty of the pictures you see, feels the pain of the burnt finger (and what is it that tells you to remove the hand immediately), feels the taste of ice cream (and makes you grab your neighbour’s too), feels the enthusiasm of going to vote (and feels the pain of having to see utterly useless people being elected and causing losses running into astronomical numbers). Think hard. What do you think really is you? What is it in your body that really gets excited on playing your favourite game. What is that which thinks of various options to put your money in, balancing the tax benefits and some reasonable returns? Who/what is the you that is understanding this post as you are reading it.

You might say it is my mind. But that is really not an answer. You have just given a name for it. It is like telling somebody when he sees for the first time a yellowy shiny material, that it is gold. It does not answer much. The question that follows is, what is mind then?

Before you get bored, I will tell you that I am not here to analyse deeper questions about mind/consciousness. The purpose of this post is to explain what is called the mind-body dualism. This dualism is the theory that each one of us have a mind (some might call it the soul) which is what does all the thinking, deciding, enjoying, suffering and so on. So any kind of experience that the body has, like a knife cutting its finger, travels to the mind, and an instruction comes back from the mind, to withdraw the hand immediately. More importantly, the key aspect of the theory is that our mind and our body are two different things (that is why it is called dualism). In this sense, the mind is the non-physical you, while the body is the physical you.

The question of what non-physical means is an entirely complex question in its own right. So far there has been no evidence of anything non-physical happening in this world (though there are numerous myths). But let us for a moment assume that there is some workable definition of non-physical (though I don’t think think that even such a definition is possible).

The key argument for countering this theory is as follows. Assume that a non-physical mind exists. So whenever you cut your finger, there must be messages that reach the brain via a chain of cause and effects like the skin telling the nerves that your hand is being cut, the nerves taking the messages to the brain, the brain somehow informing the mind, the mind doing the thinking and deciding that this is not good and therefore sending back the instructions that the hand must be instantly withdrawn. So somewhere along the chain of events leading to the withdrawal of our hand, there must be a point where the physical brain, interacts with the non-physical mind.

It is this interaction which is the crux of the problem. How can a non-physical entity and a physical thing interact. Imagine anything else that we see happening in this world: opening a door, keying in text on a computer, cooking food. All of these things are only to do with physical things and in each case some energy gets converted from one form into another. At no point do we use non-physical thing to get our job done. If the starting point of any action is a thought, like say the thought of writing an email, and if that thought is non-physical (since it is in your non-physical mind), then how does it result in the actual physical activity of sending an email. At what point does this non-physical thought create a physical effect in the chain of causations from thinking to doing. And how can that happen, since the thought cannot have its energy (If you say it has, then it becomes physical).

Today, in scientific circles, it is widely believed, that consciousness is indeed an outcome of entirely physical processes of the brain. How much ever surprising it may sound, if an exact physical duplicate of your brain, complete with all the neurons and connections, is made, it will be a second you without any difference at all. In such a scenario which one will be you?? Spend some thought on that question. Our technology is nowhere near duplicating brains, but that does not prevent us from doing such intriguing thought experiments.

This is the reason why dualism is not considered to be a correct explanation of consciousness (and it also leaves out explaining how the non-physical mind works). Our physical brain is indeed the mind that we all have. The existence of a soul or a mind different from your brain is not possible. They are one and the same.

I know that this is a somewhat slippery topic and I have not covered the counter-arguments that could come up, and their responses. That would have made the piece too lengthy, and the topic is too complex for me to write much about. So let the argument continue in the comments section.

Is it obvious that I posed for it?

Categories: Uncategorized

An article to the Open Page of the Hindu

May 1, 2011 Leave a comment

My previous post about Dr.V.Mohan (Chairman of Mohan Diabetes Centre) certifying Sai Baba’s “miracles”, reminded me of an earlier piece in the Hindu by one Prof.B.N.Hegde. In that he criticised modern medicine heavily without any kind of logic. To that, Lakshmi, a friend, who is also a doctor, and I had written a response (in Dec 2010). It was not published. So, I thought I can post it here. But before that read the original article, to which we responded.

FLAWED LOGIC + POOR MEDICAL ADVICE: A DANGEROUS COMBINATION

 This is in response to Prof.B.M.Hegde’s article in the Open Page of the Hindu edition dated 5th Dec 2010. In his opening line, the professor declares that “The foundation of modern medical science is shaky“. To support this statement he refers to articles and books where he says he has written about the unscientific basis of randomized controlled trials (RCTs). He also says that these methods do not meet the standards of NASA-TRL or Modern Systems Engineering. The definition of TRL from Wikipedia says “Technology Readiness Level (TRL) is a measure used by some United States government agencies and many of the world’s major companies (and agencies) to assess the maturity of evolving technologies (materials, components, devices, etc.) prior to incorporating that technology into a system or subsystem“.

TRLs are meant for materials and devices, not human bodies. Materials and devices can be fully understood; their behaviour is deterministic and predictable. In comparison, human bodies are vastly complicated and we do not understand them fully. Thus we have to rely on statistical methods. If statistical methods tell us that a therapy is effective, say, 90% of the time, that is a very strong indicator that it works. This will obviously not meet the standards of TRLs. Expecting human bodies to be as predictable as the machines we make is unrealistic. Moreover, though the professor insists that the foundation of RCTs is shaky, he does not suggest an alternative method to assess effectiveness of therapies.

Further in the article, he says “Many of the present expensive anticancer chemicals have not even gone through the inadequate RCT test!” He talks about how Pharmaceutical industry “could go to any extent to fool even the governments” and cites a recent example. That companies do indulge in such practices is common knowledge. Citing the malpractices of the pharmaceutical industry as the rationale for dismissing modern medicine is illogical.

He also states that “the industry is keen only on imaginary diseases (the so-called silent killers) that need lifelong drug therapy.Blood pressure, sugar and cholesterol are the three biggest milch cows“. While claiming rightly that companies do try to exploit consumers, he takes a scientifically invalid stand that diseases like diabetes do not exist.  As a respected physician, does Prof. Hegde realize the impact of his words? If the diagnoses of hypertension and diabetes are delayed or missed, people could end up with strokes, nerve, eye and kidney damage. For those individuals, waiting for the ‘first symptom’ to go to the doctor may be too late. Moreover, a timely check-up can actually serve as a warning regarding one’s weight or cholesterol or BP, help make lifestyle changes, and possibly avoid medications.

The final statement to which we wish to respond is “The tall talk of evidence-based medicine is as hollow as are many of our claims to superiority to all other modalities of treatment such as Ayurveda and Homoeopathy. In fact, most of them have a better scientific base than our modern medicine“. To this we would like to point out to the readers and Prof.Hegde that the British House of Commons Select Committee on Science and Technology has issued a report on homeopathy, saying “systematic reviews and meta-analyses conclusively demonstrate that homeopathic products perform no better than placebos” and concludes that “The funding of homeopathic hospitals – hospitals that specialise in the administration of placebos – should not continue”. The report can be seen at http://www.publications.parliament.uk/pa/cm200910/cmselect/cmsctech/45/45.pdf.

The professor who earlier in the article tries to equate modern medicine with placebo by stating that “Most modalities of treatment, using both drugs and surgery, have no scientific base, although many of them seem to work through a very powerful placebo effect” goes on to say that Homeopathy, which is actually a placebo, has a better evidence base than modern medicine.

The real problem (that Professor Hegde repeatedly alludes to in his article) is regulation of the Pharmaceutical industry. But he is barking up the wrong tree by saying all modern medicine is wrong and that homeopathy and Ayurveda have more evidence. The professor, with his flawed logic and poor medical advice, is actually doing more harm than good.

Categories: Medicine, Uncategorized

Sai, the fraud, Baba

May 1, 2011 6 comments

It was utterly nauseating to see the media coverage for Sai Baba’s death. He was undoubtedly a fraud, a cheat, a trickster fooling millions of people, including those in the highest offices in our government. All those talks of how there is going to be a re-incarnation further irritated me. If you are somebody who has not given much thought about him or are wondering why I am so critical of him, look at the following videos to see what a fraud he was.

There is also a BBC documentary on the Sai baba talking about allegations of sex abuse against him. There was only one article that I saw in the Times of India, about how some rationalists had attempted to expose him, and the Sai baba evaded all their challenges. Which trickster wouldnt? I knew about Sai Baba all along, but what shocked me today was this article from the open page of the Hindu written by Dr.V.Mohan Chairman of Mohan Diabetes Centre. In that he says:

Miracles do happen, people get cured of serious illnesses and, as doctors, we have seen such cases. But that is not everything about him…

This is ridiculous. What never fails to irk me is that people like him, in very high positions in the field of medicine, supporting all sorts of woo. What this does is it creates an impression that even “science” admits that miracles are possible and makes them flock even more to such charlatans. How can Dr.Mohan say that? Would he next start re-directing people coming to his center with serious illnesses, to go and seek the blessings of Sai baba at his grave? If miracles indeed do happen, why did Sai baba build a hospital? Can’t he just cure people by touching them?

I know it is tough to move people away from such superstitions, but people like Dr.Mohan, who are experts in their fields, should know better than making such statements. Can Dr.Mohan back his claims up with the most important thing, evidence, which is something I am sure, he would demand for all cures for Diabetes? He won’t, because he can’t, because nobody can, because miracles do not happen.