Archive for September, 2011

The God FAQs – 2

September 28, 2011 Leave a comment

Continued from a previous post.

3. Is there not a lot of science in our scriptures? How can you say it is wrong?

The reference is normally to Hindu scriptures, since the majority of people I meet are Hindus. I admit I don’t know anything about “our” scriptures. But as far as I know, there has not been a single aircraft, an oven, a TV or a mobile phone that was designed based on Hindu scriptures (let me know when you see one). If these scriptures really have far more advanced Science than we have now (as is frequently claimed by forwarded power point presentations and some of my relatives too) how come not even one useful technological innovation has come from our scriptures? Is that not strange? I recently had an email which claimed that it was specified in the Hindu texts that Humans had 23 pairs of chromosomes. Again the question is why is it that, they infer this from the scriptures, only after Science has found this out and never before. Why can’t any of those experts, say something before science confirms it? Why can’t our scriptures today give us a cure for AIDS or cancer? I don’t mean to demean the texts, nor do I mean to say Science is perfect. What are given in the texts could have been the best attempts at that time to understand things, but to say that their science is more advanced than what we have today is, at best, wishful thinking.

4. You keep harping on evidence for god. Does everything need evidence? What about things like love?

Evidence is needed for everything. In fact, even though unconsciously, we do indeed look for evidence for everything. When somebody says that a particular investment avenue will fetch us a rate of return of 100% annually, we will look at it suspiciously. When friends give excuses for doing or not doing something, we try to do some amount of cross verification. Even when somebody says I love you, we look for evidence. I am not being insensitive here, but the claim that my mother loves me, is supported by more than 30 years of evidence, during which she spent enormous amounts of time and effort to ensure I have a good environment to grow up in, to ensure I am well-fed, to ensure I study well and so on. That is clear evidence that my mom loves me. And my father spending close to 35 years in an uninteresting job, is evidence of his concern for me. Tomorrow, if your spouse stops loving you, you will know it through a lot of indications. And once this goes beyond a point, you will conclude that he/she has stopped loving you. Thus, we all look for evidence, even though unconsciously. But when it comes to the question of god, we give up our skeptical attitude. If something as important in life as love, requires evidence,  why do we say we don’t need evidence for god?

5. Is not religion a good thing? Does it not teach us how to live a virtuous life? Why do we need to give up on that?

The first thing about this question is that this question is not about whether the existence of god is true or not. This is more about whether religion, irrespective of whether god exists or not, is a good thing or not. This is not a black and white question, but I would like to point out one thing here. We, at least in India, have been brought up saying that all religions essentially preach only love and compassion for other people. I too naively believed this. But the religious books are full of instructions that would disgust any reasonably good human being. The Bible and Quran, are terrible books. The annotated bible and the annotated Quran are good resources to see why they are terrible. The books promote violence, actively encourage intolerance towards other religions and atheists and treat women like dirt among so many other things. Go through the books or the website to see why the books are indeed bad. Hindu texts are, to my little knowledge,  comparatively better, but not blame less. Hindu texts promote casteism, one of the biggest evils that persist till date. The way women are treated in texts like Mahabharatha nauseates me. Fathers “giving away” the hands of their daughters to please other males, as if the woman concerned does not have any role to play in the entire “transaction”. For example, in the story of Vinayaka Chaturthi, when Krishna fights with Jambavan and he wins it, Jambavan eventually gives his daughter Jambavati in marriage to Krishna.  Immediately after this, he returns to meet the King Satarajit to return his pendant, that king gives his daughter Satyabhama to Krishna as his wife.

The claim that religions preach good things is a lie. This is perpetuated because nobody actually reads the supposedly holy books. If only more people read their texts fully, we would have less religion in this world.


Chromosomes and Inheritance

September 26, 2011 Leave a comment

In an earlier post, we saw about genes and compared it to a sentence, where the codons are its words and the nucleotides are its letters. Let us move forward from there to see where this DNA sits in our body.

It is common knowledge that our body has billions of cells. Cells make up everything in our body. From our fingers, to bones to heart. At the centre of each cell is a nucleus. It is this nucleus that contains what are called chromosomes. The chromosome is nothing but a long piece of DNA that is coiled up and it is this DNA that we talked about in the last post. Each chromosome will contain anywhere between a few hundred to few thousand genes.

Every species contains a specific number of chromosomes. We humans have 46 chromosomes in each of our cells. But these chromomes exist in pairs. That is, we have 23 pairs of chromosomes. To get our idea clearly here is the hierarchy of organisation: Body contains cells, cells contain nucleus, nucleus has chromosomes, each chromosome has genes.

Continuing the analogy from the previous post, if we can look at a gene as a meaningful sentence of words, the chromosome can be looked at as a chapter. All the chromosomes together, which forms the genome of a human being can be considered the book of life.

In the rest of this post, I will talk about chromosomes with reference to our human body. As mentioned before, we humans have 23 pairs of chromosomes in each of our cells. Out of these 46 chromosomes, two of them are the sex chromosomes. They are the famous X and Y chromosomes. Males have 1 X and 1 Y chromosome, while females have 2 X chromosomes. The remaining 44 are called autosomes.

Let us number the 22 autosomal pairs from 1 to 22. Since chromosomes occur in pairs, let us name them 1A-1B, 2A-2B and so on till 22A-22B, and then the sex chromosomes. If you are wondering what the pairing is all about, let me clarify that. To build a human body, 22 chromosomes and 2 sex chromosomes are sufficient. You can just take all the A chromosomes (1A, 2A, 3A and so on) with two sex chromosomes and build a body. Similarly, all the B chromosomes will be sufficient to build a body. You can also take 1A, 2B, 3A, 4B and any such combination. This process is called recombination.

But recombination is not just choosing 1 chromosome over another. Recombination usually works by choosing parts of different chromosomes. Thus, you can even choose the top half of 1A and the bottom half of 1B, and make a new chromosome. The chromosomes can be taken apart to be brought together in different combinations.

Back to our analogy. We can consider each cell in our body to have not one but two copies of the book of life. Either of the books is sufficient to give you the instructions to build a body. So you can pick one chapter (chromosome) from one book and another chapter from the second book. You can also split up chapters, such that you take some sentences from the chapter 1 of the first book, and the remaining sentences from chapter 1 of the second book, thus creating a new chapter. You can go on creating chapters like this and form a different book.

Suppose for example, there is a gene to determine what colour of eye, one has. Let us assume that it resides on the 13th chromosome. Let us also assume that 13A has the gene for the black eye colour, and 13B has the gene for the brown eye colour. During recombination, any of the two colours could be chosen, to be part of the daughter cell.

When does recombination occur?
Normally when cells reproduce in our body (all the growth and repair of our body is because of cell reproduction), it produces an exact copy of the 23 pairs (with some rare mistakes, which are called mutations). Such a reproduction of cells (not to be confused with reproduction of individuals) is called mitosis. Thus if a heart has to grow in size, the heart cells will keep reproducing till the desired size is achieved.

But there is a special type of reproduction of cells where in a cell with 46 chromosomes, gives birth to cells with 23 chromosomes. Such (half)cells, called gametes, is what we call as a sperm in a male and an egg in a female. The sperms and eggs are special kinds of cells which have only half the number of chromosomes as its parent cell. You must be able to guess now that when an egg and a sperm come together, they form a fertilised egg having 46 chromosomes, leading to the formation of a new life (now we are talking of the reproduction of the individual).

There is something else that is more important about this kind of cell reproduction. When this special cell reproduction happens, it undergoes recombination and all that we discussed previously (about chapters and books) comes into play. Thus it is really not predictable to say which part of the 1st chromosome, which part of the second chromosome and so on are part of the newly formed daughter cell. So it might either have a brown eye gene or a black eye gene, brown hair or black hair and so on for different features.

Sex determination
The egg from the female will always have only X chromosome, since it is the daughter of a cell from the female which has X chromosomes. But the sperm (the half cell coming from the male which has both X and Y chromosomes) could have either X or Y chromosome. A sperm with a X chromosome combining with an egg will lead to the child being a female, while a sperm with a Y chromosome combining with an egg will mean that the child is a male.

An aside: I remember this fact that the gender of the child depends on the male half cell (sperm) and not the female, was once used in AID India’s health team to make a poster, to counter the ridicule that women face when they fail to deliver boys. The poster tries to tell the viewer that if anybody is to blame it is the father and not the mother. In reality of, course, it is nobody’s conscious decision.

Now we have come to the final part of the post. It is because of this recombination, that we inherit some traits from the father and some from the mother. This recombination, also ensures that each one of us is a unique individual and not a clone of either of our parents. So a specific gene from your father, has a 50% chance of being in your genome too. Similarly a gene from your mother could have a 50% chance of being in your genome too. But any gene in your body should have come from either of your parents. And since your siblings share the same parents, a gene in your genome has a 50% chance of being in your sibling’s genome too.

There are some interesting details that I have not talked about here. We will discuss them in the coming posts.

Speed of light exceeded?

September 23, 2011 2 comments

It has been a long gap since the last post. I was traveling for 2 weeks, and I was planning on some posts, but this one that I saw a couple of hours ago needed an instant update.

Scientists at CERN (Eurpoean Organisation for Nuclear Research), which is doing the Large Hadron Collider experiment, have reported that some particles have been found to be travelling faster than speed of light. Reports say that the result has been verified, but also that the scientists themselves are skeptical about the result and want others to do tests and confirm it.

To see why this is too good to be true, there are two things. One is that, Physics had looked at the speed of light being the upper limit as a fundamental fact and that for any particle to travel faster than speed of light, it must have infinite energy. Hence it was considered impossible to travel faster than the speed of light.

If you have read my previous post about the speeed of light, I had mentioned that for a particle travelling closer and closer to the speed of the light, time starts running slower and slower. When you reach the speed of light, time stops flowing. But now if there are particles faster than the speed of light, does that mean that time is running in reverse for them? Are they travelling back in time? This is another reason why the result is perplexing.

Of course, I dont understand much of these concepts, but if this result turns out to be true, it could be a terrific advance in Physics. So let us keep a watch on this.

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