A new planet in our Solar system?

I was stunned recently by this report that there may be a massive new planet that we did not know about in our very own Solar system. I thought this must be a hoax report but apparently it is being considered as a serious possibility.

The hunt is on for a gas giant up to four times the mass of Jupiter thought to be lurking in the outer Oort Cloud, the most remote region of the solar system. The orbit of Tyche (pronounced ty-kee), would be 15,000 times farther from the Sun than the Earth’s, and 375 times farther than Pluto’s, which is why it hasn’t been seen so far.

But scientists now believe the proof of its existence has already been gathered by a Nasa space telescope, Wise, and is just waiting to be analysed.

You would have thought that our knowledge of our own stellar neighborhood was complete but apparently not. The suggestion that Tyche existed was first made as far back as 1999 but not everyone is persuaded that it exists.

We should know with greater certainty either way by 2012. This is what makes science so much fun. There are always new discoveries to look forward to.

Solar sail vessel unfurled

The idea that the electromagnetic radiation can exert pressure is an interesting idea that I taught in my physics courses. As an example, the idea of using the pressure from solar radiation to power a spacecraft has been around for a long time, and I used to give this as a homework problem.

It looks like it has finally come to fruition. Japan used one to fly by Venus in 2010 and now NASA has deployed one to orbit the Earth. Plans are underway to use one to fly to Jupiter later in the decade.

solarsail.jpeg

(via Machines Like Us.)

How the case against the MMR vaccine was fixed

Some of you may be aware that many parents are not giving their children the MMR (measles, mumps, rubella) vaccine out of fears that it may cause autism. These fears were generated by a paper published in 1998 by the British medical journal Lancet by Andrew Wakefield and others suggesting such a link. The findings were challenged but the journal only withdrew the paper in 2010.

The British Medical Journal has now published a detailed investigation and concludes that all of the twelve original cases reported had had their data misreported or altered in order to make the link.
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The story of the whale

Of all the arguments that are used by religious people against evolution, the most fraudulent is that there are no transitional forms between species. People who say this either willfully ignore the evidence that does exist or think that a transitional form must be a hybrid between two currently existing species.

Do you think that no one could be that stupid? Behold the infamous crocoduck argument.


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On free will-16: A sense of self in the absence of free will

(For previous posts in this series, see here.)

According to the writer Isaac Beshevis Singer, “We must believe in free will, we have no choice.” It is a funny line because of its paradoxical nature and yet also profound because of its multiple layers of meaning. On the one hand, it could be interpreted as saying that belief in free will is likely hardwired in our brains and we are thus compelled to believe in it, whether it is true or not. On the other, it implies that the idea of free will is so important to our sense of self as autonomous agents and to the way that our society is organized that even if we realize it is a fiction, it is a fiction that we must adopt because to abandon it might lead to cognitive confusion and social disarray. This series of posts has tried to show that this fear is unwarranted and in this, the last post, I want to address the issue of what it all means for our sense of self.
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On free will-15: Acting as if there is free will

(For previous posts in this series, see here.)

Let’s consider two scenarios. In one case, John carefully plans and executes a murder. In the other case, Susan kills an assailant who attacks her. With a belief in free will, we assume that John freely made a willful and conscious decision to commit that act and is thus more culpable than Susan who reacted on the spur of the moment out of the instinct for self-preservation and thus did not use her free will. We thus feel justified in punishing John more harshly than Susan.

If there is no free will, that means that both John’s and Susan’s actions were the result of unconscious neural activity, the only difference being that John’s neural activity had sufficient lead time to create conscious thoughts. Shouldn’t the planned murder be treated in the same way as the self-defense? Doesn’t that imply that they should be punished the same? Is this fair? [Read more…]

On free will-14: Misuse of the insanity defense

(For previous posts in this series, see here.)

Many people are suspicious of the insanity defense, suspecting that it is abused by unscrupulous criminals and their lawyers. The fact that psychiatrists and other experts can be found to argue both sides of the case adds weight to the suspicion that there is no objective basis to many of the claims of insanity.

This problem arose when the grounds for the insanity defense was loosened from the strict M’Naghten rule. In a 1954 court decision Durham vs. United States, a US Appeals Court extended the reach of the insanity defense beyond cognitive incapacity and said that “The rule we now hold is simply that the accused is not criminally responsible if his unlawful act was the product of mental disease or mental defect.” (Steven Pinker, The Blank Slate, p. 184) As a result of the Durham precedent, there was a proliferation of expert testimony on both sides to argue the question of whether the accused did in fact have a mental disease or defect and whether the act that was committed was the product of that defective mental state, and thus not truly ‘free’.
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