Visar inlägg med etikett Berkeley. Visa alla inlägg
Visar inlägg med etikett Berkeley. Visa alla inlägg

fredag 24 juli 2009

Carcinogens in natural foods - the Ames test

I have previously written about the difference between natural foods and "unnatural foods" in terms of how much carcinogens they contain. I did one post on "Irrational fear of pesticides", and another post that I called "natural foods contain more carcinogens than unnatural foods".

Just now I found a video clip from Physics for Future Presidents, a UC Berkeley lecture series that you can watch for free online, in which Richard Muller, an entertaining physicist explains what this is all about. Watch and enjoy.




torsdag 10 april 2008

MIT open courses

Nobody could have missed that I love to listen to audio and video lectures on my spare time. In particular when I am doing something where I do not have to concentrate (such as doing dishes or walking the dog). I recently wrote about The Teaching Company which is probably my favorite company in the world. I have also mentioned Berkeley webcast and in particular the lecture series called physics for future presidents taught by professor Richard A Muller.

When reading Lunkens blog I saw some really good news. MIT, one of the most prominent Universities in the world (particularly in physics, technology, and computer science), have been inspired by Berkeley and have now made a good deal of their courses available online for free, hurray for that! For example, here is a lecture series on introductory biology taught by Eric Lander (see picture above), a key figure in the human genome project.


So, make use of these fantastic resources. With a few clicks on your mouse you can enrich your life by learning about anything you wish from world leading experts, who are also in my experience fantastic teachers.

onsdag 18 juli 2007

Irrational fear 1: Pesticides

About three months ago I wrote a post on natural foods and the highly exaggerated danger associated with pesticides. I cited research done by Bruce Ames (see picture), Professor of biochemistry and molecular biology at UC Berkeley. In this very interesting interview, Bruce Ames gives his view on organic foods. In the following excerpt from this interview Ames explains that the reason why he is against spending more resources on natural foods is not that it contains more carcinogens but rather that the production and in consequence also the products is more expensive. More expensive fruits and vegetables means less consumption which will result in more cancers:

Ames: Yes. I'm much more interested in preventing cancer. Then we have to get out to the public what's important. If you tell them about trivia all the time, they get completely confused, and it's counterproductive. I just think all this business of organic food is nonsense basically. We should be eating more fruits and vegetables, so the main way to do that is to make them cheaper. Anything that makes fruits and vegetables more expensive may increase cancer.

When I cite this information people often ask where Bruce Ames gets his money from. Is he really trustworthy? This is a fair question when you take into account the fact that the food industry is a big industry, and if organic foods would suddenly become the public choice it would certainly be rather detrimental to many companies. What many people seem to forget though is that producers of organic foods also have money waiting for them, should they manage to sway the public opinion. Unless it is suggested that organic food producers have a superior morality, immune to economic incentives, this is not a valid argument, after all the economic incentive is there for both sides. Maybe those the people who tell us that organic is the way to go do so because they would get rich if people followed their advice?

I feel quite confident that Bruce Ames is not bought by the food industry. Why? Partially, I believe Ames is a good guy because of what my intuition tells me. When I read the interview (referenced above) with this scientist he just doesn't strike me as a man who has sold his soul to the devil, quite the contrary in fact. However, the main reason why I don't think Ames is bought by the food industry is that he is also the man who first proved that many synthetic pesticides are carcinogenic. For quite a while he was a hero to all the natural food proponents.



Bruce Ames showed that indeed many man made chemicals are carcinogenic, but what reason do we have to assume that natural pesticides aren't also carcinogenic? Ames did not make this assumption and when he tested natural pesticides, which are created by the plants themselves as a protection, he found that pretty much the same proportion of natural pesticides was carcinogenic. Furthermore, Ames discovered that plants which are not treated with synthetic pesticides (i.e. natural foods) contain more potent carcinogens than plants which have been treated with pesticides. (Things can be more or less carcinogenic; for example, even though mushrooms contain 50% carcinogens they are very weak and therefore doesn't do a lot of damage whereas coffee contains much stronger carcinogens.) Read my previous post if you want to understand why. Add to this that 99.9% of the pesticides that we ingest are natural pesticides and you will understand why this post is about irrational fear.

Here we are worrying about 0.1% of the pesticides we ingest which according to the data are, if anything, less mutagenic than the other 99.9%. That is what I would call irrational fear…

onsdag 4 juli 2007

The God Delusion, Part 4, Why there is almost certainly no God


I am not the only blogger who is discussing The God Delusion. If you want a view that is really different from mine you can go to the Apologetics homepage where you will find comprehensive criticism of Richard Dawkins latest book. Deepak Chopra whom I recently criticized for his abuse of quantum physics also taken the challenge of trying to break the arguments put forth in The God Delusion. Needless to say I don't think that the Apologetics or Chopra are able to break the very strong message in the God delusion, but that should be up to you readers to decide.

After having met the many arguments or proofs for God, one by one, in chapter four Richard Dawkins goes on to describe not only why we do not need a God to describe our world but also why such a God in fact is quite implausible.

He starts out by explaining why the alternative to a creator God, Charles Darwin's (see picture) Theory of Evolution, is not, as many people tend to think, the same as blind chance. It is really quite wearisome to hear people say "so you think we just popped into existence" when you say you believe in evolution, but I have already written about this issue in my blog post Evolution is NOT blind chance. Dawkins also points out that to call upon a creator in order to explain complexities which we have not yet understood does not solve nothing, all it does is to invent another complexity that needs to be explained. I would like the ID proponents to suggest an empirical test, similar to the one below, which if it succeeded would support their "theory" and if it failed would falsify it. Dawkins writes:

"Darwin himself said as much: 'If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find no such case.' Darwin could find no such case, and nor has anybody since Darwin's time, despite strenuous, indeed desperate, efforts. Many candidates for this holy grail of creationism have been proposed. None has stood up to analysis"

Another common tactic used by religious people is "The worship of gaps". Whenever there is something science cannot explain such as for instance language, certain religious people take this as proof of God's existence. After all, if science doesn't have the explanation, then it has to God right, right?

"The logic turns out to be no more convincing than this: 'I [insert own name] am personally unable to think of any way in which [insert biological phenomenon] could have been built up step by step. Therefore it is irreducibly complex. That means it is designed."

But what about the Universe and what about us humans? Why should there be a Universe? Why should we exist? Surely someone must have wanted us to exist? No not of necessity. Though I am still merely an amateur astronomer (I am trying to help that by following a lecture series by Professor Alex Filippenko available at Berkeley's webcast), I know that there are theories out there which could potentially elucidate why our Universe looks the way it does. There are also good attempts to explain how the first cells arose. These theories I admit can sound a bit far fetched an even unlikely. However, it seems that we are also relatively lonely in our Universe and so the unlikely event of a cell (see below) forming spontaneously from various organic constituents only had to happen once for us to exist. If you throw a dice billions and billions of times you are likely to at least once get say 10 sixes in a row even though the probability of this series is as low as 0.00000002.



We humans are also ill equipped to accept hard nosed scientific theories instead of explanations that invoke an agent such as God. Humans have a natural tendency to see agents everywhere. Dawkins writes:

"Maybe the psychological reason for this amazing blindness has something to do with the fact that many people have not had their consciousness raised, as biologists have, by natural selection and its power to tame improbability. J. Anderson Thomson, from his perspective as an evolutionary psychiatrist, points me to an additional reason, the psychological bias that we all have towards personifying inanimate objects as agents. As Thomson says, we are more inclined to mistake a shadow for a burglar than a burglar for a shadow. A false positive might be a waste of time. A false negative could be fatal. In a letter to me, he suggested that, in our ancestral past, our greatest challenge in our environment came from each other. 'The legacy of that is the default assumption, often fear, of human intention. We have a great deal of difficulty seeing anything other than human causation.' We naturally generalized that to divine intention."

In summary, chapter four in The God Delusion, bring up a few quite important points. It is shown that a creator God is really an inadequate answer since it merely brings up another problem namely who created the creator, or who designed the designer? The best theory we have to explain our own existence without invoking an agent is the beautiful and simple Theory of Evolution.

lördag 21 april 2007

The underweight epidemic


What is going on with obesity? For a long time now I have been walking around thinking that our modern society has some serious negative consequences in terms of diet. Our evolved preference for foods rich in fat and sugars together with fast food chains and supermarkets which put the candy where you cannot avoid it, should naturally result in an increased consumption of such foods and in consequence more obesity. Indeed this seems to be the case. Since the 1970s obesity levels have been steadily rising. However, the interesting question to ask is "what effects this increase in the average BMI (body mass index) has on our health?"

When I lived in California I was constantly exposed to commercials in which you would view pictures from a childhood where the protagonist ate way to much sweet stuff. Following these pictures a man would say something like, because of what I ate in my childhood my life has been shortened by five years. I believed this, just like I believed that obesity was indeed a dangerous epidemic, why should I not believe it?


Now I think I know better though, all thanks to a professor at Berkeley who's lectures I have been following via Berkeley's webcast (which I can warmly recommend by the way). In her lectures she presents apparently uncontroversial data showing clearly that the deaths due to diabetes have not increased one bit in the past 40 years or so. What is even more interesting, and indeed more concealed, is the fact that obesity is not associated with an increased risk of dying. In fact, if you have a BMI between 25-30, which is considered overweight, then you have the best possible prognosis. If you are underweight on the other hand (BMI less than 18.5), then your chance of dying increase substantially! Have anyone heard of an underweight epidemic? I certainly haven't! Yet, an underweight epidemic is what we should really be worrying about since it is, unlike overweight, claiming quite a few deaths in our modern society (and in developed countries as well of). Of course it should be mentioned that severe obesity, that is when BMI gets above 30, is associated with increase health problems as well.


In the light of this information I think that it is insane, the way that overweight/obese people are treated in today's society. To have some fat reserves is good. To not have any reserves is dangerous. Yet those with the more healthy bodies are dragged into shame exactly because of their bodies.

söndag 4 februari 2007

Free will and determinism

Do we have free will, or are all our thoughts and actions a result of the physical forces in our universe?

After having taken part in a discussion about consciousness on Furiku's blog I decided to learn a little bit more about the philosophy of the mind which discusses such things as the nature of the mind, consciousness, and free will versus determinism. The audio-course, which I warmly recommend, is from the teaching company (see my previous post about the the teaching company here), and it is called "philosophy of the mind". Teacher is John Searle (see picture) from the University of California, Berkeley.

My experience is that the question of free will versus determinism is a question that many people ask themselves occasionally. Are we free agents in the world or does everything, and I mean everything have a preceding cause. I cannot speak for anyone else of course, but for me it sure feels like I have free will. When I write these words I feel as if I am deciding to write these words, and I can even erase them again if I want to! On the other hand, dwelling further into this I can think of situations in which I have felt as if I had no free will, where I acted contrary to the way I wanted to act. One of my stepchildren exemplifies this point well. In the process of doing something violent to her younger sibling she sometimes says "I just could not control myself", which effectively eliminates the possibility of telling her that "that was wrong!".

I should state here what I believe; I believe that we live in a determined universe, that free will is an illusion (that we are determined to have), and I will now explain why.

We have physical laws which can, with some small exceptions, explain more or less everything that goes on around us. In most chemical and physical systems we can, if we know the current state of the molecules in the system, predict how the same system will look in the future. Our brain is a chemical/physical system (a very complex one), and therefore it should be theoretically possible to predict what our brain will look like in the future, and if we had more knowledge about the relation between the physical and mental state of the brain we would be able to predict exactly, the mental states and behaviors of the individual.

Some people will object to my view by saying that, if I don't have free will, then everything is determined and it doesn't matter what I do. I could go out and rape and kill people and that would have been inevitable. However, if the deterministic hypothesis is true, then you could obviously not decide to go out and kill and rape. If you did go out to kill and rape, it would be because of something, maybe these words (caused by processes in my brain) have had an influence of your brain which makes you go and do this, or maybe you have gotten a tumor in your amygdala, messing up your emotions. A similar objection that I sometimes hear is the following. "How can you (referring to me), believe in such a depressing thing?" Life is meaningless without free will! Of course the answer is the same, if the deterministic hypothesis is true I cannot decide to believe or not believe in free will, my beliefs were determined by the state of the universe when it began. Besides, I don't really feel sad when I think that I have no free will, rather, I think, I am a little bit amused by this thought.

Another objection is that research in quantum mechanics have shown that there is uncertainty in the universe. We cannot tell the exact location of the electron when it is orbiting the nucleus of the atom, hence free will. To me this argument sounds rather far fetched and desperate. There is no plausible reason to suggest that we would be able to control, through our mental activity, where the electron is located, and there is also no good reason (as I see it), why the location of an electron in the orbital cloud should give rise to different actions.

Summing up, I just cannot see anyway around the conclusion that there is no such thing as free will. It free will did exist it would be a big problem for science which rests on the assumption that every process in the universe have a cause. I would love to hear comments on this post, especially from people who do believe in free will...

tisdag 16 januari 2007

Get smart! Two great resources for people with "learning hunger"

Except for a weak period that I had during my teens I have always been a very curious person who loves learning. However, never before have I learned at a rate that is comparable to my current learning pace. What is this all about? I will tell you!



About two months ago I discovered two fantastic knowledge resources and since then I have been listening or watching lectures when I am on the bus, taking a walk, doing the dishes, cooking, running, playing soccer etc (OK, that last one was not true, but its close). I really really recommend both of these websites to anyone who likes to learn things.

The two sources are:
1. Berkeley webcast
2. The Teaching Company

The first one is University of California, Berkeley's webcast (see picture). Here you can watch or listen to lectures in many different field ranging from biology, physics and chemistry, to philosophy economics and non-violence. I am currently watching "physics for future presidents", which is a great great great (I don´t know how else to describe it) lecture series by professor Robert Muller. He goes through pretty much all of physics in a very interesting and intriguing way. One guy commented on Google video that "I would listen to this guy (Robert Muller) even if he had his pants down while talking". I have also been watching introduction to chemistry to try to really understand quantum mechanics, which is still difficult though...

The second resource is perhaps even better. The teaching company hand picks the best professors in the world and asks them to make a series of lectures in their field of expertise. You can order the lecture from their website, or if you are the hacker type the courses are sometimes available for download. The quality is consistently top class. I have already taken 24 or 36 lecture courses in the following fields.

(1) Neurobiology of behavior, by Robert Sapolsky at Stanford University
(2) Introduction to economics, by Timothy Taylor at Macalester College (this guy actually made me realize that economics can be interesting)
(3) Argumentation, by David Zarefsky at Northwestern University
(4) History of Russia, by Mark Steinberg at University of Illinois
(5) Understanding the Human Body, by Anthony Goodman at Montana State University (he used to be the general surgeon)

As the teaching company says in the introduction to their courses "Imagine how much you could learn if you spent 30min everyday in the best classrooms in the world".