Science thread - anything interesting?

Now THAT's a croc!

I've never really found rats scary, but when these monsters appear, I get the chills.

This was found in Denmark recently:

http://www.dagbladet.no/2010/08/21/nyhe … /13045847/

And here's one from England:

http://www.thesun.co.uk/sol/homepage/ne … dford.html

I want one.

... because rodents are cute and have lots of interesting behavior!
So the bigger the better, to observe.

I have no problem with rats, very intelligent creatures and true survivors, I love them but I wouldn't want to live with them.

Gomez very first kill was a rat, I haven't seen any since.

Rat artist's rendition of Gomez.

Very accurate.

Gomez kicks the ass of nature's farts.

He turns into nothing....he always was a sneaky bastard!

Since I'm not allowed to post in the recent reading thread, I'll post it here:

The Cosmic Landscape: String Theory and the Illusion of Intelligent Design Leonard Susskind

I do fair a amount of reading, mostly to do with science, and mostly about physics at that. I'm a science a geek and proud of it (and apparently on the wrong course at uni . Anyway.) This particular book I've recently read for the third time, which never ceases to impress and amaze, is particularly well written and covers a vast and complex subject with a superb flare for analogies and explanations. This is the book that really helped me understand the main principles of the subject, and served as a good introduction to modern physics and cosmology, and certainly isn't intended for dummies either.

I understand not everyone takes as keen an interest in science as other people, but there is one aspect I feel very strongly that people should at least be aware of. Amongst many other things, one of the most striking aspects about modern cosmology is the Anthropic Principle. Once scoffed at as non-science, as giving up and even religious-like hokum, now has a steady place in cosmological descriptions. There are various ways of wording it, but the basic premise for anthropic reasoning is "The physical laws of our environment are the way they are because it could not have been otherwise and we would not be here to observe or question them." It sounds silly on its own, and it is. But it has shown to have powerful implications when coupled with modern theories and observations. Even Fred Hoyle (famous opposer of the Big Bang theory ultimately having to concede to its accuracy), used it in the 60's to explain how carbon is formed in stars like our sun.

There are a lot of subtleties to it, and lots of other fascinating theories that go with it, but I'll describe its simplest implication without going into too much depth: there is a landscape, Susskind's landscape, of possible universes each with different properties. On its own, our universe almost certainly appears to be a 'put up' job, with so many ridiculously lucky laws and numbers permitting the existence of intelligent life that it seems almost impossible it was created by chance. The fact that this 'landscape' exists -a landscape with many dimensions, though not a real physical space, rather a space of possibilities- leads to the conclusion that every so often it is not surprising that a universe will exist permitting life, intelligent life, to exist - about 1 in every 10*120 out of a possible 10*500 in one carnation of the theory (which doesn't mean that there are 10*500 universes, although being an unimaginabley big number, especially when you compare it to 10*78 and 10*80 of atoms present in our observable universe, it 'merely' represents the different vacuum possibilities. There could be an infinite amount of one particular type of vacuum.) We happen to observe that universe because it could not have been otherwise, but at the same time there are undoubtedly many more universes too violent or too sterile for life to emerge. It's not a proven model, not nearly, and it's one of the things the LHC is working towards uncovering more of its layers, but it does appear to be a logical conclusion of String/M Theory which has provided some very powerful tools for new ideas.

That, in a nutshell, is the illusion Susskind dispels so wonderfully in this brilliant book.

And this leaving out the multiverse theories to do with infinity, which is equally if not more astounding.

I must admit I'm not the best person to explain these things, that would be Sussking* himself and other popular science authors, but it's quite simple once you get a hold of the basic premisses that lead to these conclusions!

Analogies are invaluable resources for any physicist. Richard Feynmen new this better than most, which is what lead him to create his 'Feynmen diagrams', a pictorial representation of particle reactions and events. A 5 year old could understand the simplest of Feynmen diagrams!

Edit: *A Freudian spelling mistake methinks.

That's kind of the point; the constants are inevitably going to be different in different 'locations' of the Landscape. Life can only occupy a vacuum with a small constant, which is why we do! Having read a relatively large amount on String Theory*, to me it seems like a very convincing description of reality (whatever that is). That's not to say it's right though.

I find "chance arguments" very satisfying (if daunting) explanation for life's existence. Earth itself is an extremely unlikely planet to exist, but because of the vast number of stars and planets out there, it's no surprise we find ourselves on such a planet.

*Only in popular science form. I'm about as far from being an expert on Sting Theory as The Pope is from sanity.

I must admit I don't find such possibilities very exciting until we actually have some evidence for them. I find tested, surviving hypotheses vastly more fascinating, than untested ones and untestable ones in particular.

My main problem with chance arguments is that the purpose of probability estimation is to calculate the chance of something happening from a position of ignorance. When more relevant information is gathered, the probability will either move towards 0 or 1. As soon as an event has happened, the probability of it happening will be 1. If you look at an event that you know happened, i.e. with a probability of 1, the only way to lower that probability is by ignoring current information, basically increasing your own ignorance. In addition, generally chance arguments are loaded with hidden assumptions, fueled by agendas, conclusions that doesn't follow, flawed calculations and numbers pulled out of rear ends.

Peter

It's natural for a biologist such as yourself to feel comfortable only with observed evidence for a hypothesis, so I can understand your point of view. For the theorist (which is not what I am, but for whom I tend to side with), the workings of the theory itself are almost as good as proving it - almost, but not quite. In fact, thought experiments by themselves could potentially have led to many discoveries in the 20th century. That's not saying they would have, but there's at least a chance they could have. Einstein's theories of relativity, for example, were unproven thought experiments at the time of their inception, but so powerful were their descriptions that Einstein was sure there were true. (Although he was also sure that quantum weirdness was a facet of our ignorance to original conditions, so there's always two sides to the coin!) This is circumstantial reasoning, but it does illuminate my point a little.

There's a few good reasons why unproven models can be taken quite seriously: one the one hand, if String Theory is eventually proved to be inaccurate, then it seems at this point quite unlikely that whatever else replaces it will be significantly different -String Theory is, after all, not a singular theory with absolute outcomes, but instead provides a range of possibilities. But because String Theory has proved to explain physical laws to such a satisfying degree, more than any other model, and even inherently, and therefor must include the graviton as part of its description, it's hard to imagine that such a 'beautiful' model is entirely wrong. With that in mind, the conclusion of the Landscape is a natural result of String Theory, and to me seems very likely to be true. The fact that it hasn't been proven doesn't necessarily, to me, seem like it shouldn't be taken seriously. Ignorant we may be, but there are certain times when assumptions are quite safe to tread, as long as you keep in mind that it could be wrong. This is why I feel very comfortable with a "Landscape" description of reality.