Category Archives: science

Book Review: ‘You Are Not So Smart’ by David McRaney

This great work boils down to: “Despite millions of years of evolution your brain is a jumbled mess of neurons that covers up it’s downfalls by lying to you constantly. Here are just 46 ways your brain is being an asshole.”

Just like Dawkins argues against a creator in showing that evolutionary adaptations can be flawed and seemingly badly designed, David McRaney shows in this work that despite those claims that the human mind is one of the most complex structures in the known universe, it’s shoddily put together, with bits that don’t work together and bits that were added on at the last minute and that the only way it ‘works’ is that it constantly lies to itself about the reality it exists in. You have in your head a used car salesman.

David demonstrates the limitations of our brains by picking out these 46 different ways our brain lies to us and writing a small chapter on each. Each lie is well researched and refers to different published studies for evidence. For example the chapter on why you have too many Facebook friends talks about studies about the limitations of how many people you can hold in a social circle in the physical world and compares these figures to the data on Facebook. He also talks about the reason why you ‘befriend’ all those people using the internet.

Most interesting are the chapters that highlight the limitations in vision and the comprehension of sensory input. You are not a little person in a box watching a ultra high definition surround sound movie of your existence. More like your homonculus watches a scratchy silent movie from 1908 with no sound and missing film cells, a friend tells them about the soundtrack over the phone.

There are also great chapters on how you think you are better than everyone else out there. He actually gives statistics on how many people think they are better than average drivers and how many people think they have a better than average IQ. The figures will astound you.

I highly recommend this fun and enlightening read. It certainly will make you question everything you think and perceive, which is a practice that all science endorses strongly. This book is so much more than your average pop-psychology book that litters the popular science section of bookshops and libraries. It holds no punches and approaches the subject from a critical standpoint. Weeks after reading this book I’m still laughing at my brain when I know it’s lying to me.

The Oldest Rocks on Earth

At 200 X 400 micrometres this zircon crystal extends the limits of our understanding of early Earth back to 4.4 billion years ago, a mere 100 million years after the Earth was formed and only 160 million years after the Solar System formed. This discovery pushes back the date for when Earth first had a solid crust and weakens the theory that at this time the Earth was hot and entirely molten. It seems the conditions were much milder much earlier than we thought. There are two methods of dating these minerals, via radioactive dating methods and using atom probe tomography. The research group who dated this sample used atom probe tomography, but I am going to talk about radioactive dating methods.

Zircon crystals are brilliant for radioactive dating because of two reasons. Firstly they’re tough, they last a long time and can withstand an amount of tectonic pressures. Secondly, and most importantly, they form with radioactive uranium in their structures AND they do not form with lead in their structures. Why is this significant?  Radioactive uranium degrades into lead. So we can say that any lead present in the crystal is due to the decay of the uranium and nothing else. Zircon crystals are special in another way. They form with two different radioactive isotopes of uranium which both degrade at their own independent rates into two differing isotopes of lead.

Radioactive decay happens with precise timing. We know how radioactive decay works and at what rate it happens at. It’s an exponential decay that is as regular as clockwork. Whether this happens over billions of year, hours, minutes or microseconds, all radioactivity follows exponential decay that is given in a simple mathematical expression.

So essentially zircon crystals are like clocks that were set to zero when they solidify from molten rock. Actually more like two individual clocks in each crystal because of the two different radioactive decays. All we need to do is to look at the ratio of uranium to lead to tell what time it is, just like looking at the two hands of an analogue clock. And the beauty is that we have two clocks running simultaneously and confirming each other.

So you start off at time zero with 100% of the parent isotope. This degrades at an exponential rate to a daughter isotope. For example:

We can say how fast each radioactive decay occurs by a concept called ‘half-life’. A half-life is defined as the time when half the amount of the parent isotope has decayed into the daughter isotope. So at time zero there is 100% parent isotope and at the half-life there is 50% parent isotope and 50% daughter isotope. And because this decay is exponential, at 2 times the length of the half-life the parent isotope is at 25% and the daughter at 75% and so on.

Each radioactive decay happens at its own rate. For example the half-life of uranium-235 is 704 million years, the half-life of uranium-238 is 4.5 billion years, while ruthenium-106 is 1 year, carbon-11 is 20 minutes and lithium-12 is 10 nanoseconds. So for the two uranium decays in zircon you can see that the decay from uranium-235 happens at a much faster rate than that of uranium-238.

Scientists trying to age a zircon crystal look at how much of uranium-238 versus lead-206 there is and how much uranium -235 versus lead-207.

You can use these ratios to back calculate ages of the crystal. Looking at uranium-238 there is nearly a 50-50 mix of parent to daughter isotopes, so therefore it is just under the age of its half-life of 4.5 billion years. With the uranium-235 you can see that most of it has decayed to lead-207 and there isn’t much uranium left at all. It has gone through many half lives. In fact we can calculate it has gone through 6.25 half-lives and 6.25 multiplied by 704 million years is 4.4 billion years. So you can see how the correlation of the ages calculated of these isotopes are a powerful tool with both results pointing to 4.4 billion years or so.

The same method of looking at the ratio of parent to daughter isotopes is used for all radioactive dating. The other type of dating that you may have heard of is radiocarbon dating or carbon-14 dating. This method looks at the amount of carbon-14 in a sample which could be some bones of animals or humans or trees or other living things. Because all living things have a large amount of carbon in them, some of the carbon is naturally occurring carbon-14 (as opposed to the normal carbon-12). When a living thing dies it does not absorb any more carbon into its system and the carbon-14 that remains decays. So the amount of carbon-14 left in a biological sample tells us how long ago it died. The half-life of carbon-14 is 5,730 years and so if we find half the expected carbon-14 in a sample is must be around the age of 5,730 years. This method is limited to around 60,000 years or 10 or so half-lives. After this time there is only 0.1% of the parent isotope left and the error becomes too large to be reliably date a sample.

So you can see how radioactive decay is a useful tool to date objects. You cannot use every type of radioactive decay out there to age objects, it is limited to systems where you know the concentration of one isotope at time zero. But luckily there are several systems where this occurs and knowing this fact gives us a glimpse into the distant past.

Just for the hell of it here is a zircon crystal from my own collection. It’s probably nowhere near as old as 4 billion years as it is large and was from a location in the Northern Territory that is not renowned for it’s age.

Book Review: ‘Shaman’ by Kim Stanley Robinson

Kim Stanley Robinson’s new novel may seem like a change from his past works, but in a way it fits in well with his other works. Instead of spaceships we get the end of the last ice age. And although you may think that this is a huge change in what Kim usually writes, we do get a story about humans surviving and adapting through innovation and investigation, just like all of his stories. ‘Galileo’s Dream’ may have seemed like Kim was talking about the beginnings of science, but with ‘Shaman’ he shows that there are no beginnings of science and that it is essentially part of being human.

Kim has stated that his inspiration for this novel come from extensive hiking near glaciers and the type of environments that Europe would have been like at the end of the last ice age. On these hikes Kim would imagine what it would have been like to be a human at this time. Other inspiration has come from the ongoing investigation of Otzi, the five and a half thousand year old body found exposed in a glacier in 1991. Clothes and other artifacts found with the body have survived wonderfully and provide a great insight into the technology and innovation of the time.

What Kim produces is a heart-warming, coming of age tale of an apprentice shaman. We join him in his first wandering, cast aside into the wilderness naked and with no tools. We learn an awful lot about his clan and how they function in day to day life. And every character you encounter is well-drawn and is a complete individual. These people and the book itself does well to remove itself from using the standard caveman stereotype and indeed shows that ‘humanity’ has been with us all along and did not come about with the rise of civilisation.

I found that I did not enjoy this novel as much as some of Kim’s other works such as the Mars trilogy and ‘Galileo’s Dream’, but compared to most other works out there, it is still a brilliant and thoughtful work full of wonder and heart. In my opinion even when Kim is experimenting and trying something different like this, he could write the pants off all but a few authors.

Returning to the Moon

So I have been absent for a few weeks from the blog. Well, at least I didn’t abandon you all like we did to the moon. Thanks to China, after 37 years we have finally put another craft on the surface of the moon. The Chang’e-3 lander contained a rover called Yutu, or Jade Rabbit in Chinese. After a landing on Saturday everything seems to be go for the little rover.

The rover has a twofold mission; to explore the landing area, the dark lava plains of Bay of Rainbows in the north of Mare Ibrium, as well as deploying a telescope on the surface. The Bay of Rainbows has piqued the interests of the China National Space Agency due to its geological features. Investigation of the lava plains will lead to greater insights into the history of the moon, from when there was volcanic activity on the surface. These lava flows are presumed to have left behind lava tubes, as occurs in lava flows on Earth. Lava tubes are formed by hotter flowing lava accumulating in channels that run through cooled lava. These tunnels can be small, about 100 mm diameter, up to very large tunnels several metres in diameter. I recently visited one at Mount Kilauea, Hawaii that was large enough to take a leisurely stroll through.

These structures under the lunar surface would be perfect for future human settlement as they will easily convert to a sealed environment, with the benefit of having radiation deflecting rock above. The lack of atmosphere on the moon allows for all radiation from the sun to contact the surface; a very dangerous long-term environment for any life. The importance of finding and exploring these structures is important to future space efforts.

To aid in this underground investigation, the rover carries a ground penetrating radar system, estimated to be able to detect structural changes down to about 150m below the lunar surface. The rover also carries a scoop with a spectrometer to analyse lunar regolith samples.

Deploying a telescope on the moon is of great interest to astronomers due to the lack of atmosphere, the same reason why the Hubble telescope was so successful also. Looking through an constantly shifting atmosphere at distant stars can prove to have its difficulties.  The lander also carries an ultraviolet camera in the aim of photographing the Earth’s plasmasphere, a distant part of the atmosphere where the Earth’s magnetic field deflects incoming radiation from the sun. Although the plasmasphere has been mapped before, it has only been mapped from within. The new photographs will confirm the structure of the plasmasphere from the outside.

The new rover is part of the beginning of China’s space program. Previously two orbiters have been successfully launched by the program, and there are plans for many more including a mission to return rock and regolith samples back to Earth in 2017. With South Korea and other countries also initiating space programs in the last year, it is definitely an exciting time for humanity. The collaborative efforts of space exploration are proving to be beyond politics. It’s time to be optimistic about our futures.

Book Review: "Feynman" by Jim Ottaviani and Leland Myrick

I have been slow to discover the delights of Feynman, but I recognise a similar thinker, albeit a much, much brighter man. I love his famous BBC interview that was towards the end of his life and I did greatly enjoy his autobiographical sections in “Six Easy Pieces”.

A graphic novel adaptation of Feynam’s life works very well. While it does not present any new material, it takes the best snippets from all different sources and makes his life come alive with wonderful and simple illustration. Another great advantage to this medium is that the authors presented sections of Feynman lecturing and explaining physics problems. This works wonderfully and could only be bettered by watching a video of these lectures. (You can find some of his filmed lectures on Youtube).

So this was a wonderful read for a rainy Sunday afternoon. It really did capture his voice and his philosophies if I could use that term.

Library Copy of ‘Fifty Shades of Grey" Tests Positive For Herpes

For a laugh two Belgian toxicologists borrowed 10 books from their local public library and put them through toxicological and bacteriological screenings. What they found was quite intriguing.

All books were rife with bacteria. Well that should be a no-brainer, but did they run some background readings on other books, say from their own library?

Another finding was that all showed trace amounts of cocaine. Not enough for a reader to display physiological symptoms, but possibly enough to alert a drug screening.

Also, “Fifty Shades of Grey” tested positive for the Herpes virus. Very low amounts mind you and the experts say not enough to transmit the virus. But what if you have a suppressed immune system?

Anyway, support your local libraries, they do great work. Keep your cocaine away from the books though. And anyone borrowing “Fifty Shades” from the library, well you deserve what you get.


Book Review: "Heretics: Adventures with the Enemies of Science" by Will Storr

In my mind Will Storr is the brilliant love-child of Mary Roach and Louis Theroux, both of whom I adore. I think Will may have to join their lofty heights in my respectability/adoration mind shrine.

Will’s “Will Storr vs the Supernatural” was a wonderful and random find that I made several years ago. Will took it upon himself, Louis Theroux style, to get immersed in the lore and activity of the supernatural. What was different about the other supernatural books is that Will approached it from a skeptical point of view. His conclusions were  that most of what he investigated was utter bullshit, but there were a few instances that made him think. That book was much better than Mary Roach’s approach taken in her book “Spook”.

Anyway, this time Will has taken on the enemies of science. Well more like the enemies of reason. SO each chapter or two is dedicated to an interview or an activity with a fringe group or person. You start with a creationist preacher, move through to holocaust deniers and take on homeopathy. All sections are well-researched and Will approaches each instance with a sympathetic ear. That ear may not last long, but he does have the best of intentions.

All throughout Will is bringing this all back to the nature of belief and the apparent need for the human brain to make reliable sense of the world it exists in. So there is a greater message other than “Look at these dickheads” and a great attempt to try and understand human thought processes.

In it’s own way I think that this book adds it’s own to a religion vs. science argument and should be considered essential reading for anyone tackling this subject. It definitely should be as popular and as read as Dawkins’ “The God Delusion” and makes a much more logical assay of belief than Hitchens’ “God is Not Great”. It had a die-hard atheist like myself thinking as opposed to going “right on!” to every point.