Stanley Miller, primordial soup and the origin of life

Today we celebrate the birthday of Stanley Lloyd Miller (7 March 1930 – 2 May 2007), the American chemist and biologist known for his experiments into the origin of life.

The most famous of his experiments was the so-called ‘Miller-Urey experiment’, where he and his research partner Harold Urey showed that it was possible, using simple chemical and physical processes, to create organic compounds from inorganic substances. This was considered a logical explanation of how organic life could have started on an planet made up of inorganic chemicals.

In my minds eye I've always imagined primordial soup as a rather ominous-looking pond of bubbling and steaming chemical liquid, very much like the thermal geysers at Rotorua, New Zealand. (© All Rights Reserved)
In my minds eye I’ve always imagined primordial soup as a rather ominous-looking pond of bubbling and steaming chemical liquid, very much like the thermal geysers at Rotorua, New Zealand.
(© All Rights Reserved)

The famous Miller-Urey experiment, conducted in 1952 at the University of Chicago, tried to recreate the conditions existing on the early Earth before organic life existed. The experiment combined a number of chemical compounds – water, methane, ammonia and hydrogen – sealed in an connected loop of glass tubes and flasks. The first flask, containing the chemical mix, was heated to cause evaporation, and the gas was allowed to flow into a second flask where sparks (simulating lightning) were fired between electrodes installed in the flask. The ‘electrocuted gas’ was then cooled again in a subsequent flask, and the condensed liquid was allowed to trickle back into the first flask. This cycle was continued over an extended period.

After about a day, the chemical liquid was reported to turn pink, and after about 2 weeks of operation, Miller and Urey found that some of the carbon in the system had turned into organic compounds. By this stage the mixture included amino acids, sugars, bio-molecules and hydrocarbons.

The Miller-Urey experiments showed, quite compellingly, that simple organic compounds – building blocks for proteins and other organic macromolecules – could be created from basic chemical compounds with the addition of heat and electricity.

The spontaneously created brew of life-yielding organic compounds support the ‘primordial soup’ theory first proposed by Soviet biologist Alexander Oparin in 1924. Very simply stated, the theory suggests that the early Earth’s atmosphere, exposed to various forms of energy, produced simple organic compounds, which accumulated as a ‘soup’ in various locations, and through further transformations, more complex organic polymers were formed, leading ultimately to the formation of water-based organic life forms.

Creating sparks on Static Electricity Day

Today we celebrate Static Electricity Day – a day for some serious electricity fun.

Work up some static electricity (a balloon rubbed against cloth is a great source) and use it to get your hair to stand on end. Rub your feet on a carpet and generate some sparks between you and the person next to you. Cut small pieces of paper, rub a plastic ruler on your hair, and see the paper pieces magically fly into the air as it gets attracted to the electrically charged ruler.

Making paper pieces fly - the magic of static electricity.(© All Rights Reserved)
Making paper pieces fly – the magic of static electricity.
(© All Rights Reserved)

So how does it work? As two surfaces rub against each other, electrons are exchanged, moving from one surface to the other. The resultant mismatch of electrons means that the one object will have a negative charge, while the other will be positively charged. Doing this repeatedly (e.g. rapidly rubbing feet on a carpet, or a balloon on a cloth) can result in the build-up of a fairly large charge. If you have a significant positive or negative charge in your body, and you touch a metal object, the static electricity is rapidly discharged, creating a tingle, or even a small spark.

Of course static electricity is not all about fun and games. In industry, positive and negative charges are useful in applications such as spray painting and dust removal. Printers also use static electrical charges to attract ink or toner to paper.

Some of the most impressive, and dangerous, examples of static electricity in everyday life occur during an electrical storm, when huge electrical charges lead to the development of lightning – instant discharges of many thousands of volts – definitely not something to play with.

Here’s hoping you’ll have a great, positively charged Static Electricity Day – go on, create some sparks!