Top Ten Scientific Discoveries of the Past Ten Years

MONDAY, 13 OCTOBER 2014

1. Discovery of exoplanets

Exoplanets are planets that are not located within our solar system. Although these stellar objects were thought to exist for centuries, they had remained elusive to our detection. The first confirmed exoplanets were discovered in 1992 in orbit around pulsar PSR B1257+12. Since then, around 2000 more have been identified, sparking renewed interest in the search for extraterrestrial life. In order to support living organisms, the exoplanet needs to be in the habitable zone of a star, allowing liquid water to exist on its surface. In February 2014, development of the statistical technique ‘verification by multiplicity’ allowed NASA to identify 715 new exoplanets using the Kepler Space Telescope, four of which were in the habitable zone of their central stars.

2. Publication of the human genome

The Human Genome Project (HGP) began in 1984. Its purpose was to ‘understand the human genome’ and gain ‘knowledge of the human [which] is as necessary for the continuing progress of medicine and other health sciences as knowledge of human anatomy has been for the present state of medicine’. The project was brought into existence through the collaborations of several workshops within the US Department of Energy. In 1990, after much debate and deliberation, the $3 billion project was officially funded by the US Department of Energy and the National Institutes of Health, and was envisaged to take 15 years to complete. With the assistance of multiple other facilities around the world, the 3.3 billion base pair human genetic code was methodically broken down into chunks, amplified in bacteria and sequenced. In the project’s later stages, another privately funded quest was launched in 1998 by Celera Genomics. The firm tried to patent its findings but an announcement in 2000 by President Bill Clinton forbidding this meant that the information from both groups was freely available to all researchers. The drafts were published in 2001, with both Celera and HGP credited. In 2004 the project was completed. Now, the analysis of variations in DNA continues in order to identify the roles of these changes in disease.

3. Isolation of graphene

Graphene is a one atom-thick layer of the carbon form Graphite, and looks a little like molecular chicken wire. Unlike the graphite ‘lead’ in your pencil however, a graphene monolayer is extremely strong, light and almost transparent. It is also a very good conductor of both heat and electricity. This makes graphene extremely useful for a wide range of applications, such as flexible display screens, ethanol distillation and solar cells, to name but a few. Graphene is very difficult to produce however. Since its isolation in 2004, graphene was at one time or another one of the most expensive materials on Earth. But this has not stopped the European Union making a €1 billion grant to fund research into potential graphene applications.

4. 3D printing

Additive manufacturing or 3D printing is the creation of solid three-dimensional objects from a digital template. During this process, layer upon layer of the object is built up to give the final shape. Currently, 3D printing is commonly used for making prototype objects in the engineering industry. However, 3D printing is now spreading into the fashion world, with designers using the technique to design shoes, bikinis and dresses. Sports manufacturers Nike and New Balance are even using 3D manufacturing to custom fit their shoes.

5. Optogenetics

Optogenetics involves the use of light to selectively and precisely control neural activity. A gene coding for a light-sensitive algal protein is inserted into specific neurons in the brain. These neurons can now be activated by light, firing an electrical impulse in response. Using this technique, the activities and roles of individual neurons can be studied in real time. In 2010 optogenetics was chosen as the ‘Method of the Year’ across all fields of science by the interdisciplinary research journal Nature Methods and was also featured in “Breakthroughs of the Decade” in the scientific research journal Science.

6. Nanobatteries

Unlike traditional lithium ion (Li-ion) batteries, which are extremely limited in the amount of power that they can retain, nanobatteries store energy at the molecular scale and so are much more compact. Li-ion technology uses materials such as cobalt-oxide or manganese oxide particles that range in size between five and twenty micrometres. In contrast, nanobattery particles measure fewer than 100 nanometres (200x smaller). If a Li-ion battery is charged too quickly, the lithium moving through the electrolyte liquid causes a ‘bottleneck’ as it moves from the negative electrode to the positive. Under slow charging conditions this does not cause a problem, but it limits the rate at which batteries–for example, in your mobile phone–can be recharged. Toshiba is one of several companies currently researching nanobattery technology, announcing the development of a Li-ion battery with a nanostructured lattice at the cathode and anode that recharges eighty times faster than its Li-ion counterpart.

7. Discovery of the ‘ageing gene’

The cells in our body are constantly dividing and replacing themselves to keep us ticking over. Each time a cell divides, the chromosomes within it are replicated to pass on their genetic information. At the end of each duplicated chromosome is a telomere–a repetitive nucleotide sequence which protects the end of the chromosome. During cell replication, DNA duplication cannot continue all the way to the end of a chromosome, and so over time the telomere becomes shorter. Eventually replication becomes impossible and the cell dies. This is biological ageing and some people are more prone to it than others with their telomeres shortening faster over time. In 2010, it was discovered that the Telomerase RNA component (TERC) gene determines not only how long the telomeres are when someone is born but also how quickly they shorten. The effect of this gene is considerable in those with the variant, equivalent to between three and four years of biological ageing as measured by telomere length loss.

8. RNA interference

RNA interference (RNAi) refers to the biological mechanism by which small ribonucleic acid (RNA) molecules inhibit the expression of genes. RNAi is initiated by the introduction of short double-stranded RNA molecules into cells and can be applied to specifically inhibit genes of interest. RNAi shows promise in a number of fields - clinical trials are underway in the treatment of macular degeneration and respiratory viral infection, and RNAi research is also focusing on the reversal of liver failure and silencing of genes that promote the growth of cancer tumours. RNAi in vivo delivery to tissues still eludes science – especially to tissues deep within the body, and is currently limited to surface applications (for example, the eye and respiratory tract) where it is applied in direct contact with the tissue. For deeper applications, the RNAi must be targeted and protected from degradation. Higher levels of RNAi have been trialled to combat this, but have resulted in toxic side effects.

9. Light observed from the ‘big bang’

The ‘Big Bang’ theory is a widely accepted cosmological model for the early development of the Universe and marks its birth, which is thought to be in the region of 13.798 ± 0.037 billion years ago. Now, the £515 million Planck Space Telescope has captured a ‘map’ of light originating from the dawn of time, and reveals patterns which support the Big Bang theory. The maps were compiled over a period of 15 months by the European Space Agency, by focusing on the faint glow of microwave radiation found in space known as the Cosmic Microwave Background (CMB). Their findings suggest that the Universe contains slightly more matter than expected and a little less dark energy, the force thought to propel the expansion of the universe.

10. The large hadron collider and the discovery of the Higgs Boson

Named after Peter Higgs, an Edinburgh University physicist, the Higgs boson or ‘God’ particle is an elementary particle that was initially theorised in 1964, and its discovery was pivotal to the Standard Model of particle physics. Determining the existence of the Higgs would allow physicists to explain why some particles have mass when they should be ‘massless’ and why the ‘weak force’ has a much shorter range than the ‘electromagnetic force’. Proving the existence of the Higgs would finally allow physicists to validate the Standard Model, a quest so important that it resulted in the assembly of the Large Hadron Collider (LHC), the world’s largest and most powerful particle collider. Located in Switzerland, the 27 kilometre subterranean LHC was a collaboration of over 10,000 scientists and engineers from over 100 countries. Operated by the European Organization for Nuclear Research (otherwise known as CERN), the LHC finally enabled the discovery of the Higgs in 2013. The analysis of the by-products of high energy particle collisions has been invaluable to the discovery of new and theorised particles that would be impossible to study in other ways.