The Breakthroughs of the year

2009 is coming to its end... and it is time to review the most important scientific contributions of the year.
For this reason the magazine Science has published a special issue with the top 10 breakthroughs of the year (according to Science). And the winners are...

1.- Ardipithecus ramidus. Ardi was an Ethiopian woman, 1.20 m tall... and who lived 4,4 million years ago! It is the most ancient hominid fossil ever found.
2.- Pulsars. Gamma rays Fermi NASA telescope has allowed to detect pulsars. The telescope was put in orbit in 2008, and providing a measurement that was a proof of the relativity theory has been its most important success so far.
3.- ABA receptors. Major advances in the knowledge of the structure of the drought hormone have been achieved during 2009.
4.- Monopoles. Two research group have achieved magnetic pertubations of monopoles from spin ices.
5.- Rapamycin. Rapamycin (a medicine used to prevent transplant rejection) can prolong mammal's life. The experiment was carried out in rats, that prolong their lives between 9% and 14%.
6.- Water in the moon. NASA announced on the 13th November that the Lcross spacecraft sensors had detected water vapour and ice in the moon.
7.- Genetic therapy. Advances in genetic therapy to treat blindness.
8.- Graphene. Latest research about the graphene properties has revealed that this material could replace silicon in chips.
9.- Hubble repair. Hubble repair mission prolonged its life and improved some features.
10.- X-ray laser. Since we reported in a post some months ago, SLAC laboratory started running the first X-ray laser.

And what is the most important discovery for you? Fill in the survey you can find on your right!

Also, you can also find a really interesting and comprehensive podcast about the 10 most popular stories of Science in 2009 (the transcript can be downloaded here).

PHD Comics: Laser in Use!

Dont worry. There are real lasers in our optic labs ;).
(click on the picture to enlarge it)

If you want to know how graduate students are living or how life in the lab really is then visit:

"Piled Higher and Deeper - Life (or the lack thereof) in Academia".

PHD Comics

A comic strip by Jorge Cham. In general every 2. or 3. day there is a new phd comic strip online and he hits absolutly the situation :)! Click here if you want to go directly to his most popular 200 comic strips! Enjoy!

p.s. have a visit in our optic labs!

Refractive Index Database

Who dont know this problem: you need something urgent but you have to spend two hours until you have found it. In optics, knowing the refractive index of a material at a certain wavelength could be such a problem. The long solution is to search a book or a paper which helps you to calculate the refractive index, the short solution...

...is going to RefractiveIndex.INFO



created and maintained by Mikhail Polyanskiy. The Database is very extensive and includes:

Crystals/ Metals/ Liquids/ Gases/ Glasses/ Optical Glasses/ Plastics/ Liquid Crystals and even Metamaterials.

Simple choose the material and enter the desired wavelength. But you can do more as only calculating the refractive index. You can choose too from the optical property caculator things like:

reflection coefficient/ Abbe number/ Brewster´s angle/ critical angle or chromatic dispersion.

Simple things, but it save a lot of time. Enjoy!

Modelling an artificial eye with a CCD camera: see how they see!

In September I attended the "IX Reunión Nacional de Óptica" (Spanish National Optics Meeting); one of the posters presented there by the Optics Group from Zaragoza (J. Ares, V. Collados, J. Arines and A. Sánchez-Cano) was "Adiestramiento de la refracción subjetiva con ojos simulados mediante cámaras web". In this communication, the authors reported a system based on a CCD camera to simulate an artificial eye that is used to teach optics and optometry.

Let's start by explaining how the eye works.

Figure 1: Scheme of the eye

In the image an schematic view of an eye is represented; in a very simple model, we can consider the eye as a system formed by a refractive surface, the cornea, and the lens. In a normal eye, the light is focused at the fovea and the image is well-defined. When a person suffers from myopia, light is focused before the fovea; when a person suffers from long-sight, image is formed after the fovea.

Now, how can it be modelled with a web camera? Well, basically the webcam is a CCD sensor with a lens. If we replace this lens by a 35mm focal length lens (typical value for a human eye) and a diaphragm (which will act as a pupil), we can build an artificial eye.

Once, the webcam is ready you can try how people see. Ask for example for a pair of glasses and place them immediately before the webcam. If the person who has lent you the glasses suffers from myopia, you will see a blurred image: this is how this person sees without glasses (or better said, the opposite to the way this person sees: it corresponds to the vision of a long-sighted person with the same gradation):

Figure 2: Pictures from the first row represent a near-sighted eye without (left) and with (right) glasses to correct the myopia. The second row corresponds to a normal eye (ie., the webcam) without (left) and with (right) the same lenses as used in the previous case.