Incidentally...

... since I've just mentioned Science in School, I guess there is no harm in a little publicity to this magazine I've been collaborating with for almost three years now - mostly translating into Italian, and finally with my first writing effort. ever. (despite the delay...)


It's a great tool for secondary school science teachers and students, with feature articles about the latest discoveries in every scientific field, bios and profiles of scientists and teachers, ideas for didactic activities, and much more...

If you subscribe on their website, you can receive a printed copy of the magazine in English for free. Otherwise, many translations in several European (and non) languages are available online, courtesy of many volunteers and enthusiasts - just like me!

Interview on Science in School

Finally, after a gestation longer than a year, my interview to Alessandro has finally been published on Science in School!
Here is an excerpt from it:

A star-struck teacher in Italy

Research offers exciting and challenging job opportunities, but sometimes the price to pay in terms of personal sacrifice is very high. CM interviews a young astronomer who found satisfaction in the classroom – teaching mathematics.

Astronomy has always been Alessandro Berton’s greatest passion: after his undergraduate studies at the University of Padua, Italy, he moved to the Max Planck Institute for Astronomy in Heidelberg, Germany, for his PhD. His research focused on the development of new, cutting-edge techniques to detect extrasolar planets. The quest for planets outside our solar system has been one of the most fascinating topics in astronomy for the past 15 years, and Alessandro was thrilled to be a part of it. Yet something was missing.

“During those years, I always felt the lack of social, human interaction – a lack that is typical of many research environments,” he explains. “I longed for a job where I could spend more time with other people than in front of my computer screen.” Hence, a few months after receiving his PhD, Alessandro enrolled in the Italian high-school teacher-training program, and at the same time he began to teach mathematics to his very first students.

[...]

Read the full text on the website of Science in School.

I'm finally on my way to becoming a science & society opinion writer... or, well, whatever. yay!

Physics: the Nobel seizes the light

The prize goes to Willard Boyle and George Smith, fathers of digital photography

On Tuesday, October 6th, the Nobel Prize in Physics 2009 has been awarded to Willard S. Boyle and George E. Smith, the fathers of digital photography. In 1969, the two scientists from Bell Laboratories, in New Jersey, USA, invented a device able to capture light without using photographic film — the so-called CCD (Charge-Coupled Device).

The technology behind the CCD exploits the photoelectric effect, through which light is transformed into an electric signal. The explanation of the photoelectric effect won Albert Einstein the Nobel Prize in 1921. Boyle and Smith faced the challenge of converting this effect into a practical application, and designed a sensor able to catch light at several different points (called pixels) and to transform it, over an extremely short time lapse, into electric signals to then be transported and reproduced on a monitor or stored in a file.


The CCD has revolutionised photography and our approach to it for ever, as it is the very heart of tens of millions digital cameras produced in the world, including those integrated into many mobile phones and other gadgets. However, digital photography meant an even more remarkable revolution for science, and for astronomy in particular, a field which literally lives off the images of the sky.

All current professional telescopes are in fact equipped with digital sensors, vastly more sensitive than the old photographic plates astronomers made use of until only a few decades ago. Furthermore, CCDs can be used again many times and their output signal, being already in digital form, is ready to be stored and analysed by computers. In fact, without this new technology, it wouldn’t have been possible even to conceive the massive catalogues containing detailed information about hundred of millions of far-away galaxies, which allowed astronomers to understand the properties of the Universe better and better.

Boyle and Smith shared the most prestigious of all scientific awards with physicist Charles K. Kao, for his work concerning the transmission of light signals through optical fibres. Optical fibres, just like the CCD, also contributed to the digital revolution, making the sharing of data and information possible over increasingly short time intervals. Without them, the internet as we know it could not exist.

It is interesting to note how, during the International Year of Astronomy 2009, the Nobel Prize in Physics has been awarded to three scientist whose research focussed on light and has contributed to the production of vital tools for astronomers, professionals and amateurs alike.

Image credit: NASA

Translated from Il Denaro, 08.10.2009

Dr.Rer.Nat.

Planck and the Cosmic Microwave Background

The European Planck surveyor satellite will map the entire sky at microwave wavelengths - why is this important? Scientist will be able to scrutinize models which explain the formation of galaxies by measuring fluctuations in the distribution of dark matter, only a mere 300 000 years after the big bang. These fluctuations manifest themselves as small variations of the mean sky temperature of 3 degrees Kelvin and have been generated when the first atoms were formed in cosmic history. From these seed fluctuations larger and larger objects were assembled by gravity which finally resulted in the formation of galaxies and clusters of galaxies. Important cosmological parameters are the amplitude of these seed fluctuations and the mean density of matter, which Planck will be able to measure.


A large part of the scientific programme is devoted to so-called secondary anisotropies: these are fluctuations of the sky temperature which are generated by the interaction of photons of the microwave background with the large-scale distribution of galaxies. There are basically two categories of interactions: gravitational lensing, which can be used for precision measurements of cosmological parameters, and Compton-interactions with electrons of the hot gas inside clusters of galaxies - a potential new powerful way of detecting clusters of galaxies.

Planck's advantage over previous experiments is its high sensitivity and angular resolution: it can measure fluctuations of a few microKelvin, and its angular resolution is better than a tenth of a degree. The survey will be carried out from the Lagrange-point L2, at roughly 1.5 million kilometers from Earth - 5 times the mean Earth-Moon distance. The science team of Planck comprises about 500 scientists who are anxious to see the satellite launched on 14 May 2009, after 15 years of preparation.

Written by Bjoern Malte Schaefer
Appeared in the Italian translation on Il Denaro, 14.05.2009

Image: map of the microwave sky as observed by NASA's satellite WMAP, launched in 2001. Different colours represent the tiny fluctuations in temperature: the difference between red and blue spots is only 0.0002 degrees. Planck's maps will be even more precise than that. Credits: NASA/WMAP team.

A high for geeks

Ok, these days all the astronomers and astrophysicists I know - and, with me being a geek, this is a substantial fraction of the people I know and hang out with - have been overly excited with the launch of Planck and Herschel, the two satellites I mentioned in the previous post.

Will they launch them?
When?
Why is the launch being constantly delayed later and later?
Will they be launched eventually?
Today?
Tomorrow?
In two weeks?

Please, shoot the freaking rocket!
And indeed, they did. :-)


And, although I would have never expected neither me nor some of my friends exhibit a similar reaction, we were in fact all somehow high, and strangely happy for the two big thermometers finally flying in the sky.

They say Planck is super-cool.
The coolest thing in the universe.
Literally.
Well, almost.
Well, only for a year.

Well, whatever. Once a geek, always a geek.

In the previous post, I promised to write more about Planck and what it's going to probe, the CMB. Which is great, and cool, yay! However, I'm also *pretty* busy with something else, just this little thing, you know... my phd defense... so sorry, Planck high or not, I'm clearly busy. Busy freaking out.

But don't despair! I delegated the explanation of the mysteries of the universe that will be unravelled by Planck to my friend and colleague Bjoern, who happens to be a much more respected authority than myself, mainly about everything, and in the specific case, about the CMB, of course --> see next post.

Image: abridged from Andy Riley, The Book of Bunny Suicides.
Credits: well, my friends :-)

Disclaimer: the US flag is not supposed to be there!!! Planck is not a US mission, but mostly European (ESA)!!!

We decline responsabilities.
It's a poetic licence.
Please, forgive us.
Turns out, we're not that geek, after all.

surprise surprise!

as this picture shows, the (visible) light that we see with our own eyes is just a teeny tiny portion of what is called the electromagnetic spectrum:

the picture actually comes from a t-shirt (but if you happen to land on that page, please do not read any of the comments, they're all wrong!!!) but the designer borrowed the idea from a science book, so it's pretty useful. look at the names above: don't they evoke any memories?? gamma rays, x-rays, ultra-violet, infra-red, microwave, radio... although we might relate different real-life concepts to each of them, they are basically the same thing: radiation, light, just like the one we see with our very own eyes. just, with different, very different energy, the gamma rays being the most energetic, and down all the way to the radio.

astronomical objects, such as stars, galaxies and other stuff, emit all these sorts of radiation, from gamma to radio. fortunately for us, the earth's atmosphere absorbs most of them (because they would be dangerous or even lethal to living creatures), that means that from earth we can only observe in the visible and in the radio band. yes, they are also referred as spectral bands.

but if we shoot a nice (and super expensive) satellite up into the skies, so that it orbits the earth, then we can observe in the whole spectrum, and gain a lot more information about all sorts of astronomical sources and the physical processes happening there. that's why Planck and Herschel will be launched soon (check prev post) and many other satellites are already up there doing this job.

********

beware: recently i'm reading over and over people writing that waves in other bands besides the visible are sound waves. like that we could listen to the sound of the stars. SO NOT TRUE. sound waves are one thing, electromagnetic waves (ie. light) are a totally different thing. maybe it's the "radio" word that creates confusion. maybe the word "frequency". whatever. the only difference between radio and visible and gamma rays is THEIR ENERGY!!!

don't know if i managed to be clear enough. maybe not. i'd need to get started with an intro to waves. and if you happened to be on this blog, you probably already know.

anyway: don't listen to stars - or to whatever other weird ideas crazy people have!!!

Image credits: Threadless - www.threadless.com

so cute!

ok, i'm not usually this cheesy, but i really find this photo so cute!

it shows the satellite Herschel reflected in the mirror of the satellite Planck, which will (hopefully!) be launched next week, sharing the same rocket. that's why i actually found the picture totally sweet!

Herschel will observe the sky in the infrared, whereas Planck will scan it in the microwave, focussing on the CMB (cosmic microwave background), ie. the relic signature coming from the big bang.

ok, maybe it's a bit confusing... if infrared and microwave don't tell you much, check the next post for clarification. and check this blog soon for more about the CMB and Planck...

Image credits: ESA

the unbearable expansion of the universe

i just realised it's exactly 80 years now that Hubble found out we live in an expanding universe. yes, the galaxies all move away from each other, just like the points in this cute vintage photo do, as space itself is expanding. but i don't know how widely known this fact actually is. sometimes people ask me "since you're an astronomer, tell me, do you believe in the big bang theory??" like if it was a choice to believe in it or not! hell yes, this is my answer! true, it was a controversial topic, but those were... the 60's!! i mean, i reckon it IS a theory, and science wouldn't go on if theories weren't to be proven wrong from time to time, but up to now, with the experimental data collected so far, there is no other competing explanation at all. sure, the expansion is probably accelerating, and whatever is driving the acceleration, we almost know anything about that. true. but the expansion is a fact. people, deal with it!!!

Image credits: Life Magazine

developing astronomy globally

one of the key ideas of the International Year of Astronomy is to point out the contribution of astronomy to development.

in this context, it has just been announced that there will be grants available for projects related to the development of astronomy all over the world, especially in those regions that do not already have strong astronomical communities.

i thought it's an interesting opportunity, although i have no particular idea in mind and i have no experience whatsoever in planning such a project. so i thought i'd advertise it, at least...

the grants amount to 1,000 euro each, and the call for proposals can be found at the following address:

www.developingastronomy.org

Deadline: April 3rd, 2009
Watch out: deadline is next week!!!!

Note that, although this funding is aimed specifically at "developing countries", exceptions with appropriate motivation will be accepted - the main concern simply being who the beneficiaries would be.

Into the clouds where stars are born

Looking at the sky in the daytime, weather permitting, it is possible to see the Sun, the star which provides us with light and heat, thus making life on Earth possible. Looking at the sky during the night, one can see millions of stars: the firmament is abundant in large and small suns, located here and there in our galaxy, the Milky Way. Looking further away, with the aid of a binocular or a telescope, it is possible to perceive other galaxies, each of them containing from tens of millions to hundreds of billions of stars. Stars, stars, and even more stars. Where do all these stars come from? How did they form? They all derive from a mixture of gas and dust, known as interstellar medium, which is another important component of galaxies. The interstellar medium is rather homogeneous, but regions occur where the gas is particularly dense: it is exactly in these clouds, or nebulae, that stars are born.

When the gas within a nebula is so dense that its pressure cannot balance its own weight, the so-called gravitational collapse begins: the cloud starts breaking down into small fragments, which keep contracting and become rotating spheres of gas, increasingly denser and hotter. Collapse continues for a long time (up to a million years), until the temperature achieved within each “sphere” is so high that nuclear reactions set it, turning hydrogen into helium and producing energy: the gas “sphere” has now become a star. From the collapse of a single nebula, hundreds to thousands of stars with different masses are formed: the most massive ones will only live a few million years, whereas the smallest ones will go on burning for billions, even hundred billions of years.

This image of the Eagle Nebula is an example of a “stellar nursery”: the elongated structures visible in the centre are huge pillars of gas and dust, larger than our own Solar System, where stars are born. The bluish light permeating the central regions of the nebula comes from the first, young stars which formed: with their energy, they heat up the surrounding gas, thus making the formation of new stars even more likely. This image, obtained with the telescope on Kitt Peak in Arizona, USA, has an extremely high resolution, which allows to study star formation in detail; however, the Eagle Nebula can be observed even with a binocular, in the constellation of the Serpent, visible from Europe from May to September. New stars are formed all the time: in order to see them, we only need to lift our eyes up to the sky.

In the image, the Eagle Nebula, an open window onto the processes of star formation. Credits: T. A. Rector & B. A. Wolpa, NOAO, AURA.

Translated from Il Denaro, 12.02.2009

In search of the ideal site for astronomy

or: why is it convenient to build observatories on a volcanic island or a desertic plateau?

One fifth of the world population can no longer enjoy the sight of the night sky with the naked eye: close to urban and industrial areas, light pollution allows one to see only a few stars. It is a well known fact: anyone can perceive it, whenever looking up to the sky. If asked “which is the ideal site for astronomy?”, many would answer “far away from big cities.” Right, but not enough. Because escaping from light pollution is not the only problem to handle, in this case.

The key instrument in astronomy is the telescope. As the name itself says, its purpose is to look at objects which are located far away. In order to observe distant stars and galaxies, a telescope has to catch as much light as possible: this means that very large mirrors (currently with diameters of order 10 m, but up to 100 m for future generations) and very long exposure times are needed to achieve a good image. Unfortunately, before reaching the telescope, the light rays coming from stars and galaxies have to pass through the atmosphere of the Earth. Here, the cosmic light interacts with the turbulent atmosphere, thus losing track of much information about the objects (stars or galaxies) it comes from.

The atmosphere is not static nor homogeneous, but extremely turbulent. At every instant, a star or galaxy produces a slightly different image, according to the varying characteristics of the portion of atmosphere overlooking the telescope. A long exposure, needed to capture as much light as possible, is a superposition of the individual images obtained in several, consecutive instants. Because of atmospheric turbulence, the image resulting from such a superposition is blurred: this phenomenon is referred to as seeing.

It goes without saying that modern astronomy needs accurate and precise images, and the limiting effects due to the atmosphere have to be taken under control. Hence, in the last decades telescopes are being built in dry regions, preferably at high altitude, close to oceans or deserts, so that the surrounding air temperature is as constant as possible and the turbulence minimal. This is the reason why the ideal sites to build cutting-edge astronomical observatories are volcanic islands, such as Hawaii or the Canary Islands, and desertic plateaux, such as the Atacama desert in Chile.

An even more radical solution to remove the effect of seeing is a telescope orbiting around the Earth, outside of the atmosphere: though rather expensive, this formula has already been pioneered with the Hubble Space Telescope, and is the subject of several projects for the upcoming future.

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The photo, taken by Bobb Tubbs, shows the European telescopes in La Palma, on the Canary Islands: at an altitude of over 2,400 m, the observatory is higher than the clouds and the seeing is one of the best in the world.

Translated from Il Denaro, 22.01.2009

happy year of astronomy!

well, this blog didn't turn out to be a great success, i didn't really write a lot and stuff... lack of time, lack of ideas. whatever. the science magazine exercise idea was probably too ambitious, time-demanding, whatever...
but this year's the international year of astronomy, so i'll try to blog more, at least about astro stuff...

and if you want to celebrate the year of astronomy, visit www.astronomy2009.org and enjoy it :)