Personal Blog

I recently saw a clip from the City Slickers movie about the midlife crisis. Ready to start my 30s, this was a friendly reminder about how to spend our valuable time. Here it is: Value this time in your life kids, because this is the time in your life when you still have your choices, and it goes by so quickly. When you're a teenager you think you can do anything, and you do. Your twenties are a blur. Your thirties, you raise your family, you make a little money and you think to yourself, "What happened to my twenties?" Your forties, you grow a little pot belly you grow another chin. The music starts to get too loud and one of your old girlfriends from high school becomes a grandmother. Your fifties you have a minor surgery. You'll call it a procedure, but it's a surgery. Your sixties you have a major surgery, the music is still loud but it doesn't matter because you can't hear it anyway. Seventies, you and the wife retire to Fort Lauderdale, you start...

Recently i visited Barcelona Supercomputing Center and UPC for the Computing Systems Week and the Block Review of Euroserver project. During my visit, I had the opportunity to visit the MareNostrum supercomputer. MareNostrum is a supercomputer in the Barcelona Supercomputing Center initially build in 2004. The initial setup was containing around 3564 cores based on BM 64-bit PowerPC 970MP processors running at 2.3 GHz. In November 2006 its capacity was increased due to the large demand of scientific projects. MareNostrum increased the calculation capacity until reaching 94.21 Teraflops. The system was based on 2560 JS21 blade computing nodes, based on the same processor for 10,240 CPUs in total. The machine is using Myrinet interconnect for communication. In 2013 MareNostrum upgraded and changed the CPU architecture. With the last upgrade , MareNostrum has a peak performance of 1,1 Petaflops, with 48896 Intel Sandy Bridge processors in 3056 nodes, and 84 Xeon Phi 5110P in 42 nod...

Three and half years have passed since i left Greece. Couple of months ago i decided to accept an offer in a small company ( OnApp ) that provides tools to manage virtual machines. Today i received emails regarding me pending email account deletion from my previous work ( IBM Canada and Barcelona Supercomputing Center). I felt strange. A mix of feelings, but mostly nostalgia. Although, last two years were not the best in my life, i will really miss Barcelona and Toronto. I rediscovered myself in these places. I will miss the traveling, the excitement for walking on new grounds, discovering new places and new people. I will never forget, the fear of traveling to Canada, the disappointment and the problems of searching temporary room only for three months, in north of Toronto (Markham).  And then the coming back in Barcelona. Europe with a small taste of mediterranean life. From about 10 people i was collaborating, four already are in a different company and in a different project...

When someone buys a new telescope his first question is what i can see with it. The second is what is the highest zoom i can achieve. Although the maximum zoom can be an attractive measurement when buying a new telescope, the buyer should focus on the aperture size: how much light i can gather? This is the main difference from theoretical to practical highest zoom. So, what can you expect to see with this telescope? During the tests i did, the average seeing conditions with medium-low light pollution. These two factors can really improve your experience or.. to destroy it. In my place i would categorize the light pollution in class 5, based on Bortle 's scale . I also tried to improve the lenses by blackening the edges, as i described in earlier post . A quick note here before discussing my personal views on the topic. Planets and stars have different brightness that we call it apparent magnitude . Lower the number is, brighter the stellar object is. The practical limit of...

Recently i was looking to buy a second smaller telescope, ideal for traveling. I concluded on Celestrron Travel scope 70 that has the best value for money. During my research about the quality and the characteristics of the scope, i  came up to a page that was commenting how to improve the quality of the scope . Here are some thoughts about my scope: - The quality of the tube is slightly better, but still it has some issues. - You also have some bolts inside the tube, but not  many as the travelscope. - Collimation is an issue also here. You should use a collimator to fix this. However, in my case i wanted to avoid buying anything new. - Lenses are not blackened (neither in eyepieces) Collimation without tools: Collimation is usually not an important issue in refractor telescopes compared with the reflector, but it can improve the views and the experience of star gazing. You have to disassemble the telescope without caution. Take care the lenses! The easie...