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Sunday, July 28, 2013

3D printing


Although 3D printing has been around for quite a long time it is now becoming a buzzword the social networking sites and Internet are abuzz of stuff being 3D printed. Here is an example of what 3D printing can lead to.


The video above shows a 3D printed prefabricated house ,we can print mementos,sculptures ,plates ,dishes using a 3D printer.

There are 3D printers that are being developed that are printing metal objects so we will have some or many of our kitchen utensils made out of 3d printers.

The real exiting stuff about 3d printing is that scientists are now planning to make human tissue cells out of 3d printers and NASA  is now embarking on a project to 3D print food for astronauts in space and make the technology cost effective enough to 3D print food for people where there is scarcity of food. If successful this will change the way we live imagine having a 3D printer where as raw materials you put in the basic ingredients put the choice of your dish and  the flavour ,calorie content and nutritional value  and the 3D printer will print the dish as per order .

The advantages of 3D printing will be many fold first of all people would be able to print out whatever they want at their homes rather that  go shopping for that product. In time 3D printers will get cheaper and will be affordable to more and more people.

One can visit Youtube and see videos of various kinds of 3D printing done there are people who want to 3d print homes also  shoes are being 3d printed.

3D printing is process in which a computer model of a desired object is printed layer by layer in many cases the raw materials is plastic or fine steel powder.

This is one technology about which we will hear and see more and more as time rolls on and it is very much possible that it may have a considerable impact in the way we live and do things.
Do check the video below.

3D printing metallic objects

      

     

Wednesday, July 17, 2013

Visual Perception

    There are events in nature that are very fast ,there are events that are very slow while there are others that can be perceived as neither too fast or too slow what we call in common terms normal pace.


         While we have 5 senses to perceive things and events around us viz. touch, see,hear,taste and smell there is also one more sense known as the sixth sense that let us know things that may happen it is used highly but in scientific terms very little is known about it. However this post will focus on visual perception.


         For our eye to see some event in continuous motion on a video screen it has to have at least 24 frames displayed one after another at continuous time intervals ,now there are events that are too fast to see like in sports a ball hitting a bat or what happens when a boxer lands a punch on his opponents face. With the help of high speed cameras this problem is solved however the term high speed may confuse people. Actually High Speed cameras are nothing but cameras that can record a very high number of frames per second in order of 2000 fps. Once this recording is done the video can be played back at normal 24 fps thus a one second video would now be played in 83.33 seconds so an event that occurred at 1/100th of a second can be seen easily and this has lead to many new findings in the field of sport.


        In cricket it can be seen that when a ball hits the bat at high velocity the bat moves at the point of impact for a very short span of time this fact was totally unknown to everyone before the advent of high speed cameras. In the same sport there was a rule that if at the point of delivery a bowler's hand straightens  by a certain angle that particular delivery would be considered illegal and the bowler would be warned for chucking. It was 5 degrees for spinners,10 degrees for medium pacers and 15 degrees for fast bowlers. When biomechanics study was done with the help of modern high speed cameras it was found that almost every bowler subconsciously ends up straightening  his arm at the point of delivery there was a famous chucking incident involving ace Sri Lankan spinner Muttaiah Muralidharan where he was called by the umpire for chucking. Thankfully his team-mates,his captain  and board backed him and when video analysis were done on all bowlers it showed that Murali straightened the arm as much as other bowlers did although at normal pace the videos tell a different story even a bowler with copybook action like Glenn McGrath was found to be straightening his arm by more than 15 degrees at times. Had it not been for high speed cameras the racist umpire could have ended up ending Murali's carrear right there and after that Muralidharan went on to become a great bowler picking up 800 wickets in his entire carrear.


          Also high speed cameras are used to by various authorities to ascertain whether a person is speaking the truth or not while questioning him/her taking the high speed images of their subconscious facial reactions and then watching it at normal speed.


          Now talking about events that are slow in nature like the growth of a tree in that case a normal camera may be used and programmed and installed in such a way that it would take 1 photograph an hour and stay in the very same position focused on a plant now after a certain point of time when the plant has grown to a certain extent the images and then taken and played at normal 24 fps the view of the video one would get is that as if he is able to see the plant grow slowly in a matter of minutes. Such cameras are also installed at construction site the rate of taking photographs maybe varied as per necessity but again when the video is played one can see how the construction of a building or stadium is done in a matter of minutes without any focus on unnecessary parts.

Rakesh

Wednesday, July 3, 2013

GNU (GNU is Not Unix)


       As the title of these blog suggests the full form of GNU is GNU is Not Unix.The father of Free Software Movement Richard Stallman started the Free Software Foundation in 1983. There is an interesting description he gives as to why he started the Free Software Foundation , while working at MIT's Artificial Intelligence Laboratory in the 1970s he says they lived in an Free Software Enviroment there were lots of operating systems and other software with source codes available alongwith freedom to modify and distribute them in the community  but by the 1980s things changed and free software kept disappearing and the enviroment changed to more of proprietry software which Stallman felt was ugly , morally ugly.

           So Richard Stallman started the Free Software Foundation in 1983 with a goal to make it possible to use software and have freedom. For that to be practicle they needed an Operating System that was Free the only free OS at that time was PDP 10 which was obsolete in 1980s and so was many of the software that they had previously written.

         So they decided to build an operating system that was UNIX like and was totally FREE. For this the GNU project was started to build the GNU operating system.The following question was asked to Richard Stallman regarding the journey of  building the GNU OS (it is followed by the detailed answer given by RMS)

What was the journey to develop GNU/Linux like?
We had to start from a point that was just a little more than zero, and work our way up to freedom. There were a few free programs in 1983 when I started GNU, but those were in no way near a whole OS. There was a lot of work to do, and during the 1980s, we did it. There are hundreds of components that you need to have a UNIX-like OS, even at the most basic level. A few components we found with somebody else, who wrote them for different reasons, but were free software. But the other components we had to develop.
So I wrote some of them, and recruited people to write others, and in some cases, convinced people to develop free programs — for instance, the CSRG (Computer Systems Research Group) at Berkeley. They had written a lot of code to change UNIX, but their code was mixed in AT&T’s code, and so was proprietary. I met them in 1984 and requested them to separate their software and release it as free, which they subsequently did. I wanted to use that code in the GNU system.
By 1992, we had almost the complete GNU system, but one essential component was missing: the kernel. We started developing one in 1990. I chose an advanced design, which gave it somewhat the character of a research project, and it took six years to get a test version. Unfortunately, nobody succeeds every time. But we didn’t have to wait, because in February 1992, Linus Torvalds, who had a proprietary kernel called Linux, decided to make it free. The combination of the Linux kernel with the rest of the GNU system made a complete OS, which was basically GNU, but also contained Linux. So calling it only the Linux OS is wrong; it is the GNU/Linux OS.
 So you see what we call today LINUX  is actually GNU+LINUX it should be described as GNU/LINUX people are of the misconception that it was LINUS Trovalds who started it off Linus provided the Kernel to the GNU project and and GNU/LINUX  came into existence being free is was constantly developed and improved upon  to our present day Fedora,Debian,Android,Ubuntu,Mint and thousands of other distributions of GNU/LINUX .           
          

Monday, July 1, 2013

Solar Power very soon


       In the last few years the price of solar panels has come down drastically at the same time the price of coal and petroleum has shot up even natural gas prices are high and in the coming years they may get even more expensive since petroleum is a limited natural resource non recycle able. As in the previous blog I pointed out whether its wood,coal or petroleum all the sources of energy that we use has come from the energy of the sun so why not tap the original source of energy directly. It has been many decades since solar cells have come into existence these solar cells were till recently very expensive but now the prices have come down to an extent that it is cheaper to have electricity from solar panels than diesel electric generators not only that as the production increases and production processes improve along with improved technology the solar panels will not only be even cheaper but also will be more efficient than the ones today.

There are still huge number of people in developing countries who are devoid of electricity even if electricity is there the quality of electricity is very poor. Solar panels and inverters will end this problem since harnessing solar electricity won't entail laying of power cables all one needs is a solar panel and an inverter to avail the benefits of solar electricity. With solar electricity a certain amount of transmission quality will always be guaranteed. In a country like India which is blessed with lots of sunlight for the entire year where a large section of the population has access to a very bad quality of electricity or no electricity at all this would be a blessing.

The present solar power prices in India are between Rs 7.90 to Rs 10 which are likely to come down to Rs 5-7 in the coming years same as gird electricity charges and just at that point there would be an avalanche of people converting to solar electricity , the world would be vastly benefited from solar energy since it would save millions of tonnes of unrecycleable and pollution producing coal. Solar energy would cause no pollution at all its totally green electricity there is lot of research that is being done in producing cars that runs on electricity those electric cars would be fed by the power generated by solar cells. India has to import hundreds and thousands of tonnes of coal and petroleum this bills would come down with solar power. Also being green the atmosphere of the cities would be much less polluted thus our cities would be far more live able than today should every car , every truck be run totally or partially from electricity harnessed from the sun.

Lets hope the sun be the everlasting solution to our never ending energy problems.