Inspiring, Photonic Crystals

Entertaining double slit experiment

“My personality is who I am, but my attitude depends on how you treat me”

Recently you might have heard a lot about light, wave, matter, particle and more scary stuff like quantum mechanics, thanks to Nobel Prize for Boson guys. You might thought it’s too crazy stuff, only few people can understand. But we can see this crazy stuff in front of our eyes very easily. I will share with you today one of the most important things in quantum mechanics, that is wave nature of light. Light is a wave as well a particle at the same time. But depending on our experiment we find it as either a particle or a wave, but not both states at a time like the above quote. I want to share with you a double slit experiment in which we find light behaving as a wave. Often times you see only a boring graph or simulated video of double slit experiment, but how in real life we can see the double slit experiment.  I do not want to waste your time, so watch this entertaining video. If you don’t have time, just watch it for less than a minute part between 4.20 – 5.00 minutes in you tube.

(This guy is crazy he has amazing videos on science, they really blow your mind)

Why did this I posted, because something interesting will follow this. That later post will explain the beauty of butterflies.


Raspberry Pi Robot in action

In this post I would like to share few pics and video of the RC car modified Robot.  For the time being I am controlling only forward and backward motion of the Robot. Although I connected the Left/Right  steering motor to the Pi, I did not shoot the video of that control. We can give intelligence to the Robot by connecting sensors such as Ultrasonic, IR.  I will do that later, if time permits. I also wish to shoot a better video in future!SP_A0024




How the Robot turns away?

If there is no object in its way, both the motors of the Robot will rotate in forward direction, so that the Robot body moves in the forward direction. If the Robot is obstructed, then the ultrasonic sensor detects that obstructing object and sends a signal to the brain of the Robot (*Arduino in my case). Then  Arduino stops one of the motor and makes it spin in the backward direction. Now one motor is spinning forward and another motor is spinning backward, therefore there will be a Rotational force on the body of the Robot. That force rotates the Robot through the axis of the third wheel (an omnidirectional caster wheel). We can see this total rotation of vehicle body in daily life,  when one of the wheel is stopped and  another wheel is still spinning. In the case of this Robot, to increase the effect, we not only stopped one of the wheel but we made it spin in the other way, so that we have more rotational force on the Robot. I am trying to improve the Robot’s strategy of moving away from the obstructing objects. I will post the updated video soon.

*Arduino is a micro controller, you can think of it as a mini-computer, that can be programmed very easily.


Nobel prize in Physics 2013

Today the Nobel prize for Physics 2013 was awarded jointly to François Englert and Peter W. Higgs. You might remember Higgs…yeah that Higgs Boson or God* particle guy. So the prize is awarded for their theoretical discovery  that explains how mass is originated. They proposed for the first time in 1964 that a Boson (later called as Higgs Boson) was responsible for the mass of the particles inside the atom. Those sub-atomic particles indeed give the mass to atoms, and after that you know how to build the story. Atoms give mass to everything we know, you, me and all the objects around us. Therefore it was very important in the first place to understand how the mass enters in and around us. This is a very fundamental question, since Englert and Higgs answered it for us; they were awarded the greatest prize of Physics. Don’t forget though the contribution of CERN’s Large Hadron Collider (LHC) that generated all the interest of common people around this God* particle by confirming the existence of Higgs Boson on 14th March 2013.

I listed below some interesting facts about Higgs Boson

1) Higgs boson is the missing piece in the puzzle of standard model to prove that standard model indeed correct.

2) Why standard model is important? Although there are many other theories to explain the origin of world around us, standard model is widely accepted theory but it is also incomplete and, in fact, internally inconsistent.

3) According to standard model theory, the Higgs particle is a Boson with no spin no electric and colour charge. It is very unstable and it decays in to other sub-atomic particles immediately.

4) LHC not yet confirmed all the properties of Higgs Boson that were predicted by standard model, but it confirmed the most important properties such as + parity and zero spin.

5) What’s the impact of this discovery?

Good question, world will not change just relax. We cannot predict the impact of fundamental discoveries immediately. When quantum mechanics was proposed even their discoverers described it as an “interesting laboratory experiment” with “no useful purpose” whatsoever. But now we have its applications in computers, mobiles, satnav and many others.

6) At least any immediate side benefits?

You know World Wide Web was created by physicists working in global collaborations on particle experiments at CERN to share their results, and the results of massive amounts of data produced by the LHC

Similarly cloud computing was created by them as it was difficult to analyse 300 trillions of proton–proton collisions that amount to 25 petabytes (1000 petabytes)  of data per year as at 2012.  Now we all use www and some cloud computing service.

So keep your fingers crossed and wait for new discoveries out of Higgs Boson. First congratulate our Nobel Prize winners Englert and Higgs and remember remaining four physicists who contributed to the theory and many others who worked on alternative models. Every small contribution counts in science.

*Finally don’t call Higgs Boson as God particle. It is nothing to do with God. It is a name given by media.


The six authors of the 1964 PRL papers, who received the 2010 J. J. Sakurai Prize for their work. From left to right: Kibble, Guralnik, Hagen, Englert, Brout. Right: Higgs.

(Most parts of the information for this post is collected from Wikipedia)


Robot in action

In the below video we can see the object avoiding Robot and how it is changing its direction either by sensing my hand or the walls in its way. The principle behind this object avoiding robot is very simple. Notice the ultrasonic sensor, which look like eyes at the front of the robot.  You might know about ultrasonic diagnosis. We use a similar principle here. One of the eyes is an ultrasonic source that shoots an ultrasonic pulse, in simple words a sound wave. If this sound wave hits any object in its way like my hand or the wall, it gets reflected. Then the second eye listens to this reflected echo of the sound wave. If there is no object in the vicinity of the sound wave we sent, nothing comes back to the second eye. I will explain in the next post how the Robot is able to change its direction after detecting an object in its way.

PS: Sorry for the shaking of video. It shows my video editing inexperience.

PPS: Please give your feedback.


Robot work in progress

Picture 27 Picture 28 Picture 29 Picture 32

I am building an object avoiding robot with the magician chassis, adafruits motor driver shield, and an ultrasonic detector. Every thing is set up as you can see in the video and pics. I need to sort out the apt power source. Current six cell battery pack is not able to drive the robot.