The Big Bang Theory

Robot implementing Rear Wheel Drive

2010-01-23T01:36:00.000-08:00

After a long break, I'm finally getting some time to write about my new robot(not named yet).
After making a couple of differential-type bots, I decided to switch over to a car-type bot which would implement A Strearing mechanism similar to the one in real Automobile. Here's the robot I've made.

There are several Streaing mechanisms like Rack and Pinion, Recirculating ball, Worm and Sector out of which I chose the Rack and Pinion. The building materials were:

1. A base
2. A Rack and a suitable Pinion which exactly meshes with the rack.
3. DC motors ( I've used two)
4. Wheels
5. Other building material like metal strips, bolts, nuts, axles etc.
6. Gears (I will deal with them later)

First design: (Without Differentials)

1. My first design was similar to one seen in the above image except for the use of gears. Instead , I used a single axle driven by belt drive and wheels connected to both ends.
(Unfortunately, I don't have an image of my old design)

2. Here's the schematic representation:

3. However, it possesed a serious drowback. Since the rear wheels are connected to the ends of a same axle, they are forced to move at a same speed. But each wheel of a car travels different distances while turning and the inside wheels travel a shorter distance than the outside wheels. Since Speed= Distance / Time, hence the wheels that travel shorter distance should travel with lower speed. Therefore, the inside wheels travel with a lower speed than the outside wheels.

4. Since the front wheels of my car are not driven by the motor, they stand out of this scene and can easily rotate at different speeds.

5. However, the rear wheels are forced to spin at the same speed (since connected to the same axle). This does not allow the rear wheels to travel at different speeds while turning. As a result, the car is not able to turn properly and slips on the floor.

6. If a real Automobile is without differentials then for the car to be able to turn, one tire would have to slip. With modern tires and concrete roads, a great deal of force is required to make the tire slip. This force would have been transmitted through the axle from one wheel to the another, putting heavy strain on axle components.

Second design: (With Differentials)

What is a differential ?

A Differential is a device which allows the two axles connected to it to rotate at different speeds.
As seen there are two axles to which each wheel is connected and these axles are fed to the differential. The key is use of two axles and the beauty is both wheels travel at same speed while moving straight but at different speeds while turning.

Videos below explain working of differentials.

Procedure:

1. In my differential, the driving gear is a spur gear connected to motor shaft.

2. It drives another spur gear which drives the entire differential unit. ( In automobiles, Crown wheel is used)

3. A set of 3 bevel gears perform the functioning.

Rack and Pinion mechanism

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1. Rear wheels of my car are driving wheels, whereas front wheels perform the stearing action.

2. Pinion is connected to the motor which meshes with rack.

3. Ends of the rack are connected to wheels.

Advantages over Differential type bot:

1. This bot can take turns on the curved path.

2. It can take turns while moving forward as well as backwards.

3. Use of 4 wheels increases stability and only 2 motors make it efficient. Whereas differential type bot needs 4 motors for driving 4 wheels.

4. This bot looks nice. :)

Comment any feedback or suggestions. Thanks to all.

XBox 360: Project Natal

2009-08-23T11:10:00.000-07:00

Check out these videos. Experience a whole new level of technology.

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The Obstacle Detector

2009-07-27T03:49:00.000-07:00

Recently, I attended a robotic workshop from Technophilia institute, Mumbai. The workshop covered modules of microcontroller programming. While learning about IR(Infra Red) standards, I understood the idea of an obstacle detector bot. I bought 2 obstacle detectors and the ATMEGA16 microcontroller from the institute and made my bot:

Building materials are:

1. Two DC-motors

2. Two wheels

3. ATMEGA16 microcontroller

4. IR obstacle detectors

5. 12V lead-acid battery

Steps followed:

1. This time, I needed a stronger body than the nokia box since I had to mount the PCB(Printed Circuit Board) as well as the obstacle detctors on it. So I made one using ply-wood.

2. Then, I fixed 2 DC motors in the body and one supporting wheel in a same way as I have done previously in my movement bot.

3. In the next step, The microcontroller PCB and the obstacle detectors got their place and my bot was ready. This process took a one and half day.

4. The next part was vital but very easy and less time consuming and that was to program my robot. Using a software called WinAVR I programmed the IC ATMEGA16 to work as an obstacle detector.

Functioning:

1. The IR obstacle detector mounted on my bot has a transmitter and a receiver.

2. It has one IC which continuously sends logical 1 to transmitter pin. This causes the transmitter to emit infra-red rays in forward direction. The IR ways travel upto a certain distance and then die off.

3. If any obstacle comes within that distance the rays are reflected and are received by the transmitter.

4. When the transmitter receives waves, Logical 1 appears at that pin. My job is to detect this 'Logical 1' at regualr intervals.

5. When my program founds that IR rays have reached the transmitter, it orders the bot to turn. i.e. I move one motor backward and the other in forward direction.

It's a simple if_else structure within an infinte while loop.

while(1)

{

if('Logical 1 is detected')

Order the bot to turn

else

Order the bot to go straight.

}

6. The second obstacle detector on the right is used to control the direction of the turn. If 'Logical 1' is detected at receivers of both detectors, imply that there is an obstacle to the right as well as in the front. In such a case, I order my bot to turn to the left instead of right.

De-merits:

1. Only those obstacles can be detected which are in front of the transmitter since IR rays travel in nearly straight forward direction.

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Thanks to all for helping. Programming is done is language C.

The Pipe-Tracker Bot

2009-07-10T07:48:00.000-07:00

While searching some stuff on the net, I found this design of the robot. The thing which attacted me was the mechanism of driving wheels using rubber bands. I loved this idea since it enables one to rotate those wheels which don't have the diameter of their central hole equal to the axle of the motor.

I decided to make a similar robot. Here's the bot I've made:

Building materials used are:

1. DC Motors

2. Two driven wheels(Or something which looks like a wheel), I've used a part of a sewing machine(Unknown to me). I found it in Tailor's shop.

3. Supporting wheels

4. 9V Batteries.

5. A pipe(as the path)

Steps followed:

1. First step was to make the actual functioning body of my robot. I tied 2 DC motors and driven wheels together using a tape. It looked like this:

2. The gap between the two wheels was adjusted so that the pipe easily fits in between.

3. Then I made the holder for supporting wheels using a copper wire and mounted them on it.

4. The holder is designed with a gap in the middle for the pipe.

Function:

1. When the motors are connected to battery they start rotating.

2. Since a rubber band is passed over the axle of the motor and the wheel, Rotation of motor also drives the wheel.

3. The rubber band acts as a belt. Thus the energy is transmitted from the motor to the wheel.

4. Note that the wheel will only rotate if the rubber band is streched tight over the axle and the wheel. If the rubber band is loose the wheel will not rotate. The reason is, The energy is transmitted only when the rubber band is under tension and there is friction present is between the wheels and the rubber band.

5. If the pipe is put in the gap between the two wheels, the bot pulls or draws out the pipe depending on the terminals of the battery.

6. If the pipe is stationary(fixed), the bot travels along the pipe forward or backward .

7. The gap between two driven wheels can be adjusted for different diameters of the pipe. In a way, we can call him simple line-tracker bot made without use of any sensors.

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Thanks to all for helping.

A simple wired bot

2009-06-28T07:41:00.000-07:00

Before entering into complexity, I decided to make a bot which can be controlled from a distance using remote. This wired bot can move in forward as well as backward directions, can turn and also rotate about itself. The purpose was to study the electrical connections required to control a bot.The building materials used were:

1. 2 DC motors. (Motors working on DC supply which can rotate in both directions.)

2. 4 two-way-switches

3. 2 wheels.
4. 9V battery.

5. Other raw material to build the body. (I used the 'Nokia' box).

Here's the bot I've made.

Steps followed:

1. Making the body was the simple task. I just installed DC motors in the 'NOKIA' box and then connected wheels to them.

2. To make the remote, I used a plastic box which can accommodate 4 two-way switches and fixed them as shown. Left 2 switches are used to control left motor and right 2 switches are used to control right motor.

3. The reason behind using two-way switches follows a story. First of all, I tried making a remote using 4 one-way switches and a battery. However, it was found that this idea required more than 1 battery to control the bot hence was neglected. After this, I thought of a circuit which uses 2 four-way switches, one for controlling each motor. This time the problem was to find four-way switches in the market. But then using 4 two-switches I successfully managed to convert them into 2 four-way switches and my problem got solved. It took me around 2 months to tackle this riddle.

If two blue squares are closed, +ve of the motor connects to +ve of battery and -ve of the motor connects to -ve of battery. Therefore, the motor revolves in forward direction.

If two red squares are closed, +ve of the motor connects to -ve of battery and -ve of the motor connects to +ve of battery. Therefore, the motor revolves in backward direction.

4. I then attached the third supporting wheel to the body and my bot was complete.

5. The thing which I learned was the circuit. I can now use the same remote for controlling movements of any wired bot.

Note: The type of this bot is Differnetial-type drive. There are two more types viz. Car-type and sychronized-type.

Two-way switches and converting them to four-way switches:

In the left diagram, the bulb glows in both situations by the use of a two-way switch. Right diagram shows how 2 two-way switches can be combined to form a four-way switch.

Drawbacks I observed:

1. Since both motors are operated independent of each other, one motor may rotate at a faster speed than the other. Due to which, the bot may move along a curve even when we want him to move in a straight line.
2. To turn the bot, either we can switch off the right motor so that it turns right. Or we can switch off the left motor so that it turns left. The point is, while turning the bot rotates about a vertical axis passing through the switched-off motor. As a result, the bot is not able to turn while moving forward or backward.

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Thanks to all who helped me.

Pixel Shaded Graphics

2009-06-21T00:02:00.000-07:00

In this post, I'm introducing to you a type of graphics which has the nature exactly opposite to the Cel-shaded graphics. Cel shading is used to give a comic effect to objects whereas Pixel Shading is used to make objects appear more real. As the name suggests, in this graphics a single pixel is coloured and many such pixels brought together produce the required image.

What is a pixel?

A pixel is the smallest unit of an image. They are arranged in 2-Dimensional grid and are often represented using dots, squares and rectangles. Each image on computer is made of pixels. These pixels can be observed by holding a magnifying glass in front of the computer screen. Or when you draw some picture in paint, magnify it and observe. You shall see even the smooth curves to be made of rectangular pixels.

Now, Let's do something very interesting.

1. Open MS Paint. Open a 'New' drawing.

2. Access the 'Image' menu and click on 'Attributes'.

3. A window opens. Set Width=7 and Height=1. Make sure that units are in pixels.

4. The drawable area shrinks to very small size. 'Zoom' the image from the 'view' menu.

5. By using pencil, fill each block of drawable area with colour of your choice. Each block represents a pixel.

6. Save this image and set it as desktop background.

7. You can increase the number of shades by increasing width.

So, as you can see, By painting each single pixel and then placing such pixels side by side, a beautiful wallpaper has shown up.

The pixel shading is also done in a similar manner. A pixel shader computes colour and other attributes for each pixel. Other attributes include lightning, bump mapping, shadows, translucency, depth etc. Many such pixels, which are designed independent of each other, when brought together produce the required pixel shaded image, scene, i.e the texture.

Once the texture becomes ready it is applied on the required 3-D object. It is similar to that when we wrap an object in a paper. Paper here is the texture. We draw the design on the paper(Design the texture) and apply it on the object(Apply the texture to the object).

Unlike cel-shading, Pixel shader contains various shades of a color which make the object appear more realistic.

Observe these two images.Especially the material applied on Tyre of bike and the girl's frock.

The various attributes like Bump mapping, Z-buffering etc. which are applied to the pixel will be discussed in later posts. Here are more examples of Pixel Shading.

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Thanks to Siddhesh for help. This post needs to be improvised. If you have any suggestions or content, please let me know. Thank you.

Murloc: My simple robot

2009-06-19T00:05:00.000-07:00

I made this little guy just to study the rotation of motors. And thus, Murloc jumped out of the water.

Construction was pretty simple. I took following materials and tools for building this tiny.

1. DC motor with plastic gear box
2. 9V battery
3. Paper clips
4. Wheels

Steps followed:

1. Attach 2 DC motors to each other which forms base as well as body for the bot.

2. Mount 9V battery on this base using a tape. The terminals of the battery appear as eyes of the bot.

3. Attach two wheels, one to each motor.

4. Attach one extra wheel or some object that can roll with the help of a paper clip, so that the bot can stand on three wheels.

5. Connect both motors to the battery.

6. Instead of using wheels, one can also use clips to make 'Murloc' jump.

Jumping murloc can climb heights. It dies when battery discharges.

Why so serious?

2009-06-05T02:40:00.000-07:00

Yup, quite late, but my blog just can not miss this one.

So, Here's Joker with his super dynamites to blow the things out of proportion.

1. "I am an Agent of Chaos!"

2. Why so serious?

3. I believe whatever doesn't kill you simply makes you... stranger.

4. See, I'm a man of simple tastes. I like gunpowder...and dynamite...and gasoline! Do you know what all of these things have in common? They're cheap!

5. This town deserves a better class of criminal... and I'm gonna give it to them. Tell your men they work for me now. This is 'my' city.

6. You see, madness, as you know, is like gravity. All it takes is a little push!

7. Do u know why I prefer knives?..Guns are two quick,You cant savor all those little emotions...In their last moments people show you who they really are...So...In a way I know your friends better than you ever really did. Would u like to know which of them were cowards?

8. Who would I play with if i kill you?

9. Why don't we cut you up into little pieces and feed you to your pooches, hmm? And then we'll see how loyal a hungry dog REALLY is!

10. You die as a hero or live long enough to see yourself become a villain.The only sensible way to live in this world is to live without a rule.

11. GAMBOL: What do you suggest we do...???
JOKER: Kill the Batman...!!!!
GAMBOL: Then why haven't you done it as yet..???
JOKER: When you are good at something never do it for free..!

12. "You just couldn't let me go could you? This is what happens when an unstoppable force meets an immovable object. You truly are incorruptible aren't you? You won't kill me out of some misplaced sense of self-righteousness, and I won't kill you, because you're just too much..... fun. I think you and I are destined to do this forever."

13. You look nervous. Is it the scars? You want to know how I got them? Come here. Hey, look at me. So I had a wife, beautiful; like you. Who tells me, I worry too much. Who tells me, I ought to smile more. Who gambles, and gets in deep with sharks. One day they carve her face. We have no money for surgeries. She can't take it! I just want to see her smile again. I just want her to know that I don't care about the scars. So I stick a razor in my mouth and do this...

14. Wanna know how I got these scars? My father was....a drinker. And a fiend. And one night he goes off crazier than usual. Mommy gets the kitchen knife to defend herself. He doesn't like that. Not. One. Bit. So, me watching, he takes the knife to her, laughing while he does it. Turns to me and he says "Why so serious?" Comes at me with the knife,"Why so serious?" He sticks the blade in my mouth. "Lets put a smile on that face!" And..... Why so serious?

15. (Batman bangs joker's head)Joker: Never start with the head. The victim gets all fuzzy and can not feel the rest pain.(Batman hits his hands)Joker: see...

16. We made it.. Good evening ladies and Gentlemen.. We are here for tonight's entertainment... I have only one question.. Where is Harvey Dent?

17. I just did what I do best. I took your little plan and I turned it on itself. Look what I did to this city with a few drums of gas and a couple of bullets. Hmmm? You know... You know what I've noticed? Nobody panics when things go "according to plan." Even if the plan is horrifying! If, tomorrow, I tell the press that, like, a gang banger will get shot, or a truckload of soldiers will be blown up, nobody panics, because it's all "part of the plan." But when I say that one little old mayor will die, well then everyone loses their minds!

18. I had a vision of a world without the Batman,
The mob grounded out a little profit,
The police trying to shut them down 1 block at a time,
and it was so boring.....

19. Do I really look like a guy with a plan? You know what I am? I'm a dog chasing cars. I wouldn't know what to do with one if I caught it! You know, I just do things. The mob has plans, the cops have plans. Gordon's got plans. They're schemers. Schemers trying to control their little worlds. I'm not a schemer. I try to show the schemers how pathetic their attempts to control things really are.So, when I say that you and your girlfriend was nothing personal, you know that I'm telling the truth.

20. Gordon:Where's Harvey Dent?
Joker: What is the time??
Gordon: What's time got to do with that?
Joker: Oh,Depending on the time he may be at one place or in several.
Gordon: OK,So you Want To Play a Game,Right?(releasing joker's handcuffs)
JOKER(seeing GORDON releasing him):The same Bad cop Good cop routine.

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Reference: The Dark Knight(Movie)
Lead Cast: Christian Bale(The Batman), Heath Ledger(The Joker)
Something about: We might see Christian Bale as Batman in upcoming movies but unfortunately we won't see The Joker. Some people are born to do something....amazing, beautiful and that which can not be challenged. We might wonder, What would have happened if he was to die 'before' instead dying 'after'. Perhaps, the time wraps them only when they have finished their job. They live for that legendary role. Heath Ledger died from an accidental toxic combination of prescription drugs. A few months before his death, Ledger had finished filming his penultimate performance, as the Joker in The Dark Knight. He received about 31 awards for the best actor and the best villain for his role. He gifted the world with 'Joker' and now rests in peace.

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Watch this movie. It's nice. A true masterpiece.

GFX and Technical Drawing

2009-05-08T04:13:00.000-07:00

I've introduced a new category, GFX(Graphics) and Technical Drawing. It's an attempt to show and share with people, the information I've collected or received about technical aspect of drawings and paintings.

Posts of this category will contain stuff about Computer graphics, Technical drawing and it's implementation in games,physics stimulation, media entertainment and academics .

Thank you!:)

Cell Shaded Graphics

2009-05-08T01:49:00.000-07:00

In this post, I'm going to introduce to you,one of the most beautiful and spectacular types of computer graphics,'Cel-Shading'.

Cell Shading) is a non-realistic rendering designed to make Computer graphics to be hand-drawn. Rendering is the process of producing virtual computer graphics which are used in gaming,entertainment industries or in stimulations.

The cel-shaded object appears to be an object in cartoons or in comics. By using Cel-Shading, we can draw lovely cartoons on our computer which were used to be hand-drawn before.

Now,Let's understand 'how a cell-shaded object differs from a real one'. But before that, I need you to recollect the paintings which you have drawn in Paint or PowerPoint etc.

Do you remember this window? Yup, It's a window from paint and is used to generate colours which are not available in the colour box. You can form the desired colour by dragging the mouse pointer over or you can enter the values for three fundamental colours,Red,Green and Blue to form a particular shade.Now observe the following drawing:

As you can see, I've drawn bands of various shades of a colour. The numbers indicate the amount of red color present in the shade.

When you see a real-life object you don't see a perticular colour but various shades of that colour.Just as the bands I've drawn above. See the car below:

Cel-shaders are different in nature. In cel-shaded animation, an intermediate colour from a group of close shades is selected and that is used to paint the object. Confused? Observe below...

The colour shade having RED=225 is selected from group 200-255. The colour shade having RED=175 is selected from group 150-200. These two shades are put side by side, eliminating all the other shades in between. See the cel-shaded car.

The bottom section of the car is darkish shade of green.However, the shade changes abruptly as we move from bottom to the top section and it becomes light green.

Property 1: In cel-shading all the shades of a particular colour which are very close to each other are represented by a single colour and used to paint the object. The selected shade is not changed unless and until there's a drastic change in the colour of the object. Drastic change refers to 1. Change of surface 2. Direction of light 3.Completely different colour(say one surface is Red and the other is Blue).

Ok,Let's move to the next point. Observe the following painting. It seems like an ancient tomb. Anyways, It's cel-shaded as you can clearly see. The point to be noted is, all the boundaries of each and every object in the painting are drawn, which you don't see in the real-life object.

Following images also illustrate the fact.
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Property 2: Thus, In a cell-shaded object all the boundaries are drawn very clearly.

Here are some more cell shaded objects:

The Grand Cannon-----Teapot

Due to the above properties and some other and it's beauty, Cel-shading is becoming very popular nowadays. It is a relatively recent addition to computer graphics, most commonly turning up in console video games.

The recent Computer/Console games which have used cel-shaders are Prince of Persia 2008, No more heroes etc.

I hope, You would love this powerful and fabulous art of drawing.

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Want to know more about games? Visit: All about gamez!

Note:Though the end result of cel-shading has a very simplistic feel like that of hand-drawn animation, the process is complex. Softwares like 3ds-max provide ready made cel-shaded textures. Soon, I'll be posting a tutorial on 'how to apply cel-shading to an object'.

Dragonball Z: Vegeta and Shenron

2009-05-05T21:41:00.000-07:00

Here's a video I found on YouTube. This guy is drawing my favourite character Vegeta from one of my favourite anime Dragon ball-Z.

Dragon ball is a Japanese manga(comic)series written by Akira Toriyama. It was originally serialized in weakly Shonen Jump.

Wave or Particle?

2009-05-01T00:43:00.000-07:00

Here's a video,I found on YouTube. Why did 'Quantum Mechanics' take birth when the world had the 'Classical Mechanics'? The following video gives the answer.

You see,the electrons are particles, however they behave like waves. These are some of the questions which the 'Classical mechanics' couldn't answer. So came the 'QUANTUM MECHANICS'.

Let me put some light on the history of Quantum mechanics.

Developmental milestones:

1. It started with Huygens' wave theory of light. Huygens was the one to propose that Light behaves like a wave. He tried to explain phenomenon of reflection,refraction with his theory, but couldn't give satisfactory explanations. We all know that, Light does not need any medium like air,water for it's propagation. It's due to this fact, we can receive sunlight even though there is void between the sun and the earth. However, Huygens assumed a invisible medium to be present everywhere,called as 'Luminiferous ether'. He said that this medium is essential for propagation of light. Many scientists tried to locate it, but their attempts were in vain.

2.Then came,one of the most famous men in the world, Isaac Newton. He proposed the 'corpuscular theory of light'. It said that, the light consists of small,little particles called 'corpuscles'. With this theory he could easily explain phenomenon of reflection. Somehow, he also managed to explain Refraction, the propagation of light through the lens etc.

3.In the early 1800, Young and Fresnel put forward their experiments to support the Huygens' wave theory of light. Young's double slit experiment was the first to discover that the light travels as transverse waves but not longitudinal waves. He observed that when the light is passed through two slits, a pattern containing alternate bright and dark bands is observed on the screen. This pattern is called as 'Interference pattern'.

4. In the late 1800, James Maxwell explained light as the propagation of electromagnetic waves using some mathematics. This theory was accepted widely.

5.In 1901, Max Plank proposed that light propagates as small packets of energy called as 'Quanta'. The theory was carried forward by the person of century, 'Albert Einstein'. However, Einstein preferred calling 'Quantum' as 'Photons'. He explained the phenomenon of photoelectric effect using theory of photons for which he received the 'noble prize' in physics in 1921. Who switches off the lamp posts on highways in the morning? Why can't a bugler break in a house so easily,nowadays? How do we measure intensity of light? It is all possible because of this one man and the photoelectric effect.

6.De Broglie's Hypothesis: Mr.De Broglie claimed that not just the light, but all matter behaves as a particle as well as waves.He called them 'matter waves'. He found a relationship between momentum of photon and the wavelength. This guy also was awarded a noble prize in physics in 1929.

So, "Is light a wave or a particle?” Perhaps it depends on the type of experiment you do,as you can see above.

-reference Wikipedia

Note: If you find any mistake in information or logic written above, Please let me know. Suggestions are welcome.

Obulis: The Physics game

2009-04-29T03:25:00.000-07:00

NOTE: This post is designed based on the videos. So please do watch videos before reading to their descriptions.

Here's another fabulous physics game. This one is based on one of the most interesting concepts in physics, Kinetics of particles(Dynamics). You must have seen on YouTube, mechanisms in which the narrator releases a ball or slightly pushes a plate and then everything happens on its own. This game is kind of similar to such mechanisms. In each level, our target is to put the coloured balls in corresponding vessels.

Oscillations, Impacts, Work Energy Principle are some the frequently encountered phenomena in this game. Following videos explain some of them:

The red ball takes the cover of two gray balls. Unfortunately, I'm a bit smarter. I kicked butts of two gray balls and eventually the red ball got one on it's own. Also observe the position of the ball when I cut the rope. It's the center!

Logic:(i) The velocity of oscillating particle is maximum at the center and minimum at the ends of it's path.As a result, when I release the ball when it is at the center of its path, it strikes the gray one with maximum velocity.

(ii) When you strike a ball with another ball in rest, the latter is set into the motion. This happens because of the concept called as 'Inelastic collision'. The part of kinetic energy of the first ball is transmitted to the second ball, due to which it starts moving. In the above case, the impact of oscillating gray ball on the stationary one, transmits the kinetic energy of former to the latter. This energy travels through and eventually reaches the red ball. As a result the red ball is set into the motion. Whenever two bodies collide, such that there is loss of kinetic energy, then such a collsion is called as Inelastic collision.

This case is quite similar to previous one. But, note that the height up to which the blue ball reaches is equal to the height achieved by the gray one.

Logic: The concept is, THE LAW OF CONSERVATION OF MOMENTUM.

Momentum is the product of mass of the particle and it's velocity (mv). Let me explain this in simple words. You may survive if you get hit by a car traveling at 20 m/s. However, You are doomed if you get hit by a train traveling at 2m/s.

The reason is, the mass of the train is very large as compared to that of the car. Hence the product (m*v) i.e. the momentum for train is huge even if the speed of train is less.

Anyways, The law states that,

(m1v1)i+(m2v2)i=(m1v1)f+(m2v2)f

[m1 and m2=> masses of colliding particles.

v1 and v2=>velocities of colliding particles.

'i'=>Initial values

'f'=>Final values]

If blue and gray balls have same mass then m1=m2.

Blue ball is initially at rest. (v2)i=0

After collision, gray balls remains stationary. (v1)f=0

therefore, (v2)f=(v1)i. Thus,velocity of blue ball after collision is equal to the velocity of gray ball before collision.

Following are some more cool mechanisms implemented in the game.

I'm sure you must have liked this one as well. I think, these games make physics more interesting to learn and to teach.:)

Programming Logic: Introduction

2009-04-24T02:36:00.000-07:00

Wikipedia defines logic as the study of the principles of valid demonstration and inference. When we face a problem, we apply brain to get through it. i.e. We apply some logic considering the surroundings, the type of problem and the tools we have to solve it. The problem we face might be a real life difficulty, a mathematical problem, a scientific query etc.

Sometimes, Logic gets applied even when we are not conscious of it. On the other hand, sometimes we have to think really hard to solve a simple problem. Sometimes, In spite of knowing the solution, we fail to reach the same. Why do you think this happens?

Now, Consider the following problem.
Draw a circle when you are provided with a pencil and a scale.
Solution:

Draw a circle when you are provided with a pencil and a pro-circle.
Solution:

What do you observe? The logic applied in both the cases is different from one another. Also, The nature of your circle changes depending upon the instrument you use. By using a pro-circle, fine circle can be drawn. Circle drawn using a scale is not fine. A particular problem can be solved in many ways. The nature of solution differs for each approach. Now, if I reduce the length of each line used to draw the circle, the circle drawn using the scale can also be made fine. To find an optimum solution for a problem, sometimes you may have to apply extra efforts. For a brain, these efforts depend on the 'things' and 'tools' a man has and also the surroundings.

Now, let us come to my topic. Wikipedia defines Programming logic as the use of mathematical logic for computer programming. My experience is,'more than 60% of people find it to be very hard'. At first, I used to think in the same way. But when you know the reason of it to be difficult, it starts becoming easy. Let me explain my point. C++,Java,HTML, Visual Basic, Game editors are some of the programming languages, I'll be using for reference.

In computer science, Programs are written in specific languages which can be understood by the computer. C,C++,JAVA,Visual Basic are some of them. Now, my point is, one can not draw a circle if he/she doesn't know how to use a pro-circle. It does not mean that one doesn't know, how a circle looks like. The only problem is, he is unaware of the approach to complete the task.
The main reason of one being unable to write a program or to apply a logic, is not because he is an dumb-ass in computer programming. The cause behind this is, he is not familiar with the ways and tools to approach the problem. I don't disagree the fact that the lack of knowledge of a concept is responsible for one being not able to tackle a problem. But, I think all of us know 'how to add two numbers'.

Consider an simple example.

A variable 'a' has a value '10' and 'b' has a value '15'.

Consider following code snippet.(Code is in C++)

if(a>8 & b=15)
cout<<"true";
else
cout<<"false"; ('cout' in C++ is used to print a message.)

The output of the above program should be 'true'. However, the computer gives an 'error' and can not execute the code. The correct code is:

if(a>8 & b==15)
cout<<"true";
else
cout<<"false";

Now the output is 'true'.The logic I applied was perfectly all right.You also must have applied the same logic. The only thing I didn't know was the symbol for 'equal to' in C++ is '==' but not '='. Is it not cool? One thinks that the logic he has applied is wrong.

Once you get familiar with different tools, accessories, options, commands and techniques of a programming language, the only thing that remains is to apply logic which suits the above environment. You need to apply different logic in different languages for solving the same problem.

'Logic' and 'Language' are two different things.But they follow the same universal law.The 'Logic' can not be expressed without a 'language'.The 'Language' is senseless without the 'Logic'. Language and Logic do influence each other. Apply the logic, know the language and your problem gets solved. That's the way of programming.

You should ,Someday, peep into the world of programming. It's easy. It's simple. It's beautiful. You would love it. I'm sure.
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This post is dedicated to my wonderful brother 'Siddhesh' who was the first to teach me the true meaning of 'PROGRAMMING'.

Warcraft: Storm before the War

2009-04-20T10:53:00.000-07:00

I was sitting on the chair,My friend 'Pranav', on the sofa and my brother Sid, on the tea-poy. We were discussing Warcraft. In the game, I play as Night elves, Pranav as Humans and my brother as Orcs. We were planning to battle on LAN. Now,the question was, who is stronger?

I and Sid: (To Pranav) You might be the professional of all other games. But there's no way you can match us in Warcraft.

Me: Are, We have been playing this game since last 5 years.

Pranav: Don't worry, I'll catch you in 5 weeks. Now,I've designed a perfect strategy for Humans. Within few weeks I'll be a master.

Me: Impossible, Even Sid is of no match with me in Custom Games. I'll crush your base in an eye's blink.

Sid: Hey C'mon, You know what happens, when I bring Taurens with me. Nothing can match the blow power of a Tauren. One Tauren can easily take two or more of your huntresses.

Me: Unfortunately,You orcs suck at ranged attacks. My one 'Chimera' can knock half of your army.

Pranav: Hello! My one Gryphon Rider is enough for thousands of your chimeras. Those basterds can't even attack flying units. "It's hammer Time"!!

Sid: And you know,what I've got,don't you? 'Troll Batriders'.

Pranav:What are those?

Sid: Ultra effective against Air units. They also receive damage bonus against buildings.

Me: My Dryads won't be playing 'goti's with your grunts then. I also carry 4 Hippographs with me only to counter Air units.

Pranav: Both of you! Bring anything,my one Gryphon Rider is enough.

Me: And how do you plan to counter 'Fan of knives','Searing arrows','Starfall','Shadow Strike'?

Pranav: Abe, Ek 'Thunder Bolt' padi naa,Seedha tera Hero altar mein.

Sid: And no matter how many times you kill my 'Tauren Chieftan',It'll always reincarnate. The cooldown is just 4 minutes.

Me: Since when did you start taking Tauren Chieftan? You always take 'Blademaster' and 'Shadow Hunter'.

Sid: I don't need him against you. My normal units are enough.

Pranav: 'Thunder Bolt' can also damage Buildings.

Sid:It's a 'Storm Bolt',not a 'Thunder Bolt'.

Me: My base defences are too strong. I can raise my ancients if required.

Sid: Ye dekh, Ye saleko pata bhi nahi tha ki, there's a Research called 'Nature's Blessings' which increases movement,attack and strength of ancients. Base defence ki baat kar raha hai.

Pranav:(To me)Your Ancient protector looks better while he's standing than when he throws those Thermocol stones.

Sid: My buildings have Spike Protection. Half of your melee army dies destroying just one structure.

Sam: I don't use melee units.

Pranav:My Gryphon Riders are not melee.

Sid: I never research 'Spike Protection.'
........
..........
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The battle continues. Even though,There's a road gap between my building and my brother's. and we don't have a LAN wire and we still find it hard to defeat 'Difficulty:Insane' computer AI.

Sid: Insane AI receives double the amount of resources we recieve.That's unfair.

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For those who got nothing:

Warcraft is a 'Real Time Strategy' computer game designed by 'Blizzard' Entertainments. This game has won many awards including 'THE GAME OF THE YEAR' from more than six publications. Humans,Orcs and Night Elves are the major races of Warcraft history. All the rest terms mentioned above, are parts of this wonderful game.

WORLD OF GOO: An Ultimate Physics game

2009-04-19T03:58:00.000-07:00

NOTE: This post is designed based on the videos. So please do watch videos before reading to their descriptions.

Goo? What is Goo? Is the game all about 'shit'?
I thought the same when I heard about this game. But when I played it, I found it tastier than anything.

World of Goo is a puzzle game with a very strong emphasis on PHYSICS by 2D boy. Design,story,art and music are by Kyle Gabler. The game is programmed and produced by Ron Carmel. Here are some reasons why you should play this game...

Concept :

This game picks some of the most simple but beautiful concepts,theories of physics.

In each stage, our target is to reach upto the escape pipe. In doing so,we encounter various phenomena in mechanics like Gravitation, Oscillations, Projectile motion, Buoyanct force exerted by liquid, Resonance, Circular motion, Archimedes' principle etc. Tackling and clearing each problem is really a fun and we get to learn a lot from it. The game is simple,small but needs brain.

Let me introduce to you some nice concepts of physics.

This is one of the initial stages in World of Goo. Two strong gates prevent Goo balls from reaching their goal. But I use round round baloons to open them and Goo balls fly high up in the sky.

The escape pipe is situated well above the ground. So goo Balls had to make a huge tower to reach their goal. It was OK at start, however as the tower grew tall, it's top started oscillating due to motion and weight of Goo balls. To prevent the tower from collapsing, I used whistle(look at the cursor) to pull Goo balls to the lower part of the tower. As a result, the mass of Goo balls got concentrated in the lower part and upper part became stable, thus allowing me to build further.
Logic:Considering damping is present, Amplitude of oscillation of pendulum depends on mass.
If mass is less,Amplitude is small. Since the mass at the top was reduced, amplitude decreased.

The escape pipe is at a height above the water surface. In order to take Goo balls there, I used the concept of Buoyanct force exerted by liquid. The yellow Goo ball took others well below the water surface and then realesed it's hold to sprang out of the water.Whoooooooosh!!!!
Logic:When a object is submerged in a fluid (completely or partially), there exits an upward force on the object that is equal to the weight of the fluid that is displaced by the object. This is what Archimedes s aid when he got old.

Goo balls were trying to dispose that 'undelete' block in the water. Their plan was to jump on that rope, swing the rope and when it comes exactly below the fire, jump through the fire to destroy the structure. However, due to some reason,they couldn't execute the plan. I helped them and the mission was accomplished. What was that mistake they have been doing? They were jumping on the rope while it was coming towards them.
Logic: Logic is simple. When a body is hit by an another body travelling in opposite direction, velocity of former decreases and if directions are same, then it increases. If Goo balls are thrown on the rope, when it is heading towards them, AMPLITUDE OF OSCILLATIONS of rope will obviously decrease. Therefore,they must be thrown,when rope is going away from them,so that bottom end of rope comes exactly below the fire.

Yooohooo! Goo balls experiencing NEWTON's gravitation. Goo balls jump into the space to reach their goal.
Logic: Everyone knows! Sir Isaac Newton was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian and one of the most influential men in human history. He proposed the law of gravitation. It states that, any two objects in universe exert gravitational force of attraction on each other.

So, You should play this masterpiece.

No wonder, this game receives the title of 'THE BEST PUZZLE GAME OF YEAR 08'.

Why the name?

2009-04-15T04:25:00.000-07:00

The Big Bang Theory is a fabulous situation comedy created and executive produced by Chuck Lorre and Bill Prady. This series is all about geekiness of 4 scientists. Physics, Logic, Games, Comics, Superheroes are the things which build their lives. Their clash with normal humans is used for comic effect.

This blog is typically a science blog and contains my experiences,views and collection of Logic,Games,Comics and some fun physics. These are some of the things around which my world revolves. This blog is free for descriptions, essays, poets, emotions etc. It's an attempt to take people through the beautiful, stunning and a little geeky world.

Note: If you find any flaw in Logic or concepts of Physics mentioned in my blog,I'll be very glad to know. Suggestions are always welcome.