Imagine that you are on a game show. Consider the following two scenarios:
The host has given you $2000 to begin with. You are now given a choice – you can stay with your money or participate in the “Double or Nothing”. Should you choose the event, the host would flip a fair coin. Should the coin land heads, you will get an extra $2000. Should it land tails, you lose the $2000 you have.
The host has given you $4000 to begin with. You are now given a choice – you can participate pay a fine of $2000 or participate in the “Trap of Doom” event. Should you choose the event, the host would flip a fair coin. Should the coin land heads, you get to keep all $4000. Should it land tails, you loose all $4000 to the “Trap of Doom”.
Would you participate in the “Double or Nothing” event? Would you participate in the “Trap of Doom”? Are your answers different?
My last post talked about cryptography, its motivation and its primitive techniques. In this post, we shall learn about modern security techniques and how they keep us secure. We will touch upon the mathematical basis behind modern cryptography, talk about symmetric key cryptography and talk about a technique for exchanging secrets out in the open known as the Diffie-Hellman key exchange. To start off the discussion, I would like you to consider the following situation. Alice is a diplomat in a foreign country and has some sensitive information that she would like to communicate to Bob, her superior. The only means of communication available to Alice is a phone line that she and Bob knows is constantly being monitored and eves dropped on. How could Alice and Bob communicate a message in a secure manner starting from this state? We saw in the last post how, with some pre-decided shared secret (such as a codebook when using a substitution cipher), one could attempt to obscure a message and make it hard (but not too hard) to guess. More curiously, starting with no secret state between the two parties, is it possible to establish a secret codebook? In other words, sharing no secrets beforehand, is it possible to begin sharing a secret?
What is a polymer?
Polymers are all around us. They are in our cars, they are in our adhesives, they are in our food, and they are in our bodies. Plastics, rubbers, glues, starches, and even DNA are all polymers. What could all of these things possibly have in common? The answer lies in the name. Polymer is a word stemming from the Greek words for many, poly, and parts, meros. A polymer is simply a molecule which is made up of many parts. These parts, called monomers, are often many repetitions of only one or two molecules, though it is conceivable that a polymer in which every monomer differs from every other can be produced.
We have all heard the word ‘encrypted’ used many times on television or in movies. It is usually implies some form of security or an obstacle that needs to be overcome by some button pushing by a man in a lab coat. Shows such as CSI and Law and Order use it, almost indiscriminately and often inaccurately. So what exactly is encryption and what does it mean to say that a message is encrypted? In this post, I shall describe the motivation behind cryptography, a number of early encryption schemes and the idea behind modern cryptography. In the second post in this series, I will describe more modern algorithms as they are used today in computers to protect your identity, privacy and security on the Internet.
Ever wondered how an electric incandescent bulb, an electric room heater or an electric stove worked? Ever wondered how they produce so much heat and light? Today, we will explore the working of electric bulbs and heaters. I will given an overview of how electric power is converted to heat and light. As a bonus, here is a quick poll to give you a teaser.
Today, I will tackle the conundrum of Which came first: the chicken or the egg? This is an age-old dilemma, confounding early philosophers. The core argument takes the form of a catch-22. All chicken hatch from an egg. Hence, to have a chicken, one must first have had an egg. But chicken eggs need to be laid by a chicken. Hence, to have an egg, one must first have a chicken to lay it. Phrased this way, this question does not seem to have a good solution. Nevertheless, evolutionary biology has been able to resolve the issue with a correct but perhaps unsatisfactory answer.
Here is a video of some astronauts on the International Space Station (ISS). It depicts some common (and uncommon) activities that they do aboard it. It has background music – so turn down your volume if you are at work.
As you can see, astronauts in space operate in a ‘zero-gravity’ environment. They float around effortlessly and don’t fall toward the ‘floor’ of the space station. Water, in a space station such as the ISS, automatically assumes the shape of a ball and floats around. This is indeed, quite a strange environment. But have you ever stopped and wondered – why are the astronauts actually floating? Is it because there is no gravity in outer space? Is it because the earth’s pull is so weak that it no longer affects them? Is it because they are constantly being pushed away from the earth by rockets? Or is it something more subtle? In this post, we shall explore the phenomenon of micro-gravity.