Just found this links bookmarked while cleaning my Laptop links mess :P. The Lectures are from Indian Institute of Technology, Madaras (India) by Prof. V. Balakrishnan.
Prof. Balakrishnan does a remarkable job at explaining these confusing issues, avoiding common pitfalls; and he demonstartes honesty of not trying to sell the theory, avoiding the common “shut up and calculate” style that is very common (and which I am suffering in my undergraduate years). The lectures doesn’t uses any advanced mathematics and keeps at a complete basic and easily understandable level, and I think it should be understandable by anyone with a ‘next to nothing’ knowledge.
There are a total of 31 Lectures available online i.e. almost a 31 hours of fun:D Prof. V Balakrishnan certianly keeps the lectures intresting; certainly worth watching.
Note : Almost all the lectures are of around 1 hr so keep in mind you bandwidth, if any.
Today I was reading the book titled “World of Physics Volume II by Jefferson Weaver”; a great book that contains Nobel speeches and information on some of the greatest contributions in science, but more on that later. Anyways back to the topics, in that book in the chapter regarding the Scattering Experiment by Lord Rutherford, in it he coined the terms as Alpha(α), Beta(β) and Gamma(γ). But in the paper he called them as Alpha, Beta and Gamma Rays. While I discarded it as irrelevant, in my further reading the terms used were as α and β particles while γ Rays. That was what burned my curiosity : Why α and β as particles while γ as rays?
Now when I looked up for definition of a particle I found this
“… a particle is a small localized object to which can be ascribed several physical properties such as volume or mass…” – Wikipedia
And the answer to question is the mass of the three elements.
Alpha (α) : Alpha particles are made of 2 protons and 2 neutrons.
This means that they have a charge of +2, and a mass of 4.
Beta (β) : Beta particles are made of 1 electron. Beta particles have a charge of minus 1, and a mass of about 1/2000.
Gamma (γ) : Gamma are not particle rather they are a bust of energy i.e. they are in wave form. Thus it has neither any charge nor any mass.
Hence Gamma as called rays while the other as particles.
Well just today morning I was reading in the college library a basic book that was, if I am correct, a 11th grade physics book. The first topic was unsurprisingly about the ‘States of Matter’ and some student, in the past, had written in the margin a small but interesting question; which I admit I dismissed. But later in further reading the question came back to hunt me 🙂
Now back to the interesting question :
“Why do transparent objects, like glasses, have shadows?”
After dusting through various books i found this accurate description of shadow :
“Shadow, a dark area within or next to an illuminated one. Shadows are caused by the blocking of light by an object….”
Finally after almost 2 hrs I found the answer that is hopefully accurate :
In general, if any body or object is sheded with some light on it. It is observed that some of the light passes through the body, while others are reflected off it, the rest is absorbed by it. In the Transparent materials, the intensity of incident light passing through the body portion in most cases is much larger than the intensity of the reflected and absorbed, but this is highly dependent on the angle of incidence of light. Therefore, edges, curved parts of the incident light passing through the body portion varies from place to place. Hence the transparent bodies do allow light to pass but the shadow created is essentially of the wind and dust particles, which is seen as darker spots.
Do excuse any grammatical mistakes. And if there is any mistake please do comment. This is my first time of writing the blog and I intend to update it a frequently as possible with more such curious questions that arose in my mind.