# 10. On Physics Capsule as a book

Over three years ago we started Physics Capsule with an idea that had excited us immensely. It took us these three years, however, to fully shape that idea. On the way we have had guest authors, friendly editors, lots of well-wishers and more people than ever giving us suggestions and ideas. We appreciate all of this and we realise that while our intentions with Physics Capsule have undoubtedly changed over the past four years our core purpose is now better defined than ever before.

# Major changes

In the briefest sense, Physics Capsule has become streamlined over the years. It had the flair of a magazine when it was founded and has the stateliness of a book today. We have decided to completely cut down on reporting current research on a regular basis–we will still do so once in a while when we feel it is necessary, perhaps a couple of times a year. If reportage is what you seek there are other excellent sources out there, most of them magazines.

Instead we took the decision to focus our efforts on what we realised was the kernel of Physics Capsule, the old Learn section. This entire website is now what was a single section before. This benefits us and our readers in two ways. Firstly, saving the extra effort that went into beautifying articles–cover images, credits, legality and what not–means we can focus even more on our content and work towards automating and modernising as much of our presentation as possible.

# Filling a void

Secondly, we have long noticed a downside for people who want to learn physics online–and there are many who do–which is that video content is time-consuming, audio content is incomplete for mathematics, and written content either treats a subject for practising physicists or at the high-school level. What we have always wanted Physics Capsule to be is a one-stop solution for anyone who wants to learn physics without being crippled by a lack of mathematical knowledge or having to be handheld and spoon-fed all the way.

Both my friend (and co-founder of this website), Roshan Sawhil, and I believe in Heisenberg’s words: ‘Even for the physicist the description in plain language will be a criterion of the degree of understanding that has been reached’. These are the words of a man who was famously mathematical. What we look for, at the end of the day, is to strike the right balance between verbal physics and mathematical physics.

More important, we want to address the notion of exhaustiveness. Most online resources shine because they connect to the rest of the world. This makes them bottomless wells: promising but somewhat unrealistic. I have myself always strongly believed that the beauty of a book, as opposed to the internet, lies in its finiteness. You can finish a book; you can never completely read the internet–and not for a lack of trying. You would gain little on the way too.

# The online book

What we want Physics Capsule to be is a self-contained compendium of knowledge in physics, suitable for all levels of understanding, for people with all sorts of educational backgrounds. At the same time we want it to neither be unrealistic about its capabilities nor be skeuomorphic. We will connect to other sources, but we will prefer chapters and webpages to volumes and websites; and we will embrace the idea of a book without losing the benefits screens and the internet bring with them.

This brings me to our final–and perhaps most obvious–change here: the design. Almost everything the old Physics Capsule had is now gone. Almost: the articles are now undeniably front and centre and you need no ‘reader view’ to improve readability here. Equations, for example $E = mc^2$, look great, as do derivations like \begin{align*} \dot{T} &= {\textrm{d}\over\textrm{d}t}\left( {1\over 2}mv^2 \right) \\[.5em] &= {m\over 2} {\textrm{d} v^2 \over\textrm{d}t} \\[.5em] &= {m\over 2} {\textrm{d} \mathbf{v\cdot v} \over\textrm{d}t} \\[.5em] &= {m \over 2} \left( \dot{\mathbf{v}}\cdot\mathbf{v} + \mathbf{v}\cdot \dot{\mathbf{v}} \right) \\[.5em] &= m\mathbf{a} \cdot \mathbf{v} \\[.5em] \implies \dot{T} &= \mathbf{F} \cdot \mathbf{v} \end{align*}

The design, therefore, maintains harmony between our intentions and our presentations in a way we have never seen before on Physics Capsule. Read it at once, cover to cover, or pick your favourite topic, or flip open a random page. Physics Capsule is a book through and through but online, blending the best of both worlds.

# Make it yours

While this new Physics Capsule, the second edition, was inspired by books and $\LaTeX\$, two things we physicists surround ourselves with, we still wanted it to be your book. No two people read alike, so why should one size of Physics Capsule fit all? Scroll down to the bottom of any page—including this—and find our special display preferences toolbar: change the font size and/or choose from among a handcrafted selection of paper styles. Make Physics Capsule look like you want it to and only do it once: the next time you drop by we will remember and restore your old settings.

We have always wanted this to be more than just a website; we now have a name for this: an online book, a fast expanding but planned, vast but not exhaustive resource that can help almost anyone learn physics academically.

But not all has changed: we started out with the assurance that we would try to use some form of monetisation but not force advertising on readers–this is still valid. And we believed that this is a platform, now a book, not for one-sided learning but for all of us–teachers and learners–to learn together–this too is still valid. Physics Capsule is still the excellent reading material it has always been except it is now more focussed and is a better version of itself by any measure, in more ways than one.

## We hope you enjoyed this chapter.

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