C. R. Kitchin - Understanding Gravitational Waves

Physics is essentially a concrete and descriptive science. The mathematics gives us only the means in hand to express the law according to which the phenomena are taking place. (Albert Einstein. Lettres Maurice Solovine. Gauthier-Villars, 1956)

There it isEinstein himself said itPhysics is a descriptive subjectMaths is just a means to an end.

So, when you open most other books or articles trying to tell you about gravity and gravitational waves, why are you faced with page after page filled with equation after equation, with maybe just the odd word or two here and there?

That is because to astronomers, astrophysicists and physicists, mathematics is their shorthandthey can describe things quicker using it, than if they were to use plain language.

However, just as a shorthand typist transcribes the squiggles of shorthand into plain language, so the squiggles of mathematics can also be transcribed into plain language. As Einstein may also have said: You do not really understand something until you can explain it to your grandmother. (Widely, but not reliably, attributed to Albert Einstein).

Thus, the objective of this book is to explain the natures of gravitational waves; what they are, why they are so significant, where they come from and why nobody has noticed them before nowto all grandmothersand also to all grandfathers, mothers, fathers, children, grandchildren, aunts, uncles, sisters, brothers, nieces, nephews, cousins, everywhere, using just plain languageor to express this more plainly; just using words. There are no equations in this book with which you have to wrestle.

Describing gravitational waves in plain language, though, does not mean that the ideas and concepts being described will be easy to comprehend. In reading this book, you will need to concentrate, work and think carefully about those ideas and concepts even though, or perhaps especially because, they are expressed non-mathematically. As Einstein saidand third time pays for all:

A hundred times every day I remind myself that I must exert myself in order to give in the same measure as I have received and am receiving (Albert Einstein. The world as I see it. Forum and Century, Volume 84, 1930).

All that saidI hope you find this book wonderful in the literal sense, illuminating, interesting and informative and I have no doubt at all that you will find that:

the Universe is not only queerer than we suppose, but queerer than we can suppose. (John B.S Haldane. Possible Worlds and Other Essays. Chatto & Windus, 1927).

The readership for this book may range from people who have vaguely heard of gravitational waves somewhere or other and now want to know a little more, to amateur and even professional astronomers and astrophysicists whose specialisms lie elsewhere than with gravitational waves. To enable all such readers to use the book profitably, it is written with its main theme as the backbone, together with separate tutorials which provide additional information for when it may be needed.

It is unlikely that all readers will need to look at all tutorials and many readers may prefer to skip the tutorials on a first run-through, coming back to them afterwards or at a point where they find they do need that information after all.