Why waves never stop - E-book - ePub

This is a book about the physics of space and time. The main goal ofthis book is to explain why time passes slower on a movingtrain. Unfortunately, this is not easy to explain. Or rather, itcannot be explained at all.  This is, of course, a provocativestatement, whose meaning will depend on the interpretation of the wordto explain. We will therefore first deal with explanations in themselves andanalyse the question of what it means to explain, of how explanationswork.
That, you may think, is of no concern to you.  After all, finding explanations is my job. But, we are in the same boat, asexplanations are, obviously, closely linked to how we understand. Inthis context, we will encounter rules, that will be very simple intheir structure, but lead to very complicatedconsequences. Understanding has more to do with the complicatedconsequences than with the simple rules.
This is what makes explainingand understanding difficult.  In fact, we will even see, that thosecomplicated consequences cannot really be understood at all, but thatwe rather just get used to them.  Understanding is therefore aninappropriate vocabulary to describe what we are about to do in thisbook, and so is explaining. These are good news, as now, there cannotbe anything in the book that cannot be understood.
Instead, you justhave to get used to it. That, I think, should be doable. Nonetheless, we will then embark on a search for explanatory modelsthrough the history of physics. This search will be successful becausewe will find the only true, the ultimate language for an objectivedescription of nature. What language might this be?With this language, we will explore how classical physics uses thequantities space and time.
We will wonder why it takes time to movethrough space. What does time have to do with it? Waves will teach usthat space and time have to be treated on an equal footing. Shouldn'tit then take space to move through time? Shouldn't time depend on howsomething is moving through space? Shouldn't time be individual, relative and not absolute?Time is not what we think it is.  We will discover, by looking at awater bottle and by throwing dice, that the flow of time is anillusion.
The way physics describes time is fundamentally differentfrom the way we experience it, from what we think time is. In a slightly more technical chapter, we will learn how differentobservers can compare their locations and clocks, that is, space andtime, with each other and, based on that, how they can converse abouttheir respective views on nature. It is a curious thing that this typeof conversations, that such a theoretical argument, will directly leadto the most famous equation of all, E = mc2, with all of itsdramatic consequences for the real world.
Finally, we will learn how waves force us to treat space and time onan equal footing and how this merges space and time into a union, intospacetime.  Waves are, furthermore, responsible for the constant speedof light.  Just think of your last visit to the beach. Have you everwondered why waves seem to always go at the same speed? Have you everasked yourself, why waves never stop?