TIME AND TIDE WAIT FOR NO MAN

Timing is everything, and where tides are concerned, synchronized timing is everything.

Let’s take Julius Caesar’s attempted invasions of Britain for example. The time is 55 BC and Julius is having a field day in Gaul, racking up victory after victory. Across the channel lies the little island of Britannia and a bunch of unruly barbarians. Shouldn’t be too hard for the greatest commander and army in the world, right? Except for one thing. He comes from the Mediterranean, which does not really experience tides (more on that later). When he arrives, he encounters resistance. Instead of retreating, he boldly forces his ships to anchor closer to shore so his men can jump off in more shallow water. That night, under the watchful eye of a full moon, the spring tide comes in, and many of the Roman warships are filled with water while others smash against each other. Caesar and his troops have to stick around and fight those pesky Brits until more ships come to the rescue – and all because they were not aware that time and tide wait for no man.

Technically, the Mediterranean Sea does have tides, but because they are at such low amplitude, they are hard to notice. Caesar had other things on his mind, and did not bother reading the ancient Greek explorer Pytheas of Massilia’s accounts of tide rising up to 80 cubits in Britain. It took Pliny the Elder to read Pythias and report his tidal findings, but that was decades after Caesar’s assassination. Oh well, mark another point for bad timing.

So why is it that tides are so much more dramatic outside the Mediterranean? 

Basically, tides are the rising of the Earth's ocean surface caused by the tidal forces of the Moon and the Sun acting on the oceans. What this means is that Earth and Moon are attracted to each other like magnets. The Moon’s gravity pulls at the movable water and this gravitational attraction causes the oceans to bulge out in the direction of the Moon. The closer the Moon to the seawater the bigger the bulge and, on the exact opposite side of the earth, another tidal bulge is produced away from the Moon. 

Now we know that the Moon has just as much gravitational pull over Rome as it does over the Bay of Fundy, so why such minimal tides in the Mediterranean? The simplest explanation is that there is only one natural opening to a major ocean (Strait of Gibraltar) which limits the tidal flow. Also, the Mediterranean is a small body of water compared to the Atlantic or Pacific, and the smaller the body of water, the smaller the tides.

There are times when tides are at their weakest and strongest. When the sun and the moon are aligned, which we see when the moon is full or new, the gravitational forces are at their strongest, which makes for especially strong tides. These are called spring tides, which is what Caesar’ s ships experienced (that’ll teach you to count on the full moon for your getaway). Had he arrived during a quarter phase, things might have been different. This is when the sun and moon are at right angles, which makes the tides at their weakest since the gravitational bulges cancel each other out. These are called neap tides.

The forces that cause tides are strong, perpetual and can be measured. We can’t control the tides. Instead we adjust as best we can to their rhythms. Much of the same can be said for time and synchronization. Whether we like it or not, time marches on, is perpetual and can be measured. However, it often moves at different rates in separate computers across an IT network. Where time synchronization differs from the tides is that through NTP synchronization, we can harness these separate time clocks and their rates, and control them in a way that ensures time is precisely the same throughout the network.

The other difference between using a time server to synchronize time through a network and synchronizing your movements to the tides is that with a time server, like the SyncServer S300, you can set it and forget it. Not so with tides, as our friend Julius Caesar learned on his second invasion attempt of Britain a year later in 54 BC.

Once again he lands close to shore, makes his beach head and starts marching inland to find Britons to conquer. While he’s away another pesky tide comes along, this time accompanied by a storm, and his boats smash against each other. It takes his forces ten days to repair his ships and get more reinforcements. As we like to say in the world of synchronization, when one’s timing gets out of sync, bad things happen. And if you let it happen more than once, well maybe you too could have been a General in the Roman army.