Springs and neaps, ebbing and flowing

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For the student of English, two of these words will probably be familiar. Spring could mean that part of the year when nature wakes up again, or a coil of wire which stores kinetic energy. Flowing is a word describing smooth liquid movement, but can also be used to describe any process which moves, or should move, in this way (i.e. work flow, traffic flow etc).

However, put together, these four words are used to describe tides along the coast. Britain is very much a maritime island and tidal behaviour is something we need to think about when building a house or planning land use near the sea, or simply taking a walk under some cliffs.

Careful planning is needed when building close to water.

Careful planning is needed when building close to water. These swans had not read the flood-risk warnings.

Spring tides happen when the sun and moon line up together and have the greatest gravitational pull on the sea. The result is the highest and lowest water levels along coasts and in estuaries, where rivers meet the sea and where tides can travel far inland along the river. High tides can be made even higher by low air pressure (about 1 cm per millibar of pressure), and by strong winds from a certain direction. The result is often then floods. Many communities just tolerate flooding, as the cost of protecting against it can be higher than the benefit.

Flooded garden in Totnes - photo copyright Malcolm Pemberton

Flooded garden in Totnes – photo copyright Malcolm Pemberton

Neap tides happen when the sun and moon are at right angles to each other, viewed from the earth. These tides have the least difference between high and low water levels.

If the earth had no land masses to stop these tidal flows, tides would be a fairly simple one-metre high lump of water travelling around the planet, with a one-metre deep trough following, about six hours later. However, the English Channel is a fine example of how things change when land gets in the way. This lump of water travels west to east across the Atlantic (actually, of course, this is caused by the spinning of the planet in the opposite direction), and then Europe and Africa get in the way.

The result of this is a massive build up of water in the Bay of Biscay (west of France and north of Spain), and a funnelling of water up the English Channel, causing water level changes of over five metres along the coast, not to mention a flow of water travelling up to 5 knots (five nautical miles per hour) eastward up the Channel for just over six hours, and then back westward as the tide ebbs. As you see, tides flow and ebb, rising and falling and travelling up and down channels and estuaries.

As tides depend on the spinning of the earth plus the positions of the sun and moon, they are completely predictable and the working lives of many people are dictated by them. Sailors must wait for there to be sufficient water to enter or leave a harbour, and sailing boats need also to wait for the tidal current to be going their way. Obviously, if your sailing boat can only travel at 5 knots with the available wind and you are sailing against a five-knot current, you will have an unchanging view of the coast!

Thoughts on approaching 60

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I must admit that I have been avoiding the whole subject of becoming 60 years old. I mean, it’s such a big number, such a milestone, such an image. People will think, “Oh, he’s 60 now, he’ll soon be retiring and getting ready to relax in his Golden Years. We should cut him a bit of slack and go easy on him. After all, he’ll soon start slowing down and forgetting stuff …”

Young ladies will start opening doors for me, instead of the other way round.
I’ll visit offices and the assistant will kindly ask, “Can you use a computer?”
I’ll be tempted to respond, “Yes, of course, how can I help you?”

The trouble is, far from slowing down, I feel like speeding up! Not physically of course – I would like to run a marathon some day, but at my own speed. I absolutely love biking, but I’m not interested in entering the Tour de France. What I mean is that my mind has never been so full of new and creative ideas. There is so, so much that I want to do. I have recently discovered the joys of filming, video editing and even acting, albeit as an extra. New technology has opened up a whole new world to ordinary people. Making movies is now something that anyone with the will can do. Thanks to YouTube, we can all now have our own TV channel. This is brilliant! I want to do it, and I’ve started already.

So, far from going to seed in front of the TV, with an occasional visit to the health centre and the library bus, and joining the other seniors in the park to discuss my latest ailment and what medicines I am currently on, I view this big number 60 as just the beginning of the next exciting phase of my life. I am going to do a ton of stuff that seems to have been on hold. I’m going to write great books, make great movies, try my hand at acting, get my mind round quantum physics, figure out the mystery of black holes and prove that travelling faster than the speed of light is no more difficult than breaking the sound barrier.

All this I am going to achieve whilst still earning a living and prospering. Screw New Year resolutions, they never work. This is my plan for the rest of my life, which starts, by the way, not tomorrow, but right now. There’s not a moment to lose!

Does Leap Day happen every four years?

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The answer to this question is yes, and then again no.

We think that Leap Days occur every four years because we have learned that the year is 365.25 days long, and therefore once every four years we need an extra day to catch up. However, it’s not quite that simple. Read more …

Being late shows how much you care …


Business Etiquette 1 – On Time, In Time or Late? – Or will the gates have closed on you?

Just what ‘late’ actually is depends on both culture, environment and circumstances, so I’m not going to be too picky about minutes. There is the idea of ‘fashionably’ late at a party, which can save the host the embarrassment of not being ready. There are the ‘academic fifteen minutes’ where the 10 o’clock lecture actually starts at a quarter past. There are phrases like ‘Just in Time’, the other side of which is ‘Almost too Late’ (hence the person kept waiting at the cinema door may choose the latter, where the friend who arrives panting with seconds to spare might choose the former). So how late is late can be pretty flexible, but less so in the business world, especially the further north you go.

What I’m saying is that late is late, and late is rude, and being late shows just how much you care.

Is Time Real?


Yes – so what is the problem?

The problem lies with the definition of time. On a day-to-day level, I believe that time is functionally constant and reliable. We can create mechanical and electronic devices to divide time into useful tiny pieces, small enough to measure the minute triangulation differences needed for GPS, large enough to let us know when it’s time to take a tea break. This is time as we need it, to control processes, to know what day it is and to be absolutely sure when an astronomical event will occur, or when Santa will come … read more:


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