Bulgarian orthodox Easter Eggs.
Bulgarian orthodox Easter Eggs. (Photo credit: Wikipedia)

At a time like Easter it is common to ponder on one’s faith. Whether one is religious or considers religion to be a delusion and waste of time and effort, one almost certainly aware of the origins of Easter, if one lives in an even nominally Christian country.

One may feel disgust that a religious occasion has been hijacked by commercialism, even if one is not religious, but one may still tuck in to Hot Cross Buns and chocolate Easter Eggs, and even partake of a slice of Simnal Cake.

Kulichs (kulich is a kind of Easter cake, trad...
Kulichs (kulich is a kind of Easter cake, traditional in the Orthodox Christian faith) (Photo credit: Wikipedia)

Some people pride themselves on having no faith, maybe even declaring themselves to be atheists. I feel though, that deep down everyone has some foundation philosophy or beliefs that seem to them to be unquestionable and obvious, that are in fact part of their make up.

Some people think that religion is silly and obviously wrong. They forget that religion as a world view has a long and successful heritage that has enabled people, in the main, to get along, and survive, and cooperate with other people.

The Army of Super Creatures
The Army of Super Creatures (Photo credit: Wikipedia)

It has, it is true, been blamed for a long list of atrocities as well (and still is, of course), but much of that is as a result of people’s’ usage of religion and not the idea of religion itself.

What is religion? It is the belief that the world is controlled and run by some supernatural being or beings, and that everything happens as a result of the aims and intervention of these supernatural being or beings.

English: "Hands of God", symbol of t...
English: “Hands of God”, symbol of the early ethnic religions of the Slavs and Vandals. (Photo credit: Wikipedia)

Before the invention of science, this would have seemed to be a reasonable theory. Of course, since we are only physical beings, we can only imagine why the supposed divine being causes things to happen that happen to us and to others.

And that’s what people do. In the absence of any other information, they imagine aims and objectives of the divine being or beings. The people who do the imagining are often called prophets or shamans or priests.

Retouched photograph of a shaman of the Ket pe...
Retouched photograph of a shaman of the Ket people. (Photo credit: Wikipedia)

Of course the shaman’s own people should be the ones favoured by deity, and of course they would be justified in all sorts underhand actions. All the people who did not belong to the shaman’s own people were obviously wrong or deluded and needed to be shown the error of their waves.

One might reasonably ask of the shaman, how does he know the wishes of the deity when the deity doesn’t converse with human beings. The shaman will have all sorts of esoteric methods for determining the wishes of the deity. Tossing bones, disemboweling chickens and taking various mind altering substances to enter trances.

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In many cases the shaman may believe that he is receiving instructions from the deity, though in some the shaman is possibly at least partly a pragmatic politician – it would career and life threatening to tell the tribal chieftain that he is going to lose the next challenge to his supremacy, or that the big tribe next door were going to conquer them.

Of course someone decided to write all the information about the tribe into a big book. Mostly the stuff written down was the history of the tribe and tall tales were OK, as it “proved” that the tribe was big and powerful and supported by the supreme being.

English: Title page of a 1830 copy of The Book...
English: Title page of a 1830 copy of The Book of Mormon: An Account Written by the Hand of Mormon upon Plates Taken from the Plates of Nephi (Photo credit: Wikipedia)

Of course such and such a hero defeated 1,000 opponents single handed. How could he do otherwise with the deity on his side? The trouble with writing it down is that fixes the story. There is no scope for the shaman to, shall we say, ad lib.

Also included in the written down texts, handed down from the aural tradition were the rules that the people had to adhere to, and the punishments handed out. Or supposedly handed out. As a punishment for a transgression some ancient person was put to death, but to deter others the punishment was supposedly horrific. And this punishment was enshrined in the holy text, so it became the official punishment.

English: Type of contracts at sharia law
English: Type of contracts at sharia law (Photo credit: Wikipedia)

As religion got institutionalised, it was used to justify wars and genocides and other atrocities, and still is to this day. One of the issues with religions and religious books is that things happened in the past and stuff got written to the books, and only a tenuous link between the two. There probably was a king called David, and he probably did some of the things attributed to him, but it is unlikely that the Bible gives an accurate description of his reign.

There is a philosophical problem with the idea of supernatural beings anyway. The only way that we can conceive of such entities is by giving them physical and human attributes – the supreme being is usually male for example. Generally the supernatural being is paternal and judgemental, and favours one particular set of people over others.

Although the Norse god Freyr functions as Hraf...
Although the Norse god Freyr functions as Hrafnkell’s patron deity, the saga contains few supernatural elements (Photo credit: Wikipedia)

To influence matters in the physical universe a supernatural being would need to manifest itself in physical ways. The problem is that a supernatural being is, by definition, non-physical and therefore cannot affect the physical world.

Some people have considered this issue and suggested that the supernatural being merely set up the universe and its laws in the beginning and has had no input since. While that removes the initial problem of the physical/supernatural interaction, it doesn’t address the physical question of how the universe was set up in the first place. It merely pushes the issue back beyond the Big Bang.

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Besides, many religions would be uncomfortable with a deity who merely set things up and then stepped away. Where would they get their laws and stories from? They’d have to make them up!

That’s the problem. Even if somehow the supernatural being’s wishes came to be embedded in a book (or even an aural tradition) someone has to read the book and interpret the words (as originally, the man in the street would not have been able to read) and for any number of reasons, the reader might, probably unconsciously, interpret the words in a way favourable to his biasses.

Setting aside (ordination) as readers of semin...
Setting aside (ordination) as readers of seminary students in Russia (Photo credit: Wikipedia)

And that might be the start of a crusade, and it’s difficult to conceive of a supernatural being who would favour people killing one another in its name. But the get out clause is that we can never understand the aims of such a being, should there be one, and this may be what the supernatural being needs to happen.

Captioned as "Balder und Nanna". The...
Captioned as “Balder und Nanna”. The god Baldr and his wife Nanna. (Photo credit: Wikipedia)



Thinking my Thoughts

Swirling thoughts
Swirling thoughts (Photo credit: Wikipedia)

Thoughts. We pump them out like a sausage machine pushes out sausages.Some of them we even push out onto paper or a computer screen and some pass on to other people by way of speech.

Thoughts are private to us and are never visible to the outside world. Each of us has their own thoughts, unless you are all zombies and my thoughts are the only ones that exist. Most people, I would guess, have thoughts that they would rather that other people do not know about, which would embarrass them if made public.

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Descartes believed that since he thought, that he must exist. One can chip away philosophically at that belief, but there is no doubting that Descartes exists and that he thought. We all do, solipsistic philosophy aside, even if Descartes’ argument is not correct.

The difficulty comes when we look at where thoughts come from and, indeed, what thoughts are. We may think “Did I leave the gas on?” or “I must change my library books”. Thoughts seem to happen unconsciously at first, and then move into the consciousness, at some level or other.

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The type of thought that I mention above about the gas and the library books spring right to the front or top of the consciousness, sometime surprising us. Other thought don’t impact so much on the consciousness, such as the thoughts that occur during a conversation.

For instance, suppose that you were chatting to friends, someone might question how you all got onto a subject. You are having coffee and find that you are discussing Amazonian Army Ants. How did you get on to the subject? On thinking back you piece together a chain of thought, that goes back to some totally unrelated topic, like the quality of fruit in the supermarket.

To be sure, I’ve suggested a conversation between several people, but similar happens in one person’s brain, as you can verify for yourself. Just grab a passing thought and work backwards from there and you will see what I mean.

Thoughts tend to be like cetaceans or some varieties of fish that live beneath the surface but sometime broach the surface before sinking back into the depths. It appears that the actual generation of thoughts happen below the level of consciousness, and then sink back into the unconscious. Memories of past thoughts can however be retrieved.

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Although we do not perceive thoughts being created, the thoughts passing through our consciousness and things happening external to our minds play a part in creating our thoughts. If I think of the first few digits of π, it is because I am looking around for an example of prior thoughts affecting current ones – I consciously decide to think of an example, and immediately became a past thought and so I thought of the first few digits of π.

I suggested that we pop out thoughts like a sausage machine pops out sausages. Unfortunately that analogy breaks down somewhat as current sausages are not influenced by prior sausages unless you really stretch the analogy by saying that the delicious taste of past sausages leads you to create the current sausage!

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The analogy does help a little though. What comes out of the sausage machine depends on what is put into the hopper. You won’t get pork sausages by filling the hopper with bits of beef of course, and in much the same way you will only get certain thoughts coming out if you have certain inputs going in.

The type of thoughts that we have can be changed by various methods, including repetition and example. We can learn by example and it influences what thoughts we have. If we see people standing for others in the train, we think to do this on other occasions.

English: Seat on Hoist Point A very smart new ...
English: Seat on Hoist Point A very smart new seat in a dramatic position with astonishing views (see 1511570, for instance). At the risk of being thought churlish, however, I have found more comfortable seats on which to rest aching legs. (Photo credit: Wikipedia)

A group of people will often start to think similarly, as the group forms and develops. A team that works well together may act as if they are reading one another’s minds, simply because they have learned to think in similar ways, and the team is said to have gelled.

It’s possible to force someone to think the way that you want them to think, by repetition and making things uncomfortable for them. This is called brainwashing and is for obvious reasons frowned upon. A fictional example come from the end of the book 1984 where Winston Smith is brainwashed into loving Big Brother by O’Brien.

Big Brother (David Graham) speaking to his aud...
Big Brother (David Graham) speaking to his audience of proles. (Photo credit: Wikipedia)

When people live closely together they tend to start to think alike as in the sports team mentioned above. Another example would be the cases where hostages have come to espouse the aims and objectives of the people who have taken them captive, such as the heiress Patty Hearst who was kidnapped by a terrorist group but came to support their cause even to the point of taking part on in armed robberies.

Thoughts can be directed by a person, but only to an extent. One can concentrate one’s thoughts on study, but it is difficult to know how that happens. The experience of study (or the loosely related one of computer programming) can an in depth totally encompassing one, leading to a condition known to programmers as “being in the zone“. This can also apply in other fields of human endeavour too.

Often though, without the person being aware, the zone drifts away and the person ends up in the day dream state, thinking of things other than the topic that is supposed to be being thought about. This usually happens when the person has difficulty in concentrating on the topic as it bores them or they don’t understand it.

Some thoughts are completely below the level of the conscious, such as those that one has when one is asleep. Like all thoughts they soon fade into the depths and mostly leave no impression on the memory. Occasionally though, some dreaming thoughts survive in the memory through the process of waking, but they often seem bizarre or irrelevant to anything to do with our conscious lives. Sometimes though, they can be source of inspiration, as in the case of one of the inventors of the sewing machine, Elias Howe.

Sewing machine, type Calanda 17
Sewing machine, type Calanda 17 (Photo credit: Wikipedia)


A Kahn process network of three processes with...
A Kahn process network of three processes without feedback communication. Edges A, B and C are communication channels. One of the processes is named process P. (Photo credit: Wikipedia)

When an output of a process is taken and fed back to the input of a process it causes changes to the output. This changed output is then fed back to the input and so on. This basic idea has myriads of applications, in nature, in science, and in real life.

Feedback can be positive or negative. If it is positive, it adds to the input, which increases the output, which is then fed back to the input, which increases it still more, and we have a runaway increase. This is what causes the howl that occurs when the output from a microphone amplifier is accidentally fed back to the microphone.

US664A University Sound Dynamic Supercardioid ...
US664A University Sound Dynamic Supercardioid Microphone (Photo credit: Wikipedia)

Negative feedback subtracts from the input, which can result in a reduction of the output  of the process. It won’t necessarily result in NO output however, as the amount of feedback is reduced as a result of the output being reduced, and therefore the output may drop to a fixed value. There are relatively complex equations which govern feedback behaviour which I’m not going to go into here.

Of course the input and output must be related for feedback to be possible. Electrical circuits are a classic example, of course where the input and output are both voltages, and in the case of a cruise control system, the speed of the car is converted to a signal (which may be a voltage, I’d guess) and the feedback is via a signal applied to the fuel control system, which again could be a voltage.

Illustration for bowden cable. Highlighted vie...
Illustration for bowden cable. Highlighted view of the throttle cables on a 1998 model Chrysler Town & Country minivan. To the best of my knowledge, one cable comes from the gas pedal and one comes from the cruise control. (Photo credit: Wikipedia)

Feedback is inevitably delayed with respect to the inputs. In any real system the input takes time to be fed back, and sometimes this interferes with the intended operation of the feedback loop. It can cause swings in the size of the output, and the system state oscillates.

This is how electronic oscillators are designed to work, but in control systems such oscillations are unwanted and could be destructive. One way to deal with this is to “damp” the circuit, which effectively slows the feedback so that the system state moves more slowly towards the desired state rather than attempting to jump directly to it. Such damping helps reduces overshoot where the momentum of the raw feedback would cause the output to go past the required value.

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The input and output together with the feedback form a feedback loop. Feedback loops can be found everywhere, in mechanical and electrical systems, in climate systems and biological systems.

One interesting question is whether or not there is a long term feedback loop that will react to global warming to reduce the effects after a while. If so, would the feedback be more detrimental to the human race than global warming itself.

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Such feedback could be something like increased storms and disappearance of seasonal rain that will eventually finish off the human race, perhaps. According to the Gaia hypothesis the Earth is a dynamical system that help to maintain life on Earth. If that is true, it may be broken by global warming, or it may react against global warming in ways which may not yet be apparent.

Systems may have more complex feedback going on than a single simple positive/negative. A process may have several independent positive and negative feedback loops operating at the same time. The various loops may be connected in complex ways and the behaviour may be impossible to accurately predict.

A general representation of a closed loop feed...
A general representation of a closed loop feedback system (Photo credit: Wikipedia)

A biological example is the case of the rabbits and the foxes. The population of the rabbits depends on many things – how many bunnies there are, the extent of their food supply, the maturity of the average bunny – how many are mature enough to be able to produce more bunnies. Similarly such factors apply to Basil Brush and his cohorts.

If the rabbits food is plentiful, then they will breed, well, like rabbits and the population will rise. This provides an increased food supply for the foxes and their population increases. Eventually the rabbits manage to increase to the stage where the food becomes limited and the population stops increasing.

Die Gartenlaube (1889) b 497
Die Gartenlaube (1889) b 497 (Photo credit: Wikipedia)

Alternatively the increase in the fox population may grow faster than the rabbit population. The foxes kill more rabbits than the rabbits can replace and the rabbit population crashes. The foxes then starve to death as the rabbits start to recover. There are various opinions as to the exact mechanism is concerned, but there is no doubt that boom and bust cycles are seen in the predator/prey relationship, and there is no doubt that feedback cycles are involved somehow.

It is often said that negative feedback acts to return the system to equilibrium. While this may be true in the short term, any such equilibrium is temporary, and as the rabbits and foxes example shows, it is more likely that a system will only temporarily return to the equilibrium and often a system will pass through equilibrium many times as it oscillates too and fro.

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In fact, in most cases the “equilibrium position” will rarely be occupied by the system for any length of time. The typical system that oscillates about an “equilibrium position” is a pendulum. A pendulum is travelling its fastest when it passes the lowest point of its arc. The “feedback” in this case is provided by gravity of course.

Feedback also describes the missives and reports sent to an organisation about its services. The organisation may have sought such feedback by distributing questionnaires, by links on a web site, or maybe by word of mouth. Respondents have the opportunity to provide both positive and negative feedback depending on their experience with the organisation.

English: Overview of four different options to...
English: Overview of four different options to be A/B tested for Wikimedia’s Article Feedback Tool V5. This A/B test would let us compare these different options for an improved feedback form, to find out which version is most effective for engaging readers and improving article quality. See project page (Photo credit: Wikipedia)

Such research and feedback is called “market research” and has seen organisations change their stance on some topics. McDonald’s Corporation has banned plastic food containers (in 1990) and plastic drink containers (in 2013) as a result of feedback from environmental lobby groups.

Politicians also get feedback from the voters in the form of opinion polls and surveys. It would be a brave politician (perhaps a soon to be former politician) who ignores the opinion polls. Such a politician would be looking for a fresh job after the next election.

UNDP Helen Clark meeting with New Zealand Prim...
UNDP Helen Clark meeting with New Zealand Prime Minister John Key (Photo credit: Wikipedia)

(I believe that I am now all caught up on the posts that I missed. Yeah!)



English: Cumulus cloud above Lechtaler Alps, A...
English: Cumulus cloud above Lechtaler Alps, Austria. Español: Nube cumulus sobre los Alpes austriacos. Deutsch: Cumuluswolke über Lechtaler Alpen, Österreich. (Photo credit: Wikipedia)

Clouds are collections of water droplets suspended in the air. A cloud is formed as the water vapour in the air condenses onto particles of dust or other water droplets. The water in a cloud weighs tonnes! It’s a good job that the droplets don’t have time to coalesce into great balls of water before they reach the ground, but I suppose that to insects a droplet is a huge ball of water, and able to cause havoc.

As anyone who has flown in an aircraft is likely to know, clouds are not well defined, and in fact they could be described as nebulous or hazy. From a mathematical point of view they are fractal and the fractal dimension (a measure of their fuzziness) varies depending on the cloud.

Fractal plant curve, made using an L-system
Fractal plant curve, made using an L-system (Photo credit: Wikipedia)

A common pastime on a summer’s day is to imagine shapes in the clouds. That one may look vaguely like a car, that one like a dog, and so on. But really, the only shape that clouds have is “cloud-like“.

There are many types of cloud shape, depending on the conditions and the altitude where the cloud is forming, but the usual depiction of a cloud generally looks like a cumulus type. This type forms the usual shape like piles of cotton wool in the sky, with mountain, canyons, and even castles.

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There is always water vapour in the air, even if it doesn’t form clouds, although we cannot see it. As I said above, clouds are formed when this water vapour condenses on small particles in the air (and other conditions are right). Sometimes there are attempts to make rain by “seeding” a cloud with small particles to increase the rate of condensation and thus increasing the size of the water droplets.

At a certain  size the droplets become to big to be buoyed up by the air and start to fall, picking up more moisture as they do. As I understand it, this cloud seeding process is limited in its success, but I may be wrong.

Cessna 210 (OE DSD), rebuilt for cloud seeding...
Cessna 210 (OE DSD), rebuilt for cloud seeding, with 2 silver iodide generators (Photo credit: Wikipedia)

Clouds sometimes form at ground level, if the conditions are right, and then we call them fogs or mists. This often happens when light rain is falling and there is a lot of moisture in the air, but it can happen simply because the conditions are right.

Living where I do, I occasionally have reason to visit the local airport in Wellington. The airport is situation on a section of land that was brought up by a an earthquake, so that it is on a narrow stretch of land between two sets of hills. Over the hills to the East of the airport is the entrance to the Wellington Harbour.

English: Aerial view of the Miramar Peninsula,...
English: Aerial view of the Miramar Peninsula, Wellington, New Zealand. Wellington International Airport is visible and the beach just above the left-hand end of the runway is Lyall Bay. Downtown Wellington city, the harbour and port can be seen in the distance. (Photo credit: Wikipedia)

On several occasions I have seen sea mist roll in from Cooks Strait to the South and extends tongues of thick mist over the airport and the Harbour entrance. This causes the airport to shut down until the conditions have cleared, spoiling the travel plans of hundreds of people.

Other clouds which are familiar to many are the stratus clouds. These clouds are layers which cover all or most of the sky under some conditions. They often presage rain or other forms of precipitation. Stratus clouds range from light to dark and in many cases might cause a drop in one’s spirits.

English: Stratus undulatus clouds. I took this...
English: Stratus undulatus clouds. I took this picture out the car window on the way to Vancouver. (Photo credit: Wikipedia)

Certainly the dark stratus has that effect on me, and there is little that is more spectacular than breaking through a layer of cloud in a plane. The tops of the clouds will be brightly lit by the sun, and sometimes whorls or rivers of cloud can be seen from above.

The tops of the clouds can be quite lumpy and cumulus-like, and descending into the clouds is like descending into mountains and canyons and the lumps and bumps of the cloud can whizz past like scenery on a train, until the plane finally breaks through the greyer, darker ceiling of the cloud layer.

English: "The two main cloud types are St...
English: “The two main cloud types are Stratocumulus mixing with Cumulus in the foreground with Cumulus beyond” ~ Identified by (Photo credit: Wikipedia)

However, broken stratus clouds are the clouds which produce amazing sunsets as the sun drops through the layers and gaps in the clouds. Very often a beam of sun breaks through a stratus layer and lights up the water droplets or dust producing what looks like a column of light. These rays are known as crepuscular rays.

Add to that the amazing colours that result from the breakthrough sun beams and the dust and water droplets and sunsets can be very beautiful, even if the sun light is in fact refracting or reflecting from pollution in the air.

Crepuscular Rays and over
Crepuscular Rays and over (Photo credit: Wikipedia)

When the sun has gone below the horizon, it can still illuminate clouds above the horizon causing them to glow with an orange light, as the blue light is absorbed by the thick layer of atmosphere these rays which are almost tangential to the earth’s surface have to pass through.

Cumulus clouds are often sought out by glider pilots, since they are often formed by an up welling of air over a particularly warm piece of land. The up welling of air provides the glider pilot with extra lift, which allows them to travel vast distances, but a downside is that some clouds can be chaotic and turbulent. Birds will often guide a pilot to the up draughts there is no cloud.

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Another totally different sort of cloud has appeared over recent years, and that is the Internet cloud. The Internet cloud is also somewhat nebulous, and allows us to take a photograph on one device (computer phone or tablet) and view it almost immediately on another device.

The cloud (often the Cloud) also allows for automatic backups for devices – if your device implodes or is lost or stolen, your data is safe. Mostly. For if you sync (synchronise) your device with the Cloud, and then delete a photograph, it will shortly be removed from the Cloud and lost.

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To prevent data loss, you can backup to somewhere else on the cloud, so there are two (or more) cloud copies, or you can backup to a local computer or local storage, so that if you delete something by mistake you can always get it back. As anyone in the computer business will tell you, one backup is never enough!

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Impact from a water drop causes an upward &quo...
Impact from a water drop causes an upward “rebound” jet surrounded by circular capillary waves. (Photo credit: Wikipedia)

The title of my post may look odd, but it represents one of the most important chemical compounds on earth. Without it, life would not exist and the search for evidence of the possible existence of life on other planets often comes down to looking for this molecule. It is of course, water.

If you still don’t understand my title, the formula for water is H2O, where the “2” should be subscript representing the fact that there are two Hydrogen atoms in water and one Oxygen atom. This could be misheard as “H to O”, hence my title.

The water molecule with its electric charges
The water molecule with its electric charges (Photo credit: Wikipedia)

Water could be considered to be an oxide of hydrogen, or hydrogen oxide. There is a closely related compound called hydrogen peroxide (which has two oxygen atoms) which is sometimes used as a bleach and disinfectant. Surely everyone over a certain age has heard of “peroxide blondes“.

Water is sometimes referred to, usually jokingly, as dihydogen monoxide. This silly pseudo-scientific name in sometimes used to create fake polemics against water to trick gullible people, causing them to call for a ban on this noxious and toxic chemical!

The logo of, primary current residenc...
The logo of, primary current residence of the dihydrogen monoxide hoax (Photo credit: Wikipedia)

We see water all around us, in all three normal states of matter, solid, liquid and gas. Well, ice and water can be nearly transparent, and water in the gaseous state is invisible – we can only see the water vapour that forms when water in the gaseous state condenses into small particles of liquid water suspended in the air.

Water molecules have a slight “V” shape which gives it some amazing properties. it has a minimum density at 4 degrees Centigrade. It freezes at 0 degrees Centigrade so ice is slightly less dense than liquid water and the ice floats. This results in icebergs and the inevitable reference to the Titanic, which as everyone knows hit an iceberg on its maiden voyage, and endless discussions on whether or not both Jack and Rose could have survived the disaster.

TITANIC life boats on way to CARPATHIA
TITANIC life boats on way to CARPATHIA (Photo credit: Wikipedia)

Not only does ice keep our drinks cool, but it also forms a skin over ponds and puddles in winter which has the effect of protecting small plants and animals from the worst of winter. This is because the ice acts as an insulating layer and allows some warmth to remain in the waters of the pond.

Most animals can’t survive freezing but some really small ones, like certain frogs and toads and some spiders and insects survive being frozen solid. It is believed that this is because of some constituents of their blood acting as an anti-freeze agent, prevention the destructive formation of ice crystals in the cells and blood of the animal.

English: Frozen pond The water here has frozen...
English: Frozen pond The water here has frozen hard. It is believed to be excess field water not a natural pond. (Photo credit: Wikipedia)

Gaseous water is found all around us. It is dissolved, as it were, in air. It’s the water in the air which gives it its humidity. Gaseous water is swept up by the air and boosted to high altitudes by air currents and condenses to clouds, which are masses of water vapour. Ultimately the water falls to earth as rain and runs off into the seas. This whole cycle is driven by heat energy from the sun which causes the evaporation.

On average a human being’s body contains approximately 60% water. It can be higher as in a new-born baby or lower as in obese persons. If a normal person refrains from drinking liquids he or she may become dehydrated, which can result in mental issues and physical ones (which usually go away if the person is rehydrated.

(From source) This cholera patient is drinking...
(From source) This cholera patient is drinking oral rehydration solution (ORS) in order to counteract his cholera-induced dehydration. The cholera patient should be encouraged to drink the Oral Rehydration Solution (ORS). Even patients who are vomiting can often be treated orally if they take small frequent sips. Their vomiting will subside when their acidosis is corrected. (Photo credit: Wikipedia)

A person loses water by sweating and by urinating. If he or she is in an arid environment, such as a desert, he or she will lose water faster than usual, and if it is not replaced, the dehydration could kill. In hot humid climates, sweating is less effective in controlling the person’s temperature and he or she may die of overheating.

Our planet is (mostly) blue from space mainly because the presence of the water that makes up the seas. However in small quantities and in very shallow depths the colour of water is often due more to the mineral content of the water than anything else. This leads to rivers being called “Blue Nile” (because of the black sediment carried by the river – the word for black is also used for blue in the local dialect) or “White Nile” (because of the light clay sediment carried by the river) for example.

The Earth seen from Apollo 17.
The Earth seen from Apollo 17. (Photo credit: Wikipedia)

Apart from making up most of our bodies, and being essential for the body’s proper functioning, water has a myriad of uses to humans. It forms a part of many industrial processes for example, and it often provides the power for them, by way of hydroelectric generation. It helps make our crops grow, and we use it and flavour it to provide our beverages.

We also use water for recreation. We swim in the seas and rivers, we sail on them and we dive under them. We hike many kilometres in some cases to view places where water flows over a drop, and we even explore the caves created by the action of water on some rocks.

A windsurfer with modern gear tilts the rig an...
A windsurfer with modern gear tilts the rig and carves the board to perform a planing jibe (downwind turn) close to shore in Maui, Hawaii, one of the popular destinations for windsurfing. (Photo credit: Wikipedia)

The deep waters of the seas provide much of our food. Our fishermen haul great numbers of them from the seas with some difficulty and at some expense. There are people who believe that we are doing great damage to the planet by doing this, and that we are causing much marine life to become extinct, which seems to be a big risk to us in the future.

We look for water on other planets, to determine whether or not they will or have supported life. The reasoning behind this is that our way of life, and the way of life of all creatures on Earth depends on water. We cannot conceive of a life form that does not depend on water in some ways. That doesn’t mean, of course, that such life forms do not exist, but just that we can’t currently conceive of a way that such a life form could exist. As Mr Spock might say “It’s life, Jim, but not as we know it”.