HOW DO WE GET DRUNK ?

There are actually many kinds of alcohol in the chemical world, but the one we drink the most is ethanol. It's the particular shape of an ethanol molecule that gives a glass of beer or a shot of the hard stuff its specific effects on the human brain.The molecule is very tiny, made up of just two carbon atoms,six hydrogen atoms, and one oxygen atom.
Ethanol is water soluble,which means it enters the blood stream readily, there to be carried quickly to all parts of the body (most notably the liver and the brain). It's also fat soluble; like an all-access pass through various cell membrane sand other places that are normally off limits.

A certain portion of the ethanol you drink passes through your stomach to your small intestine,
then absorbed into your blood stream and carried to your brain.That's what we're really concerned with. Research has not conclusively determined exactly how ethanol accomplishes all of its various effects in the brain,but there are some well-supported theories. The slow reactions, slurred speech and memory loss of a drunk are probably caused by ethanol attaching to glutamate receptors in your brain's neural circuitry.These receptors normally receive chemical signals from other parts of the brain, but instead they get an ethanol molecule.This disrupts the flow of signals and generally slows the whole brain down.

Ethanol also binds to GABA ( gamma-aminobutyric acid) receptors,which normally serve to slow down brain activity.
Unlike glutamate receptors, ethanol actually makes GABA receptors more receptive, causing the brain to slow down even more.
But alcohol isn't simply a depressant, because it also stimulates the production of dopa mine and endorphins, chemicals that produce feelings of pleasure. Research hasn't yet revealed the exact mechanism involved, but it may be similar to the way ethanol stimulates the GABA receptors.

WHAT'S INSIDE THE HEART ?

Your heart is a turbocharged double ¬ pumping muscle that beats more than 40 million times every year

Not only does your heart do amazing things, it does so tirelessly, every minute of every day from the moment you're born (actually, even a bit before then) to the instant that you die.It weighs somewhere between eight and 12 ounces - slightly more if you're male,less if you're female. Its sole purpose is to push blood through your circulatory system, providing crucial oxygen and other nutrients to all your organs.

The heart is considered a double pump because the right half sends 'used' blood to your lungs.There, the blood drops off a load of carbon dioxide and picks up some fresh oxygen, which you have helpfully provided by breathing.Then the oxygenated blood returns to the left half of the heart.This 'heart-to-lungs-to-heart again' trip is known as pulmonary circulation.The left side of the heart then pumps this oxygenated blood to every organ in your body other than your lungs.
Your brain,your skin, the musclesin your thigh,yourspleen-theyall get blood (and therefore oxygen) by virtue of your beating heart.

Even the heart itself gets blood, via a special set of veinsand arteries known as the coronarysystem.The myocardial muscle within the wall of the heart needs oxygen and other nutrients to keep beating. Unfortunately, the coronary arteriesthat do this jobarevery narrow, between1.7and 2.2 millimetres in diameter. If they become clogged with cholesterol or other fatty deposits, the
heart stops working.This is bad for you.

Of course, the relatively simple concept of the double pump is fairly complex in practice. A series of valves control blood flow to the heart's four chambers, allow for the build-up of enough blood pressure to get the job done,and direct the blood to the correct veins
and arteries.

HOW DOES A CAMERA TAKE PICTURE ?

Many camera owners are content to shout "Cheese" and push the shutter button to get an image, but we go under the hood to find out how it happens

There is no doubt that the digital format has revolutionised the imaging industry and in turn the way we work our cameras.Furthermore the internal DNA of the camera has been entirely restructured to make way for the new electrical system...or has it? In fact film and digital cameras operate in a similar manner.Varying the size of the lens's diaphragm(aperture) in tandem with the amount of time the shutter is open, focusing light onto the image detection material...the only difference is that now received in an electrical rather than chemical form. A DSLR (digital single-lens reflex) camera employs a mechanical mirror system that directs the light travelling through the attached lens upwards at a 90-degree angle allowing the photographer to compose the shot through the viewfinder.As the shutter button is pressed the exposure takes place: the mirror swings out of the way and the shutter opens allowing the lens to project the light onto the image sensor.

In low light scenarios the shutter will need to stay open for a longer period of time for the image to be recorded, which is why photographers support their cameras with tripods as the smallest degree of camera shake will disturb the quality.

The sensor is formed of millions of pixels laid out in thousands of rows and columns: the more pixels or dots of light, the higher the megapixel count and in theory the higher the resolution. The light travels through a col our filter above the sensors and is converted from light waves in to an analogue signal which is then processed through a digital convertor. Next the conversion is fine tuned through a series of filters that adjust aspects such as white balance and colour.The resulting image can be made in to a JPEG by compressing the file size and discarding unnecessary pixels.The final image is shown on the LCD.

WHAT IS GRAVITY ?

Surprisingly weak yet mysteriously powerful, gravity is the super glue of the universe

Everything in the universe is made of matter the cosmic 'stuff' of creation. Mass is measurement of the amount of matter contained in any object, from planets to protons.

The Earth, for example,has a mass of 5.9742 x 1024 kilograms,while the mass of a single proton is 1.67262158 x 1027 kilograms.

When we think of gravity,we usually think of the gravitational force exerted by massive celestial bodies like the Earth,the Moon or the Sun.But the truth is that any object of any mass-even a sub-atomic particle- exerts a gravitational pull on near by objects.

Sir Isaac Newton proved that objects of greater mass exert a stronger gravitational force.That's why we typically talk about gravity in reference to planet sand not protons.

But the shocking truth about gravity is that even a colossal hunk of rock like the Earth exerts an exceptionally puny pull.An infant,in fact,can defeat the combined gravitational pull of every single atom on the planet by simply lifting a wooden block off the floor.

That's what makes Newton's discoveries so amazing,even today.Gravity-this wimp of a force-is somehow powerful enough to pull the moon in to orbit and keep the Earth cruising in a perfect elliptical path around the Sun.Without the constant tug of gravity,planets would crumble into dust and stars would collapse.

Gravity is also responsible for giving objects weight.But don't confuse weight with mass. While mass is a measurement of the amount of matter in an object,weight is the downward force exerted by all of that matter in a gravitational field.In the zero-gravity vacuum of space, objects are weightless,but they still have mass.

On the surface of the Earth, where the force of gravity is essentially constant,we consider mass and weight to be equal.But that same object-with the same mass-will weigh 17 per cent less on the Moon,where the gravitational pull is weaker.On Jupiter-not the best place to start a diet- that same object will weigh 213 per cent more.

HOW DOES THE OZONE WORK?

 We may hear about it a lot, and mainly how we're slowly destroying it, but just what is the ozone layer?

The ozone layer is essentially Mother Earth's safety net. residing some 50 kilometres above the planet's surface. created from O3 or ozone gas,it is up to 20 kilometres thick and 90 per cent of this gas can be found up on the Earth's stratosphere.
This protective gas is vital to the nurturing of life on our planet,and here's why.
Ozone gases act as a shield against ultraviolet,or UVB, radiation. These harmful emissions are sent through the Sun's rays,and without the ozone would severely affect the planet's ecological balance, damaging bio-diversity.UVB rays reduce plankton levels in the ocean,subsequently diminishing fish stock.Plant growth would also diminish in turn disrupting agricultural productivity. This would in turn affect the human populace,who would be exposed to an increase in skin-related diseases such as cancer.

So how does the ozone protect us? Ozone molecules consist of three oxygen atoms, hence the chemical formula O3.Stratospheric ozone absorbs UVB high-energy radiation,as well as energetic electrons, which in turn splits the O3 in to an 0 atom and an O2 molecule. When the 0 atom soon encounters another O2 molecule they re-merge and recreate O3.This means that the ozone layer absorbs the UVB without being consumed.The ozone layer absorbs up to 99 per cent of the Sun's high frequency UV light rays, transforming this in to heat after its combustible atomic reaction,therefore creating the stratosphere itself.This effectively incubates life on Earth.
But ozone doesn't reside only in the world above.
This gas is also present in the layer around the Earth's surface.Ten to 18 km above us, this is known as the tropospheric ozone or 'bad ozone',comparative to the function of the stratosphere.
This ozone occurs naturally in small doses, initiating the removal of hydrocarbons,released by plants and soil,or appearing from small amounts of stratospheric ozone,which occasionally migrate down to the Earth's surface.
However,it gets a bad reputation due to its interaction of ultraviolet light, with volatile organic compounds and nitrogen oxides,emitted by fossil-fuel powered machines and internal combustion engines. The produces high levels of ozone which are formed in high temperature conditions, ultimately toxic to all forms of organic life.

WHAT DOES THE LIVER DO ?

The human liver is the ultimate multitasker - it performs many different functions all at the same time without you even asking

the liver is the largest internal organ in the human body and has over 500 functions. In fact it's the second most complex organ after the brain and is involved in almost every aspect of the body's metabolic processes.Its main functions are energy production, removal of harmful substances and the production of proteins.These tasks are carried out within liver cells called hepatocytes, which sit in complex arrangements to maximise efficiency

The liver is the body's main powerhouse, producing and storing glucose as a key energy source.It is also responsible for breaking down complex fat molecules and building them up into cholesterol and triglycerides,which the body needs but in excess are bad. 

The liver makes many complex proteins, including clotting factors which are vital in arresting bleeding.Bile,which helps digest fat in the intestines, is produced in the liver and stored in the adjacent gallbladder.

The liver also plays a key role in detoxifying the blood. Waste products, toxins and drugs are processed here into forms which are easier for the rest of the body to use or excrete.The liver also breaks down old blood cells, produces antibodies to fight infection and recycles hormones such as adrenaline. Numerous essential vitamins and minerals are stored in the liver:vitamins A, D, E and K, iron and copper.

Such a complex organ is also unfortunately prone to diseases.Cancers (most often metastatic from other sources),infections (hepatitis)and cirrhosis (a form of fibrosis often caused by excess alcohol consumption)are just some of those which can affect the liver. 

HOW DO KIDNEYS FUNCTION ?

Find out what your kidneysare doingto keep you alive

Kidneys organs the back are situated just bean-shaped under halfway the down
ribcage, one on each side of the body,and weigh between115and 170 grams each, dependent on the individual'ssex and size.The left kidneyis commonlya little larger than the right and due to the effectiveness of these organs, individuals born with only one kidney can survive with little or no adverse health problems. Indeed, the bodycan operate normallywitha 30-40 per cent decline in kidney function.This decline in function would rarely even be
noticeable and shows just how effective the kidneysareat filtering out waste productsas well as maintaining mineral levels and blood pressure throughout the body.The kidneys
manage to control all of this by working with other organsand glandsacross the bodysuch as the hypothalamus, which helps the kidneysdetermineand control water levels in the body.
Each day the kidneys will filter between150and180 litres of blood, but only passaround two litres of waste down the ureters to the bladder for excretion.Thiswaste product is primarily urea-a by-product of protein being broken down for energy -and water,and it'smore commonly known as 'urine'.The kidneys filter the blood by passing it through a small filtering unit called a nephron. Each kidney hasaround a million of these, which are made up of a number of small blood capillaries, called glomerulus,and a urine-collecting
tube called the renal tubule. The glomerulussift the normal cellsand
proteins from the blood and then move the waste products into the renal tubule, which transports urine down into the bladder through the ureters.
Alongside this filtering process, the kidneysalso release three crucial hormones (known as erythropoietin, renin and calcitriol) which encourage red blood cell production,aid regulation of blood pressure and help bone development and mineral

HOW DOES THE BRAIN WORK ?

The human brain in the most mysterious and complex entity in the know universe

It’s a computer, a thinking machine, a fatty pink organ, and a vast collection of neurons. But how does it actually work ? The human brain is amazingly complex – in fact, more complex than anything in the known universe. The Human brain effortlessly consumes power, stores memories, processes thoughts, and reacts to danger.

In some ways, the human brain is like a car engine. The fuel – which could be the sandwich you had for lunch or a sugar doughnut for breakfast – causes neurons to fire in a logical sequence and to bond with others neurons. This combination of neurons occurs incredibly fast, but the chain reaction might help you compose a symphony or recall entire passages of a book, help you pedal a bike or write an email to a friend.

Scientists are just beginning to understand how these brain neurons work – they have not figured out how they trigger a reaction when you touch a hot stove, for example, or why you can re-generate brain cells when you work out at the gym.

The connections inside a brain are very similar to the internet – the connections are constantly exchanging information. Yet, even the internet is rather simplistic when compared to neurons.

They are ten to 100 neurons, and each one makes thousands of connections. This is how the brain processes information, or determines how to move an arm and grip surface. These calculations, perceptions, memories , and not just a few times per minute, but million. According to Jim Olds, research director with George Mason University, if the brain would be an complex as our galaxy. In other words, we have a lot to learn. Science has not given up trying, and has made recent discoveries about how we adapt, learn new information, and can actually increase brain capability.

In the most basic sense, our brain in the center of all input and outputs in the human body. Dr Paula Tallal, a co-director of neuroscience at Rutgers University, says the brain is constantly processing sensory information – even from infancy. « It’s easiest to think of the brain in terms of inputs and outputs »,  says Tallal, «  Inputs are sensory information, outputs are how our brain organises that information and controls our motor systems ».

Talla says one of the primary functions of the brain is in learning to predict what comes next. In her research for scientific learning, she has found that young children enjoy having the same book read to them again and again because that is how the brain registers acoustic cues that form into phonemes (sounds) to become spoken words. « We learn to putt things together so that they become smooth sequences » She says. These smooth sequences are observable in the brain, interpreting the outside world and making sense of it. The brain is actually a series of interconnected ‘superhighways’ or pathways that move ‘data’ from one part of the body to another .

HOW BRAIN FREEZE HAPPENS

Technically called sphenopalatire ganglioneuralgia, ice cream headaches are related to migraines

The pain of a brain freeze, also know as an ice cream headache, comes from your body’s natural reactions to cold. When you body senses cold, it wants to conserve heat. One of the steps it takes to accomplish this is constricting the blood vessels near your skin. With less blood flowing near your skin, less heat is carried away from your core, keeping you warn.

The same thing happens when something really cold hits the back of your mouth. The blood vessels in your palate constrict rapidly. When the cold goes away (because you swallowed the ice cream or cold beverage), they rapidly dilate back to their normal state.

This is harmless, bit a major facial nerve called the trigeminal lies close to your palate and this nerve interprets the constriction/dilation process as pain. The location of the trigeminal nerve can cause the pain to seem like its coming from your forehead. Doctors believe that this same misinterpretation of blood vessel constriction/dilation is the cause of the intense pain of a migraine headache.

HOW DO BOATS STAY AFLOAT

How do boats stay afloat ?

Displacement enables huge ships to stay above the water

At first displacement appears to be far from fascinating. Simply put, the volume of an object, when submerged in water, pushes aside the same volume of water. This simple process allows anyone to measure the precise volume of any object by then measuring cylinder. It’s all very ‘science textbook’.

It becomes a little more interesting when you consider that it’s this effect that enables enormous supertankers weighing up to 400,000 tones to float. For example, when a supertanker is launched into the sea it will sink if the water it displaces is equal to or exceeds the weight of the ship itself. However, if when  launched its weight is less that that of the water displace the weight faster that the water will reach the tanker’s submerging point, no matter how large or full of cargo, then it will float.

Of course, if you were to drop a solid iron bar into a swimming pool, it would sink straight away because : firstly, its weight fat outweighed that of the water it was displacing and secondly, even if its weight was less than that of the water, its shape would not allow it to displace the weight fast enough. This is why ships hullsare shaped how they are.

So while the scientific principle might lack wow factor, it does enable fantastic feats of engineering like the TI class supertankers, the largest ocean going-ships in the world. They’re an incredible 379 meters long, 68 meters wide and have a dead weight of some 441,585 metric tons and float thanks to the law of displacement discovered by Archimedes in the original Eureka moment.

HOW FISH BREATHE UNDERWATER?

How do fish breathe underwater ?

The process of absorbing oxygen and the release of carbon dioxide is called ‘gas exchange’. Fish need oxygen in the same way humans do, they just go about getting it in a different way.

A fish has gills behind its mouth, on the side of the head (unless you’re bottom dweller like a stingray, then your gills are on the top of your head). Each gill begins with a gill arch which then splits into two filaments, much like a wishbone. Those filaments are lined with lamellae, which are little  discs that are filled with capillaries. Those capillaries have oxygenated blood running through them, which is why the inside of gills are red. The more active a fish is, the more oxygen it needs, and the more lamellae it has.

As a fish swims, the water moves into the mouth and flows through the gills. When a fish is stationary, it can still push water through the gills by opening and closing its mouth. When water passes over the lamellae, the oxygen in the water diffuses into the capillaries, oxygenating the blood.

Fish have a ‘countercurrent system of flow’, which means that the blood flows in the opposite direction of the water. They need this clever little trick because the diffusion only works if there is less oxygen in the blood than there is in the water. So, the blood with the least amount of oxygen is meeting the ‘oxygen depleted’ water first, taking what’s left, and then moving on to fresher, more oxygenated water.

Like humans, fish must get rid of the carbon dioxide created by absorbing and using oxygen. Gills are multi-taskers- they diffuse the carbon dioxide our of the body and into the water. Fish are then free to focus on swimming.

HOW DOES TIME WORK ?

How does time works

You may want to sit down to read this feature. when considering time, It’s easy to quickly get lost in the complexity of the topic . Time is all around us, ever present, and is the basis of how we record life on Earth. It’s the constant that keeps the world , the solar system and even the universe ticking. Civilizations have risen and fallen, stars have been born and extinguished, and our one method of keeping track of every event in the universe and on the Earth has been comparing them to the present day with the regular passing of time. But is it really constant ? Is time really simple as a movement from second to the next ? We’re about to find out.

13.7 billion years ago the universe was born, and since then time had flown by to the present day , overseeing the creation of galaxies and the expansion of space. But when it comes to comparing time, it’s daunting to realize just how little of time we've actually experienced. The Earth might be 4.7 billion years ago , but we modern humans have inhabited it for no « You would have to relive your life 150,000 times  just to match the age of the youngest known star in the universe »
More than 400,000 years, just 0.003% the age of  the universe. Feeling small yet ? It gets worse. You've experienced so little time on the Earth that in astronomical terms you’re entirely negligible. You would have the relive your life 150,000 times  just to match the age of the youngest known star in the universe.

In the 17th Century Newton saw time as an arrow fired from a bow , travelling in a direct straight  line and never deviating from its path. To Newton, on second on Earth was the same length of time as that same second on Mars, or Jupiter, or in deep space. He believed that absolute motion could not be detected, which meant  that nothing in the universe had a constant speed, even light. By applying this theory he was able to assume that, if the speed of light could vary, then time must be constant. Time must tick from one second to the next, with no difference between the length of any two seconds. This in something that you probably think to be true . Every day has roughly 24 hours, you don’t have on day with 26 and another with 23. However, in 1905, Einstein asserted that the speed of light doesn't vary, bit rather it was a constant (roughly  299,782,458 meters per second). He postulated that time was more like a river, ebbing and flowing depending on the effects of gravity and space-time. Time would speed up and slow down around cosmological bodies with differing masses and velocities, and therefore one second on Earth was not the same length of time everywhere in the universe. This posed a problem. If the speed of light was really a constant, then there had to be some variable that altered over large distances in the universe expanding and planets and galaxies moving on a galactically humongous scale, something had to give to allow for small fluctuations. And this variable had to be time.

It was ultimately Einstein's theory that was not only believed to be the truth, but also proved to be entirely accurate. In October 1971, two physicists named Hafele and Keating set about proving its validity. To do this, they flew four caesium atomic clocks on planes around the world, eastwards and then westwards. According to Einstein's theory, when compared with ground-based atomic clocks (in this instance at the US Naval Observatory in Washington DC), Hafele and Keating's airborne clocks would be about 40 nanoseconds slower after their  eastward trip and about 275 nanoseconds faster after travelling west, due to the gravitational effects of the Earth on the velocity of the planes. Incredibly, the clocks did indeed register a difference when travelling east and west around the world, about 59 nanoseconds slower and 273 nanoseconds  faster respectively when compared to the US Naval Observatory. This proved that Einstein was correct, specifically with his theory of time dilation and that time did indeed fluctuate throughout the universe.

Newton and Einstein did agree on the thing, thought that time moves forward. So far there’s no evidence of anything in the universe that is able to dodge time and  move forwards and backwards at will. Everything ultimately moves forward in time, be it at a regular pace or slightly warped if approaching the speed of light. Can we answer why time ticks forwards, though ? Not quite, although there are several theories as to why it does. One of these brings in laws of thermodynamics, specifically the second law. This states that everything in the universe wants to move from low to high entropy, or from uniformity to disorder, beginning with simplicity at the Big Bang and moving to the almost random arrangement of galaxies and their inhabitants in the present day. This is known as the ‘arrow of time’, coined by  British astronomer Arthur Eddington in 1927. He suggested that time was not symmetrical, stating :  « if as we follow the arrow we find  more and more of the random element in the state of the world, then the arrow is pointing towards the future ; if you were to observe a star in almost uniformity, but later saw it explode as a supernova and become a scattered nebula, you would know that time had moved forwards from equality to chaos.

Another theory suggests that the passage of time is due to expansion of the universe. As the universe expands in pulls time with it, as space and time are linked as one, but this would mean that if the universe were to reach  at theoretical limit of expansion and begin to contract then time would reverse, a slight paradox for scientists and astronomers. Would time really move backwards, with everything coming back to an era of simplicity and ending with a « Big Crunch » (as opposed to find out, but we can postulate on what we think might happen.

It’s incredible to think of the progress we have made in our understanding of time over the past century. From ancient sundials to modern atomic clocks, we can even track the passing of a second more closely than ever before.

Time remains complex topic, but thanks to scientific visionaries, we are getting closer to unlocking the secrets of this not-so-constant universal constant.