pH - Have you ever thought what it really is?

Most of us should know that the pH of a substance determines its acidity (or alkalinity). We know that both acids and alkalies are opposites of each other. An acid will react with an alkaline to neutralise it. pH is measured on the pH scale, with water being 'neutral'. However, have you ever thought what pH actually is?
In a nutshell, the pH of a substance measures how much a substance will dissociate when put in water.
This is when a hydrogen atom, attached by a covalent bond (shared electron) to a compound in an acid, breaks  free of the bond. However, with it breaking free it leaves behind its only electron: it is now a single proton with a positive charge. This little proton then attaches itself to a nearby water molecule (as the acid/alkali is in water) and forms the compound H3O. This is just water (H2O) with an extra hydrogen (H). Although the proton has now lost its electron it is still considered a Hydrogen molecule. The H3O ion (as it is now a positively charged particle - extra proton, but no extra electron) is extremely important, to the extent it has a special name of its own: hydronium. It is the measure of hydronium in a solution of an acid or base (which is an alkali dissolved in water) is rated on the pH scale. A low pH indicates there is a lot of hydronium, whereas a high pH indicates there is a smaller and smaller amount. Here's an example of an acid and water reaction, you can clearly see that H3O is left behind:
H2SO4 + H2O → H3O+ + HSO4−
The pH scale isn't just limited between 0 and 14, those are just the values which are naturally available, it can go above and below that into the minus numbers! However, if you have pure water, as much as you might like to think it is almost never pure. In fact, pure water self-ionises naturally over time. This is when one proton (hydrogen atom without its electron) transfers itself from one water molecule to another. This produces two oppositely charged ions and here is the equation:
H2O + H2O  H3O+ + OH−
However, water does not go on like this for ever, otherwise its pH would just keep falling! Eventually enough of it has undergone chemical change for it to be considerably less likely to react - a kind of equilibrium - the pH of that equilibrium just happens to be pH 7. That's why we call pH 7 neutral - its the pH of stability, and we base the scale around that.
So, any acid will naturally be a very good electrolyte (a substance which contains free ions, making it a good electrical conductor). This also explains why they use battery acid inside of batteries, as when the protons leave the acidic compounds, they make the compounds positive ions. Since electricity is the flow of charge (not electrons! That is just a very common method of transmitting charge) this means electric current can pass through!
If you have any questions please feel free to post below.

What is Mass - Really? Do we know anything?

We all know that almost everything in our universe is made up of what we so affectionately call matter. This matter makes up everything we see and use everyday, it even makes up what we've never seen or used. Distant planets, stars and galaxies - all made up of this weird substance. With every physical 'theory' there is always an element of indefinite uncertainty, and yet mass is one theory that we can almost solidly call "fact". Or can we? Have we ever really thought of what mass is? You may respond that mass is what 'is there'. But how do we know 'what's there' is there? Or what isn't seemingly 'there' is in reality... there? What is 'there'? What are 'space' and 'dimensions'? They didn't exist before the universe began. 

Mass, as you can see, is a much more fiddly concept than you might ever imagine. On a large scale, relative to us, all masses obey a set of rules which we call 'forces' and 'physical laws', and yet on an atomic level, electrons do not. They seem to inadvertently flit around, sometimes seeming to be in two places at once! We cannot predict them entirely. Due to this a new theory was developed, called string theory, suggesting that everything in the universe is bonded together by strings so small that if you enlarged a hydrogen atom to the size of the galaxy the string would be only the size of a human hair! This theory may have yet to explain these tricky conundrums which inundate us in the universe. Yet, as with any theory, it is never perfect and there are always questions surrounding it. In fact, all the facts that we learn in everyday life, that we take for granted. All of them, are probably FALSE! They are in reality just attempts at trying to explain what happens around us. You may say that many of these theories are too robust to simply discard as mere attempts! Yet, that is exactly what philosophers and scientists would have said about ancient theories long ago. Back then, everyone believed that the world was the centre of the universe, that everything was made up of just four elements (earth, fire, air and water) and were completely perplexed by why there were different 'types of air', some of which could kill you! In response to these, instead of finding the correct solution, they simply tangled themselves up in knots, experimenting and trying to find an explanation using primitive theories. We know now that if pioneering scientists such as Isaac Newton and Albert Einstein hadn't come about, we would still be living, ignorant to the world around us.

This is why I believe that we have yet to come close to touching the reality of the universe. Our generation is simply another step towards simplifying these many "proven" theories and finding the real answer to life around us. Every generation brings with it new advancements and one day I think that in someone, somewhere's head the real solution will finally click. We are all on a constant adventure of mishaps and discoveries, some completely unintentional, and yet it is these accidents that will one day let us tumble into the bliss of understanding.

It doesn't have to be genial scientists or scholars which make these discoveries. Most of their minds have all been shaped and warped by the theories which surround us today. Most of them will never have the 'ignorance' to question scientific theories. This is why I believe that to advance in science we must all be willing to completely discard all that we have learnt, have an open mind, and fundamentally question the roots of stable theories. Without that there would be no scientific advancement whatsoever. In fact it is not knowing the answer which helps us advance, it is the question. As implied by the word 'creativity', you must 'create' the question to be able to think of finding the right answer. Even then there will always be more questions coming. What's to stop me or you finding the next question?

Air - The Thing Which Keeps us Alive Could Mean our Demise

Air is all around us all the time. It surrounds us every single minute of our lives, from start to finish: literally. Air is extremely important, and without it life may never even have come into existence. Air is mixture which helps us do things such as breathe, make fires and fly aeroplanes. One tiny change in the composition of air and we might have had very different lives, if none at all!  

A common misconception is that air is just one ‘element’. This is completely untrue! Air is not on the periodic table (you can check if you like). Air isn’t even one simple compound. In fact, air is actually a mixture of a variety of different elements and compounds in gaseous form, the most notorious of which being oxygen. However, this is not the gas in most abundance, in fact if it was we would most probably be dead, as pure oxygen is poisonous!

Air is actually made up mainly of nitrogen (around 78%), oxygen generally only makes up about 20-21% of air. There are also small amounts (around 1%) of noble gases such as argon and helium in the air. Finally, air contains substances essential for plant life: carbon dioxide (0.03%) and water vapour (0.97%, but it can vary!) Plants need carbon dioxide and water for the process of photosynthesis, where they convert these substances to glucose and oxygen in the process of photosynthesis. You may have heard of humidity levels. Since the amount of water in the air can vary, this can raise or drop humidity levels. It can go from 4% to 0.5%!

Air however does not only contain these set substances. It also contains minutely small amounts of other substances such as aerosols (which are tiny particles of dust from the ground or from volcanic ash.) If you can imagine zooming up into the sky, the composition of air there would be very different. There lies the notorious gas known as ozone, which environmentalists are currently making a big fuss about (due to the theory of global warming). There is also a lot more helium and hydrogen up there, as they are lighter elements, less dense than the others, so when they float up the others sink down.

You have probably heard of air pressure as well. This is just basically the weight of the air pushing down on everything on the earth – including us! Air pressure is measure in something called Pascal units which is just how many kilograms of ‘weight’/’force’ (measured in Newtons – “N”) act over 1 m² of area. So if 3kg of air was pressing down on 1 m² of area then the air pressure would be 3 Pascals. However the real pressure of the air comes nothing close to that. In fact for every 1 m² of area on the earth, air pressure results in a force equivalent to the weight of a large elephant pushing down on it! You may ask why we aren’t crushed by this force. This is because the blood in our bodies pushes out with an equivalent pressure and the two cancel out. This also explains why when we enter different areas of pressure, for example when flying on a plane, sometimes people get nosebleeds as the difference in pressure causes the blood vessels to expand and burst. Imagine if you entered a vacuum (space) without a special suit, you would just burst due to the pressure of your blood being too strong for your body to withstand!

physics.org | Explore | Radiation dose chart

Just came across this while looking at radiation from mobile phones on the 'physics.org' website. It shows how much radiation you can get from doing different things and loads of other random information. Thought it might be interesting - enjoy. (Click here for a bigger view.)

Elasticity - How does it physically work?

I was reading about elasticity and came across the basic principles:

• 
  
• Every material has a certain degree of elasticity
• There is a point, called the elastic limit, where the material permanently deforms and can't be returned back to it's original shape (it gains a new elastic limit as well). This is also called plastic deformation or plasticity.
• Robert Hooke described the amount stretched as directly proportional to the force it would produce and vice versa (e.g. a bigger gravitational force acting down upon the elastic material - hanging a weight off of it - would produce a bigger stretch/extension)

However, I couldn't quite understand how this actually worked on a molecular level. It took me a while to find all the information, but I eventually understood (after much searching on Google!).

So here is the explanation I collected up (from various sources):

Basically, materials can stretch due to inter-molecular forces between atoms. There are different charges in different parts of the material and these attract. If you try to squash the material like charges repel too much and so the material tends to try to stretch out again. If you stretch the material the opposite charges attract too much and the material tends to attempt to go back to its original shape. This shape is the shape in which the material is balanced: there is an equal amount of attraction and repulsion and so this is the preferred state for the material.

However, there is also the aspect of the elastic limit. This works because beyond a certain point the atoms become to far apart or close together to be pulled back into their original positions. The atoms have so much force exerted on them that they displace. However, once they have displaced they will settle in their new positions and assume a new elastic limit. This explains why elastic bands snap: the atoms move so far apart from each other that the whole material gets pulled apart!

I hope this makes things slightly clearer. If you don't understand anything just comment below!

Difference Between Centre of Mass and Centre of Gravity

Whether it makes a difference or not all depends
on size...

Now, as I mentioned in my previous post, the terms 'centre of mass' and 'centre of gravity' can be used almost interchangeably. However, this is only when we refer to relatively small objects, such as those which we find on the earth.
The difference between centre of mass and centre of gravity is fairly simple.
The centre of mass is a single point inside (or outside) any object where all of its mass effectively acts. In a regular 3D shape, such as a sphere, this would be the dead centre, however in a more complex shape it would be different.
The centre of gravity however, is where all gravity acts on an object. On earth the centre of mass is practically where all gravity acts so they can be used interchangeably. However, we know that gravitational pull depends on two things: distance between two objects and the mass of the object. The mass of the object will obviously always stay the same, however the distance from the object can change.
Consider an object as big as the moon. The distance from the earth on one side, would be much smaller than the opposite side. This means that since there is a substantial difference in pull between different parts of the 'object', the centre of gravity will be affected.
So there you go. There is always a difference between centre of mass and centre of gravity, but sometimes it is so minute that we consider it insignificant. This is due to the object being fairly small. However as the object gets larger, we begin to feel the need to distinguish between the two.
If you have any questions then, again, please feel free to leave them in the comments box below.

Unbelievable Experiment Demonstrating Centre of Gravity

What happens in the experiment:

Two forks seemingly magically balance on the rim of the cup, with the support of a mere toothpick.


Watch the video
Here is a video of an experiment I did (see it on youtube).

How it works:

This is due to the law of centre of gravity.
This law states that every objects has a point, where all gravity will effectively act. This is the midpoint of all the mass in the object. In a simple shaped structure such as a cube, this will just be in the middle, as there is an equal amount of mass in all directions of that point.
However, in the complicated, but symmetrical structure of two forks wedged together, the centre of gravity will act somewhere in the air (that is why two forks dip inwards if you hold them by the prongs)! I know this is complicated to understand, but the rest of the object does not affect the gravitational pull. If you piled up ten more forks, equally on both sides, the structure would still balance (if you had a really strong toothpick!).
Some people may use the term 'centre of mass' as well. On earth we can use these terms interchangeably, however in different gravitational fields, there is a difference.
If you are confused about the difference between centre of mass and centre of gravity, don't worry, as I will go over this in a later post, if you can't wait till then, click here.

View us on YouTube!

I have made a YouTube profile on which I will be posting a variety of different videos and experiments relating to this blog. Feel free to check it out now at http://www.youtube.com/user/Rockhoppable?feature=watch. I'll post new videos on the blog as well so you don't miss out!

In my next post, I'll tell you about center of mass, and how to do an amazing experiment using this simple law!

How to improve your life with a 'P'...

I've thought up a little system composed of ten words. These words describe and include ten things that apply to everyone in the world, and will make your life better if you improve on them. I know it is quite random, but oh well.

1) Politeness - be nice to other people!
2) Punctuality - be on time, don't be late and get yourself organised!
3) Procrastination - stop putting off tasks you should be doing. It will make life much easier.
4) Personal Hygiene - this is obviously essential...
5) Prayer - may only apply to those who are religious and actually pray, but communication with a divine being is proven to make you feel a lot more satisfied!
6) Priority - if you get these straight, then workloads and commitments seem to sort themselves out...
7) People skills - your social life is obviously important, and being able to communicate with others effectively is a must.
8) Perseverance - when you get things done there is that great sense of accomplishment.
9) Perspiration - this can refer to both exercise (keep a healthy lifestyle), and working hard in whatever you do, to do it the best you can.
10) Personality - probably the most important! Be yourself and be a good person!

Improve on these ten 'P's and I can guarantee everything will seem a lot better!