Momentum - A Law with a Determination

Momentum is a measure of how much inertia an object has. This means how hard it would be to change its velocity. All moving objects have momentum, as every object has mass and momentum is mass multiplied by velocity. If an object has a high momentum then its going to be harder to change its velocity than an object with a smaller momentum. You can think of momentum a bit like determination. If someone has a bigger determination to finish a task then they are more likely to succeed, as they cannot be deterred from their path as easily as someone with a smaller determination. Similarly, an object with greater momentum has greater inertia and therefore is less likely to have its velocity changed or its direction altered. This is the general equation to calculate the momentum of an object.

f = m x a

force = mass x acceleration

If you had an apple thrown at you at 5m/s and another apple thrown at you at 10m/s then blatantly you can see that the faster apple would be harder to stop. This apple, pretending it had a mass of 0.5 kg, would have a momentum of 0.5 kg x 10 m/s = 5 kg m/s.That is the unit of momentum: kg m/s. The other apple on the other hand would have a momentum of half that: 2.5 kg m/s (0.5 kg x 5 m/s).

However it is just not sufficient to describe momentum with just these numbers, because momentum is a vector quantity  This basically means that it has not only magnitude, but also direction (like speed and velocity - if you don't understand this visit this link.) This means of course that we would have to say the direction of the apple. For example South East or North North West.For example. 

The Grand Finale - Newton's Third Law of Motion

Now we've come to Newton's last law of motion. This one's pretty simple to be honest. Here it is:




"For every action there is an equal and opposite reaction."

Yoshi knows his physics!

It's quite short, isn't it. The definitions short and simple too, whenever a force acts (a push or a pull - the action), then another force acts in the opposite direction with exactly the same amount of force (what we call the reaction force. So when you punch a wall, the wall punches back and that's why you're hand doesn't move: the wall is pushing back with an equal force. But what if your hand goes through the wall I hear you ask? Well, that's the clever bit. Since there's no more force to support the wall the ground pushes the opposite way to account for the remaining force and so you topple over as your feet are pushing one way, your arms are moving in the other.
Another example is in a tug of war. When you pull on the rope you have to dig your feet into the ground to stop yourself falling over. You wouldn't be able to do it on ice! So when you pull your feet push the other way with an equal force.
You can see this if you step onto one of those really small boats. Try and walk forwards and you'll find the boat moves backwards. This is because your feet are pushing the other way!
If you have any questions please let me know in the comments :D!

Newton's Second Law of Motion

Now another great thinker whom I'm sure you've heard of - the infamous Aristotle - once said that the force of an object is equal to its mass multiplied by its velocity. Now any one with common sense would believe this to be true. However, Aristotle did not take into account the amazing forces of friction and this blinded his insight. However of course as you know, another clever man, called Sir Isaac Newton came and proved this fellow wrong with his second law of motion:

"The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma"


In other words, he took upon Galileo's original idea, but tweaked it so that it was RIGHT. He found that when you took into account frictional forces, force was not equal to mass multiplied by velocity, but mass multiplied by acceleration. As he proved in his first law, an object tends to maintain a constant velocity and when a force is applied it does not keep this velocity, but accelerates in accordance to the force. Since Aristotle didn't think about friction, he saw an object slowed down if force was removed, and so thought that you needed to apply force to maintain a constant velocity, which we of course know is wrong.

This is one of Newton's most powerful laws as it gives us these useful equations:

Force = Mass x Acceleration

and from this...

Acceleration = Force / Mass

and...

Mass = Force / Acceleration


You can think of an example of this law very easily. Think of a huge ball of mass 10 stone (or 60 kg), then another ball of mass 20 stone (or 120 kg). If you imagine these two balls each being rolled towards you in turn at the same acceleration (ouch!) which would hurt more? The answer of the heavier ball is obvious. This is due to it having double the force due to its mass being doubled. Similarly you could think of two balls of the same mass each being rolled at you at different accelerations. The one speeding up more quickly would produce more force. You can see from the derivatives of the original equation that we can calculate mass and acceleration as well as force if we have the other values.

I hope you know understand this law, crucial to physics as we know it! If you don't, or just generally have something you'd like a post/topic on, just feel free to leave a comment below :).

Newton's First Law of Motion

In this post I'll try to explain to you what inertia is and how it works.
Here is the Newton's first law of motion:
"Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it."


In simple this means that:

If something is moving at a constant speed (e.g. a car going at 40mph) or even if it is stationary, it will tend to remain at that speed unless a force acts on it (e.g the friction on the ground or in the air - air resistance).


On earth we don't often see this directly as forces are constantly acting on everything such as gravity, friction and air resistance. However, if we were to imagine a car being pushed off a ramp in deep space at a set speed, for example 10mph, it would theoretically keep travelling at this speed forever until some force came into contact with it (hitting something for example).

Galileo, before Newton, also developed a law called the law of Inertia. This basically means that an object which is at rest tends to stay like that unless another force acts upon it.

This is because of friction of course. Have you ever noticed that when you try to push something heavy on the ground you need a huge force at the start, but when it gets going its much easier? You may also have noticed that as soon as you stop pushing the object quickly stops.

Friction does this because, if you can imagine, every object (even flat objects) have uneven surfaces. They have rumps and bumps all over them and friction is caused by the different bumps getting stuck between each other on two surfaces. Inertia happens because when an object is at rest the object's bumps are

nicely settled into the surface beneath it's cavities. You need a big force to get the bumps out, and then after that the object just skips over the cavities making it easier to push. Once you stop pushing the object stops once more.

An example of this is in a clock-work mouse. When you wind up the mouse and set it going it goes for a while, and sometimes it stops. If you then give it a little tap then the mouse starts going again. Know you know why.

I hope this has made the law clearer to you. If not, or if you have any questions, please feel free to leave them in the comments below. I'll be posting on the other laws of motion soon.

The World Upside Down

We all know about the laws of physics and gravity and the like. We know that previous societies thought that the sun and stars revolved around the earth. We also however know about relativity and the position and speed of objects varies in relation to other objects. For example a car travelling at 30 mph would see another car travelling at 20mph in the same direction as travelling at 10mph.
There is a saying that very egoistic people think about themselves 'the world revolves around them'. Who says that this isn't true.

Try getting up and walking around the room. YOU are moving around the ROOM, correct? Try thinking that you are stationary - the center of the universe - and are pushing the room away from under your feet. That you are constantly located in the same position.

It's a strange thought, but there is no theory about the center of the universe, therefore there is nothing to disprove this theory. For all we know you sitting at your computer or mobile phone or whatever could be moving the universe as you take each step. For all we know gravity could be working in reverse. You could be moving the world, which the sun is revolving round, which the planets are revolving round, which the solar system is consequently affected by, which the whole universe is constantly affected by! You could argue the world is seen to be moving and revolving. But what's to say that the whole universe isn't moving and giving that impression.

Think about holding an object (for example a cup) on a table in place on top of a table cloth then pulling the table and the table cloth from underneath it. If you then asked the cup who was ignorant to the rest of the room (the universe) to relate its experiences it would say that IT moved along and off the table. You could think about us as human beings as that cup.

This also leads onto another thing. What is to say that you or me or anyone isn't the only properly thinking human in the world. We could each be on our own in the world, the people and events happening around us CREATED for us, made specifically for one person (yourself). You can never see into other people's minds to see if they think in the exact same way. Who is to say that any of the events in history (before we were born) actually happened. WE weren't there to SEE them or EXPERIENCE them, and until someone invents a time machine we never will.

Just a couple of things to get you thinking. Feel free to comment about your thoughts below :).

Arrogance about Knowledge

Of course, many of us in the world have often said: 'Oh, I know all about that' and therefore don't listen to what others have to tell us. We can't blame anyone for that to be honest, but of course, we can blame them for not trying to improve their attitude. Here is a story about a man who did just that.


One day two men from the same university with exactly the same experience decided they wanted to learn how to draw. They decided they wanted to learn how to draw, so they went up to an art teacher who decided to start giving them both private lessons in drawing. The day approached and finally arrived and the two men went up to have their first lesson.

"Okay", started the teacher, "Today I'm going to teach you the very basic drawing techniques."
"Oh", said the first man,"I know all the basics, I want the more advanced stuff!"
"Fine, I'll teach you tomorrow instead." said the teacher, and the young man went away.
The other man however, although he thought he knew what the teacher was going to be teaching him, listened intently and found that his drawing improved, and that not only was it the techniques that helped him, but the different view on drawing and the experience that the teacher had.
The two men continued their lessons for about half a year, the first man walking out of the lessons whenever he thought he knew everything.
Finally the time came when the teacher asked them both to draw a picture using all of the techniques they had used this term and compare it to their previous artwork to see how much they had improved.
Both men spent ages on their drawings and in the end presented their artwork.
The teacher found that both were very good, but the young man's was somewhat generic and cliched. However the other man's was of the same standard, but much more original and out of the box.

That shows us that what makes us stand out from the crowd is not knowledge but experience and the willingness to listen again and again. That is what makes people in the world interesting: the mix of skill and originality through experiences with life and other people. So remember. Successful people are always successful listeners.

Fiber Optics - What's So Great About It?

Just what the label says- data transferred by
light along fibers (basically)

Here are three things I know about you:

• You may be under the impression that fiber optics refers mainly to internet transmissions
• You sort of maybe think you know what they are
• You either completely agree with the comments above or were offended by them.

If you feel offended I recommend wasting your precious time feeling offended and arrogant instead of reading this and learning. As this won't affect me in any way whatsoever. I'll tell you a story about that in the next post ;).

So anyway, you have two options:

1. Read the long, boring account by clicking here.
2. Read this post and get all the information for half the price. Every little helps.

So, anyway lets get down to what fiber optics actually are.

Now I'm sure you've heard of fiber optic cables. In short they are long strands of pure glass which act like electrical wires, except they transmit the information using light (infra-red radiation wavelength). They're as thin as human hairs and look something like the branches on those little decorative trees with light coming out of the ends. They can transmit digital information over long distances and have many (other than super-fast internet) in lots of different categories, here are just a few:

• Tiny cameras which can see inside really small areas
• Lasers for surgery
• Light guides - they can shine bright lights on hard to reach places
• A variety of sensory equipment

You can see more here.

You need lots of optical fibers to produce something usable as they are so thin, and so lots of these bundled together are collectively called a fiber optic bundle.

The composition of a fiber-optic cable

It's amazing to see how you could engineer these wires ,even though they are so thin, to make them up of three layers. Each of the wires are made up of three main parts.

Core - The thin glass tube at the center which the light travels along

Buffer Coating - The middle part which basically acts as a shield to protect the wire

Cladding - The outer coating which reflects the light back to the core to prevent loss of information

There are two types of fiber-optic cable

1. Single-mode fibers - Transmit data via infra-red laser radiation
2. Multi-mode fibers - Transmit data from LEDs via infra-red radiation

I will talk more about radiation and the electromagnetic spectrum in later posts (if you're interested)

So how does the light get through the wire? You may or may not have been wondering.

Well, since light travels in straight lines, it doesn't bend along the wire. It basically bounces along the wire in zigzags, getting reflected off the cladding, meaning it can travel great distances. This is called total internal reflection as none of the light is absorbed by the cladding so it can basically keep going on and on and on and on and on...

However, the light signal does degrade due to the glass never being 100% pure and reflective, and this is why high quality fiber-optic cables can transmit data longer distances without "losing quality/information". The higher quality the fiber the purer the glass in short.

How the information gets from A to B...

Three stages... Three different jobs... One at the start... Several in the Middle... One at the end.

1. Transmitter - This produces the light signal by encoding it from the information provided and beaming it along the cable(example - makes video collected from camera at the end of the optical fiber into an encoded light signal).
2. Optical Re-generators - As I mentioned before, the light signal degrades (especially over long distances). These are situated at intervals along the fibers and just give the signal a boost every now and again to keep it strong.
3. Optical Receiver - This is what translates the message back into the form the user/machine at the other end wants (example - video from the camera at the other end of the optical fiber).

What really is so great about fiber optics?

• Cheap - Lots of these cables can be made more cheaply than copper wires, for example transmitting electrical signals
• Thin - They are obviously very small and lightweight making their uses very versatile and open-ended (for example - there could be more data being sent at the same time in the same bundle of wire)
• Better quality - The signal degrades less and the data being received is of a higher quality
• Non-flammable - They don't catch fire. Pretty self-explanatory advantage.
• Low power - They take up much less energy. Hooray! :D

I thought you might like to watch a VIDEO of how fiber-optic cables were made so...

So I hope you understand fiber optics more now. I'm open to complete criticism or questions in the comments. Remember, no-one is perfect and therefore I have DEFINITELY made a mistake in this post. See you next time.

A Small Word of Warning

Firstly, welcome to this blog.
Now, before you read any further I feel that it would be pointless of you following these posts if you're not into any of the things I will be posting about, If you pass the following test I have devised and make it to the end of the page without committing suicide then this blog is for you.

Have you ever used the internet?
Yes - That's quite surprising.
No - I suggest you should try it.

Can you read?
Yes - Perfect :)
No - Well I'm sure we can improve on that.

Are you alive right now?
Yes - Well, that's a start.
No - 

If you are still reading right now then you're obviously interested. If you're not here reading this right now, but still know that I have written about you not reading this or reading this without you actually being present to read this then you are some sort of super-human being and deserve to read this blog anyway. So either way, this blog is for you.

If you didn't understand any of the sentence above...

1. You obviously can't read which is in ways very difficult to understand seeing as you couldn't read two seconds ago but can now read
2. You phrased the sentence wrongly and meant the grammatical construction and word order with repeated phrases and inverted phrases confused you to the point of loss of hope in humanity.

If you can read this word now ---->>> , then you have in theory passed the test. Although you couldn't have been reading the word at the time you read 'now' because you would have had to have two brains, effectively reading the two words simultaneously and that is not impossible (as are most things in life), although it is highly unlikely. 

If you are reading this sentence at the moment (that's better), you may have skipped to the end and cheated because you couldn't be bothered, but that just demonstrates initiative and you have also passed the test.

Till next time. Bye :).