What could be tinier than a Proton or a Neutron. Obviously electrons are smaller, but are there anything smaller or as small as the electrons? In the mid 20th century, the answer to this became quite clear. There were many "sub-subatomic" particles that interact with each other. These smaller than small particles are what makes up the Standard Model.
The standard models explains three of the 4 fundamental forces that occur in nature. The Weak Nuclear Force, the Strong Nuclear Force and the Electromagnetic Force. The force of gravity cannot currently be explained by the Standard Model. All matter has these interactions between them and are always subdued to each force (yes light is affected by gravity, hence light cannot escape a black hole).
There are three classifications in the Standard Model: the Lepton, the Quark and the Boson (currently sought after, the Higgs boson). These are the building blocks of the material world. For example a proton is made up of 2 up quarks and a down quark "glued" together by a gluon, which is a boson (or a force particle).
So what is an electron made of? Crazy enough, the little buggers are made of itself! They are their own type of particle. An electron is a Lepton.
The difference in Leptons and Quarks are the interactions that they participate in. Both are interactive and participants of the electromagnetic, gravitational and weak nuclear force. Leptons differ because they do not participate with the strong nuclear force.
So these are the building blocks of all matter, living or non-living. They are quite important in studying how things interact. Maybe one day we will learn how to build the strongest atom, piece together the lightest atom that can be harnessed... or build the most energetic atom and use it as fuel.
**Go Canada Go!**
Showing posts with label electomagnetic. Show all posts
Showing posts with label electomagnetic. Show all posts
Sunday, 28 February 2010
Thursday, 30 July 2009
See and Be Seen

Hello Reader,
As a society that really wants to be seen, make a scene and individuals wanting to be noticed for something, we seem to be putting a bit of effort for the opposite! Ever wonder if not being seen is possible? Reader, I'm talking about invisibility. Using a device to hide oneself from other people's vision. Kind of like the Invisibility Cloak from Harry Potter.
*key idea: you need 2 main things for vision to occur. Object to be seen and an observer. Without either one, nothing can be seen*
For invisibility to work, the material being used must not be seen by the observer. As shown in the picture to the right, the material has to be able to reflect of the material, hit another above the object and bounce off the back. Unfortunately, this is very hard and maybe even impossible to do (have something follow you from above).
Let's take a step back for a second though. Light is an electromagnetic wave (we also know now, that it is a particle). That is, it changes from an electric field to a magnetic field very quickly. We know this thanks to James Maxwell. He also had thoughts about invisibility.

We know that most liquids and gases are "invisible" (transparent), but why is that? Atoms in higher excited states (due to heat, pressure or a bigger volume) have more spaces between them. This is a key role for such visibility problems. If the spaces between the atoms are greater than the wavelength of the light, then light is not given off. What about diamonds? Why can I see right through them? Some solids have special properties.they are called Lattices'. The atoms are arranged so that there are equal spaces between each other and is organised!
So how do we use such properties to become unseen? New materials are being worked on in laboratories called Metamaterial. These are materials that can bend light waves. So far, we are able to bend microwaves (smaller than infrared).
Light have a property called the index of refraction. If you have ever gone fishing and saw a fish in the water and decided to put a net over the fish, you know that you didn't catch it. this is because the index of refraction is responsible for the bending of light. This concept needs to be applied to an invisibility device. Metamaterial is special, in which it actually has a negative value for the index of refraction (everything you can see will always have a positive value).
This is quite close to the concept of Fibre Optics. In a fibre optic tube, light is bent at a 90 degree angle so nothing passes through it but stays contained in the tube. The US military has a device that uses fibre optics for an "invisible" cloaking device. this is the closest we are to such a cloaking device.
In Michio Kaku's book, Physics of the Impossible, he rates invisibility a class 1 impossibility. This means that it is not possible now, but will be in a matter of a decade.
Labels:
atom,
cloak,
electomagnetic,
harry potter,
heat,
impossible,
invisible,
james,
james maxwell,
light,
maxwell,
particle,
physics,
pressure,
see,
visibility,
vision,
volume,
wave,
wavelength
Subscribe to:
Posts (Atom)