We humans , animals , plants , all forms of life , the Earth , the planets , and stars , are actually made of? And whether the familiar objects really exist for the Universe ? It is a question that seems simple, straight to the core of dark matter search . In this book we have to explore various aspects of the material and its partners , energy , and have been thinking about why some types of material that has not been discovered so scientists suspected that invest a lot of money on a device - by- device search for it . It is a story about the origins of the Universe and how it carries on the type and amount of material that we see today . Here we review the basic idea of the nature of matter , made of what he is , and how it was formed .
DEFINITION OF MATERIALSThe first thing to understand about the matter is that not all material can be seen directly , and not all that you see around you is matter . A common example is the air and light . We could feel the air , and even see their effect on objects like clothes in a clothesline ; but in fact we can not see it - at least not without special equipment . In contrast , the light allows us to see everything around us . Every sunrise , we are bathed in light - and the lives of dying without light . But light is not matter : it is energy .
So , what's it matter ? There are several criteria that must be met before an entity can be described as a material . First , he had to occupy the space . You are made of matter , and you can prove that you are consuming the room each time you climb into a tub full of water . Water level rise is proof that you have the volume . Other evidence that is less obvious is that you reject changes in motion . Perhaps a better example is a car breaking down. Faced with the need to push it out of the way , you experience inertia - resistance to change of motion , although the motion remain. Undeniably, tire friction with the road giving further rejection , but even if you try to push the car on top of the ice field , you will find it much less mobile than you , because he had more inertia than you . In other words , there are more cars than you .
Finally, the matter has mass . Mass is defined as the amount of matter in an object , but this should not be confused with weight . Examples familiar form of the similarity weight on the moon with your weight on Earth may momentarily make you feel more comfortable - but your mass and volume remain the same in both environments .
Therefore, matter is anything that can be weighed , pushed , pulled , can change shape , and so on . It is intuitively obvious , but it needs to be stated directly . Even less clear is the nature of the material . If we study the composition effect, what will we see ? Around the year 500 BC , the Greek philosopher , Democritus , devote earnest thought to this , and in his mind the small particles that can not be divided that make up all matter . He called them atoms - which means ' can not be cut ' . Democritus as smart - smart - but he was right - he was just speculating . He had no evidence to support the idea , and at that time a lot of people who do not agree with him . But today we are not only able to learn the material world to see what is there , but we have no evidence to support our conclusions regarding this strange world . Some evidence was as beautiful as the disclosures in this book , while several others - like a nuclear bomb - was terrible . The point is that we are now closer than ever to understanding the true nature of the material - material that can at least take a look , and perhaps even material that we can not see .
Macroscopic : CELLThink of an example of an easy matter : the pages of this book . Look closer , through the words , letters , and marks the point at the end of this sentence . Pandangilah fibers that make up the pages - the fibers that was once a living tissue in trees . The network is made up of cells , and the cells were made of very complex parts innumerable - membrane , cytoplasm , mitochondria , and so on - who have had a life process that has now ended . The parts were made of some of the largest and terkompleks molecule in the Universe - a familiar example is the molecule of life , DNA , which contains the genetic code that allows us and all living things to reproduce .
MOLECULESThe molecule has a surprising variety of shapes , and most of the materials that affect our lives are composed of types of different molecules . Examples of water , without which life would cease . It is a molecule that consists of two types of smaller particles called atoms . Atoms have different characteristics which are called elements , about a hundred of them have been known . Two elements in water , for example , are oxygen and hydrogen . Elements fused to form all the molecules around us , and react together to form a new substance in a chemical reaction . Common examples of when cooking , for example , or when the oil blend with oxygen in your vehicle . In both cases , there was an exchange of energy , but not matter . In the case of cooking , the input energy is so diverse molecules react and make a fluffy cake . On the other hand , the vehicle's engine , the input energy is initially small ( spark from the spark - plug ) triggers a reaction between oil and oxygen to release energy , which drives the vehicle . In both these examples , the new combination of elements and compounds generated , but the material is not created or destroyed.
ELEMENTSThe whole of the Universe is almost only consists of two elements : hydrogen and helium . All that you think you and I are so interesting in everyday life ( with the exception of dark matter , of course ) made of elements that are very minority . But all of these elements - from the lightest and simplest ( hydrogen ) to the elements with a heavy mass and heavier names like ununnilium - made of atoms . But atoms are not understood by Democritus .
ATOMAtomic otherwise made of four things : protons and neutrons that make up the nucleus , the electrons around the nucleus , and a large amount of space . But how much space is there ? Imagine that the nucleus of an atom is the size of a walnut . At this scale , the electrons will be buzzing in a sphere with a diameter of more than one kilometer . Although the space is very large , 99 % of the material in the nucleus of an atom are very small . So what is keeping the unity of it all ? The answer is energy : electric charge of the electron is negative , while the nucleus ( cause we shall see in a moment) is positive . Positive and negative charge attract and hold electrons in place . But the atom is meeting other atoms , they reject each other for the simple reason that they have electrons in the outer - and two negative electrons repel surely . These properties allow you hold this book . Negative electrons in atoms and molecules of your hand reject the electrons in atoms and molecules books . If this does not happen to repel each other , not only this book will really take through your fingers , but you also will terperosot seat and then penetrate into the Earth . It's not as stupid as it sounds , because there are particles of matter in the Universe that do so . We are now going to wade through the material essence .
ATOMIC STRUCTURE : ELECTRON , PROTON AND NEUTRONIn the nucleus we find two types of particles again : protons and neutrons - which has a mass of heavy components . Protons have a positive charge - the same charge that attract electrons and atoms prevent rupture . Neutrons have no charge at all , but , even so , are held in place in the nucleus by other different styles of electric force : the strong nuclear force .
QUARKMore fundamental than protons and neutrons are particles that compose them : quarks . There are different types of quarks - up , down , strange , charmed , top , and bottom - which join different ways to prepare the material . Proton , for example , is composed of two up quarks and one down quark , while a neutron is composed of two down quarks and one up quark . The names of the quark is not at all related to their attributes , and only a label .
leptonWhat about electrons ? Of what it is composed ? Electrons are part of a family that is much lighter particles called leptons . Other members of the family include the lepton muon and tau particles , and each of the three have associated particle called neutrinos : electron neutrinos , tau neutrinos and muon neutrinos . Neutrinos are strange beasts that can penetrate ordinary matter as if the material does not exist . This presents an interesting challenge for physicists not only intended to detect them but also try to measure their mass . Leptons invisible composed of anything other than the leptons , in other words they do not show signs of having internal structure .
In addition to all this , there are still lots of other particles , and there are more than two hundred who have known or predicted .
ENERGYAsk a physicist what it is energy , and the answer is that energy allows doing a job . It is a concept that is elusive , and , although we can describe its attributes , classifying it in different ways , and predict their behavior and also to do with the matter at the beginning of the Universe , the nature of energy is still a mystery .
Energy is the capacity to do work - to change things . Here are some types that are common , although there are many variations :
Kinetic energy . Movement . Riding a bike , waltz , fly to the moon , then you 're running the kinetic energy .
Potential energy . Stored energy , which manifests itself in various forms such as chemical energy and gravity . Food , petroleum , and water at the top of the cliff that will plunge , everything has potential energy . One of the amazing things we are trying to do in this millennium is to save energy in everything from food warehouses that give us food to fuel the nuclear reactors miniature space vehicles in interplanetary travel .
Thermal energy . Heat - the amount of energy contained in the moving particles that make up matter . The faster the particles move , the more thermal energy they have, and , with a sufficient amount , they can produce large amounts of energy . Although referred to as heat thermal energy , thermal energy an object with large amounts of hot uncertain , while certainly not a hot object contains a lot of thermal energy . Heated swimming pool , for example , contain significantly more thermal energy than incandescent nails , the reason is simple , because more water than nails !
Electrical energy . One of the most familiar forms of energy - for good reason , we use it in large quantities . It is the flow of electrons , which is amazingly easy to transport once the infrastructure is already in place. Once electricity is delivered to our homes , we can transform it into many other forms of energy .
Radiant energy . The most familiar example is light , but there are other forms : gamma rays , infrared ( used for heating and remote - control devices in the household) , microwave ( for communication and cooking ) , X-ray ( treatment ) , radio waves , and ultraviolet . All of this is part of the electromagnetic spectrum .
Each of these forms of energy ( and which are not mentioned here ) are included in one of the four fundamental forces in nature , which is transported from one place to another by massless particles called bosons . These forces and their transporter is :
Electromagnetic force , carried by photons .
Gravity , transported by gravitons .
The strong nuclear force , carried by gluons .
Weak nuclear force , carried by particles W + , W - , and Z0 .
The importance of the relationship between matter and energy is that the relationship can be exchanged : Matter is converted to energy in the stars, for example , and the conversion is what allows us to continue to live . But for the sake of our story , it is important to understand that the Universe contains a number of materials and the amount of energy , and , as we have discovered , a number of dark matter . Just that. Nothing more , nothing less . In the history of the Universe , there have been some odd conversion between matter and energy , and , no doubt , dark matter , but the total remains the same . One of the goals of cosmology is to determine how many of them - matter , energy , and dark matter - which exist in the Universe , because this will help unravel the fundamental attributes of the origins , evolution , and destiny of the Universe in which we live .