The Work of Energy

Energy: The ability of a system to do work.

According to Special Relativity energy has mass and that the mass all matter is a result of energy. E = mc²² so all substance is based on energy.

The 1st Law of Thermodynamics says that energy in any interaction is conserved. That is the total amount of energy in the universe is constant. It is also stated as energy can not be created or destroyed but it can change forms.

The SI Unit for energy is the joule (J):  Newton-meters = m²·kg·s^-2

Common Types of Energy

Heat energy: The energy associated with the temperature of an object.
Light energy: The energy associated with visible light.
Electrical energy: The energy associated with an electric current.
Chemical energy: The energy associated with the reactions involving molecules.
Nuclear energy: The energy associated with reactions involving atomic nuclei.
Kinetic energy: The energy associated with motion.
Potential energy: The energy of a system based on its position or condition. Stored energy.
Rest mass energy: The energy of an object that is not in motion. E= mc²

Energy is one of the three main parts of the Universe space, time and mass and relativity shows them to be inter-related. Space and time are so interrelated that they form a single entity. Furthermore mass warps space-time forming Gravity and the motion of mass contracts both space and time. 

In conclusion in common experience energy is what moves us and allows us to move thing. Physics has shown it to be a lot more. It is a fundamental part of the universe.

Space is Not Nothing

Space: The 3 dimensional extent in which objects and events occur, with a relative position to other objects and events.

In a more general sense space can refer to an nth dimensional hyper-volume. 

Space is often illustrated by 3 lines representing the three spacial dimensions. They are the axis of a 3d graph. In 3d space you can move in 3 directions forwards and backwards; up and down and left to right.

Not so empty space

General Relativity depicts space and time as a fabric that can be warped, bent, twisted, stretched and contracted. Quantum Mechanics describes subatomic particles coming and going even in a vacuum. Space is not empty, it is not nothing. Yes I know this is a double negative however empty space is normally thought of as nothing but it is something.

Units of Measure

Basic SI unit – meter.

meter(m):  The distance traveled by light in a vacuum in 1/299,792,458 of a second.
Kilogmeter – 1000 meters
Astronomical Unit (AU): The average distance between Earth and Sun.  - 1 AU = 149,598,000 km
Light year (LY): The distance light travels in one year. Note this is a unit of distance not time. 1 ly = 9,460,528,400,000 km  1 ly = 63,240 AU (s07c)
Parsec (pc): The distance with a parallax of one arcsecond. 30,857,000,000,000 km 206,260 AU 3.26156 ly (s08d)

Measurement

Most common methods of measuring space are rulers.

Odometers are another common way of measuring distance and  there by space
Other methods include bouncing light, radio waves, or sound off of an object using the return time to measure distance. These include radar and sonar.
Parallax uses geometry to measure distance it is used in Astronomy and land surveying.

Distance and position must be measured according to some standard. The standard has to be a chosen point in space. The point is selected by ether convenience or convention with out such a starting point determining distance and position is impossible..

Space is one of the three main parts of the Universe space, time and mass. Relativity shows them to be inter-related with space and time are so interrelated that they form a single entity.  Intern mass warps space-time forming gravity and motion of mass contracts both space and time.

In conclusion based on common experience space is basically where you are. You are at a particular point in space relative to other objects. Physics however has shown it to be a lot more. It is a fundamental part of the universe.

The uses of Measurements in Science

Measurement: The process of obtaining a numerical value representing a physical property, such as length, mass, or time, by way of a unit of measurement

Unit of Measurement: A magnitude representing a physical quantity by use of  a standard for measurement of that physical quantity.

Measuring Device: A piece of equipment used to measure a physical quantity based on a standard for measurement.

Measurement and Objectivity

Measurements are the most objective part of science because the resulting numbers are what they are. The mechanical devices used for measurement aide objectivity by removing the human factor that is human subjectivity. The validity of a measurement is only as valid as the theory behind it.