Showing posts with label Units. Show all posts
Showing posts with label Units. Show all posts

Tuesday, October 4, 2011

Space is Not Just Nothing

The three dimensional extent in which objects and events occur, with a relative position to other objects and events is called space. In a more general sense space can refer to an nth dimensional hyper-volume. 

Often illustrated by 3 lines representing the three dimensions of space the linese 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. 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.

Basic SI unit – meter (m) which is the distance traveled by light in a vacuum in 1/299,792,458 of a second. The most common methods of measuring space are rulers but 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. 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.

Wednesday, September 7, 2011

Units of Measure in Physics

Unites of measure are numerical values given physical quantities relative to some standard. The International System of Units (SI) is the system of units of measure used as a global standard by international treaty.


Seven SI Base Units



meter
distance


kilogram


mass


second


time


ampere


current


kelvin


temperature


mole


amount of substance


candela


intensity of light



There is a list of
SI unit prefixes
that that multiply the values from 1024 and
10-24 below is a partial list.



SI Prefixes



Prefix



Symbol



10n



Scale




decimal



giga-


G
109

billion


1,000,000,000


mega-


M
106

million


1,000,000


Kilo-


k
103

thousand


1,000


Hecto-


h
102

hundred
100


deca-


da
101 ten 10
- - 100 one 1


deci-


d
10-1 tenth

0.1


centi-


c
10-2

hundredth


0.01


milli-


m
10-3

thousandth


0.001


micro-


m
10-6

millionth


0.000,001


nano-


n
10-9

billionth


0.000,000,001
As a result 1,000 meters is a kilometer, a hundredth of a meter is
centimeter and a thousandth of a meter is a millimeter.