Chapter 2 The Scientific Method and Space There are three ingredients that make up the universe Space o Objects would be lumped together if there wasn t space o Universe is made up of three different dimensions all of which have finite infinite closed or upon universe Finite a dimension that can be measured Infinite a dimension that cannot be measured Closed universe a universe that has set boundaries Open universe A universe with no ending have an end but cannot prove it o It is unknown which category our universe falls in to Scientists believe that our universe does o Examples of a 1D world A piece of string A string can be measured therefore the universe is finite and the universe has an end therefore it is closed A loop of string The string can still be measured therefore the universe is finite however one can continue to go around the loop of string for forever therefore the universe is open o Examples of a 2D world A box A cylinder o Two systems of space Open and finite Closed and finite has boundaries The English system food yard mile inch Originally based on human anatomy The metric system meter centimeter kilometer Everything is based on the meter Origin scientists measured the distance from the North Pole to the South Pole then divided this number into 10 million segments each called a meter As time progressed the meter was redefined o Therefore the distance around the entire earth is 40 million segments total o For a brief amount of time approximately 20 years the meter was defined as the wavelength when electricity was passed through krypton gas The new definition of the meter was 1 650 763 7321 wavelengths of krypton gas He told the class that we won t ever need to know that number The newest definition established in 1983 states that the easiest way to define a meter is by the speed of light The length of time is 1 299 792 458 of a second He said we won t need to know this one either Meters can be broken down through the 10s system o 100 centimeters 1 meter o 1000 meters 1 kilometer o 1000 millimeters 1 meter Chapter 3 Time and Matter Time o Origin of the pendulum clock Galileo conducted experiments and noticed that no matter how large or small the arc of a pendulum is it will complete the same amount of swings in the exact same time 10 swings at a 70 degree angle takes 17 seconds 10 swings at a 20 degree angle also takes 17 seconds Even though the time is the same the speed will be different based on how long o The most accurate clock is the atomic clock the string is Uses three cesium atoms Oscillates with no friction o Units of time are universal o The day is defined on how long it takes the Earth to spin once on its axis The day IS NOT 24 HOURS LONG but 23 hours 56 minutes and 4 seconds Called the sidereal day The day that we refer to is 24 hours and is called the solar day o Our 7 day week is based on a superstition from the Babylonians They noticed that a few points of light in the sky moved differently from the other stars They saw 7 that could move this way which included the sun the moon and five planets Our 7 day week and their origins break down as follows Sunday named by the sun Monday named by the moon Tuesday named by Mars Tiu Wednesday named by Mercury Woden Thursday named by Jupiter Thor Friday named by Venus Freya Saturday named by Saturn o The month was determined by the time it takes the moon to complete a cycle of phases The time from one full moon to the next full moon is 29 days 12 hours 44 minutes and 2 9 seconds o The year was determined by how long it takes the Earth to revolve around the sun This takes about 365 days Also every 4 years we have a leap year due to this day being added each year o Platonic year How long it takes for the Earth to complete a wobble on its axis approximately 25 800 years After a platonic year is complete the north star changes Matter o A kilogram weighs 2 2 pounds on Earth o Weight and mass are not the same Weight How strong gravity pulls on an object Mass The atoms that make up an object o The slug the fundamental English unit for mass A slug weighs 32 3 pounds on Earth Chapter 4 The Earth o The Earth s equator is about 25 000 miles around and divides the Earth into northern and southern hemispheres o Lines of latitude north south o Lines of longitude east west o The North Pole is 90 while the South Pole is 90 o 0 longitude runs through Greenwich England o The outermost is the crust a 20 mile thick layer of light rocks o The next layer is the mantle which is 1800 miles thick of heavy rocks Kent s coordinates are 41 N 81 W The Earth s layers divided into three sections o The innermost layer or the core has two layers The outer core is 1300 miles thick and consists of molten The inner core is 800 miles thick with solid materials The Earth s atmosphere divided into three sections o Troposphere closest to our planet Extends upwards for 7 miles and contains most of our air and is where our weather occurs o Stratosphere o Ionosphere Extends 7 to 45 miles upwards Very cold Air too thin to support life Extends 45 to 200 miles upwards Reflects radio waves o Air composition 78 nitrogen 21 oxygen and 1 Carbon Dioxide Chapter 5 The Celestial Sphere Horizon When looking at a celestial sphere it is the circle at the bottom where the sky seems to touch the ground celestial sphere Zenith The point directly overhead on a Meridian the line that cuts the sky in half Drawn from the north through the zenith and to the south not shown North on the horizon is 0 East is 90 South is 180 and West is 270 object in the sky Azimuth The direction to use when finding an o Found using 0 360 from the horizon o Altitude how high the object is in the sky Ranges from 0 on the horizon to 90 on the zenith o Though this is an easy system to use it is only the local system In order to pinpoint location on earth using a universal system we go by the geocentric theory which assumes the Earth is located at the center of an imaginary sphere called the celestial sphere North celestial point NCP directly above the north pole South celestial point SCP directly above the south pole Celestial equator The circle around the sky over the equator Polaris our north star is very close to the NCP The only place on Earth where Polaris is seen directly overheard …