Physical Science Q2 P1

Motions and Constellations

Terrestrial Motion

Movements of the things made of the four elements such as earth, water, air, and fire.

Natural Motion

Motion that occurs according to the nature of a body. It does not require any external force, just the nature of the object itself.

Violent (Forced) Motion

Motion caused by an external force acting on a body moving it contrary to its natural place

Rest

Not motion in the modern sense but Aristotle considered __ as the natural state of many bodies.

Celestial Motion

Refers to the apparent or actual movement of celestial bodies in the style as observed from earth or in space.

Diurnal Motion

Daily movement of celestial objects across the sky, from east to west, caused by the rotation of the earth’s axis.

Earth’s Rotation

23 hours and 53 minutes

Annual Motion

Yearly movement of the sun among the stars caused by the earth's revolution around the sun.

Earth’s Revolution

365 days 5 hours 48 minutes 45 seconds

Precession of the Equinoxes

The slow, gradual shift in the orientation of the earth's rotational axis.

Equinox

Northern hemisphere and Southern hemisphere are equal.

Solstice

One hemisphere is longer than the other

Summer Solstice

North: June 20-21

South: December 21-22

Winter Solstice

North: December 21-22

South: June 20-21

Polaris

Northern star when left

Vega

Northern star when right

Ships disappearing into the horizon

When ships sail, their bottom vanishes first, then the sails last.

Shape of Moon’s Shadow During an Eclipse

Earth’s shadow is casted on the moon, always round no matter the position.

Different Stars in Different Places

Travelers see diff. stars/constellations in diff. directions.

Change in Sun’s Angle

Diff. angle of the sun from syene and alexandria at the same time.

Eratosthenes

Compared the sun’s angle from two cities, using geometry he calculated the earth’s circumference accurately.

Orion

One of the most brightest and recognizable constellation.

Ursa Major

Visible year-round

Ursa Minor

Contains polaris at the end of its handle

Cassiopeia

Looks like a big “W” or “M” shape of bright stars

Scorpius

Bright and shaped like a scorpion

Leo

Bright constellation that looks like a crouching lion

Taurus

Best seen in winter

Cygnus

Contains the northern cross

Centaurus

nearest star system

Carina