Download Light Phenomena Around Us

Light
Phenomena
Around Us
Crepuscular Rays
aka “twilight” rays or “heaven” rays
Saint Peter’s Basilica,
Vatican City
Detail of gold throne
panel of King Tutankhamun,
Egypt, 1332-1322 BC
Aurora Borealis by Lawrence Zeltser
Aurora Borealis is such a beautiful sight.
The Northern Lights are one of Earth’s
greatest phenomena. The lights include
a variation of intensity and color as well
as it is very rare for it to occur.
What Causes Aurora Borealis?
Aurora Borealis occurs when charged
particles from the sun interfere with
the Earth’s magnetic field and the
atoms in the atmosphere. When a
charged particle reaches the atom it
causes the electrons to move to a
higher energy state. When it goes
back to its normal state, it releases a
photon, a light particle that produces
varied colors.
Fun Facts:
• Aurora Borealis is usually seen in the north.
• Discovered in 1621 by Pierre Gassendi.
• Named after 2 roman gods, Aurora and
Boreas.
Aurora (Northern Lights)
The aurora forms when charged particles emitted from the Sun
(solar wind) get caught up in the Earth's magnetic field and collide
with atoms and molecules in the top of the atmosphere.
Different colors of the aurora
are produced by different
atmospheric components:
 Red – oxygen atoms at ~200 miles high
 Blue – ionized nitrogen molecules
 Green-Yellow – oxygen atoms at ~60 miles
high – most common!
 Pink/crimson/purple – mix of the above
• Fireworks use a chain
reaction of two explosives
which are lit by a fuse.
• Fireworks usually contain
”stars” -explosives which
are coated in different
metals so there’s different
colors when the “stars”
burn and blow up :)
Fireworks
What is Iridescence?
By: Mark Sasanuma
• Iridescence is
various colors
you see on the
surfaces of
bubbles and CDs.
• Iridescence occurs
when white light
bounces off a thin
reflective film and
interfere with each
other.
Iridescence
Bioluminescence
Bioluminescence is emission of light by a living organism
by means of a chemical reaction (type of Chemiluminescence).
It occurs widely among
animals (many creatures of the
open sea, and insects) as well
as in some fungi and bacteria.
SUN
Solar Eclipse
Lightning
Phases of the Moon
• Half of the
Moon is always
lit by sunlight.
• As the Moon
revolves around
the Earth, we
see the lighted
part of the
Moon's surface
from different
angles.
• The different
shapes we see
are called
"phases" of the
Moon.
Twinkle, twinkle, little star…
• The scientific term is
“astronomical scintillation”.
• Observed from the Earth, a star is
essentially a pin-point light source.
• As starlight travels from space into
the Earth’s atmosphere, the rays
are refracted.
• Since the atmosphere is constantly
changing due to turbulence, the
amount of refraction also
constantly changes.
• This causes the image of a star to form in a slightly different part
of our eye retina every moment – we perceive it as twinkling.
• Planets usually do not twinkle – why?
• You might actually see a planet twinkling if it appears low at the
horizon – why?
Colors of the Stars
What Makes a Diamond Sparkle?
http://www.pbs.org/wgbh/nova/physics/diamond-science.html