The Sun

1
The Suns Size, Heat, and Structure
2
The Suns Size, Heat, and Structure
3
Drawing the Suns Layers to Scale
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Layer Radius in km Scaling Factor Radius of Each Layer in cm Characteristics (List these on drawing)
Convective Zone 495,000-695,000 km 69,500 km 1 cm
Radiative Zone 190,000-495,000 km 69,500 km 1 cm
Core 0-190,000 km 69,500 km 1 cm
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4
The Solar Wind is the cause of geomagnetic
storms and the Aurora Borealis (Northern Lights)
5
The Aurora Borealis (Northern Lights)
6
The Sun is powered by nuclear fusion.
7
The Sun Burns Hydrogen and converts it to Helium
Energy
8
Plasma is a fourth state of matter. Charged
nuclei of particles fuse together.
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Plasma is a fourth state of matter. Charged
nuclei of particles fuse together.
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Normal Hydrogen Atom with proton () and
electron (-)
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In Plasma, electrons are stripped away from the
nucleus.
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Since nuclei are positively charged, they will
repel other nuclei. Only tremendous heat and
pressure will cause the nuclei to fuse. Such
temperatures and pressures occur naturally in
stars where they are ultimately caused by
gravitational forces.
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Summary of Fusion Reactions
14
Solar Energy is derived from the conversion of
mass to Energy.
15
Albert Einstein is famous for his equation Emc2.
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AssignmentYour job is to draw the model of the
sun on butcher paper using colored pens/pencils.
You should describe all the layers and
temperatures. You also need to discuss how the
sun makes energy (fusion), how/when sunspots
form, and the solar wind and what it does to
Earth.
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Historical Observations of the Solar System
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The idea that the Earth was stationary and the
sun moved across the sky was the idea that
prevailed for over two thousand years.
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What is a geocentric model?
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Its the idea that Earth was at the center of
the Universe. The stars were thought to move
around the Earth.
21
The same constellations were noticed to be
visible at the same time each year.
22
A few points of light seemed to move however, or
wander. What were these things?
23
These were the planets! Planet means wanderer.
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The most perplexing of all was retrograde motion
of Mars, the observation that it stopped moving
eastward and moved westward for a few weeks.
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Retrograde Motion
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Ptolemy, a Greek Astronomer in the 2nd Century
A.D., believed that the planets orbited Earth in
Epicyles. This idea was accepted until the 16th
Century.
27
Copernicus (1473-1543), proposed the
Heliocentric Model, the idea that the sun is the
center of the solar system and the planets
revolve around the sun.
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We use Copernicuss model to this day.
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Enter Tycho Brahe in the 16th Century. This
Danish astronomer made very accurate observations
of the movement of planets and their moons.
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Tycho Brahe in his observatory, Uraniborg.
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Brahe died in 1601. His work was extended by his
assistant, Johannes Kepler.
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Kepler went on to make an unexpected discovery
and formed Keplers Laws! What was this?
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The planets orbit in ellipses with the sun at
one foci. This is Keplers First Law.
Earth
Sun
Focus
Focus
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The planets sweep out equal areas in equal
times. This is Keplers Second Law.
Earth 1
Sun
Focus
Focus
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Keplers Third Law says that the Period squared
equals the average Distance Cubed. P2 D3
Earth 1
Sun
Focus
Focus
36
Isaac Newton and His Physical LawsNewton
invented calculus, studied the composition of
light, and established classical physics.
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Newtons First LawAn object in motion will stay
in motion unless acted upon by an outside force.
An object at rest will stay at rest unless acted
upon by an outside force. This is the foundation
of space travel.
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Newtons Second LawThe Force on an object
equals its mass X acceleration (gravity).Force
mass x accelerationF ma
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Newtons Third LawFor every force, there is an
equal and opposite force. The basis behind rocket
propulsion.Force a on b Force b on a
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Newtons Law of GravitationThe gravitational
force on two bodies (planet and sun) is
proportional to mass and inversely proportional
to the square of distance.Forcegravity Gm1m2/d2
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Earths Rotation and Revolution
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Rotation is the spinning of Earth around its
axis. Its takes 24 hours for the earth to rotate
on its axis.
43
Evidence for Earths Rotation is given by a
Foucault Pendulum. YouTube video of the Foucault
Pendulum at the Griffith Observatory!
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We also know that the Earth rotates from west to
east because the sun rises in the east, moves
through the southern sky (in the northern
hemisphere), and sets every day in the west.
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Time Zones are needed to account for the fact
that the Sun is not in the same position
everywhere at the same time.
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Revolution is the movement of Earth around the
Sun. It takes 365 ¼ days to revolve around the
Sun.
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Evidence for revolution is indicated by the
changing view of the stars throughout the year.
The Earths seasons also give evidence of
revolution.
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Star Parallax, an apparent shift in star
position, is another piece of evidence.
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The Earths seasons also give evidence of
revolution.
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Earths Axis is tilted at 23.5 from the
vertical. This gives way to the seasons.
51
Solstice means sun still. Equinox means equal
night.
Autumnal Equinox September 22nd
Winter Solstice December 21st
Summer Solstice June 21st
Vernal Equinox March 21st
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Table of Seasons
Season Summer Solstice (First Day of Summer around 6/21) Autumnal Equinox (First Day of Fall around 9/22 Winter Solstice (First Day of Winter around 12/21) Vernal Equinox (First Day of Spring around 3/21)
Day Length at LCHS Around 14 hours 12 hours Around 10 hours 12 hours
Sun Directly overhead 23.5 N at Tropic of Cancer 0 at Equator 23.5 S at Tropic of Capricorn 0 at Equator
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Here are two animations for the reasons for our
seasons. Animation 1 and Animation 2
54
What kinds of radiation does the sun emit?
According to Wiens Law, 2,900,000/Temp in
Kelvin, the peak emission of the sun is
2,900,000/6000K. This is equal to 483 nm, the
color of blue-green light. This is why our eyes
have evolved to detect the visible spectrum.
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The electromagnetic spectrum.
According to Wiens Law, 2,900,000/Temp in
Kelvin, the peak emission of the sun is
2,900,000/6000K. This is equal to 483 nm, the
color of blue-green light. This is why our eyes
have evolved to detect the visible spectrum.
56
What kinds of radiation does the sun emit?
According to Wiens Law, 2,900,000/Temp in
Kelvin, the peak emission of the sun is
2,900,000/6000K. This is equal to 483 nm, the
color of blue-green light. This is why our eyes
have evolved to detect the visible spectrum.
57
What kinds of radiation does the sun emit?
UVA and UVB light can get through to the Earths
surface. Lucky for us, UVC light is blocked.
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Consequences of Not using sunscreen
Sunburn Skin Cancer Melanoma Cataracts
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Sunscreen Lab Chemistry of Sunscreen
Active Ingredients Contains Octinoxate 2
(Sunscreen), Padimate O 1.4 (Sunscreen)Inactive
Ingredients Mineral Oil, Aloe Barbadensis Leaf
Extract, Cocos Nucifera Oil (Coconut), Theobroma
Cacao Seed Butter (Cocoa), Musa Sapientum Fruit
Extract (Banana), Tocopherol Acetate (Vitamin E
Acetate), Retinyl Palmitate (Vitamin A), Daucus
Carota Sativa Root Extract (Carrot),
Phenoxyethanol, Methylparaben, Isopropylparaben,
Isobutylparaben, Butylparaben, Fragrance
60
Sunscreen Lab
Active Ingredients Padimate O 5.4, Oxybenzone
1.2Inactive Ingredients Acrylates/C10-30
Alkyl Acrylate Crosspolymer, Aloe Barbadensis
(Leaf Juice), Cetyl Alcohol, Cocos Nucifera
(Coconut Oil), Fragrance, Glycerl Stearate,
Hydrolyzed Collagen, Imidazolidinyl Urea,
Isocetyl Alcohol, Methylparaben, Mineral Oil,
Mink Oil, Polyethylene, Polyglyceryl 3 Dioleate,
Propylparaben, Quaternium 15, Sorbitol, Stearic
Acid, Theobroma Cacao Cocoa Seed Butter,
Tocopheryl Acetate, Triethanolamine, Water
61
Sunscreen Lab
Did you notice the inactive mink oil ingredient?
This comes from the thick fatty tissue just under
the skin of the mink. It is used in cosmetics and
is used to coat shoe and baseball glove leather.
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Sunscreen Lab
Active Ingredients Padimate O 5.0 (Sunscreen),
Oxybenzone 3 (Sunscreen), Octinoxate 2
(Sunscreen)Inactive Ingredients Acrylates/C10-3
0 Alkyl Acrylate Crosspolymer, Aloe Barbadensis
(Leaf Juice), Cetyl Alcohol, Cocos Nucifera Oil
(Coconut), Fragrance, Glyceryl Stearate SE,
Hydrolyzed Collagen, Imidazolidinyl Urea,
Methylparaben, Mineral Oil, Mink Oil,
Polyethylene, Polyglyceryl 3 Oleate,
Propylparaben, Quaternium 15, Sorbitol, Stearic
Acid, Theobroma Cacao Seed Butter (Cocoa),
Tocopherol (Vitamin E), Triethanolamine, Water
63
Sunscreen Lab
Active Ingredients Octinoxate (7.5 -
Sunscreen), Oxybenzone (5.25 - Sunscreen),
Octisalate (4.75 - Sunscreen), Titanium Dioxide
(1.2 - Sunscreen)Inactive Ingredients Aloe
Barbadensis (Leaf Juice), Alumina, Aluminum
Stearate, C12-15 Alkyl Benzoate, Ceteareth 20,
DMDM Hydantoin, Glyceryl Stearate, Hydrolized
Collagen, Hydroxyethylcellulose, Imidazolidinyl
Urea, Iodopropynyl Butylcarbamate, Isopropyl
Myristate, Magnesium Aluminum Silicate, Methyl
Acetyl Ricinoleate, Octadecene/MA Copolymer, PEG
40 Castor Oil, PEG 7 Glyceryl Cocoate,
Polyethylene, Polyhydroxystearic Acid, Quaternium
15, Silica, Stearic Acid, Stearyl Alcohol,
Tocopheral (Vitamin E), Triethanolamine,
Trisodium EDTA, Water
64
Sunscreen Lab
Active Ingredients Avobenzone (1.5)
(Sunscreen), Homosalate (15) (Sunscreen),
Octisalate (5) (Sunscreen), Octocrylene (1.25)
(Sunscreen), Oxybenzone (6) (Sunscreen)Inactive
Ingredients Water, Hydrogenated Dimer
Dilinoley/Dimethylcarbonate Copolymer, Stearyl
Alcohol, Glycerin, Caprylyl Glycol, Aloe
Barbadensis (Aloe Vera) Leaf Juice, Tocopherol
Acetate (Vitamin E), Retinyl Palmitate (Vitamin
A), Tocopherol, Sodium Lauroyl Sarcosinate,
Behenyl Alcohol, Glyceryl Stearate, Glyceryl
Stearate Citrate, Disodium Ethylene Dicocamide
Peg 15 Disulfate, Cetyl Alcohol, Dimethyl
Capramide, Cetearyl Alcohol, Sodium Lauroyl
Lactylate, Lecithin, Carbomer, Xantham Gum,
Methyldibromo Glutaronitrile, Methylchlorisothiazo
linone, Methylisothiazolinone, Phenoxyethanol,
Disodium EDTA, BHT
65
Sunscreen Lab
Active Ingredients Octinoxate (7.5 -
Sunscreen), Oxybenzone (6.0 - Sunscreen),
Octisalate (6.0 - Sunscreen)Inactive
Ingredients Water, Aloe Vera Gel, Mineral Oil,
Stearic Acid, Propylene Glycol, VP/Eicosene
Copolymer, Triethanolamine, Acrylates/C10-30
Alkyl Acrylate Crosspolymer, Cetyl Alcohol,
Glycol Stearate, Phenoxyethanol Methylparaben
Ethylparaben Butylparaben Propylparaben,
Disodium EDTA.
Target Ultra Sunblock SPF 30
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When the suns rays are more direct, we get more
intense rays.
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We get more solar insolation in the summer
months also because the sun has less atmosphere
to travel through if it is overhead.
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If there is more atmosphere to travel through,
less radiation reaches the surface.
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So, is it easier to get a sunburn when the sun
is overhead, or when it is on the horizon?