THE SOUTHWORTH PLANETARIUM
70 Falmouth Street      Portland, Maine 04103
(207) 780-4249      usm.maine.edu/planet
43.6667° N    70.2667° W  Altitude:  10 feet below sea level Founded
January 1970
2021-2022: CXV
"Keep your face to the sun and you will never see the shadows."
-Helen Keller

THE DAILY ASTRONOMER
Friday, April 29, 2022
Quiz # 27: Here Comes the Sun...We Hope

Yes, indeed, spring is here.
In fact, we're now nearly six weeks beyond the vernal equinox along the
time continuum.   Of course, being hinterland denizens, we've not yet
experienced an excessive amount of spring-like weather.  However, now that
we're a few hours shy of May 1st, the enveloping warmth and
soul-rejuvenating temperatures should be just around the corner!  In
commemoration of the warm season's imminent return, we're posting a quiz
about the Sun: that gloriously bright, life-sustaining source of heat,
light and merriment.


[image: sun_large.jpg]


1.  If hollowed out, the Sun could accommodate how many Earth sized spheres?
a.  16,700
b. 113,879
c.  435,978
d.  1.2 million

2.  When is the Sun closest to Earth?
a.  Earth's orbit is circular so its distance from the Sun remains constant
b.  early July
c.  early January
d. the autumnal equinox

3.  About how much of the Sun's energy does Earth receive?
a.  3%
b.  1.5%
c.   one millionth
d.   one billionth

4.  As far as size is concerned, how does the Sun compare to other stars?
a.  it is smaller than most.
b. it is smaller than half of them
c.  it is larger than about 90% of the other stars
d.  the Sun is larger than any other star

5. How old is the Sun?
a.   6006 years old
b.  3.5 million years old
c.  5 billion years old
d.  10 billion years old

6.  True or false:  The Sun is yellow.

7.  True of false:  The Sun will become a black hole in about 6.5 billion
years

8.  The Sun consists primarily of hydrogen and helium.    It contains
"trace" amounts of other elements.   How many other elements have been
detected in the Sun so far?
a.  5
b.  17
c.  34
d.  67

9. How long does the Sun require to complete one orbit around the galaxy?
a.  it hasn't completed an orbit yet and probably never will before it dies.
b. 10 million years
c.  113 million years
d.  225 million years

10.  The energy created in the Sun at this very moment will need how much
time to escape into outer space, approximately?
a.   8.4 minutes
b.  10,000 years
c.  45,000 years
d.  200,000 - 300,000 years

ANSWERS

1.  d.  1.2 million
Now, that's a humbling thought.    Compared to us, Earth is unfathomably
huge!    Compared to Earth, the Sun is immense.   One could pour Earths
into the hollowed out Sun like 200 galloons of Skittles poured into a large
vat.    (Yes, we did the math....no, we probably didn't do it right...)

2.  c.  early January
Yes!    Despite the frigid and bitter conditions of early January when
we're huddled together inside our in home bon-fires while watching globules
of liquid oxygen dripping off the branches, we're actually closest to the
Sun.   Earth reaches perihelion, the point of least distance, around
January 1 - 4.    At this time, we're 91.5 million miles from the Sun.
 When at aphelion around July 4th, Earth's heliocentric distance is about
94.5 million miles.     The distance difference doesn't affect our weather.

3. d.   one billionth
Wow!  I mean, wow!     Venture out into a steamy hot tropical rainforest
and realize that the oppressive heat is almost a negligible fraction of all
the heat energy the Sun generates.

4. c.  it is larger than about 90% of the other stars
Most of the stars are red dwarfs, which are considerably smaller than the
Sun. However, some stars literally dwarf the Sun.  Look at the size
comparisons between the Sun and some of the larger stars

[image: size_comparison.en.png]

5.  c.  5 billion years old
The Sun is about mid way through its life cycle.

6.  False!
Big, bold false!   The Sun appears yellow because of our atmosphere.   In
fact, the Sun would appear white if one approached it in space.    The Sun
produces light along the entire EM spectrum.  It produces the most
radiation along the green portion of the spectrum (483-520 nm).

7. False!
Big, bold, bloated false!  The Sun will never become a black hole.    When
it perishes, the Sun will turn into a white dwarf surrounded by a planetary
nebula.

8. d.  67
We remember that the solar system formed from a nebula chemically enriched
by the introduction of supernova remnants.  Such remnants contain an
abundance of elements.   These particles would have been incorporated into
the Sun.  The three most abundant elements (by number of atoms) in the Sun
are   hydrogen, helium and oxygen.

9. d.  225 million years
A galactic year.    The Sun has completed  more than 20 revolutions around
the galactic center through its life.

10. d.  200,000 - 300,000 years
Every time you are outside on a sunny day you are awash in ancient
starlight.



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Jolly Roger Astronomy
            or
Misadventures in Dark Adaptation
            or
Stretching a Point So Far it Will Never Regain its Original Shape Even if
you Freeze it

[image: skull-scarf-flag-8x5.gif]
*Ahoy, ye scurvy dogs!    Batten down the hatches!  Swab the gangplank!
Hoist up the Jolly Rogers, ye swashbuckling knaves, as we plough these
white capped seas in search of ill-gotten gold, bountiful booty, and purses
aplenty in unprotected ports.   Arr!  May every skirmish with the King's
regiments be another victory for the Devil, himself, dancing in the fire
lit caverns where our shades will soon gather to...*

Yes, you're right.  Unless they're standing close to the fried dough stand
or ferris wheel, no pirate will ever actually spout such nonsense.
 Moreover, according to historians who have studied maritime history, being
visited by real pirates would ruin what would probably be the last day of
your life, anyway. Also, a pirate captain would have had to have been
unfathomably stupid to have a Jolly Roger pirate flag flapping from the
mast.  Doing so would have been tantamount to spray painting "Hey, British
Navy, cannon ball us first!"  on the bow.   All this tedious history
notwithstanding, Jolly Roger flags are now inextricably linked with pirate
lore and pirate-based theme park rides.   Now, apart from the fact that I
just bought a Jolly Roger flag yesterday in order to terrify the staff into
unquestioning obedience,  what connection could such a flag possibly have
with astronomy?

Look at the eye patch!
Have you ever wondered why pirates wore eye patches?   Theories abound, of
course, as theories are wont to do.   Many believe that the eye patches
were necessary because pirates would often lose an eye in fencing duels or
zombie sieges.    In fact, the reason might have been less about empty
sockets than contracting pupils: dark adaptation.

Let's say that a pirate is on a ship doing what pirates generally do (and
the less said about that, the better.)  As a pirate is moving from the
lower region to the deck, he (sometimes, she, Grannia), will be exposed to
different light levels:   dark and gloomy in the lowest level, fiercely
bright on the deck, with various levels of gloaming haze in between.
Now, as anybody who has spent 340 years working in a subterranean
planetarium without the faintest hope of liberation and far removed from
the sympathies of humankind can attest,  ascending out of deep darkness
into open sunlight can inflict some pain on ye here soul windows.     The
pirates would have experienced the same discomfort and, most importantly,
might have been temporarily blinded by the sunlight when ascending onto the
upper deck. Conversely, they would also have been blinded by the shade when
venturing down below.        Having a patch on one eye would keep that eye
steeped in darkness and therefore always dark adapted.   As the pirate
rushes down into the ship's lower regions, he/she could switch the patch
from the dark adapted eye to the one that isn't, thereby preventing the
temporary loss of vision.

[image: dilated-pupils.jpg]

Our pupils expand and contract in response to light levels.    In bright
light, the pupils contract for self protection to prevent an excess of
incoming radiation.   In dim light, the pupils expand to allow for the
reception of more light to see.  When one wants to have a good view in a
dim region, the larger the pupil the better.   (We remember that telescopes
are essentially allowing for the gathering of more light so one can gain a
much clearer view of a dim celestial object.)

Tonight, if you're planning to venture outside to admire the sky, you could
keep a patch on your eye for about 20 - 30 minutes beforehand.    That
patch would protect your eye from the micro sources of light pollution:
televisions, lamps,  computer screens, smart phones, and the various other
trappings of our modern world.        You might look like a pirate, but
you'll be able to see the sky like an astronomer.   A perfect time to make
a comment about moral equivalency, but we won't.












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