Tuesday, May 21, 2013

Sunrise Sunset

July 13, 2010 by Jack  
Filed under Jack's Blog

On February 6, an inquisitive reader of this column, whom we will call
Dorothy, sent me an email: “I have a question for you. This year I have been
keeping track of the times of sunrise and sunset. I have been surprised that the
morning daylight isn’t increasing as much as the evening light. I took the times
from the weather report on TV. On December 22 the sunrise was at 7:58 am and
sunset was at 4:55 pm. On February 5, sunrise was at 7:39 am and sunset was at
5:45 pm. Am I right in figuring that means 50 more minutes of light in the
evening, but only 19 more minutes in the morning? I had expected that it would
be about the same increase both times. My question is why doesn’t it increase
the same morning and evening?”
I sent her an email saying that I’d wondered about that too, and that would
try to find an answer. (Translation: I was basically clueless!)
On March 6, Dorothy sent another email. “I have still been charting the
sunrise and sunset times. For the past 30 days the sunrise has gained 42
minutes while sunset has gained only 39 minutes of light. I am guessing that by
summer the total gain will be equal when it again begins losing minutes of light.
It will be interesting to see.”
Again, she got no explanation from me. I was still in the dark about the sun.
On April 12, Dorothy sent another email. “I notice now that morning light is
increasing faster than the evening one so the total is getting more even. I sure
don’t understand how it works though.”

Okay, Dorothy, let’s see if I can take a stab at answering your question.
First of all, the reason for our seasons is the 23.5 degree tilt of the earth’s
axis. In the summer, the Northern Hemisphere is tilting toward the sun. In the
winter, the Northern Hemisphere is tilting away from the sun. Winter solstice
occurs when the earth’s axis is most tilted away from the sun. It is the shortest
sun-lit day of the year for us in the Northern Hemisphere. It occurs on or about
December 21. From that day on, the Northern Hemisphere gets more and more
minutes of sunlight. From our point of view on the earth we see the path of the
sun, instead of being in the southern part of the sky, begin to creep northward.
Sunset and sunrise times change in such as way as to give us more sunlight every
day. The summer solstice occurs in June when the earth’s axis is most inclined
toward the sun. It is the longest sun-lit day of the year. We discussed this in the
March 27 issue of the Standard Journal.
Second big idea: There are two ways to define when one day has passed.
See the figure below, taken from the Millennium Mathematics Project, University of
Cambridge web site:

The figure shows the earth (in blue) at position 1 at noon at some place on
the earth. The earth then makes one complete rotation, shown as position 2.
Ordinarily, we would think that one complete rotation of the earth about its axis
should equal one day, right? But if we want to go from noon on day 1 to noon the
next day, the sun (yellow at the center of the figure) should be directly overhead
each time. However, because the earth has been traveling through space in its
orbit at the same time it’s rotating about its axis, it will take a little more rotation
for the sun to be directly overhead. This happens at position 3 on the figure.
Confusing? Try this analogy. Imagine you’ve taken a child named Johnny to
an amusement park. On one ride, kids sit on a large ball that is attached to a track.
The ball (and Johnny) moves slowly around an oblong track at the same time the
ball rotates. You stand in the middle and take Johnny’s picture when he’s directly
facing you at position 1 in the figure.
4
When Johnny is at position 2, he calls out, “Take my picture! Take my
picture!”
You say, “No, Johnny, I’m not going to take your picture until you’re directly
facing me.”
Because Johnny is both rotating and moving along a track, before you take
the second picture, you have to wait until Johnny is at position 3, when he’s facing
you again. Replace you by the sun and Johnny by someone looking at the sun at
noon on two different days, and you’ve got the idea of what this is all about.
In astronomy, the time it takes to go from position 1 to position 3 is called a
solar day. The time it takes to go from position 1 to position 2 is called a sidereal
day.
This extra time to go from position 2 to position 3, on average, is about four
minutes. According to the Cal Tech outreach web site, “This little difference in
time would cause no concern if it were always the same, but it is not!”
Now we have to add one more complication: The earth moves in an elliptical
orbit. (An ellipse looks like a circle that someone has sat on.)
5
As shown in the figure, on January 3, the Earth is the closest to the sun.
This position is called the perihelion of its orbit. On July 4, the Earth is the farthest
away from the sun. This is called the aphelion.
Back to you and Johnny again. Suppose that the ride that Johnny is on
speeds up along the track some of the time and slows down at other times. This
happens with the earth too. And that affects the length of the solar day.
According to the New Scientist web site: “The asymmetry in the rates of
change of sunrise and sunset times arises from the nature of the Earth’s orbit
around the sun, and is caused by variations in the length of the solar day, the time
between solar noons on successive days, throughout the year. Sunrise and
sunset are essentially symmetric about solar noon, but solar noon is not always
clock noon.”
6
“The Earth speeds up as it approaches the perihelion of its elliptical orbit,
the point of closest approach to the sun, and slows down as it approaches the
aphelion. The increased speed at the perihelion, together with the shorter distance
to the sun, means the angle swept out by the Earth about the sun every day is
greater near the perihelion than near the aphelion. So more rotation is needed to
complete a solar day near the perihelion, causing the solar day to lengthen.”
That is what introduces the lack of symmetry between the changes in
sunrise and sunset as noticed by Dorothy. There’s much more that could be said,
but we’ll leave that for another day.
Thanks for the question, Dorothy! It’s been fun to try to fin d an answer.
Weyland welcomes your comments. He can be reached at
jack.weyland@gmail.com

March 3, 2010 by Jack  
Filed under Jack's Blog

HOW TO TALK TO A MAN

1.    Instead of saying: “The steps are so icy!”
Some men might answer with one of the following:
a.    “I know. I nearly fell myself coming up the stairs.”
b.    “Duh!  That’s why they call it winter.”
c.     “Come into the house through the garage like I do.”

Say this, “I need you to get the ice off the steps.”

2.    Instead of asking, “Are you going to wear that tie?”
Some men might answer with one of the following:
a.    “Yeah.”
b.    “Duh!  That’s why I’m tying it around my neck.”

Say this, “That tie doesn’t go with your shirt.”

3.    On your anniversary, instead of saying, “Honey, what do you think?  Did we do the right thing to get married?”
Some men might look puzzled and ask, “As opposed to what?”

Say this: “I am so happy to be married to you!”

4.    Instead of saying, “You’ll never believe what crazy policy my boss announced today for all the secretaries!”
After you explain what your boss said, some men might answer with one of the following:
a.    “If you don’t like your job, just quit!”
b.    “That’s it! You’re not working there anymore.”
c.    “I’m going down there and telling him what I think of him!”
c.    “Maybe you and the other secretaries did something to cause him to do that.”

Say this: “I am so mad at my boss today for a policy he  announced today for all the secretaries!  All I need you to do is listen and sympathize.”

Question: Can you come up with any other phrases which women say that men never respond to properly? Also, please give suggestions on how to say it so a man will understand.

The Blog is Back!

February 25, 2010 by Jack  
Filed under Jack's Blog

In my latest novel, “Brianna, My Brother, and the Blog,” I have Austin hauling Brianna, her harp, along with Sophie, her friend who plays flute, to wedding receptions where they provide background music to make a little money. Austin sits among the guests and listens in on their conversations.
The truth is I’m a lot like Austin in that I also listen to conversations of people I’ve never met.
Several months ago I was standing in the hall just before a meeting was about to begin. A young wife hurried in. As she came into view, he scowled and grumbled, “It’s about time! Everyone’s waiting for you.”
I thought he could have done better than that. This is the woman he loves more than anyone else, his partner, and she deserves kindness and respect.
She knew she was late. I’m sure there were reasons for it too. Him saying “Everyone’s waiting for you” did not make her feel appreciated. What will he say when they have kids and she’s trying to get them ready for church?
This is not about being late. It’s about showing kindness and respect.
Here’s my question for you: What should this young husband have said to her when he first saw her?

Gerald Giraffe – a Christmas Poem

November 20, 2009 by admin  
Filed under Jack's Blog

giraffeGERALD GIRAFFE
A Dr. Seuss-type Christmas Poem
by Jack Weyland

This poem may be used with Jack’s permission.   Please be sure to give him credit for it.

[Read Gerald Giraffe]

New Short Story!

October 15, 2009 by Jack  
Filed under Jack's Blog

Please read “Kayla’s New Criterion” (found by clicking the Story Club icon.)  It was inspired by an article by Elder Dallin H. Oaks in the June 2006 issue of the Ensign.

Another Book Signing

October 12, 2009 by Jack  
Filed under Jack's Blog

On Saturday, October 17, from 4:00 to 6:00 pm, Sherry and I will be at the new Ogden Junction Deseret Book Store. The address of the store is 339 East 2250 South, Ogden, UT 84401. If you get a chance, drop by and see us!

Global Warming Takes a Vacation!!

October 10, 2009 by Jack  
Filed under Jack's Blog

Want an update about global warming? Read my latest “Graph That” column. Apparently we’re in for a 5 to 20  year cooling period. Who knew?

Free Book!!

September 26, 2009 by Jack  
Filed under Jack's Blog

Saving KristenIf you go to www.deseretbook.com/free you can download my novel “Saving Kristen” for free!  Also, for anyone interested, I’ll be signing books in Utah on Saturday, October 3 at the Fort Union Deseret Book Store located at 1110 E. Fort Union Blvd in Midvale, UT.  I will be there from 4:00 to 5:30 pm. You’re all invited to drop by and visit.

For Men: How to be a True and Faithful Friend to a Woman

September 24, 2009 by Jack  
Filed under Jack's Blog

friends1. Never speak badly of her to anyone. If someone is critical of her, stand up for her.
2. Be true to the friendship you share even when you’re mad at her, or when you feel that you’ve been shortchanged in some way. When you’re both tired, take care of her needs first instead of your own.
3. When you’re first getting acquainted, remember that you’re not applying for a job so don’t constantly brag about past accomplishments. That will only make her think you’re conceited and arrogant. Focus your attention on finding out all the wonderful aspects of her personality.
4. Act in such a way that she always feels safe in your presence. For instance, if she thinks you drive too fast, when she’s with you, drive slower.
5. When she’s been hurt by something you’ve said or done, instead of defending your good intentions (such as “I was only trying to…”) listen carefully to what she says. Do not transfer blame to her by saying, “I’m sorry you misunderstood what I said.” Begin your apology with these words, “I’m sorry that I…”
6. When she wants to talk, turn off the TV, log out of your laptop, turn off your cell phone, quit playing video games, move what you were reading far away from you, and don’t look at your watch every three minutes like you’re thinking, “How long is this going to take?” Give her your complete attention. Look at her when she’s speaking. Every once in a while, nod or say, “okay” so she’ll know you’re listening. Avoid trying to solve her problems all the time. She’s perfectly capable of doing that. Sometimes she just needs someone to listen to her, so learn to become a better listener.
7. Understand she’s not perfect but, of course, neither are you. Do your best to understand her point of view. Cherish her the way she is now.
8. Know when her birthday is and plan ahead of time what you’re going to get her. Also, know the names of her brothers and sisters. Know what her favorite color is, her favorite dessert, her favorite movie, and the music she loves. Learn as much as you can about her by asking her questions.
9. Send her flowers or a card once in a while–not for a special occasion but just to let her know you’re thinking of her. Tell her how important she is to you.
10.. If she loves to go to concerts, go with her. If she likes to go to church activities, go with her. If she loves to go wind surfing, go with her. Let her teach you what she loves to and, in turn, teach her what you love (unless of course what you love are video games).
Do any of you have any comments or additions?

TEN THINGS A WOMAN SHOULD NEVER SAY TO A MAN

September 17, 2009 by Jack  
Filed under Jack's Blog

womansayTen Things a Woman Should Never Say to a Man

  1. “You’re not thinking of trying to fix that, are you? We need to get someone who actually knows what he’s doing.”
  2. “You have no idea where we are right now, do you?”
  3. “How old were you when you first realized you were going bald?”
  4. “Are you going to eat that?”
  5. “Tell me what you’re thinking.”
  6. (Believe me, you’ll always be disappointed.)

  7. “The guy I was out with last week was such a great dancer. I wish he were here so he could teach you a few things.”
  8. “What are you going to do if you can’t find another job?”
  9. “You don’t exercise at all, do you? I can tell.”
  10. “We need to talk.”
  11. “Are you going to wear that shirt with that tie?”

Question:  Do you agree? Tell me why or why not.  What additional ones would you add?

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