Shih-Hsuan Wei

Introduction

It’s been few years for me living in Lubbock, Texas

after left home in Taiwan. I have always felt that

summers never end in Lubbock, in which it have

much more sunlight when I was in Taiwan. Is it an

illusion for me because I have not gone back to

Taiwan in summer time in the past years? Or it is an

actual scientific proof that it is the difference. So the

question I want to ask is “In summer 2010, did

Lubbock, Texas have more sunlight than Taipei,

Taiwan?” In particular, I will only determine the

summer time in 2010 in both places. What I mean

summer time is only from June 1st to August 31st.

Before starting collecting some data, let me begin with the geographies of two different cities.

Lubbock is a city of

the state of Texas. It

is located in the

northwestern part of

the state, located at

33 33“ N, 101 52” W.

The state of Texas is

1279 km (790 mi)

long and 1244 km

(773 mi) wide of total

696,241 km2 (268,

581 mi2) with the

population of 25 million.

Lubbock. http://en.wikipedia.org/wiki/Lubbock,_TexasViewed 2.23, 2011.

Taiwan, also known as Formosa (Beautiful Island), is an

island situated in East Asia in the Western Pacific

Ocean, and located at 23 30“ N, 121 00” E. The main

island of the group is 394 km (245 mi) long and 144 km (89

mi) wide of total 35,980 km2 (13, 892 mi2) with the population

of 23 million. Taipei city is the capital of the Taiwan, located

northern part of the island.

Taiwan.http://en.wikipedia.org/wiki/Taiwan

Viewed. 2,23, 2011.

Now we have some idea where Lubbock, Texas and

Taipei, Taiwan are. Then we can start finding some

data about sunrise and sunset in both cities in 2010.

The best resource to collect these data is the Naval

Oceanography Portal website

http://aa.usno.navy.mil/data/docs/RS_OneYear.php.

The U.S. Naval Observatory (USNO) provides a

wide range of astronomical data, in particular, you

can find table of sunrise/ sunset for an entire year

for any location in the world.

Start with Lubbock, Texas:

Lubbock, sunrise/set.http://aa.usno.navy.mil/data/docs/RS_OneYear.phpViewed. 2,23, 2011.

Figure 1: Sunrise/set time in Lubbock, Texas in 2010.

Since we only consider the summer time, we will

only look at the data of sunrise/sunset from June 1st

to August 31st in 2010. With a little bid math that we

can obtain the daylight of each day by calculating

the difference between sunrise and sunset

everyday i.e. subtract the sunrise from sunset. For

instance, the daylight on June 1st, 2010 can be

calculated by 1953 – 538 = 1416, i.e. it had a 14 hours and 16 minutes of daylight on June 1st, 2010.

However, let’s look at the daylight of July 1st, 2010.

2002 - 0541 = 1461, there is something odd here. How

would you have 14 hours and 61 minutes? Then we

should modify it a bid. Since 1 hour = 60 minutes. The

following is the correct way to calculate the daylight on

July 1st, 2010.

1. 2002 = 1962 (since 1 hr = 60 min)

2. 1962 – 0541 = 1421

i.e. there was 14 hours 21 minutes of daylight on July 1st,

2010.

So with the tool of Excel and some modification, we come

out the next table. In addition, we only consider the data

from June 1st to August 31 in 2010.

Figure 2: Modification of sunlight in Lubbock, Texas in summer 2010.

After the calculation and modification, we have the

summations of sunlight in June, July and August

respectively in the following.

Figure 3: Summation of sunlight in Lubbock, Texas in summer 2010.

Next, let’s look at daylight in Taipei, Taiwan. We will use

the coordinate as Longitude: W 121 degrees 30 minutes

and Latitude: N 25 degrees 3 minutes, and the time zone

as 8 hours east of Greenwich. (The tiny island in H zone.)

Time Zone Map.http://aa.usno.navy.mil/faq/docs/world_tzones.phpViewed. 2, 23, 2011.

Taipei, sunrise/set.http://aa.usno.navy.mil/data/docs/RS_OneYear.phpViewed. 2,23, 2011.

Figure 4: Sunrise/set time in Taipei, Taiwan in 2010.

There is something weird in the data table. The sun

rose at 2251 and set at 928 on January 1st, 2010 in

Taipei, Taiwan. Does that make any sense? The sun

rise at the night and the sun set in the morning.

What kind of place is that? There must be

something wrong. Nothing is wrong it is because

Taipei, Taiwan is 8 hours ahead of Greenwich. That

means when it is 10:00 am in Greenwich, it is 6:00

pm in Taipei. So the following table is the correct

time after the modification.

Again, we only consider the summer time (June to August).

Figure 5: Sunlight in Taipei, Taiwan in summer 2010.

The following table is the summations of sunlight in June,

July and August in 2010 in Taipei, Taiwan, and the total

daylight from June to August.

Figure 6: Summation of sunlight in Taipei, Taiwan in summer 2010.

Now we have the summation of sunlight in Lubbock,

Texas and Taipei, Taiwan in summer 2011. The

following table represents the difference between

these two cities.

Figure 7: Excel graph shows the sunlight between two cities in summer 2010.

The following excel graph represents the total

sunlight time in Lubbock, Texas and Taipei, Taiwan in summer 2010.

Figure 8: Excel graph shows the total sunlight time in two cities in summer 2010.

As the result came out, the daylight in

Lubbock, Texas was more than in Taipei, Taiwan

in Summer 2010. Thus, what I have felt was right

that summers seem never end in Lubbock, Texas.

In the following, there are some scientific proofs

based on the latitude and longitude in the

world, and some interesting fact about the daylight-

saving time adjustment in the U.S. and in Taiwan.

In general, the length of a day varies throughout the year, and it depends on the latitude.

World map with latitude and longitudehttp://fr.mapsofworld.com/world-maps/world-map-with-latitude-and-longitude.htmlViewed. 2, 23, 2011.

This variation is caused by the tilt of the Earth’s axis

of rotation with respect tot the ecliptic plane of the Earth around the sun.

Earth’s axis. http://blog.xuite.net/wellsli/002/35113257Viewed. 2, 23, 2011.

Because the Earth’s revolution around the sun on

one side, while around its axis. The axis with the

public-axis orbital plane into 66.5 degrees angle,

making the Earth’s movement in orbit, and with

different relative position of the sun that varies the

existence point between the Tropic of Cancer.

Before coming to the U.S., I know the time

difference between the U.S. and Taiwan would be

adjusted for summers and winters. For example, the

time difference between California and Taiwan in

summer is 15 hours, but it becomes 16 hours in the

winter.

When I needed to call my friends in Los

Angles, California, I had to call at midnight in

Taiwan, and I’d have to call around 1 in morning in

the winter.

This is because of the daylight-saving time (DST)

adjustment, the summer sunlight has longer time in

higher latitudes. Typically clocks are adjusted

forward one hour in the spring and are adjusted

backward in autumn . It is the practice of

temporarily advancing clocks during the

summertime so that afternoons have more daylight

and mornings have less.

Currently, there are about 110 countries around the

world using daylight-saving time. Since the season

in southern hemisphere is opposite to the northern

hemisphere, DST are adjusted oppositely during the

seasons. The countries in low-latitude have

relatively fixed duration of sunshine, there is no

need for DST. Does the small island like Taiwan

have DST? No, no any more. But there were some

researches said Taiwan had DST before.

Actually, Taiwan implemented DST from 1945 to

1961, revoked DST from 1962 to 1973, reinstated

1974 to 1975, and abandoned DST from 1976

onwards.

There were two main reasons behind it:

1. Time adjustment caused trouble in society.

2. The limitation of DST because Taiwan is located

in the subtropical region.

The oil crisis in 1970s, the government of Taiwan

had a brief resume of DST system, but it caused a

lot of grievances then it quickly canceled. Actually,

Taiwan implemented DST from 1945 to 1961,

revoked DST from 1962 to 1973, reinstated 1974 to

1975, and abandoned DST from 1976 onwards. But

the so-called grievances, it were most the product

of the bureaucratic system.

Therefore, people living in Taiwan do not need to

adjust the clock with the seasons. Although I have

calculated the time difference with the winter and

summer between Taipei, Taiwan and other cities

around the world before coming to the U.S., but it

has been very interesting to me to experience the daylight-saving time adjustment.

References

Day length. Retrieved February 25, 2011, from

http://en.wikipedia.org/wiki/Day_length .

Geographic Names Information System. Retrieved February 23, 2011,

from

http://geonames.usgs.gov/pls/gnispublic/f?p=154:1:413510313315132

Geography of Lubbock, Texas. Retrieved February 22, 2011, from

http://en.wikipedia.org/wiki/Lubbock,_Texas.

Geography of Taiwan. Retrieved February 22, 2011, from

http://en.wikipedia.org/wiki/Geography_of_Taiwan.

Latitude and Longitude. Retrieved February 23, 2011, from http://blog.xuite.net/wellsli/002/35113257.

References

Map of World.com. Retrieved February 21, 2011, from

http://fr.mapsofworld.com/world-maps/world-map-with-latitude-and-

longitude.html .

National Geospatial-Intelligence Agency. Retrieved February

22, 2011, from

http://earth-info.nga.mil/gns/html/index.html.

National Science Teachers Association. Retrieved February

22, 2011, from

http://learningcenter.nsta.org/?lid=tnavhp.

U. S. Naval Observatory. Retrieved February 24, 2011, from

http://aa.usno.navy.mil/ data/.

Time difference between Taipei and Greenwich. Retrieved February

23, 2011, from http://www.happyzebra.com/timezones-worldclock/difference-between-Taipei-and-Greenwich%20Borough.php.