Berikut Sedikit Menjelaskan Kenapa Kebanyakan Lampu Sorot Berwarna Kuning, Ini Adalah karena Efek Tyndall.

Penampilan system koloid pada umumnya keruh, tetapi tidak selalu begitu. Beberapa ‘larutan’ koloid tampak “bening” dan sukar dibedakan dengan larutan sejati. Bagaimanakah cara mengenali system koloid? Salah satu cara yang sangat sederhana yaitu dengan menjatuhkan seberkas cahayakepadanya. Larutan sejati meneruskan cahaya (transparan), sedangkan koloid menghamburkannya. Oleh karena itu, berkas cahaya yang melalui koloid dapat di amati dari arah samping. Efek Tyndall ini ditemukan oleh John Tyndall (1820-1893), seorang ahli fisika Inggris. Oleh karena itu sifat itu disebut efek Tyndall.
 
Efek Tyndall adalah adanya gejala penghamburan berkas cahaya oleh partikel-partikel koloid. Apabila seberkas cahaya dijatuhkan ke dalam sistem koloid, maka cahaya akan dihamburkan. Apabila seberkas cahaya dijatuhkan ke dalam sistem larutan, maka cahaya akan diteruskan.
 

Dalam Kehidupan sehari-hari, kita sering mengamati efek Tyndall ini, antara lain:

 
  •   sorot lampu pada malam yang berkabut
  • sorot lampu proyektor dalam gedung bioskop yang berasap /berdebu, dan
 
  • berkas sinar matahari melalui celah daun pohon pada pagi hari yang berkabut.
 
 

 

Efek  Tyndall tidak sama untuk setiap sinar yang mempunyai panjang gelombang berbeda. Sinar kuning, misalnya, lebih sedikit dihamburkan. Itulah sebabnya lampu warna kuning dipakai pada saat berkabut, di mana cahaya kuning dapat menembus kabut dan terlihat oleh pemakai jalan.

Karena Inilah kenapa kebanyakan lampu sorot berwarna kuning senja.

By Tensai

http://lampusorot.com
EFEK TYNDAL PADA LAMPU SOROT
Photo
 
Many bodies prepared for cremation last week in Kathmandu were of young men from Gongabu, a common stopover for Nepali migrant workers headed overseas. Credit Daniel Berehulak for The New York Times

KATHMANDU, Nepal — When the dense pillar of smoke from cremations by the Bagmati River was thinning late last week, the bodies were all coming from Gongabu, a common stopover for Nepali migrant workers headed overseas, and they were all of young men.

Hindu custom dictates that funeral pyres should be lighted by the oldest son of the deceased, but these men were too young to have sons, so they were burned by their brothers or fathers. Sukla Lal, a maize farmer, made a 14-hour journey by bus to retrieve the body of his 19-year-old son, who had been on his way to the Persian Gulf to work as a laborer.

“He wanted to live in the countryside, but he was compelled to leave by poverty,” Mr. Lal said, gazing ahead steadily as his son’s remains smoldered. “He told me, ‘You can live on your land, and I will come up with money, and we will have a happy family.’ ”

Weeks will pass before the authorities can give a complete accounting of who died in the April 25 earthquake, but it is already clear that Nepal cannot afford the losses. The countryside was largely stripped of its healthy young men even before the quake, as they migrated in great waves — 1,500 a day by some estimates — to work as laborers in India, Malaysia or one of the gulf nations, leaving many small communities populated only by elderly parents, women and children. Economists say that at some times of the year, one-quarter of Nepal’s population is working outside the country.

Nepalís Young Men, Lost to Migration, Then a Quake

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