JUNE 21 IS NORTHERN SOLSTICE DAY
(Tafasiri ya KiSwahili inafuata chini)
The Northern Solstice will occur on June 21 when the Earth’s axis will be tilted towards the plane of the Solar System by maximum angle of 23.5 degrees. The northern half of the Earth will be tilted towards the Sun so it will be vertical at noon on latitude 23.5 degrees, also called the Tropic of Cancer. At this time days are longer than nights in the northern half while in the south nights are longer than days. At the Equator days and nights remain equal throughout the year. The maximum difference between day and night at this time is within the Arctic Circle (66.5 degrees latitude North) where there will be 24 hours of daylight, while at the opposite end in the Antarctic Circle there will be 24 hours of night. At our latitudes, about 6 degrees South, which is close to the equator, nights will be just slightly longer than days by a maximum of about 20 minutes, hardly noticeable.
The bigger change which most people don’t notice is the position where the Sun sets and rises. At solstice, the Sun does NOT rise and set is east and west. We always thought the Sun always rises in the east and sets in the west. But this is not true, it occurs only on two days of the year, called equinoxes on March 21 and September 21. On all other days, the Sun rises north or south of the east and west. On July 21, the Sun will rise 23.5 degrees of NORTH of east and it will set 23.5 degrees NORTH of west. We say that the Sun is in the north. At the opposite solstice on December 21 the Sun rises 23.5 degrees SOUTH of east and sets 23.5 degrees SOUTH of west. At that time, we say the Sun is in the south. Hence, you will see that the Sun’s position from which it rises and sets changes by nearly 50 degrees. The Sun will also not be overhead at noon, but will be 23.5 degrees away from zenith.
All this should be very noticeable but we don’t even notice; which means that we do not question what we learned when we were young. This is because it is much simpler to say that the Sun rises in the East and it sets in the West and it is overhead at noon, so as not to confuse young minds with complications. However, in our later years no one bothers to correct this understanding. We need to be very aware of what is happening around us and to be able to ask about things that are different from what we knew from when we were young.
SOLSTISI YA KASKAZINI JUNI 21
Solstisi ya Kaskazini itakuwa Juni 21, wakati mhimili wa Dunia utainama kwenye bapa ya Mfumo wa Jua kwa kiasi cha nyuzi 23.5. Nusu ya kaskazini mwa Dunia utaelekea Juani, kwa hiyo mionzi ya Jua itamulika kwa wima kabisa katika maeneo yote ya latitudo 23.5 Kaskazini ambayo huitwa Tropiki ya Saratani (Tropic of Cancer, au Tropiki ya Kansa). Wakati huu masaa ya mchana yanazidi masaa ya usiku katika nusudunia ya kaskazini, wakati katika sehemu za kusini usiku huzidi mchana.
Katika Ikweta kwenyewe, mchana na usiku hubakia kuwa sawasawa siku zote wakati wote wa mwaka. Tofauti kubwa kabisa kati ya mchana na usiku hutokea ndani ya maeneo ya Mduara wa Aktiki (Arctic Circle) ambayo ni latitude 66.5 Kaskazini ambapo kutakuwa mchana siku nzima yaani masaa yote 24 yote, kwa miezi sita ijayo.
Upande mkabala yaani katika maeneo ya Mduara wa Antaktik kutakuwa usiku siku nzima yaani masaa yote 24, kwa miezi sita ijayo. Katika latitudo zetu, ambayo ni latitudo kiasi nyuzi sita (6) hivi Kusini, ambayo ni karibu sana na Ikweta, usiku utazidi mchana kwa kiasi kidogo tu cha dakika 20 hivi, ambayo hata hatuhisi.
Kitu kikubwa zaidi kinachobadilika ambayo watu wengi huwa hawatambui ni nafasi ambapo Jua lina chomoza na linapo zama katika upeo. Wakati wa solstisi, Jua halichomozi wala kuzama mashariki au magharibi. Sisi tulidhani kwamba Jua kila mara lazima linachomoze mashariki na kuzama magharibi. Lakini hiyo siyo kweli, hii inatokea katika siku mbili tu za mwaka, ambazo ni Machi 21 na Septemba 21 na zinaitwa Equnoxi. Siku ZOTE zingine, Jua linachomoza na kuzama kaskazini au kusini ya mashariki na magharibi.
Siku ya Sostisi ya Julai 21, Jua linachomoza nyuzi 23.5 KASKAZINI mwa mashariki na litazama nyuzi 23.5 KASKAZINI mwa magharibi. Huwa tunasema Jua lipo kaskazini. Upande wa pili, yaani solstisi ya Desemba 21, Jua lina chomoza nyuzi 23.5 KUSINI mwa mashariki na linazama nyzi 23.5 KUSINI mwa magharibi na tunasema Jua lipo kusini. Kwa hiyo utaona kwamba nafasi ya Jua upeoni ambako linachomoza na kuzama hubadilika kwa kiwango kikubwa sana cha nyuzi karibu 50. Pia, Jua haliwi utosini ila linakuwa nyuzi 23.5 kaskazini ya utosi wakati wa adhhuri.
Ungetegemea watu watahisi na kutambua na kuelewa tofauti hii, lakini wengi wala hatuna habari. Inamaanisha mara nyingi hatujiulizi kabisa ukweli wa mambo tulichojifunza wakati tulikuwa wadogo. Dhana ya Jua kuchomoza mashariki na kuzama magharibi inafundishwa ili kutomchangaya ubongo mdogo lakini baadya hakuna tena somo la kusahihisa elewa hii. Unatakiwa uwe macho mweyewe ujiulize kutokana na halisi unayoona Duniani.