menna okoma tiyenawa
Ayu-Kalpa - a variable time span representing the life expectancy of a typical human being in a particular era or yuga. This can be as high as one asankya or as small as 10 years. This number is directly proportional to the level of virtue of people in that era. Currently this value hovers around 100 years and is continually decreasing.
Antah-Kalpa - the time it takes for one ayu-kalpa to grow from 10 years up to one asankya and back to 10 years. The ending of one antah-kalpa (or mass-extinction) can happen in one of three ways, all involving the majority of the human population going extinct:
Sashthrantha-Kalpa - Mass extinction by wars.
Durbhikshantha-Kalpa - Mass extinction by hunger.
Rogantha-Kalpa - Mass extinction by plague.
Asankya-Kalpa - time span of 20 antah-kalpas. One is equivalent to a quarter of maha-kalpa.
Maha-Kalpa - largest time unit in Buddhism. Ending of a maha-kalpa (apocalypse) can happen in three ways: fire, water and wind. It is divided into four quarters each equivalent to one asankya-kalpa.
First quarter - time taken for this world to form.
Second quarter - stable duration of this world where all living beings can thrive.
Third quarter - time taken for this world to be destroyed.
Fourth quarter - empty time period.
In another simple explanation, there are four different lengths of kalpas. A regular kalpa is approximately 16 million years long (16,798,000 years[5]), and a small kalpa is 1000 regular kalpas, or about 16 billion years. Further, a medium kalpa is roughly 320 billion years, the equivalent of 20 small kalpas. A great kalpa is 4 medium kalpas, or around 1.28 trillion years.
Buddha had not spoken about the exact length of the maha-kalpa in number of years. However, he had given several astounding analogies to understand it.
1. Imagine a huge empty cube at the beginning of a kalpa, approximately 16 miles in each side. Once every 100 years, you insert a tiny mustard seed into the cube. According to the Buddha, the huge cube will be filled even before the kalpa ends.
2. Imagine a gigantic rocky mountain at the beginning of kalpa, approximately 16 x 16 x 16 miles (dwarfing Mount Everest). You take a small piece of silk and wipe the mountain once every 100 years. According to the Buddha, the mountain will be completely depleted even before the kalpa ends.
In one situation, some monks wanted to know how many kalpas had died so far. The Buddha gave the analogy:
1. If you count the total number of sand particles at the depths of the Ganges river, from where it begins to where it ends at the sea, even that number will be less than the number of passed kalpas.[6]
තහවුරු කරන් තියෙනවා? මේකට මූල්ශ්රයක් තියෙනවද? මම නම් අහල තියෙන්නේ පෘතුවියට බිලියන හතර හමාරයි කියල වයස 
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