A flywheel is a heavy wheel on a spinning shaft, put there to keep a machine turning at a steady speed. Many engines do not push with the same strength every moment — a car engine, for example, goes bang, then a pause, then bang. The heavy wheel keeps spinning through the weak moments and gives energy back when the push is thin, so the machine does not jerk. It stores turning force and smooths the ride.

A flywheel is a heavy wheel on a spinning shaftflywheel是裝在旋轉軸上的一個重輪, put there to keep a machine turning at a steady speed目的是讓機器維持穩定的轉速。 Many engines do not push with the same strength every moment很多引擎並不是每一刻都用一樣的力量在推動 — a car engine, for example, goes bang, then a pause, then bang像汽車引擎，就是砰一下，停一下，再砰一下。 The heavy wheel keeps spinning through the weak moments這個重輪會在力量弱的時候繼續轉動 and gives energy back when the push is thin在推力不夠的時候把能量還回去, so the machine does not jerk讓機器不會一頓一頓的。 It stores turning force and smooths the ride它儲存旋轉的力量，也讓運轉更平順

Fly here means keep moving, keep spinning — not the insect, and not flying in the sky. Wheel is just wheel.

Fly here means keep moving, keep spinning這裡的Fly指的是「持續動、持續轉」 — not the insect, and not flying in the sky不是昆蟲的蒼蠅，也不是在天上飛。 Wheel is just wheelWheel就只是輪子的意思

You will also meet the idea in a gym. A spinning bike has a heavy wheel at the front; that wheel is a flywheel too, used to make the pedalling feel smooth and hard.

You will also meet the idea in a gym你在健身房也會遇到這個概念。 A spinning bike has a heavy wheel at the front飛輪車前面就有一個重輪; that wheel is a flywheel too那個輪子也是一種flywheel, used to make the pedalling feel smooth and hard用來讓踩踏的感覺變得平順又有阻力

Though actually, in Taiwan the word 飛輪 often makes people think of that gym class first. In a science text or a car workshop, look for the heavy wheel inside the machine. Same object-idea, two worlds.

Though actually不過其實, in Taiwan the word 飛輪 often makes people think of that gym class first在台灣，「飛輪」這個詞常常會讓人先想到飛輪課。 In a science text or a car workshop但在科學課本或汽車修理廠裡, look for the heavy wheel inside the machine要找的是機器裡面那個重輪。 Same object-idea, two worlds同一個物件概念，卻活在兩個不同的世界裡