There are many scientific phenomena around us. We can always find them if we pay attention to observation. One summer afternoon, my mouth was dry with heat, and I thought, "If only I had a glass of ice water, there should be water in the kitchen. "Walking into the kitchen, I could not anticipate that there was a pot of water on the table. I was so happy that I poured the water into the cup immediately. A cup of hot air came out of the cup. It turned out to be boiling water. How can we make the boiling water cool down quickly? So I put the water in the refrigerator, and after a few seconds, I heard a "bang" and the water trickled out along the crack in the refrigerator. I was startled and quickly opened the fridge door. I suddenly froze. How could a good cup break? Through consulting the information, I know the cause of the cup explosion, is the principle of hot expansion and cold contraction: because the cup filled with boiling water makes the cup internal heating expansion, the temperature in the refrigerator and the cup external cold contraction, so that the cup internal expansion, external or cold, delayed expansion, the cup exploded. From this, I understand a truth: science is everywhere, as long as we observe carefully, we can find many things we do not know through our own efforts. 身邊的科學(xué)
我們身邊有許多科學(xué)現(xiàn)象，平時只要留心觀察，就一定能發(fā)現(xiàn)它們。
在一個夏天的中午，我熱得口干舌燥，心想：”要是有杯冰水喝就好了，廚房里應(yīng)該有水�！白哌M廚房，果然不出我所料，桌子上放著滿滿一壺水。我高興極了，馬上把水倒進杯子。一股熱氣冒出杯口，原來，這是壺開水！怎樣才能讓開水迅速涼下來呢？于是我把水放進了冰箱，過了幾秒鐘，只聽”砰“地一聲，水沿著冰箱縫徐徐流出。我嚇了一大跳，迅速打開冰箱門，我頓時愣住了，好好的杯子怎么會破呢？通過查閱資料，我知道了杯子爆炸的原因，是熱脹冷縮的原理：因為杯子里裝的開水使杯子內(nèi)部受熱膨脹，冰箱里的溫度又使杯子外部受冷收縮，就這樣，杯子內(nèi)部不斷膨脹，外部還是涼的，遲遲不膨脹，杯子就爆了。
從這件事中，我明白了一個道理：科學(xué)無處不在，只要我們認真觀察，就能通過我們自己的努力發(fā)現(xiàn)許多我們許多不知道的東西。
