How many steps do you need to “freeze” the moving atoms? You may have the answer at the sight of the question “Three! Open the refrigerators, put the atoms inside, and close the door, Bingo!” But is it that simple to cool down the “hot” moving atoms merely by a refrigerator?

　　As we know, temperature is  the sign of moving, that is to say, the temperature of an object is a reflection of the speed of dynamic micro-particles inside the object. So, to “freeze” the dynamic atoms means to reduce the speed of the moving atoms, even to zero.

　　So, what method is used to reduce the speed of atoms? How to do it? What is the application of the cold atoms? Please click the following link and find the answers in the popular science micro video - Cold Atoms, the Wing of Future Science, provided by Time Traveler Team.

　　 Click any one of the three links at your convenience.

　　Link 1:  http://www.toutiao.com/i6366738467245785602/

　　Link 2:  https://v.qq.com/x/page/y0358pszahw.html 　　

　　Link 3:  http://www.iqiyi.com/v_19rr9srvqc.html

(Qinfang Xu contributed to this report)