七厘米的光年
[qī lí mĭ de guāng nián]
In astronomy, the unit 'light-year' measures cosmic distances rather than time. A light-year equates to about 9.5 trillion kilometers. However, just seven centimeters, almost equals to three inches long in the world of physics is too short and has almost no concept. Here it means to depict a paradoxical or unattainable dream using exaggerated figures.