Amazing experiment with escaping water

Can wa­ter es­cape from a glass us­ing only pa­per tow­els? Find out in this video!

Safe­ty pre­cau­tions

None.

Equip­ment

• glass­es;
• wa­ter tint­ed with food col­or­ing;
• pa­per tow­els.

Step-by-step in­struc­tions

Ar­range sev­er­al glass­es, al­ter­nate­ly full of tint­ed wa­ter and emp­ty, and con­nect them with pa­per nap­kin bridges. Over time, the wa­ter will flow from the full glass­es to the emp­ty glass­es un­til the wa­ter lev­el is equal across all the glass­es.

Process de­scrip­tion

A pa­per tow­el con­sists of plant fibers with nu­mer­ous cap­il­lar­ies in their struc­ture. When wa­ter en­ters them, its sur­face adopts a con­cave shape, form­ing a menis­cus. Mean­while, the wa­ter pres­sure un­der this menis­cus be­comes low­er than at­mo­spher­ic pres­sure, and the wa­ter be­gins to rise. The thin­ner the cap­il­lary, the high­er the wa­ter can climb. The process will stop when the wa­ter lev­els in the glass­es equal­ize, bring­ing the sys­tem to a state of bal­ance. The main fac­tor in the process is the height dif­fer­ence be­tween the sur­face of the liq­uid and the bend in the pa­per tow­el, so the forces push­ing the wa­ter into the new glass equal­ize with the forces try­ing to push the wa­ter back.