A jack o' lantern's secrets

Safe­ty pre­cau­tions

Warn­ing! Only un­der adult su­per­vi­sion.

Equip­ment

• spec­trum gog­gles from the MEL Sci­ence sub­scrip­tion;
• or­ange fil­ter;
• spe­cial draw­ing with a ba­sic or­ange out­line and a se­cret blue out­line.

Step-by-step in­struc­tions

As­sem­ble your spec­trum gog­gles with the or­ange fil­ter. Look at the draw­ing through the gog­gles un­der good il­lu­mi­na­tion – you’ll see some­thing dras­ti­cal­ly dif­fer­ent to what you can glimpse with the naked eye!

Process de­scrip­tion

White light is com­posed of all vis­i­ble col­ors of light. The col­or of any giv­en sur­face is de­ter­mined by the light that is re­flect­ed from it and reach­es us: we per­ceive a sur­face that re­flects all col­ors of light as white, while a sur­face that re­flects a par­tic­u­lar col­or and ab­sorbs the rest is per­ceived as the re­flect­ed col­or, and a sur­face that ab­sorbs all col­ors is black. The light fil­ter in­sert­ed into our gog­gles ab­sorbs all col­ors ex­cept or­ange. Thus, af­ter pass­ing through the or­ange fil­ter, only or­ange light re­mains from the light re­flect­ed from the white back­ground, which merges with the light of the or­ange line. The mes­sage hid­den among the or­ange con­tours of the pump­kin, how­ev­er, is writ­ten in a dif­fer­ent col­or. The blue light re­flect­ed from the “se­cret line” is com­plete­ly ab­sorbed by the fil­ter, so we per­ceive it through the fil­ter as black: there is no trans­mit­ted light along this line.

This and oth­er ex­per­i­ments await you in your MEL Sci­ence sub­scrip­tion!