One explanation for thirty people
The level that suits the middle of the class loses the front row and the back row at once.
For teachers and tutors
You know the chapter. The class does not, and not all at the same level.
Upload the chapter you teach. Hear it explained at five levels, with a drawing for each idea, and use it as raw material for your own lecture or as help for a student who fell behind.
- Five levels of one text
- Step-by-step drawings
- MP3 and MP4 to share
Trascini qui il suo libro
EPUB, FB2, PDF, DjVu o TXT, fino a 200 MB
Il suo file resta privato
What gets in the way
Preparing a lecture takes an evening
Finding the example, the drawing and the order that work for this chapter is the slow part.
A student who missed a month
They need the chapter told again from the beginning, and you have no free hour to do it.
What changes
The same passage at five levels
From the text as written to the big picture. Compare them side by side and choose where your class should start.
Drawings that build with the explanation
Each idea gets a diagram that appears step by step as it is explained, in one of six drawing styles.
Eight ways of telling it
A patient tutor, a questioner, a demonstrator who starts from an experiment: the manner of the lecturer is a setting.
Something to hand over
With a studio voice a course downloads as MP3, or as MP4 with the drawings, for the student who needs it again.
Leggere, guardare o ascoltare
Voce, disegni e testo in qualsiasi combinazione. Può cambiare quando vuole.
ExplaintedPhotographic Optics
VoceImmaginiTesto
A thin lens forming an image
The first thing to know about a lens is how hard it bends light. Hold a magnifying glass in the sun: the rays arrive side by side, leave it leaning towards one another, and a little way behind the glass they meet in a bright dot. The distance from the glass to that dot is the focal length, and nearly everything else about the lens follows from it.
A lens is stronger when its glass is denser and its surfaces are more curved. Take ordinary glass, in which light travels one and a half times slower than in air, and curve both sides like a ball twenty centimetres across. Work it through and the focal length comes out at about ten centimetres: sunlight gathers into a point a palm's width behind the lens.
The book writes this as a formula, and we will come to it in a moment. It says no more than what we have just seen: denser glass or more curved surfaces, and the focal length gets shorter.
IntroductionParte 1 di 17
1:238:22
1×
Introduction
A thin lens forming an image
The distance from the glass to that dot is the focal length, and nearly everything else about the lens follows from it.
A lens is stronger when its glass is denser and its surfaces are more curved.
1:238:22
1×
How to set it up
- 1
Upload the chapter
Choose the pages you teach next week.
- 2
Try two levels
The free sample takes minutes; change the level and make it again to hear the difference.
- 3
Describe the class
In "Your own examples", say who the students are and what they care about.
Questions
May I use the result in class?
What you make from a book is for your own use of that book; the book’s copyright stays with its owner. Upload only texts you have the right to use this way, and tell students the lectures are AI-generated.
Is it accurate enough to teach from?
Treat it as a well-prepared assistant’s draft. Each part is checked against the book and each drawing is looked at before it is shown, but you are the one who knows the subject: review it before it reaches a class.
Can students use it themselves?
Yes: each of them can upload the chapter and choose their own level and their own examples.
Also for
Students
The textbook the course is built on, at a level you can follow tonight.
See howEngineers and specialists
The reference book of your field, at the depth today’s task needs.
See howResearchers
Read into the neighbouring field without losing a month to its textbook.
See howCurious readers
The great hard books you always meant to read, finally followed to the end.
See how