A lie-to-children is an expression that describes a form of simplification of material. It is itself a simplification of certain concepts in philosophy of science.

The phenomenon derives from the fact that the universe, so far as can be observed, is extremely complicated, and to present the full level of complexity to a student or child all at once can be overwhelming. Therefore, the first time one explains something to a person (especially a child), one might give an explanation that is simple, concise, or simply "wrong" — but in a way that attempts to make the truth more understandable. (Sometimes, an explanation can accompany it, such as "This isn't technically true, but it's easier to understand.") Later on, one can admit that the first explanation was not completely accurate, and replace it with the truth, or a more sophisticated lie-to-children, which is nearer to the truth. You can continue this process all through a persons' education.

Such statements are not usually intended as deceptions, and may, in fact, be true to a first approximation or within certain contexts - Newtonian mechanics, for instance, is factually incorrect, as it fails to take into account relativity or quantum mechanics, but is still a valuable and useful model in certain stituations. One particular progression of "lies" or simplifications, each of which are debunked or unraveled as one progresses deeper into a subject (in this case, physics), runs as follows (from h2g2):

1. Weight is constant.
   • Children in primary school learn that the weight of something doesn't change if you just change its shape.
2. Weight is not a constant. What's actually constant is mass.
   • In secondary school, teenagers often learn that on the moon or on Mars, an objects' weight will be different, because gravity in those places is different, but the mass will stay the same.
3. Mass is not a constant, but depends on the velocity of the object, relative to the speed of light, which is a constant.
   • Later on, college students find out that relativity says that the mass of an object can vary depending on velocity.
4. The speed of light is not, in fact, a constant, but may have been significantly larger than its current value during the early life of the universe.
   • This is a hypothesis that is likely, but may or may not be true. People finally realize this level around the time they're in their mid 20's and maybe doing their Ph.D. (And some people don't ever get to this level at all.)

The term appeared in the book The Science of Discworld, co-authored and party based on ideas created by Terry Pratchett, and in Collapse in Chaos and Figments of Reality , both by the other two co-authors of The Science of Discworld, Ian Stewart and Jack Cohen.

External links

• The Science of Discworld
• h2g2

• an example from machall