If absolute permitivity is the product of relative and absolute permitivities and the only relative permitivity changes while all other variables remain constant, I do not understand how polystyrene can have a higher dielectric strength than pyrex glass.
Meanwhile browsed the first chapter. The book is not verbose in the Bob Pease stile, so all my remarks I made before does not apply. The book itself looks good. It looks to me more like a condensed cheat sheet, a collection of formulas, typical values, rules to apply and such. It doesn't explain much.
The missing r in that formula is a typo, on the page before the same formula in words is stated correctly. That typo is easy to spot, probably not a book to throw away, but as you said, this bring doubt. Might be other mistakes out there in those 1200+ pages, and they might not be so easy to spot.
Now, about
permittivity and
dielectric strength. Those are material properties, but they are unrelated, they are
not derived from the formula in the pdf page you attached in the OP. If we re-arrange the capacitor formula from that page we can get, indeed, a unit measured in V/m (I guess that made you think that permittivity and dielectric strength are tight together by that formula - they are not). Those V/m after rearranging the formula are about the intensity of the electric field, so the E existing inside a charged capacitor. That formula doesn't tell if the dielectric material will be capable to withstand to that E field, or if it will break.
Dielectric Strength is also measured in V/m (just like the unit for measuring the electric field E), except the dielectric strength tells the maximum E field a material can withstand. If, for a given material, you apply an even bigger E field than the dielectric strength specified in that table, then that dielectric material will break down. It will lose it's properties of being an electric insulator, and an electric arch will pierce the material.
Now what's the permittivity? It's another property of materials. In regards to capacitors, it's an indicator of how much energy can be crammed inside a dielectric material. Vacuum (as in imaginary empty space) is the worst in terms of "storage" capacity. That's the epsilon zero. Dielectric materials are many times better. Epsilon r tells how many times better a dielectric material is (at storing energy) when compared to absolute vacuum.
You may wonder how come that an insulator material (dielectric materials inside capacitors are electric insulators) stores electric energy after all? And that's the funny part.
![Smiley :)](https://www.eevblog.com/forum/Smileys/default/smiley.gif)
Many will say, in a charged capacitor the energy is stored by the charges that accumulates on the capacitor's plates. This is wrong. A common misconception but dead wrong.
In a charged capacitor, the energy is stored in the dielectric material between the plates, not in the plates of the capacitor. If that seems hard to believe, here's a funny experiment: what happens if you first charge a capacitor, then you dismantle it (remove the dielectric), then short-circuit the two plates, then assemble the capacitor back?
Well, total surprise, once assembled back the capacitor is still charged, as you can see at the end of this video:
Dissectible Capacitor
TSG Physics
![Grin ;D](https://www.eevblog.com/forum/Smileys/default/grin.gif)
The energy remained stored inside the glass material (the dielectric), so after short-circuiting the plates, and after the glass and the plates were assembled back, the energy was still there (proven by that last spark).
Even more funny about electricity (and a very common misconception) the electric energy is not in volts, not in amps, not in the coulombs, not in the wires at all. The electric energy is in the fields, in the electric and/or magnetic fields.
For the charged capacitor above, the energy is in the electric field, E (which energy was stored by the glass material during the time the capacitor was disassembled and short-circuited).
Another funny thing (derived from the fact that energy is in the fields), electric energy is not transported through the wires. Electric energy is transported through the electric and magnetic
fields that surround the wires, so the energy travels
through the air, NOT through the wires. The wires only guide the E and H fields, so they dictate the path of the energy.
For example, the energy from the nearby power plant to your house does not travel through the wires. The energy travels through the air, through the electric and magnetic fields (which fields are not inside the wires, the fields are outside of the wires). The energy is always in the E and H fields, so in the space
between the wires.
This is very unintuitive and hard to accept. Shouldn't be a surprise for physicists, but most of the EE people will reject the idea of electric energy traveling through air (which air is known as an electric insulator, insulators do not conduct electricity, therefore electricity can not travel through air - well, air is an insulator for electric charges, but not an insulator for the electric and the magnetic
fields, and the energy is in the fields, not in the electric charges, such the misconception).