what is the value of h?what is h?a letter?wtf!!

Question

anonymous · Answer

$$h$$ 
is Planck's constant. Among innumerable other uses, it is the constant that satisfies the equation

$$E=hf$$

The definition that relates the energy of a single photon of light to its frequency f.  Its existence is proof that energy is transmitted in discrete bits, or quanta.  It is a MAGICAL number (scientifically speaking) that is the keystone for nearly all modern experimental and theoretical science.

It is also very, very tiny. 

It's value has been experimentally determined to be 
$$6.62606957(29) \times  10^{-34} \mathrm{J \cdot s} $$

Things on that scale compared to our normal lives are on the same scale as the distances between things our normal lives compared to the furthest ever imaged galaxy. 

It is very, very tiny.

It is also often written and used in its reduced form, "h bar"

$$\large \hbar = \frac{h}{2\pi}$$