dividing by list not possible?

[SchroedingersLion]

Greetings!

I was wondering why it is possible to create a new list by multiplying or adding constants to an old list, but not to create a new list through division of a float by an old list.

import numpy as np
import matplotlib.pyplot as plt

N=500;
R=0.5;

pressure_list=[16,25,40]
expectation_val_V=[445.186, 412.284, 390.5]
expectation_eta=(float(4)/3 *np.pi *R**3)/expectation_val_V

eta=np.linspace(0.5,0.70,100000)
p_red=6/(np.pi)*eta*( (12-3*(4*(1-(3*np.sqrt(2))/(np.pi)*eta)))/(4*(1-(3*np.sqrt(2))/(np.pi)*eta)) 
            +2.557696+0.1253077*(4*(1-(3*np.sqrt(2))/(np.pi)*eta)) 
            +0.1762393*(4*(1-(3*np.sqrt(2))/(np.pi)*eta))**2 
            -1.053308*(4*(1-(3*np.sqrt(2))/(np.pi)*eta))**3
            +2.818621*(4*(1-(3*np.sqrt(2))/(np.pi)*eta))**4 
            -2.921934*(4*(1-(3*np.sqrt(2))/(np.pi)*eta))**5
            +1.118413*(4*(1-(3*np.sqrt(2))/(np.pi)*eta))**6)


plt.plot(eta,p_red)
plt.show()

In this example, p_red is well defined. However, expectation_eta cannot be created. It gives the error 'TypeError: unsupported operand type(s) for /: 'float' and 'list''
Isn't this a bit contradictory from a programming point of view?

Regards!