A spherical soap bubble inside an air chamber at pressure \( P_0 = 10^{5} \,\text{Pa} \) has a certain radius so that the excess pressure inside the bubble is \( \Delta P = 144 \,\text{Pa} \). Now, the chamber pressure is reduced to \( \frac{8 P_0}{27} \) so that the bubble radius and its excess pressure change. In this process, all the temperatures remain unchanged. Assume air to be an ideal gas and the excess pressure \( \Delta P \) in both the cases to be much smaller than the chamber pressure. The new excess pressure \( \Delta P \) in \( \text{Pa} \) is: ___.
