Why do bubbles rise from the bottom of the glass?

Bubbles form on tiny irregularities on surfaces called nucleation centres. The bottom surface is warmer, heated from below so gas is less soluble at temperature. read more

Depending if you hold your glass all the time, then your hand would heat the side of the glass and you may see more bubbles from the side but if you leave it on the table, it will rather take heat from the table and you should see bubbles starting from the bottom. read more

But then Zare noticed that beer bubbles at the top of a glass were as much as twice the size of bubbles at the bottom. To generate that much of an increase, he realized, the pressure at the bottom of the glass would have to be eight times the pressure at the top. read more