I'm certain that "10^10^10^7 universes" is beyond my brain capacity. However, if it's valid, might OUR Big Bang have been nothing more than the addition of another universe?

Liklely you mean experimental evidence and there is none to date.

But various theories DO provide circumstantial insights that suggests it might be so.....I'm not supporting a multiverse, per say, but there are some interesting ideas I'd like to keep in mind. The main one is that when we have ignored mathematics in the past, it has been to our detriment; the other side of the argument is that not all mathematics leads to physical entities..hence the need for experimental confirmation..

Here are some suggestive ideas/theories/mathematics:

Considering we only understand about 3 or 4 percent of the matter and energy in our own universe, I'd be hesitant to say we understand all that much to rule out other universes,

There seems to be at least circumstantial evidence for a "bang" like origin to our universe, not a steady state universe, so some sort of evolution seems to be the norm for us...so why not possibly others,

There is no definitive proposal behind either the big bang nor inflation so we can either assume it was one of a kind and "boy are we lucky to be here" or it was one of an innumerable number of such events, some of which give rise to viable (long lasting) universes,

Solutions to Einsteins equations, like a de Sitter Universe, suggest theoretically that other types of universes might exist. Ignoring the math, like black hole solutions, has proved misleading in the past,

A chaotic form of inflation might lead to bubble universes...each spawning another universe; inflation might be eternal with big bangs happening all the time,

Quantum theory suggests that if one universe exists likely it can exist simultaneously in many other quantum states (the evolution of the wave function for our universe),

The simple assumption that spontaneous symmetry breaking occurs randomly leads to an endless number of different universe...with different physical laws,

Einstein Rosen bridges, (wormholes or multiply connected spaces), might correspond to a physically possibly object, possible connections to other worlds,

Brandenberg and Vafa's theoretical work on strings showed that collisions between strings and antistrings results in them unraveling...and dimensions spring rapidly outward...initiating big bangs...

The big bang 'singularity' in our three dimensions of space might not appear as a singularity in higher dimensions...so maybe it's not unusual at all....nothing special even though it seems that way from our perspective,

String theory suggests that there is a smallest distance which is equivalent to physics of larger size (T duality)..hence entire universes might exist within the smallest distance of string theory....

(Most of the above ideas are from Michio Kaku's PARALLEL WORLDS, 2005)

what about this idea, which I first heard on Carl Sagan's Cosmos: that within each individual 'tiny particle' whether it be a cell or a string, if you keep on searching smaller and smaller until you reach a point that can not be broken down anymore, you reach a singularity, and this singularity is the start of a big bang in another universe (either in a different dimension, or simply a completely new universe in itself).....