Astable Multivibrator Circuit Analysis
If you abruptly turn on the power, imbalances in charges and currents and voltages will turn one transistor fully on and turn the other transistor full off ---- with that state continuing as the base of the Off transistor slowly rises from -VDD or similar levels (unless the emitter-base breakdown serves as a clamp on the negative_going excursion). And that bas continues rising, moving above ground to turn ON what was previously OFF. And the cycle continues.
On the other hand, if you bring up the VDD very very slowly.......
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Chua developed a chaotic circuit for electronics, decades ago.
But I recall it requires a non-linear element.
https://en.wikipedia.org/wiki/Chua%27s_circuit