Does the radiation in the microwave actually absorb in the baby bottle if heated?

Not safe otherwise: I don't like microwaves for warming bottles because its too easy for you to overheat the milk & burn babies mouth. The only effective way to judge how hot it got is to stick your finger in it. Yuck! microwaves won't make baby glow in the dark or get sick. Babies don't need warmed milk anyway, if you set out a night bottle early & let it warm to room temp that's fine & some like it cold..

No!: Radiation produced by a microwave is "non-ionizing." it does not have cancer causing risks like ionizing radiation from x-rays. The biggest hazard is microwaving liquids: superheating to over the boiling point without bubbles of vapor forming in the liquid. When the liquid is disturbed-boiling can explosively start-violently ejecting boiling liquid from the container causing severe scalding.