noun
simultaneity
Abstract noun referring to the property of two or more events occurring at the same time. Used in technical, philosophical, or everyday contexts.
この実験では、二つの反応の同時性が重要だ。
In this experiment, the simultaneity of the two reactions is important.
同時性の概念は、物理学でよく議論される。
The concept of simultaneity is often discussed in physics.