This thread is about a topic that unexpectedly came up in my thread titled "Contradiction between Cosmos and what someone here told me?". I will subsequently call that thread "Contradiction" for brevity. I am not sure if this thread belongs on the Quantum Physics forum or the chemistry forum. If the moderators think it should be somewhere else, I suppose the moderators have the ability to move it to wherever forum it should be. The topic of this thread is distinct from the topic of the Contradiction thread, and I feel it deserves its own thread b/c it's so distinct. First, let me give a little bit of background on how this topic came up. In my thread "Contradiction" I mentioned how someone here explained to me the three ways that bound state electrons and photons interact with each. Then I mentioned how in the episode Hiding in the Light in the 2014 series COsmos, the host Neil deGrasse Tyson Tyson explained how photons of light and the electrons of an atom interact with each other. Tyson said that when an electron absorbs a photon, the energy of the photon will cause the electron jump up to an orbital with a higher energy level. I've known that for over a decade. But then Tyson said that nobody knows why electrons drop down to lower energy levels. The purpose of the thread Contradiction was to determine what causes electrons to drop to lower energy levels. All my life before I saw the Cosmos episode yesterday, I always thought that the cause of electron's dropping to a lower energy level is the emission of the photon. Then physicsforums member phinds told me that I had it backwards. Phinds told me that the emission of the photon is the effect of the electron's dropping energy levels, not the cause of the electron's dropping energy levels. I asked a physicist about this, and the physicist said that neither the emission of the photon nor the electron's dropping energy levels is the cause of the other. I asked the physicist how he knows this, and the physicist said he knows that neither can be the cause of the other because both events occur simultaneously. The physicist said he knows that both events occurred simultaneously because if they did not occur simultaneously, it would violate the law of conservation of energy. The cause must come before the effect. If two events occur simultaneously, neither could have caused the other. Then user phinds says phinds think that if the electron's dropping to a lower energy level happened in an infinitessimaly small amount of time (perhaps a Planck time) before the emission of a photon, the law of conservation of energy might not be violated because the time between the electron's dropping energy levels and the emission of a photon were in such an infinitessimaly small amount of time between each other. If the electron's dropping energy levels occurred in an infinitessimaly small amount of time before the emission of a photon, would the law of the conservation of energy be violated? Please elaborate on your answer.