As long as there is sexual tension in an unconsummated relationship, television programs like BBT will continue to attract an audience.
Besides, the actor who plays Sheldon is gay, and the actress who plays Amy is in a committed heterosexual relationship. Those of us who see actors acting out a script instead of people behaving in real-life situations would likely lose all interest in the show, entirely due to a critical loss of "Suspension of Disbelief".
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The mere fact that science may not yet adequately explain an object, event, or experience does not mean the immediate explanation should automatically default to a conspiratorial, extraterrestrial, paranormal, or supernatural cause.