Due to overwhelming demand, the Center for Ethics in Science and Technology is holding a lottery for tickets to the third installment in its “Ethics in Science and Technology Series,” a presentation by Rebecca Skloot, author of “The Immortal Life of Henrietta Lacks.” All tickets are free, but registering for the lottery is now the only way to get a ticket to attend the Nov. 2 lecture. The deadline for lottery registration is 5 pm Oct. 19, with seats randomly drawn by computer from all lottery entrants on Oct. 20. All lottery entrants will be notified if they have been drawn or not by 5 pm on Oct. 21. Register for the lottery here.