A lot of readers don’t want to believe they’re living in a computer simulation. The last post prompted a virtual avalanche of comments from people insisting it would be impossible for any computer to create a virtual world with virtual people with virtual nervous systems.

These readers might be right, but many them dismissed the idea without studying the argument in Nick Bostrom’s paper. He didn’t just steal an idea from old sci-fi stories; he considered how to do it and how much computational power would be required. A simulation, as he explains, wouldn’t have to include every single microscopic entity in the universe — “only whatever is required to ensure that the simulated humans, interacting in normal human ways with their simulated environment, don’t notice any irregularities.”

And what if there were glitches in the software? “Should any error occur, the director could easily edit the states of any brains that have become aware of an anomaly before it spoils the simulation. Alternatively, the director could skip back a few seconds and rerun the simulation in a way that avoids the problem.”

After reviewing estimates for the processing power of human brains and the projections for the power of future computers, Dr. Bostrom concludes: Read more …

. . . we still have some real questions to consider. Nick Bostrom’s argument that we could be living in a simulation, the topic of my Findings column, is a clever new twist on the old life-is-but-a-dream notions of Western philosophers (like the idealist George Berkeley), Eastern religions and science-fiction writers everywhere (cf. “The Matrix,” “The Truman Show,” and the “holodeck” in “Star Trek: The Next Generation”). A few of the questions:

1) How likely is it that we’re living in a computer simulation run by intelligent posthuman beings?

2) Would you consider it ethical for any intelligent beings to run such a simulation?

3) What’s the best way to live and survive in a computer simulation?

If you think it’s unlikely we’re in a simulated world, explain why. Is it because you don’t expect civilization to endure long enough reach the technological maturity required to produce a virtual world with virtual people with virtual nervous systems? Because you don’t think posthumans would run simulations? Or because you’ve found another reason not considered in Dr. Bostrom’s simulation argument?

Dr. Bostrom, a philospher and the director of the Future of Humanity Institute at Oxford University, guesses that there’s maybe a 20 percent chance we’re in a simulation, and probably a greater chance that for some reason posthumans would decide not to run these “ancestor” simulations. One big obstacle could be the ethical problem, as he told me: Read more …

When I asked readers to give their reasons for not having sex, I predicted the list wouldn’t be as long as the reasons for saying yes. This didn’t seem an especially risky prediction, given certain biological imperatives (and the survival of our species for a couple hundred thousand years or so).

But I might have been wrong. While the more than 300 readers who posted here at the Lab did indeed give more reasons for saying yes than no, a lot more of the Lab readers — more than 3,000 — responded to my suggestion to fill out an online questionnaire listing the reasons for not having sex. This questionnaire is part of a follow-up study being conducted by David Buss and Cindy Meston, the authors of the paper listing 237 reasons for having sex (a list that’s since grown to 277, thanks to the contributions from Lab readers).

Why so much enthusiasm for filling out the no-way questionnaire? Maybe it’s just because Lab readers are so devoted to the advancement of science. That’s how I like to think of you, anyway. But I can’t rule out the possibility that you simply have a lot more reasons for saying no than yes.

We won’t know which list is longer until Dr. Buss and Dr. Meston finish this new study. (You can still participate by clicking here.) In the meantime, they send their thanks to those who have participated, and I salute the ones who posted reasons here for saying no. Some of the common reasons were moral and religious qualms, fear of contracting a disease, lack of interest in the other person. A couple of the uncommon ones:

“Because if I want to feel badly about myself for being an overweight, out of shape single mom, I can just call my mother (and keep my clothes on too!).” (Posted by Smartypants).

“The guy kept leaping out of a coffee shop I passed on the way to work playing a guitar and singing Portugese love songs.” (Posted by Anon, who also reported saying no after hearing one of the worst come-on lines in history: “The guy told me I looked just like his exgirlfriend.”)

My favorite combo was from Michelle:

“Reason I didn’t want to: Because he was an idiot.
Reason I did: Because I am an idiot.”

Seek and ye shall find. Our quest for the 238th reason to have sex has been more successful than I dared hope. Hundreds of readers nominated additions to the list of 237 reasons published by Cindy Meston and David Buss of the University of Texas at Austin. The two psychologists have looked over the nominations and decided there are now 277 reasons to have sex.

Before presenting you with the 40 new reasons they found among your nominations, let me briefly give thanks. First, to my colleague Ken Chang, for raising the quality of this blog while I was on vacation. Second, to my colleague Jane Brody, the Personal Health columnist, who resolved a puzzle in my column on the 237 reasons: why some people use a headache not as an excuse to refrain but rather a reason to have sex. “It’s been known for a while,” Jane told me, “that the best non-drug method to abort an incipient migraine headache is to have an orgasm. It’s probably related to the change in blood vessel configuration.”

Thanks also to the more than 300 readers who responded (and that’s not counting the nominations we didn’t publish because they were too graphic or because they duplicated other nominations or reasons already in the original list). I’m especially grateful for the comment by fireazalea, who confirmed that the carpe-diem rationales of Robert Herrick and Andrew Marvell have been invoked by at least one woman, not just male poets.

Above all, thanks to Dr. Buss for combing through the Lab nominations to find reasons not in the list that was discussed in his paper. Here’s his analysis, including the 40 additions to the list: Read more …