The Physics Of Sex
Summary: Where Science and Intimacy Collide: From choosing the best bed for sex to selecting the perfect lubricant or sex toy for each occasion, physics is vital for optimizing your love life. Find out how the physics of sex can help make your sexual experiences better.
"Sex is good for lots of things - now it seems we can add hiccup cure to the list." If you follow the annual presentation of the tongue-in-cheek Ig Nobel Prize, then you already know that modern medicine has come up with at least one promising hiccup cure. As is often the case for the Nobel Prizes that the Ig Nobel parodies, the recognition of Francis Fesmire's work came much later than it should have. Back in 1988 Fesmire published a revolutionary paper entitled Termination of intractable hiccups with digital rectal massage in the journal Annals of Emergency Medicine (annals . . . that's funny). Listen to the podcast with our new roboreader Sangeeta. Or Skip to the Tip in this week's post. I've heard jokes about how he might have discovered the effect, but it's not really such a stretch. The key to Fesmire's discovery may be stimulation of the vagus nerve. Other researchers have noted the connection between the vagus nerve and hiccups. Unlike most of the nerves that make their way from your brain to other parts of your body through the spinal column, the vagus nerve is a major nerve bundle that starts at your brain stem and winds its way through your abdomen. In fact the FDA has approved an implantable vagus nerve stimulator for controlling hiccups with electrical bursts. Personally, I think Fesmire's discovery is a much cleverer way to stimulate the nerve. It makes sense because, among other things, the vagus nerve connects to the sphincter muscles of the gastrointestinal system (including the anus) as well as many muscles and organs involved in hiccuping. For those of you uncomfortable with the massage, there's an alternative. In 2000, Roni and Aya Peleg published a case report in The Canadian Family Physician journal reporting their observation of sexual intercourse as potential treatment for intractable hiccups. Sex is good for lots of things - now it seems we can add hiccup cure to the list. That's cool, but it begs the question as to why (and if) sex has anything to do with hiccups. Now, I consider myself to be a skeptic as a rule. But I also try to be open minded, so I've been withholding judgement on these particular cures until I could see further data. As it happens, I came down with a heavy duty case of hiccups a few days ago . . . Naturally, I thought I would try one of the cures myself. The massage thing seemed a bit involved and messy, so I went with the alternative. Considering the fact that I was in a rush to try it before the hiccups ended on their own and I didn't want the confounding complication of involving anyone else in the experiment, I went solo. It worked perfectly. At the climactic moment, my hiccups ceased. As a result, I was inspired to see if any physicists had taken a look at hiccups and whether they had anything useful to say about the phenomenon. It turns out that in 1995 W. A. Whitelaw of the University of Calgary, along with Parisians J.-Ph. Derenne of the Groupe hospitalier de la Pitié-Salpêtrière and J. Caban of the Hopital St. Antoine published a paper in the physics journal Chaos titled Hiccups as a Dynamical Disease."= They concluded that hiccups are produced by a central pattern generator (CPG). A CPG is a neuron circuit that generates a signal, which causes an action that in turn stimulates another signal, and the pattern repeats, sometimes indefinitely. Similar circuits apparently handle numerous other repetitive actions such as breathing and walking The Hiccup Generator as a "Black Box" Just what all the components are in the hiccup CPG isn't entirely clear. What's more, it doesn't really matter. Instead the researchers treated the hiccup CPG as a black box. To an engineer or scientist, a black box is a system that's studied in terms of what it does, rather than what it's made of. In other words, the physicists studied the behavior of the biological system that causes hiccups without worrying too much about the individual pieces that go into it. The work led to some interesting insi
Listen to an excerpt from the interview with Tiffany.
Science is probably the farthest thing from your mind as you make plans for Valentine's Day next week. But for this popular holiday dedicated to romance, it occurred to me that you should keep a few of the suggestions from earlier Physics of Sex posts in mind. Listen to the podcast with Text-to-Speech roboreaders Kate and Paul. If you're a regular reader, suggestion number 5 is a new one that you haven't seen here yet. The rest are taken from earlier posts. 1. Opt for a low fat dinner. Fat from your meal rapidly moves into your blood, making it sticky, thick and more difficult for your heart to pump around. Reduced blood flow dampens erectile vigor (in the genitals of both men and women), and can reduce lubrication in women. So skip the foie gras on the 14th. Salads and other low fat foods are sexier for your Valentine’s Day dinner. See the entry Pumped Up and Ready for Love, part 2 for more information. 2. Tune your bed and body for better sex. Different beds have different rhythms: firm beds are better for faster sex, and soft beds are better for slower loving. For the most versatility, start with a firm bed and add pillows or thick comforters to slow things down. If you want to take even more control of the pace, experiment with sexual positions. You will find that various positions often encourage distinct natural rhythms. See Sexual Rhythms for more details. 3. Mix it up for sensory bliss. The sensory cells that respond to touch, temperature and other information tune out sensations that don’t change much. (That’s why you may forget about the sunglasses resting on top of your head, for example.) So mix things up in bed – change how and where you touch your lover to keep the sensory cells firing and the excitement levels up. See Sex and Sensibility, part 1 4. Keep going longer with sensory repetition. If you or your lover suffer from premature ejaculation, you may be able to stave off the inevitable with the start-stop method. (The method is essentially the opposite of the suggestion above.) Just as the sensory cells and nerves in your scalp soon forget about the sunglasses stowed there, repeatedly taking a man to the brink of orgasm and stopping briefly makes the sensory system less responsive, and can help him last longer in bed. See Sex and Sensibility, part 1 5. Hum a low pitched tune. Human ears can detect high frequencies, but the nerves in the rest of your body can’t register vibrations much over 500 hertz (roughly the B note above middle C on the piano). So if you give the gift of a hummer this Valentine’s Day, keep the pitch low for the best effect. The details of this suggestion will be in the upcoming post Sex and Sensibility, part2. 6. If you still need to find a Valentine's Day date, try looking the physics way. I can't guarantee results, but researchers have found that some approaches are better than others when it comes to cruising for mates. (Valentine's Day is a week away, so you still have one more weekend to try it out.) The details are in last week's post The Physics Guide to Hooking Up. Before Valentine's Day gets here, check out other Physics of Sex suggestions in the entry Skip to the Tips.
Another Saturday night is just around the corner, and you're looking forward to cruising for action at the local hot spots. How'd it work out for you last time? Did you hook up with your dream guy or gal, or did you strike out? Either way, it's possible that you could improve your odds by applying the physics published in the journal Physical Review Letters a few years ago. Listen to the podcast with Text-to-Speech roboreaders Kate and Paul. Or, if you're in a rush, Skip to the Tip in this week's post. In 2002, a group of Spanish and Brazilian physicists looked at two types of search strategy that might be employed by such things as predators in search of prey, bees in search of flowers, or other creatures (like you) in search of mates. They found that the searchers could dramatically improve their odds by tailoring their strategies depending on the distribution and motion of their targets. Theoretically, you should be able to improve your odds of finding that special someone as well. When you go out on the town looking for love, you have at least two options. For one thing, you could pick a bar and settle in for the night, while doing your best to mingle as you work to attract or seduce someone. This type of search strategy is called a Brownian random walk. You just bounce around to search randomly for a love connection in some small area, such as the dancefloor of your favorite bar. Eventually, you might drift to another nearby establishment. But in any case, you don't cover a lot of ground over the course of the night. Alternatively, you could bar hop - drop in on a bar, work the room, and then if there's nothing promising, dash to another bar to do it again. This second type of strategy is called a Lévy flight search. Lévy flights involve poking around in one location, and then zipping off to poke around somewhere else. Lots of creatures use Lévy flights for searching large areas, when there are sparse distributions of what ever it is that they're after. Bees often hunt for pollen rich flowers this way, and there's a good chance that you look for your lost keys with a similar search pattern. (You might check the dresser, skip down to look through the desk, pop over to the closet to check your coat, etc.) As the research team ran their simulations, they found that when the targets were relatively stationary and far apart, searchers increased their odds of success by performing Lévy flights from place to place. Picture, for example, groups of eligible singles nestled at bars around town, with the bars far enough apart that you have to drive or walk a long way to get from one place to the next. If instead, the targets moved around a lot or there were many of them packed in a large area, then searchers were more successful when they avoided Lévy flights and just flitted around randomly in a small area. The first scenario sounds a lot like the club scene in most major cities, and the second scenario is more like the flowing crowds at Carnival in Rio or Mardi Gras in New Orleans. At first glance it seems like the best bet is simply to zip from bar to bar with a series of Lévy flights, so long as you're cruising in town. But if you're at a big event with lots of available singles around, you should stay in one place. Unfortunately, things aren't always so easy. If you're making lots of Lévy flights to search the clubs, and your targets are making frequent Lévy flights as well, then the chances are you're going to miss many of your potential love connections while in transit. When targets are highly mobile the physics model suggests that a searcher, like you, should pick one place and stay there to wait for your potential mate to make a Lévy flight right into your lap. In fact, the faster your targets are moving the less you should stray from your barstool. In some cases it makes sense to evaluate the traffic flow and adjust your strategy throughout the course of the night. That would've worked best for me when I was in college a
If you're eagerly anticipating part 2 of Sex and Sensibility, we'll have that for you next week. In the meantime, we decided to send two of our writers, Buzz Skyline and Martica, into the field to do an experiment inspired by a portion of the Physics of Sex post Sexual Rhythms. Specifically, we wanted them to see what physics could tell us about the Select Comfort brand adjustable bed. We hoped they would learn enough to help you determine if it's the best bed for your love life. You can listen to roboreader Heather interviewing Martica and Buzz in our latest podcast, or read the transcript below, to find out what (if anything) the Sleep Number bed has to offer for sex. Skip to the tip in this week's post, if you're in a rush. In any case, please take part in The Great Physics of Sex Bed Test. We want you to test out your bed and send us the data so that we can figure out, once and for all, what type of bed is best for sex. But don't do it for us. Do it for yourself. Do for the world. Do it for science. TRANSCRIPT OF THE SELECT COMFORT BED TEST INTERVIEW Heather: Welcome to the Physics of Sex podcast. My name is Heather. If you've been listening to our past episodes, you know we usually give a little lecture about a fascinating aspect of physics, as it applies to your love life. But this week, we decided to try something different. We sent two of our writers into the field to do a few experiments on an unusual kind of bed, in order to find out how it might affect your sex life. Here to report on what they found out about the Select Comfort sleep number bed, are Martica. . . Martica: Hi Heather. Heather: . . . and Buzz Skyline. Buzz: Hi Heather. Heather: So guys, you ventured out to test a bed. Did you do what I think you must have done? How'd you keep from being arrested? Martica: Well, we didn’t actually do anything that's not appropriate in a mattress store. We actually just went and jumped on the bed. Buzz: Well, we sat and bounced on the bed. Martica: Exactly. Buzz: We didn’t stand on the bed. Heather: OK, well tell us about the bed. Martica: It’s a Select Comfort Sleep Number bed, which [allows you to] change the firmness of the mattress. Buzz: You can change the amount of air inside the mattress. Martica: Right. Buzz: And they call it the firmness. Martica: It’s a big air mattress with a pump and a little remote control which you can use to pump the air in or let the air out and that changes the firmness, what they call the firmness, of the mattress. Buzz: And it basically is just inflating this bladder that’s inside the bed instead of springs. Heather: So this is the bed Lindsay Wagner promotes on TV. Great. How did you do the experiment? Martica: We sat on the bed and bounced up and down. Buzz: At different numbers. We set it for different numbers and we took turns bouncing on it. Martica bounced on it a few times at different settings and I bounced on it at a few different settings, a few different sleep number settings, and the last time . . . Martica: We sat next to each other and bounced up and down at the same time, which is actually really hard – but fun. (laughs) Heather: What sort of results did you expect? Buzz: So, what we thought would happen was we assumed the sleep number really was what you call firmness, which on a spring would basically be the spring constant. It would tell how strong the springs are. And that means that as you turned it up it should increase your resonance frequency- the frequency that you bounce on the bed. And as you turn it down, it should decrease your resonance frequency. And so we started out with Martica on the bed, and what we found was no matter what sleep number we chose, she bounced at about the same rate. Martica: I was trying! (laughs) Buzz: It wasn’t her fault. It was obviously the physics. And so we thought there must be something wrong. So I sat on the bed and tried it for several numbers and I also bounced at almost exactly the same rate every time. Martica: But a litt