DNC News

The Art of Making Ice Cream and the Power of Prayer

July 5, 2006
Jacob Schor, ND

The Mpemba Effect and Retroactive Prayer

There are two seemingly unrelated bits of scientific trivia that have been rattling around in my brain begging for attention.  The first is the recent solution to the Mpemba Effect and the second is the research on the power of intercessional prayer on disease.

Jonathan Katz, a professor at George Washington University in St. Louis recently published an explanation for the Mpemba Effect and in doing so answered a question that has plagued scientists since the time of Aristotle. 

It has long been observed that water which has first been heated will freeze faster than water that hasn't been heated.  Apparently this effect can be to the point that heated water can freeze first even though starting out warmer.  Or at least this happens some of the time.  The phenomenon varies depending on where and when the experiment is performed. 

Erasto B. Mpemba noticed the effect in 1963 when he learned to make ice cream in a cooking class as a student in Tanzania.  He went on to publish an account of his observations in 1967 and since then his name has been associated with and used to describe the phenomenon.

Intuitively the Mpemba Effect makes no sense.  The explanations that have been put forward to explain it, starting with Aristotle's, have been lame; Aristotle invented a physical property he called antiperistasis, which I won't attempt to explain here. It would appear that the Mpemba Effect simply defies the rules of thermodynamics that explain how things in our world are supposed to behave.

That is until the good Jonathan Katz worked out his explanation and restored our world to order.  According to Katz it's all about solutes.  "You have to ask yourself: what does heating do to water that makes it easier to freeze?" he says. "The answer is that it precipitates out solutes."

The solutes are calcium and magnesium bicarbonate, which make lots of drinking water "hard". You have probably noticed and been annoyed by these precipitates; they often form the scale that coats the inside of cooking pots or tea kettles.

Water that has never been heated still contains these solutes. As this water freezes and ice crystals form, the concentration of solutes in the remaining water becomes even higher - up to 50 times as high as normal. This lowers the freezing point of the water even further, just like the salts spread on winter roads to stop ice from forming.

There is a second, related effect that hampers the freezing of water that has never been heated. Lowering the freezing point reduces the temperature difference between the liquid and its surroundings. "Since the rate at which heat is lost from the water depends on this temperature difference, water that has not been heated has greater difficulty losing heat," Katz says.

Katz claims that these two effects explain why water that has been heated freezes more quickly than water that hasn't. And he makes a prediction that the Mpemba Effect will be 'stronger' the "harder" the water. "This may explain why not everyone sees it," he says. "Some people are using soft water."

The value of prayer in helping sick people recover has been the subject of a decent number of studies. In most it has little effect; occasionally it provides some benefit and, sometimes, as in the case of a recent Harvard study it appears to do the patient harm.

One study on prayer stands out though for its seeming implausibility.  The study, conducted in Petah-Tiqva, Israel, was published in the British Medical Journal in 2001 and produced statistically significant benefit.    This study was significant because it measured the effect of retroactive prayer.  The study was conducted in the year 2,000 on patients who had presented at a university hospital with blood infections over a six year period, from 1990-1996.   I need to repeat myself here; the study was conducted in 2,000; a full four years after the last patient presented and ten years after the first patients arrived at the hospital.  Following classic double blind randomized protocols 1691 of the total 3,393 patients were put into an intervention group.  Actually the patients weren't there; only their names and charts were.  They were prayed for retroactively. Catch that last word, retroactively. The patients had already come and gone from the hospital.  When the codes were
and the data analyzed those prayed for had a statistically significant lower mortality rate, 28% vs. 30%.  Length of hospital stay and duration of fever were also significantly shorter.  In other words prayers for a group of people conducted in the present positively improved health outcomes as much as a decade earlier.

This is the kind of information most would prefer to discount. It doesn't fit into our intuitive sense of the world.  Not anymore than the Mpemba Effect did before we heard an explanation.  And that's just the thing.  Things that don't make sense are difficult to believe until we have an explanation. Once we have an explanation, it's quickly, "Well, of course.."

Publication of this study by the British Medical Journal caused quite the flurry of letters to the editor.  Some pointed out errors in interpreting the statistics; others relied on Star Trek dialogue to explain why you can't and shouldn't attempt to change the past.  The most interesting letter to me questioned what would happen if the researchers then prayed for the control group? Whether the study results were true or not, I find the whole thing interesting.

Long ago I gave name to a behavior pattern I'd occasionally see in patients, calling it Arnica Delusional Syndrome. These people had experienced the benefit of using homeopathic arnica despite the logical assumption that it shouldn't do a thing.  It was too diluted.  Their world view was so badly shaken by the experience that they abandoned all attempts at rational judgment.  From then on they assumed, "If Arnica works and it doesn't make sense that it does, then anything that doesn't make sense also must work." 

Of course this is lousy logic. At the same time I like to keep in mind that not everything that is true will make sense, at least not until we find an explanation.  In the case of the Mpemba Effect, it took several thousand years to explain what some people noticed.  For many, until the effect was explained, it didn't exist.

But the power of retroactive prayer, can it work?  Was this study just one of those aberrations of double blind placebo controlled science that we should ignore? Or are the implications and lack of logical explanation just a little too much for us to live with? 

I've talked to a number of patients about this study.  Those deeply religious sorts take it in stride, easily accepting that the Eternal, by definition is not bound by time.  Thus the effects of prayer aren't limited to time and space.  I get a similar reaction from those new age types who read thick books on modern physics and spirituality; they apparently don't see a contradiction to this study.  They talk about quantum field theory and quickly lose me.

For those of us who still live in this world, where tomorrow comes after today, where the future is the future and the past the past, and my thoughts, wishes and prayers are inside my head and even if they touch others, do so now, in the present, and not in the past, well, this prayer study is still a bit of a stretch.  A stretch that is not unlike saying that hot water freezes faster than cold.

Sometimes, though it's good for one's health to try and stretch a bit.



[1] Marcus Chown Why water freezes faster after heating 03 June 2006 NewScientist.com news service



BMJ. 2001 Dec 22-29;323(7327):1450-1.

Related Articles, Links

•  Click here to read  Click here to read 

Effects of remote, retroactive intercessory prayer on outcomes in patients with bloodstream infection: randomised controlled trial.

Leibovici L .

Department of Medicine, Beilinson Campus, Rabin Medical Center , Petah-Tiqva 49100 , Israel . leibovic@post.tau.ac.il

OBJECTIVE: To determine whether remote, retroactive intercessory prayer, said for a group of patients with a bloodstream infection, has an effect on outcomes. DESIGN: Double blind, parallel group, randomised controlled trial of a retroactive intervention. SETTING: University hospital. SUBJECTS: All 3393 adult patients whose bloodstream infection was detected at the hospital in 1990-6. INTERVENTION: In July 2000 patients were randomised to a control group and an intervention group. A remote, retroactive intercessory prayer was said for the well being and full recovery of the intervention group. MAIN OUTCOME MEASURES: Mortality in hospital, length of stay in hospital, and duration of fever. RESULTS: Mortality was 28.1% (475/1691) in the intervention group and 30.2% (514/1702) in the control group (P for difference=0.4). Length of stay in hospital and duration of fever were significantly shorter in the intervention group than in the control group (P=0.01 and P=0.04, respectively). CONCLUSION: Remote, retroactive intercessory prayer said for a group is associated with a shorter stay in hospital and shorter duration of fever in patients with a bloodstream infection and should be considered for use in clinical practice .


Help support natural medicine in Colorado.  Colorado does not currently regulate the practice of naturopathic medicine.  Our state professional association, the Colorado Association of Naturopathic Physicians plans to introduce a bill into the Colorado Legislature.  Please put your name on our association's mailing list. You will be kept informed of our legislative activity and we will be easily able to let you know when and to whom to write letters in support of our legislation.  To sign up go to http://capwiz.com/coanp/mlm/signup/

We hope you find the information in these newsletters useful, informative and hopefully entertaining. If you want your name removed simply leave a message at the office (303-337-4884) or go to the website: denvernaturopathic.com and unsubscribe, or reply with the message "REMOVE" in the subject line.  If on the other hand you want to be added to the mailing list follow the prior instructions but subscribe. 
We are posting most of these newsletters in our 'NEWS' section of the website.  The website versions contain more complete references and often abstracts of the references quoted and links to the full text of many of the journal articles mentioned. You don't have to be a patient to sign up and we encourage you to get your friends on our mailing list so you don't have to keep forwarding the newsletters that you find interesting.

Ask the Doctor:
What's the difference between naturopathy and homeopathy?

[click here for the answer]

Submit your question here.

Enter your email to recieve the latest Health and Wellness newsletters from the clinic.