“Back in Three Minutes”

Roger:  I wanted to get your opinion on something I've noticed a great deal lately, especially since the beginning of Clear Channel’s “Less is More” initiative.  What I’m referring to is the growing trend of announcers who, when leading into a commercial break, will say something like, “I'll be back in three minutes.”  Or, dumber yet, “Back in 2 minutes and 45 seconds.”


Am I missing something?  Why would anyone tell his or her listeners how long the break is going to be?  I would guess that most radio listeners know that a couple of minutes are going to pass when a commercial break begins.


However, I doubt many of them are sitting in their cars with a stopwatch.  Why advertise it?  When what they are really saying is, “Punch around the dial for three minutes,” and hope the listeners come back.


I guess a three-minute break is something to be proud of if your station has had a history of long 5-6 minute breaks.  But, do the listeners really care?  Have you seen or performed any research on this topic?  I've noticed this as well on TV entertainment news magazine type shows. - Anonymous

:  I find the controversy/debate/discussion about the “Less is More” campaign (as well as other non-Clear Channel radio stations that are reducing their spot loads) very amusing and reminiscent of the controversy/debate/discussion in reference to telling the artists and titles of songs played on music radio stations.  Let me explain…

Somewhere around 1982, when radio research began to become important, listeners (in all formats) said that jocks should tell the artists and titles of songs they played.  What happened?  Most PDs said something like, “The listeners know all these songs and that information isn’t necessary.  Besides, saying all that stuff interrupts the ‘flow’ of the radio station.”

Year after year, listeners asked for artists’ names and song titles, and year after year, radio stations did not give them the information they wanted to hear. Then somewhere in the late 80s, a few radio stations “gave in” and started telling artists’ names and song titles (presell or backsell).  What happened?  When listeners were asked what they liked most about their favorite radio station, one of the top items was, “They always tell the artists’ names and song titles.”  Duh.  It worked.

Now, let’s move to the spot loads on radio stations.  For many years, radio stations had 8-12 minutes of commercials, but this changed when the Telecommunications Act of 1996 eliminated the cap on the number of radio stations one person or company could own.  The big companies (mostly publicly owned) needed more revenue to service their enormous debts.  The total number of commercial minutes in an hour began to creep up, and in some markets, radio stations were carrying 20 or 21 minutes of commercials per hour.

What happened?  Listeners complained.  Listeners said they were listening to radio less because they were tired of all the commercials.  What did the owners do?  They continued to air 20-21 minutes of commercials.

But a few years passed and more research (and lower Arbitron numbers) indicated that something was going on—something (duh) is affecting cume and TSL.  What could that be?  Allow me to take a wild guess—listeners were tired of too many commercials.

What happened?  The decision-makers, probably after dozens of meetings, decided to “try” reducing the number of commercial minutes in an hour.  On to your question about announcing the amount of time in the stop set…

I don’t know if it’s a good idea to say something like, “Back in three minutes.”  I didn’t know how to answer your question because I haven’t conducted any research on the topic (other people may have already done many studies.)

Since I didn’t have any information, I decided to conduct a preliminary study to (at least) get an indication of what listeners think of the practice.  I’m teaching an Introduction to Mass Media course this semester at the University of Colorado in Boulder.  There are 200 students in the class—all 18 year-old freshmen business majors.  I used them as my sample, knowing that the results can’t be generalized, but I wanted to have some information to help answer your question.  Here is what I found:

After explaining a few things about commercials on the radio, I asked the students if they prefer the DJ to say, (1) “I’ll be back right after these messages.” or (2) “I’ll be back in three minutes.”  I told them that the time—3 minutes—could vary.  I was surprised at the result because I have never seen this before….100% of the students (N = 200) said they prefer the DJ to say the number of minutes, or minutes and seconds, the commercial break will take.  I asked them why they like that approach and two answers emerged (about equally distributed): (1) They knew how long they could switch to another radio station; and (2) They knew how long they would have to wait to hear more music (didn’t switch away).

As I said, my sample is not representative of all radio listeners.  I had no information and decided to ask the students in my class just so I could get an indication of what “average” listeners think.  Obviously, it’s necessary to replicate (repeat) this study with other samples of listeners, but there is an indication that listeners may like the approach of telling how long the break will take.

So, I would say that the “jury” is still out.  I need more information in order to provide a more definitive answer.

 “Back in 3 Minutes” – Comment

Hi Roger:  Further to your comments about announcers saying, pre-commercial break and “I'll be back in 3 Minutes.”…


In my radio school, we teach the students that the phrase "I'll be back" is a TV presenter's term and is not applicable to radio.  The on-air attitude should be that events that occur within a radio show, whether they be music, commercials, news, etc., are very much part of that program and not something separate.  Meaning the presenter is there listening to them and, in fact, is not actually going anywhere.  Besides which, the listeners could very well think: "Well, if he’s not going to stick around for the commercial break, why should I?”


Just a thought.  Cheers. - Ian MacRae, Sydney

Ian:    Thanks for the comments.  I appreciate your help and I like the philosophy behind not saying, “I’ll be back…”

Backsell or Presell Songs?

I work for a college radio station. One argument that we get into a lot is whether we should presell or backsell our music. Which do you think is best? - Art

Art: First, I need to point out that it doesn’t matter what I think. What matters is what your listeners think. Now, since you asked the question, I have to assume that you haven’t asked your listeners this question in some type of research study. So the best I can do is give you a general idea of how listeners from around the country answer about your question.

Overall, there doesn’t seem to be a preference. With this in mind, it is probably best to rotate your approach—use a presell for one set and a backsell for the next set. One important thing here is the number of songs you’re playing in a row. I can tell you that reading a list of 10 song titles and artists is not preferred by listeners. So . . .

If you’re playing several songs in a row (let’s say 10), the best approach—according to what listeners say—is to split them up. For example, play three songs and do a backsell, presell the next three, and then backsell the last four. Telling artists and titles is not considered "talk" by the listeners and does not break the promise of playing "X" number of songs in a row.

Backselling Songs

A recent story reported that Paragon Media Strategies found that 82% of a sample of 407 15-64 year-olds said that it is “very important” for DJs to announce the artists and titles of songs played on the radio.  Do you think this is right? – John


John:  Although 82% seems a bit low to me, I’m not in the position to say whether the results are right or wrong.  However, research on the importance of telling the artists and titles goes back to the early 1980s, and the results by Paragon support what has been found consistently for over 20 years.


Although I didn’t read the Paragon study you refer to, the results highlight one of the advantages of the scientific method of knowing—replication.  Repeating (replicating) a research study or research question is not present in the other methods of knowing—authority, tenacity, and intuition.


Just because something was true yesterday or is true today does not mean it will be true tomorrow.  In the scientific method of knowing, “facts” about anything are always fair game for re-evaluation (replication), and scientific researchers welcome such re-evaluation.  Replication, keeps information “in line.”  Telling artists and titles has consistently been in the Top 3 most important elements on a music radio station for over 20 years.  The Paragon study provides indications that our knowledge about telling artists and titles on music radio stations continues to be accurate.


The sample size of 407 indicates that this was a study done in one market and is not a national study, which usually includes a sample of at least 1,200.  In most situations, the results of such a study could not be generalized to any other situation, but since the Paragon results support the findings of 20+ years of previous research, the results can be considered reliable.  However, do not interpret the Paragon study as a national study.  It isn't.

Back to the Future?

Hi, Doc:  I was watching a documentary about the paradoxes of going back to the past.  They said that, maybe in the future, someone would find the way to go back in time through a "worm hole" or some other method.  But if that quest could be achieved, would it be known by now or not?  I mean, if someone in the future could find a way to go back to the past, wouldn't that would be something so extraordinary that we should already know about it?  Do you know any response to this? - Anonymous

Anon:  Hi to you too.  A paradox?  Oh, my.  Before I get to your time travel question, I need to first discuss a little bit about paradoxes so that all readers are on the same level.  I'm going to try very hard to keep this short.


What is a paradox?  If you check dictionary definitions, you find that a paradox is defined as: (1) a tenet (law, rule, guideline) that is contrary to received opinion; (2) a statement that is seemingly contradictory or opposed to common sense and yet is perhaps true; and (3) a self-contradictory statement that at first seems true; and so on.  There are many famous paradoxes you can read about if you, click here.


OK, if we eliminate all the esoteric language in the definitions of the word paradox, it comes down to this . . . A paradox is something that falls in the area called a "thought experiment" because there is no hard evidence to support either side of the argument, and regardless of what one person may say, another person will always come up with an answer something like, "Well, sure, that could be true, but what if . . ."  In other words, there is always another "what if" scenario tacked on and no one ever gets to a real answer.  Again, a paradox is a "thought experiment" or a series of "what if" statements that never lead to a conclusion because there is never a verifiable answer, only additional speculations.


I equate paradoxes to walking or running on a treadmill.  Regardless of how long a person walks or runs on a treadmill, the person never gets anywhere—the person stops in the same place he/she started.  Likewise, regardless of how long people discuss a paradox, they will never get anywhere.  But some people like to argue, some people like to speculate, and some people just don't have a whole lot to do and focus on questions that don't have verifiable answers.


A good example is the "Grandfather/Grandmother Paradox," which poses this question: Suppose a man traveled back in time and killed his biological grandfather before the latter met the traveler's grandmother?  Oh, please.  My answer to that question is: "If I traveled back in time and killed someone, I would kill the grandfather of the person who asked me that question, which means that I would never be asked the question."  OK, so there are my thoughts about paradoxes.  Let's go to your time travel question.


You asked, "If that quest [time travel] could be achieved, would it be known by now or not?  I mean, if someone in the future could find a way to go back to the past, wouldn't that would be something so extraordinary that we should already know about it?"


Your question has two possibilities: (1) A person from the future has figured out a way to travel back in time; or (2) A person from the present time has figured out a way to travel back in time.


Person from the Future

If someone from the future has figured out a way to go back to the past and is visiting us right now, in the year 2010, that means we are now living in the past.  In other words, I'm not really typing the answer to your question at this moment because the activity has already happened.  Hmm.  I have a problem with that because I can't find documentation anywhere verifying that the present has already happened.  What IS is actually what WAS?  I need proof.


In addition, I would think that if the present time is actually the past and someone from the future figured out how to travel back in time, that the person or would make himself/herself known, or at least leave some evidence of his/her presence.  But I could be wrong.


Person from the Present

If someone from our present time has figured out how to travel back in time, there are two possibilities:  (1) The person does not want to discuss the event; or (2) The person is stuck in some previous year in history and can't get back.  Neither of these two possibilities is likely.


It's unlikely because there is only speculation about how time travel could occur and the speculation involves some very "out of this world" theories involving things such as traveling faster than the speed of light, black holes, worm holes, parallel universes, and cosmic strings.  Speculation on top of speculation isn't very productive.


Now, I'm not saying that paradoxes (mind experiments) aren't worthwhile.  Thinking about things is a very valuable approach to solving questions and problems.  However, in my case, I think it's more productive to think about things that have plausible answers.  For example, I don't think it's important for me to think about things like: (1) What if I could fly? (2) What if I were a billionaire? Or (3) What if I could predict the future?  I can't do any of those things now, and I will never be able to do any of those things, so I would rather spend my time thinking about things I can actually do, like: What is the best way to answer your question?


Finally, it's fine if you want to think about time travel, but if such a thing does exist, currently or in the future, I would think that there would be evidence to verify it.  Right now, I'm not aware of any such evidence.

Back to the Future? - Comment

Doc:  Great thoughts regarding time travel.  But one seemingly glaring (to me) possibility is something like a Time Traveler's Prime Directive.  The idea comes from Star Trek's "Prime Directive."  The Starfleet peeps in the shows make vows not to interfere in foreign/alien cultures.  So, why wouldn't a person from the future who possibly came to visit 2010, or any other year, be possibly held to a similar standard?  And if they were to violate it, there are authorities perhaps in place who could travel to whatever time frame was damaged to repair the mistake.

Just adding to your "mind experiment" line of thought. - Mike in Denver


Mike:  I have only seen one or two episodes of Star Trek, so I never heard of the "Prime Directive."  But I did find a good explanation of the topic in this article.  I had to read the article a few times to figure out what was being explained.  All that from a TV show?  Wow.


Anyway, since time travel exists only in fiction, there are probably an infinite number of questions and propositions that can be asked about the concept.  Your comment is one of them and it's a good stepping stone for someone else to say, "Well, what about . . . ?" or "Yes, but what if . . .?"  Great questions for people who like to use their imagination.

Bad Driving

I live in the Philadelphia area and have noticed recently that there seem to be more bad drivers on the roads. But what seems more important is that it seems that the bad drivers all have American flags on their vehicles. Do you know if there is a relationship between bad driving and American flag stickers or flags hanging on the windows? - Anonymous


Anon: Oh, please. Is there salmonella turkey being served around the country? I know there isn’t a full moon right now. There must be something and I’ll have to check it out.


If my memory serves me correctly, I believe the sudden display of patriotism via flags on vehicles began with the September 11 moron episode. Me thinks that your perception of a correlation between bad driving (whatever that means) and a display of the American flag is based on a heightened awareness of the display of the American flag on vehicles.


However, I could be wrong and will be happy to admit my error if someone can show me hard scientific data verifying the correlation. No such data exist that I know about.


Finally, I always thought that every driver in America believes in the same driving "law," which is:


There is a 100% positive correlation between bad driving and anyone who isn’t me.

Bad Language

I’m a PD and I have been getting several phone calls from listeners complaining that my morning show team is using obscene language and talking about things that shouldn’t be talked about on the air. What is the best approach to use in this type of situation? – Anonymous

Anon: As you can see, I edited your question a bit. Your original question included information that I consider proprietary and I don’t think you really want that out in public. Hope you don’t mind.

The phone calls are an indication that something may be going on, but you need to be careful here because the calls may not represent your other listeners.

If you think that the complaints have any merit, it may be time to conduct a research study to determine if the opinions exist with your audience. There is a trend showing up around the country indicating that many radio listeners are tuning away from jocks who concentrate on obscenities (whatever they are) and inappropriate topics (whatever they are). Markets and formats are different when it comes to "bad" things.

Bad Morning Show Ratings

I’m at a stand-alone Alternative that has had two horrid trends.  Trends so bad that no one could have predicted them—a 0.9 followed by 0.8.  We used to be in the mid 3s.  The small amount of research the station does shows the morning show is liked.  They describe the show as funny.  If there is a complaint, it involves not hearing enough music.  We play eight an hour most of the time.  So, can the research be so far off?  Is funny not enough? - Anonymous


Anon:  Well, let’s see here.  The bad trends could be caused by one or a combination of several things including, but not limited to:

  1. The numbers are correct and indicate a significant current problem with your radio station.

  2. The numbers are correct and indicate a significant problem in the past that has finally emerged.

  3. The numbers are incorrect and may be a function of poor samples.

  4. The numbers are close to correct and indicate a need to investigate the situation.

I can’t comment on the “small amount of research” you have done.  I don’t know what you have done.  I don’t know the type of respondents you included in the research, and I don’t know the types of questions you asked.


For example, you say that, “The small amount of research the station does shows the morning show is liked.”  Liked by whom?  Who did you ask?  Were the respondents cumers or fans (P1s) of the morning show?  Also….Liked how?  What types of questions were asked?  What did they like?


You also say, “Is funny not enough?”  While the listeners in your research may have described the morning show as funny, you didn’t indicate how important “funny” is to them.  Funny may or may not be important to them, and if it is, it may not be the only element the listeners want.  I don’t know.  However, the fact that a show is funny (or described as such) does not guarantee success.  I think Jay Leno is funny, but I never watch his show.


Your trends are obviously pitiful and there is something going on.  Check the samples when you can.  They may be the culprit.  You also need to find out what your target listeners want in a morning show.  If you do another research project, do not use only your listeners.  If the trends are correct, the study will take forever to complete, and when it is done, you’ll have answers from people you’re probably not interested in.


Is your research that “far off?”  I need to know what kind of research you did.

Balance Sheet

I have been in a few meetings when the GM has talked about our radio station’s "balance sheet." Could you explain that please? – GB

GB: A balance sheet is a brief summary of a company’s financial situation. The top of the balance sheet shows what the company has, or its assets, listed in order of liquidity—from cash, accounts receivable, to fixed assets such as property and equipment. The bottom of the balance sheet shows what the company owes, or its liabilities, listed in order of immediacy (accounts payable are usually the most immediate liabilities). On a balance sheet, the assets must equal liabilities plus shareholders equity (the amount that assets exceed liabilities).

The balance sheet is different from the income statement (or P & L), which essentially shows where money is coming from (income) and where money is going to (expenses). It also shows the company’s net income (profit or loss)

Together, the balance sheet and the income statement show the financial condition of a company—not much different from you figuring out how much you are worth (what you have minus what you owe).


Me again. I’m the one who sent the question about Tiger Woods. Anyway, it has been a boring day and I have watched a lot of TV. I saw the old TV show "Alias Smith & Jones" on cable. In the beginning of the show, the scene was at a carnival. A person was walking around selling brightly colored helium-filled balloons. That didn’t seem right. Were there such balloons in the "Old West?" - Anonymous


Anon: You must be bored today. I would say that’s an error by the production company since the balloons as we know them now were invented by Neil Tillotson in 1933…a few years after the "Old West."


Band Saw Part

Doc:  I have question about a band saw.  I have asked a few people, but no one knew the answer.  I think you know something about tools, so I'll ask you.


On my band saw, behind the blade, there is a small wheel with ball bearings in it.  Do you know the name of the little wheel? - Anonymous


Anon: I'm fairly sure that you're referring to the thrust bearing, which stops the blade from moving when something is being sawed.  A band saw can have one, two, or four thrust bearings.  The number depends on the manufacturer.


Here is a photo of a thrust bearing.  If this isn't what you're talking about, let me know—although I'm about 100% sure that this is what you mean.


Bar Over (Line Over) a Letter - How Do I Type? (aka: Over Bar and Over Line)

Doc:  Here is a research report typing question for you.  Do you know how to type a line over a letter as is often used in statistics?  An example would be the symbol for the mean of a data set where the mean is the letter X with a line or bar over it?  I use Microsoft Word if that matters.  - David


David:  It's not too difficult to do what you're asking.  I learned this a long time ago, so I can't give credit to the person who taught me.  I forgot.  Anyway, follow these steps:   

  1. Place your cursor where you want to insert a character or word with an over line (over bar).

  2. Press CTRL + F9 to insert a set of braces.  (Command+F9 on a Mac).

  3. Between the braces, type . . . EQ \x \to (X) . . . to insert an over line above an X, otherwise replace X (the second X in the formula) with another character or word.

  4. Press Shift+F9 (Option+F9 on a Mac).

 I know the process works for Word, but I don't know if it works for a Mac since I don't own any Mac products.

Barrel of Oil

With all the discussion about the cost of a barrel of oil, I was wondering how many gallons of gas are in one barrel.  Any idea? - Anonymous


Anon:  According to several sites on the Internet, a barrel of oil contains 42 gallons.  Here’s how one barrel is refined…


One barrel of crude oil makes about 19½ gallons of gasoline, 9 gallons of diesel fuel, 4 gallons of jet fuel, and about 10 gallons of other products, including lubricants, kerosene, asphalt, and petrochemicals to make plastics.


By the way, it costs about $8.00 to find and produce ONE barrel of oil.  Since the current price is about $70 per barrel, it’s easy to calculate how much money the oil producing companies are making.  (The United States uses about 17 million barrels of oil each day.)

Baseball Diamond

On a baseball diamond, the distance between bases is 90 feet. How far is it from home plate to second base? And, is the pitcher’s mound in the middle of that distance? - Gene


Gene: I’m assuming that you are not a student and I’m helping you with your homework.


OK, in order to answer your question, we need to use a formula generally attributed to an ancient dead dude, Pythagoras—the guy you studied in geometry class (if you took one).


A baseball diamond is a 90’ square. If we use home plate, first base, and second base, this forms an isosceles right triangle. The line from home plate to second base is called the hypotenuse of the triangle (the longest line).


To find the distance of the hypotenuse of an isosceles triangle, you multiply the square root of 2 (1.4142135) times the length of one of the remaining sides (90’), which gives you 127.279 feet (or 127’ 3 3/8"). This is to the back of second base since the bases are placed inside the 90’ square.


The pitcher’s mound (actually the rubber) is placed 60’ 6" from home plate, which means that it is slightly in front of the line from third base to first base.


Now, what is the distance from third base to first base (or vice versa)?

Baseball and Humidity

Doc: I was watching a baseball game and the announcer was referring to how far the ball travels in different weather.  He said, "Wait until the summer when the ball will travel farther."  I thought the more humidity in the air, the less a baseball with travel.  For the opposite, just take a look at your Rockies' stadium. Home run heaven in the thin air.  Doc, as they say in the army, "Whiskey Tango Foxtrot?" - Anonymous


Anon: I'll give you "Whiskey Tango Foxtrot."  Don't make me come out there.  On to your question . . .


You said, "I thought the more humidity in the air, the less a baseball with travel."  Actually, that's wrong and that's the reason for your misunderstanding about the announcer's comment.  In reality, humid air is lighter (less dense) than dry air.  The announcer was correct, but humidity isn't the only factor in how far a hit baseball will travel.  There are several things that will affect a baseball's flight, including, but not limited to, humidity, ambient temperature, altitude, wind, and how hard a ball is hit.  But let's concentrate on the announcer's comment about summer.


Cold air is actually denser than warm air, which means there is less friction on a hit (or thrown) baseball in the summertime than in cooler times of the year—a hit baseball will travel farther in the summer because the air isn't as dense.  Secondly, the baseball is warmer during the summer, and a warm baseball hit off a bat travels farther than a cold baseball.  (Both of these points also relate to golf balls, footballs, and soccer balls.)


A third effect on the distance a hit baseball will travel is altitude, which you referred to in reference to Coors Field here in Denver.  Air density decreases as altitude increases, so the combination of warm air during the summer, altitude, and a warm baseball generate a lot of home runs in Coors Field that wouldn't be home runs in other parks around the country.


Humidity does have some effect on a hit baseball, but the effect is opposite of your perception.  In baseball, summertime is the best time for home runs in open-air baseball parks.  (I need to mention that some sources say that humidity has very little, if any, effect on the distance a baseball travels after being hit by a bat.)


There are many interesting articles on the Internet about this topic—click here and here.

Baseball Stats

Doc, great column. I’m a baseball nut and have looked at many big league career stats.  I’ve noticed a trend in almost everyone that has played 10 years or longer. Near the end of their career, there is one year that is just awful (without injury), they bounce back for a few more years, and then they retire.  Almost every player.  Is there a statistical reason for this, or is it just coincidence? - Anonymous


Anon:  Thanks for the comment.  I’m glad you enjoy the column.  I have never seen a statistical study about your question, but I’m going to take a guess.


First, any baseball player who has been in the major leagues for 10 years is probably a person who is above average in talent.  If not, the person wouldn’t last 10 years.  In statistics, there is a phenomenon known as “regression toward the mean,” which shows that elements below the mean or above the mean will eventually gravitate toward the mean (the things below the mean get “better,” and the things above the mean get “worse.”


In the case of a 10-year baseball veteran who has played above average for several years, regression toward the mean indicates that he will eventually become a poorer player and regress toward the mean (perform more closely to the average player).


My guess is that although professional athletes (not only baseball players) don’t know about regression toward the mean, but they do know the theory behind it—that they can’t stay above average forever.  OK, so the player has played for years at a high level and then has a bad year.  It’s time for him to think about moving on to insurance or automobile sales.  But I think what happens is that most of these players think something like, “I’m good.  I had one rotten year, but I still have a few good years left.”  And they continue playing and perform at their previous level—a self-fulfilling prophecy.  (It they had one bad year and think, “I’m done,” then they probably would do that too.)


Nearly everything in life follows the regression toward the mean phenomenon—stock prices, radio ratings, grades in school, or performance on a professional field.  So I don’t think it’s rare for an above average athlete to have one bad year and then bounce back.  Statistics show that they will do this regardless of how good they are.  Even Tiger Woods will have a bad year or two…when he’s about 122 years old.

Bathtub Phenomenon

Howdy Doc:  I'm a guy who likes to take the occasional long, hot, relaxing bath.  I have noticed this weird phenomenon, and would like your take on it.  It happens after I have sat motionless in the hot water for a while.  When I suddenly move my leg, the water feels several degrees warmer for a moment.  Then that warmer feeling goes away.  I can do it time after time while in that bath, with the same result every time.  Why?  Thanks, Doc! - Geno


Geno:  I searched the Internet for the answer to your question and couldn't find an exact description, but I was able to develop an answer for you based on several articles I read.


However, I did have a problem with your question because you didn't mention if your legs are motionless under the water, or if you're lying on your back with your legs bent at the knees and up in the air spread apart in different time zones.  Since I don't have that information, there are two answers to your question.  But before I get to your answers, I think I should review the four ways humans lose body heat or transfer body heat.  I found a good summary of the four methods at PilotFriend (edited by me).


Radiation:  The transfer of heat from an object of intense temperature to an object of lower temperature through space by radiant energy.  The rate of heat transfer depends mainly on the difference in temperature between the objects.  If the temperature of the body is higher than the temperature of the surrounding objects, a greater quantity of heat is radiated away from the body than is radiated to the body.


Conduction:  The transfer of heat between objects that have different temperatures and are in contact—heated molecules from one object transfer to molecules of cooler adjacent objects.  The proximity of these objects will determine the overall rate of conduction.


Convection:  The transfer of heat from the body in liquids or gases in which molecules are free to move. During body-heat loss, the movement of air molecules is produced when the body heats the surrounding air; the heated air expands and rises because it is displaced by denser, cooler air. Respiration, which contributes to the regulation of body temperature, is a type of convection.


Evaporation:  Evaporative heat loss involves the changing of a substance from its liquid state (sweat, water) to its gaseous state.  When water on the surface of the body evaporates, heat is lost.  Evaporation is the most common and usually the most easily explained form of heat loss.


OK, with those explained, let's go to your answers . . .


Legs Bent/Knees in Different Time Zones.  This situation involves evaporation and is relatively straight-forward.  If your legs are under the water and you then expose them to the air for a while, evaporation causes your skin to cool and the water will feel warm when you put your legs back into the water.


Legs Under Water.   This situation probably involves conduction—the transfer of heat from one object to another.  The key to the answer to your question is that you said you keep your legs motionless.  Why is this the key?  Because the average human body skin temperature ranges from 90° to 93° F (although this varies depending on many variables), and your bath water is probably in the range of 100° to 104° F.  I doubt it's hotter than that because the human pain threshold in water is 106° to 108° F.  (The Consumer Products Safety Commission recommends a maximum of 104° F for a spa.)


OK . . . your normal/average skin temperature is 90° to 93º F, and the bath water is about 100° to 104° F.  Following the conduction idea, a very thin film (or layer) of water surrounding your submersed body parts will lose heat to your cooler skin.  That is, your submersed body parts cool a very thin film of water that is contact with your body, and the thin film will become cooler (closer to your skin temperature) the longer you remain motionless.  However, when you move—even the slightest movement—your submersed parts again come in contact with warmer water.  There ya go.  Go jump in the tub.


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