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Warm-Blooded Plants

Article #164 • Written by Cynthia Wood

If you live in the Northeastern US, and you walk in the woods on spring mornings, you're likely to see a skunk cabbage. Indeed, you might see a skunk cabbage growing while the snow is still on the ground. What you may not notice, unless you look closely, is that the snow around the skunk cabbage has melted. It’s not a spectacular sight, but around all of the skunk cabbages you see, there will be a small hole in the snow.

What’s happening here? Is the sun warming the darker plants and melting the snow? No. Actually, the phenomenon you’re seeing is called thermogenesis, and it’s a normal ability of the plant. Or to put it another way, the eastern skunk cabbage is warm-blooded. Its ability to generate heat enables it to grow and flower while the snow is still on the ground – even though the plant is not frost-resistant. The frost will never touch it.

Thermogenesis is rare in plants, but does occur in several species of Arum, and in the philodendron, as well as the skunk cabbage. The heat generation of these thermogenic plants is not trivial, either. Recent measurements of the titan arum “Ted”, at UC Davis, showed the inflorescence-- the flower-like structure of the arum-- could maintain a temperature of 32 degrees Centigrade (90 F), well above the surrounding air temperature of 20 C (68 F). The skunk cabbage can do even better, maintaining temperatures as high as 35 C, even when the air temperature is below freezing.

Why do these plants do this? What possible benefits could accrue? Surprisingly, it appears that they did not develop their unique ability as a way to ward off the cold. While the skunk cabbage certainly uses its thermogenic abilities to be able to bloom earlier, most thermogenic plants come from warmer, or even tropical climes. The arums being fairly ancient plants, it seems more likely that the skunk cabbage has merely found another use for an already existing ability. So why would tropical plants need to heat up?

Titan Arum - "Ted"
Titan Arum - "Ted"

The answer, according to most biologists, is simple – the need to attract pollinators. Many arums, such as the titan arum mentioned above, bloom infrequently (as rarely as every 8 to 10 years in some cases), and so their pollinators need to be able to find them quickly, and from far away. By heating up the plant can render its scent more volatile, and therefore more easily disseminated. The titan arum's distinctively horrible scent, which has earned it the name "the Corpse Flower", can be detected more than a mile away. Once the pollinators, usually insects, have been attracted, the warm inflorescence also makes an attractive place to rest. The need to spread scent widely is the same drive that gives the titan arum its enormous central spadia (the central pillar, seen in the photo). That spadia, and the surrounding inflorescence make up the largest floral structure in the plant world - up to three meters tall.

The advantage of thermogenesis must be strong, because the energy demands on the plant are huge. It is estimated that the skunk cabbage, when maintaining its heat against sub-freezing temperatures, uses as much metabolic energy as a small rodent, or even a hummingbird. Normal plant metabolism is much slower, so this much energy usage is remarkable. In order to generate all this energy, thermogenic plants use an entire alternate respiratory process, one that uses mitochondria and fats, neither of which is involved in normal plant respiration. The whole process, in other words, looks rather more like animal metabolism than normal plant metabolism. This energy cost is undoubtedly why most thermogenic plants don’t maintain heat constantly, but rather use it sparingly. In the arums, only the inflorescence itself heats up, and then only during the day. The skunk cabbage uses heat more lavishly, presumably to protect itself from the cold, but once the snow is gone and blooming is over, it too reverts to normal cold-blooded plant behavior.

Perhaps we should be grateful that plants only use this particular pathway for heat generation. After all, with all that available energy, who knows what they could do by using it for something more than just a little heat. The great monsters of tomorrow may not come from outer space, or the laboratory, but from our backyards.

Article written by Cynthia Wood, published on 15 April 2006. Cynthia is a contributing editor for DamnInteresting.com.

Article design by Alan Bellows. Edited by Alan Bellows.
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60 Comments
gorgeousplanet
Posted 15 April 2006 at 11:33 pm

Thank you, this was very interesting! I went to see the corpse flower at the Huntington Gardens, but it had already bloomed and died. All my mom and I wanted was to smell it. How fascinating to learn more about it. :)


ForestGrump
Posted 16 April 2006 at 03:56 am

Damn interesting indead. I learned something new tonight. That the plant at the end of the Dennis the Meanace movie was "warm blooded".


JustAnotherName
Posted 16 April 2006 at 04:49 am

Philodendrons. Perhaps this is why it is one of the few house plants I do not kill; it takes care of itself.


Mark
Posted 16 April 2006 at 05:17 am

That's absolutely amazing, I never knew about these plants!


grey matter
Posted 16 April 2006 at 05:36 am

WOW!
Till now I thought that only class aves and mammalia were warm blooded.


nutritionalalchemist
Posted 16 April 2006 at 06:32 am

"Feed me Seymour!!!!"
Very intersting article though. I cannot tell you how much I have learned from this site. I think it is the only site I visit this much.


sfurules
Posted 16 April 2006 at 07:02 am

Now...how is the plant able to find that much energy to remain warm? I know it was mentioned that the heat is only produced at certain times...but the energy required for heat production is rather large, especially considering the imobile nature of the roots, which are all the plants have to reach nutrients (to my very limited knowledge). Is is soil depletion avoided?


1c3d0g
Posted 16 April 2006 at 07:54 am

Now this...this is very, very, interesting! I'm amazed by our nature's incredible variety of plants and animals each and every day. Keep up the good work! :-D


fuzzhammer
Posted 16 April 2006 at 08:53 am

The triffids were warm-blooded, weren't they? its all fun and games until they start eating blind people.


another viewpoint
Posted 16 April 2006 at 09:19 am

quote "By heating up, the plant can render its scent more volatile, and therefore more easily disseminated."

Sure thing...when I get heated up, my scent becomes more volatile too (not to mention offensive). However, when there's snow on the ground, I'm usually outside with a coat on. As such, it's difficult for me to melt snow.

Just another Damn Interesting tid bit of info. Sure wish you folks could put together some kind of Damn Interesting Trivial Pursuit. Fun and educational at the same time. Tx again.


Cynthia Wood
Posted 16 April 2006 at 10:13 am

sfurules - at least in the case of the titan arum the huge energy demands are a large part of why the plant blooms so infrequently. It takes the arum a number of years to build up the energy stores to bloom, and even then it goes almost completely dormant for several months before it blooms. Basically it takes in energy at a normal plant rate, but saves up all the energy for reproduction and blows it in one lavish display.


Gaffer
Posted 16 April 2006 at 04:17 pm

Ah, the skunk cabbage. Quite a resilliant plant - thousands of them in the brooks and swamps around my house. My Uncle inadvertantly calls them "Seasonal Hosta".

They actually don't smell at all unless you disturb them (see: tear, break, mutilate, uproot, etc).

A very interesting article though.


Sandra Thurston
Posted 17 April 2006 at 11:31 am

Owww, a relaxing subject! I feel like a skunk cabbage myself, trying to survive the weather in Utah. Tanxs goodness, brazilians are hot-blooded!!:) hahaha


indra c
Posted 19 April 2006 at 03:18 pm

another viewpoint said: Sure wish you folks could put together some kind of Damn Interesting Trivial Pursuit. Fun and educational at the same time. Tx again."

You are on to something


rp2
Posted 20 April 2006 at 10:11 am

damn warm blooded plants.. I bet they come from Canada!


cyborg table
Posted 20 April 2006 at 07:22 pm

Thats so cool


paalexan
Posted 02 May 2006 at 08:03 pm

"Spadia"? The word is "spadix". The plural is "spadices".


pagan orchid
Posted 01 June 2006 at 12:14 pm

Enter your reply text here.Ah, the skunk cabbage. Quite a resilliant plant - thousands of them in the brooks and swamps around my house. My Uncle inadvertantly calls them "Seasonal Hosta".

well if they really smell as bad as a skunk(not that i've met one) i would hope the slugs dont find them as tasty as they find my hostas.


sulkykid
Posted 02 January 2007 at 02:27 pm

grey matter said: "WOW!

Till now I thought that only class aves and mammalia were warm blooded."

Tuna are warm-blooded fish. (Or so I hear.)


AntEconomist
Posted 02 January 2007 at 03:08 pm

I wonder if it is possible to harness the energy of the plants -- perhaps not on an industrial, but an individual scale. For example, my house is on a concrete slab that can get pretty cold in the winter. If I plant them around the perimeter of the house (ignoring the scent issue for a moment), would they not provide some heat to the slab?


Drakvil
Posted 02 January 2007 at 04:00 pm

AntEconomist said: "I wonder ... would they not provide some heat to the slab?"

Probably not enough to really be noticed by itself, but by reducing the snow that is in contact with the slab it would change the heat flow characteristics of the slab. I wonder about an arrangement like that causing enough melting of the snow on the roof to cause it to slough off, giving you snow walls around the house (not touching because of the plants) that will protect the house from winds... You just might be onto something there!


another viewpoint
Posted 02 January 2007 at 04:15 pm

...kinda reminds you of the person-eating plants in Little Shop of Horrors and Jumanji.

There's nothing worse than a warm-blooded plant with a cold-hearted personality!


Cesium
Posted 02 January 2007 at 04:58 pm

AntEconomist said: "I wonder if it is possible to harness the energy of the plants"

You can collect more energy from solar than these plants. For instance – A kitchen match is roughly equal to one BTU (British Thermal Unit). The heat capacity of water is equal to 1 Btu/degree F/pound. Air is equal to 1/55 Btu/degree F/ft^3. This means with 1 Btu you can heat 1 pound of water 1 degree Fahrenheit or 55 cubic feet of air 1 degree Fahrenheit.
Yes it takes more energy to heat water than air. Now the problem, as you warm air, it rises. This warm air is replaced by heaver cold air. Unless the air is contained in an enclosed structure (your home for instance) then all you are doing is wasting time and energy. Now the term heat loss is misleading. Your home will suffer loss when warm air (or cool air depending on the season) “leaks” through vents, open doors, poorly sealed windows, etc. Other energy loss occurs due to transference through friction. Heated air oscillates at a higher rate than colder air. Take a pane of glass. First understand that air is one of the best insulators you can have. It is the impurities within it (moisture, dirt, etc.) that will cause energy transference be it electricity or heat friction. Impurity molecules in the air have been raised to an excited state creating “warm air” which rubs against the glass molecules losing energy through friction. This cools the air by reducing the oscillation of the molecules while warming the glass by increasing the oscillation of those molecules. Meanwhile cold air molecules (same impurities) on the opposite side of the glass slow down the excited state of the glass molecules resulting in energy transference cooling the glass.
Now imagine a waterfall. By each window of your home is an air waterfall. During the winter warm air will cool by touching the window and “falls downward” since cold air is heavier than warm. This draws in more warm air to be cooled by the glass. The cool air flows across the room warmed by the surrounding air. This creates a natural convection flow through the room in a never-ending circle using the window as a “heat dump”. During the summer the process is reversed, as is the flow of air through the room and the energy transference.
Now for the R-factors. In insulation R means resistance to heat loss. A standard 6” batt of insulation will generally have an R-19 rating uncompressed. Any compression and the R-value will decrease due to air pockets being crushed. Understand that air is the insulation not the material, thus the smaller the individual air pockets and the more of them the higher the R-factor. A single pane of glass rates in with a meager R-0.91, while your concrete slab barely rates with an R-0.08. If your slab was poured without some form of insulation under it, it is basically a “heat-vacuum”. With all these factors in mind, then these plants just cannot produce enough energy to transfer into your home.
I tried to simplify this for better understanding.


Dr. Evil
Posted 02 January 2007 at 05:57 pm

this was the first article i ever read on damn interesting...and it is still as cool as the first time i read it


Tink
Posted 02 January 2007 at 07:01 pm

Thanks Cynthia, DI! plants!

nutritionalalchemist said: ""Feed me Seymour!!!!"
."

LOL, yeah, I thought about that Little Shop of Horrors too. I think these all may be related to the Venus Flycatchers and Pitcher plants, Humm?.

Sulkykid, I did not know that about the tuna, tho we all know that whales, dolphins,and some porpoises are warm blooded. I think the porpoise branch are related to tuna, very interesting.

Thanks to you too,Cesium, for the scientific explanation. I had always wondered why a waterbed stayed cold no matter how warm the room was. I suspected that it had to do with the ambient atmosperic temp. (outdoors). Though I still do not understand how, this helps to understand why. Sorta.

Drakvil, your on to something there, relating to a wall, as a wind break, I would venture a guess that it would also serve as another barrier to help contain the heat loss from the house. Look at igloos, they are very warm I've heard. But alas (heehee) we here in this part of TX. rarely see enough snow to be in any way educated about it.

Hope you friends up North there are staying cozy, we feel for you, here! :)


Tink
Posted 02 January 2007 at 07:13 pm

another viewpoint said: "…kinda reminds you of the person-eating plants in Little Shop of Horrors and Jumanji.


There's nothing worse than a warm-blooded plant with a cold-hearted personality!"

Oops,sorry Darlin' I missed you the first read, funny, funny honey!


Kourage
Posted 02 January 2007 at 07:43 pm

"thermogenic plants use an entire alternate respiratory process, one that uses mitochondria and fats"

Would the change in respiratory process change the taste and nutritional value aswell??


sulkykid
Posted 02 January 2007 at 08:33 pm

Tink: greetings from Up North (WI), although it is not very cold right now.

Whales, dolphins, and porpoises are all mammals, therefore all are warm-blooded. (I wonder if there is an oddball cold-blooded mammal somewhere?) You might be confused by the dolphin fish which is a cold-blooded fish and not a mammal. Lots of people get confused by the "dolphin" name, so you will usually see the fish as "mahi-mahi" or "dorado" on a restaurant menu. Can't be eating cute little Flipper now, can we? (Does anyone even remember Flipper?)


Tink
Posted 02 January 2007 at 10:25 pm

sulkykid said: "Tink: greetings from Up North (WI), although it is not very cold right now.


Whales, dolphins, and porpoises are all mammals, therefore all are warm-blooded. (I wonder if there is an oddball cold-blooded mammal somewhere?) You might be confused by the dolphin fish which is a cold-blooded fish and not a mammal. Lots of people get confused by the "dolphin" name, so you will usually see the fish as "mahi-mahi" or "dorado" on a restaurant menu. Can't be eating cute little Flipper now, can we? (Does anyone even remember Flipper?)"

Thank you Dear! Do these fish you mention have red meat like tuna or salmon? I wonder if that has anything to do with body temp?

(I wonder if there is an oddball cold-blooded mammal somewhere?)

Humm, food for thought, and research... I will get back to you on this if I find something...

LOL ,yeah I remember Flipper, and Charlie tuna comercials,"Sorry Charley".


Bill Koch
Posted 03 January 2007 at 05:11 am

Cold-blooded mammal? Naked mole rat


another viewpoint
Posted 03 January 2007 at 06:52 am

...cold-blooded mammals? What...you never heard of lawyers, accountants and corporate American CEO's?


Cesium
Posted 03 January 2007 at 07:21 am

Tink said: "Drakvil, your on to something there, relating to a wall, as a wind break, I would venture a guess that it would also serve as another barrier to help contain the heat loss from the house. Look at igloos, they are very warm I've heard. But alas (heehee) we here in this part of TX. rarely see enough snow to be in any way educated about it."

Actually this is a very correct statement. Think of your home as a large rock in the stream. As the water strikes the rock it bulges in the front while there is a large dip behind the rock.

When air strikes your home it creates this very view. With a higher buildup of air pressure on the windward side while there is a low pressure on the leeward side of your home. This creates an imbalance with air moving through your home towards the lower pressure side. Now every gap, hole, or vent on that side of the house is basically “squirting” out warmer (or cooler air, depending on season). This can and will make your furnace (or air conditioner/cooler) work 10% to 50% harder depending on the condition of your home.

You can test the movement of air in your home with various items during a windstorm. Go the leeward side during that storm and you can use “chemical smoke” (sold in squeeze tubes for this type of testing), talcum powder, a lit match, or even a burning cigarette. Use one of these devices by slowing moving them around window edges (you want to create small clouds with the talcum as you want to “dirty” the air with particulates only); electrical outlet & switch cover plates, by the base plate (kickboard at bottom of wall), vents, and door edges. If the flame or “smoke” is drawn into the edges of any of these items you have airflow moving into the wall and eventually escaping the home.

Years ago during a test we discovered that when you “add up” all the various vents and gaps in the average home, it equaled an opening 32 square feet. That is the same as a large front door. So basically it would be the same as leaving your front door open all year long. A good wind block (trees are fantastic for this) decreases energy loss year round by cutting the wind or shading the home during summer.

Recall the analogy about the stone in the stream. Next time you see one, place some type of block in front of it. Notice that now the buildup of water in front and the drop leeward decreases or even disappears. That is the same as what is happening with a wind block.


HarleyHetz
Posted 03 January 2007 at 07:23 am

Tink said: "Thank you Dear! Do these fish you mention have red meat like tuna or salmon? I wonder if that has anything to do with body temp?

Humm, food for thought, and research… I will get back to you on this if I find something…

LOL ,yeah I remember Flipper, and Charlie tuna comercials,"Sorry Charley"."

:) You are showing your age by being able to remember "Sorry Charley"!!!

DI Article, I missed this one first time around somehow...see, the re-runs aren't all that bad! :)


dday
Posted 03 January 2007 at 07:43 am

another viewpoint said: "…cold-blooded mammals? What…you never heard of lawyers, accountants and corporate American CEO's?"

OUT LOUD FUNNY in a sea of personal quips of semi-lucid thoughts.....


Radiatidon
Posted 03 January 2007 at 08:19 am

Tink said: "Thank you Dear! Do these fish you mention have red meat like tuna or salmon? I wonder if that has anything to do with body temp?


Humm, food for thought, and research… I will get back to you on this if I find something…

LOL ,yeah I remember Flipper, and Charlie tuna comercials,"Sorry Charley"."

Just a side note: Not all mammals are warm blooded. One was mentioned earlier, the Mole Rat. It like the bat cannot maintain a constant body temperature and both will cool off when not active. This really does not matter to the Mole Rat since it lives in a stable environment, otherwise underground.

Then there are the non-mammals that do generate heat such as Hawk Moth and the humble Bumble Bee that generate heat by flapping their wings.

Then we have the unusual animals. Take the Echidnas for example. This creature is like the Platypus in that it is a monotremes (egg laying mammal). It has trouble maintaining a stable body temperature that can vary from 77 to 98.6 degrees Fahrenheit. This can be a problem for them since they have very inefficient cooling systems (as with humans sweating or various animals panting). Once hatched these mammals seek the mother’s pouch where they will suckle milk not from nipples but from specialized pores.

Meat color is based on its myoglobin level. Less oxygen means whiter or paler meat. The amount of myoglobin is also determined by the muscle’s function. You see there are three types of muscle fibers: Red (slow-oxidative), intermediate (fast-oxidative), and white (fast-glycolytic). The Red oxidizes fat for energy while the White, which have less myoglobin, generate most of its energy from glucose. The Intermediate get to use the best of both worlds. The type of muscle is based on function, blood supply, and amount of use.

Due to these facts, whales have very dark meat since they store a lot of fat, thus have to be extremely oxygen and energy efficient systems.

Now a mammal with unique meat is the manatee. According to Robert Bonde of the U.S. Geological Survey, Florida Caribbean Science Center in Gainesville, Florida, the manatee’s meat varies from a very light pink to a very dark purple. Its body does not contain high levels of the oxygen-binding protein myoglobin typical of other marine mammals. Plus according to where the meat is cut from the animal, depends on the taste. It has been reported to have seven distinct flavors.

Trivial Pursuit? No one will play with me :(


Xoebe
Posted 03 January 2007 at 10:26 am

Best D.I. thread ever! Interesting about the meat color and function. I had never given it much thought.


Saustain
Posted 03 January 2007 at 11:51 am

Turtles have different color meats (at least Alligator Snapping Turtles). The old trappers knew their stuff, because they told me the different colors of the meat were for different movements.


Radiatidon
Posted 03 January 2007 at 12:06 pm

Saustain said: "Turtles have different color meats (at least Alligator Snapping Turtles). The old trappers knew their stuff, because they told me the different colors of the meat were for different movements."

Thanks Saustain you reminded me that the Leather Back Turtle is a warm-blooded reptile unlike its other turtle cousins that are cold-blooded.

Also since most of us have dined on turkey this past holiday season, then you know about the dark & white meat. This is an example of the Red (slow-oxidative), intermediate (fast-oxidative), and white (fast-glycolytic) tissue. Since the turkey does not fly, the breast muscles are white (fast-glycolytic), and the leg and wings are Red (slow-oxidative) since the bird walks and periodically flaps its wings. If you have ever dined on game birds (duck, grouse, geese, etc) then you would have noticed that these flight birds have dark meat on their breasts.


Tink
Posted 03 January 2007 at 12:25 pm

You guys and gals are great! Thank you for all the lovely information. I LOVE THIS SITE!! (And all yall, too.)

another viewpoint said: "…cold-blooded mammals? What…you never heard of lawyers, accountants and corporate American CEO's?"

LOL, started to mention my ex-MIL but well, I just let it pass. Lets not for forget HMOs.
So the insurance agent died and is at heavens gate. St. Peter asks "What did you do on earth?" the guy says "I ran a HMO." St. Peter goes to check the files, comes back and says"OK. You can come in but you can only stay for 3 days". :)


Cesium
Posted 03 January 2007 at 12:46 pm

Tink said: " I had always wondered why a waterbed stayed cold no matter how warm the room was. I suspected that it had to do with the ambient atmosperic temp. (outdoors). Though I still do not understand how, this helps to understand why. Sorta. "

Well, it is due to location. Unless you have in-floor heat the coldest part of any room is by the floor. Remember warm air rises and cold air settles. We have a tendency to set our environments according to where our chest to head section of the body is comfortable. This is a basic instinct since our most vital organs reside in these areas. Thus the room is uncomfortably hot above our heads and too blasted cold by our feet.

You waterbed resides below the waist region of the body, thus closer to the colder portion of your room. Usually we do not notice the zone temperature changes from floor to ceiling. These can best be experience if you are working with your back close to the ceiling (phew its hot up here) or lying on a bare floor (no carpet, rug, or in-floor heat) in skimpy pjs or al natural (I’m freezing my butt off here).

Thus when you jump into your waterbed (and the bed heater is not cranked to shellfish steamed level) it always seems colder than the room. Due to the heat exchange occurring with the colder convection flow of air underneath (if open frame with no sheet filled drawers) and sides of the bed frame.

One final thought – if you have every jumped into your waterbed or awoke to discover that you have become wet, its cold. Remember the dryer your bedroom atmosphere the faster water will evaporate off you. That evaporating water will also take the surface heat of your skin with it. Same as sweating during the summer, being hit by a cool summer breeze when you are sweaty gives you the shuddering shivers.


Silverhill
Posted 04 January 2007 at 01:20 am

Tink said: "Do these fish you mention have red meat like tuna or salmon? I wonder if that has anything to do with body temp?"

In the case of salmon, the pink/orange color comes from carotenoid pigments in their diet (from copepods, I believe). Farm-raised salmon are fed carotene supplements so that their meat will look like that of wild salmon--otherwise, it would look pale and un-colorful, as in most fish.

Cesium said: "Well, [the coldness of a waterbed] is due to location."

Largely that, I suspect, but remember also that water has a very high specific heat--that is, it takes a lot of energy input to raise its temperature by even a small amount. Unless a waterbed mattress is well heated, its water will feel cool (if not cold) simply by absorbing lots of heat from warm things such as humans.


Drakvil
Posted 04 January 2007 at 01:41 am

Things I learned about water from being a lifeguard to pay my way through college:

Water is roughly 20 times denser than air, so to give an equivalent amount of water the same change in temperature requires about 20 times the engergy. So if you are in the water you will lose body heat that much faster. So if your waterbed heater is not warm enough, the mattress acts as a heat syphon and you end up freezing. A thicker mattress pad will help keep the moisture from your body collecting and sticking you to the plastic mattress, so you will feel much more comfortable.

There are basically 5 different ways for heat to leave your body, but I can only remember the big 3:
conduction - contact with a cold object
radiation - loss of heat through a surrounding medium such as air or water
convection - the circulation of the surrounding medium to keep replacing what your body has heated with the colder stuff. Remember, the rate that heat travels is governed by the difference in temperature between the two objects.


Techno-Kid
Posted 04 January 2007 at 08:44 am

Excellent article and supremely excellent comments. The other day I was thinking about my high school Physics teacher telling me that a pot of cold water will boil faster than a pot of warm water when you put it on the range and I could not for the life of me remember the principle he was demonstrating.


sulkykid
Posted 04 January 2007 at 09:47 am

Techno-Kid said: "Excellent article and supremely excellent comments. The other day I was thinking about my high school Physics teacher telling me that a pot of cold water will boil faster than a pot of warm water when you put it on the range and I could not for the life of me remember the principle he was demonstrating."

"They" also say that hot water in an ice cube tray will freeze faster in a freezer. These hot/cold claims cause huge arguments among intelligent people. I think that "The Straight Dope", or some other such know-it-all, has addressed this issue. (But I am not going to try to look it up.) Personally, I suspect that cold water ice cubes will freeze faster, and warm water will boil faster.


sulkykid
Posted 04 January 2007 at 10:19 am

Cesium
Posted 04 January 2007 at 10:39 am

Techno-Kid said: "Excellent article and supremely excellent comments. The other day I was thinking about my high school Physics teacher telling me that a pot of cold water will boil faster than a pot of warm water when you put it on the range and I could not for the life of me remember the principle he was demonstrating."

Actually cold water takes longer to boil than warm. This is a long-standing myth. There are two ways to change the boiling point. One is to change the density (adding salt raises the boiling point. Though to notice it you would have to add more than you would care to eat.), the other is to pre-boil it (this removes air from the water allowing better energy transference).

The reason this is a myth is that the cold water still has to reach the temperature where the warm or hot water started. Since cold water does not contain trans-warp technology or time distortion ability it still can only acquire energy as fast as the warm/hot water and no faster. Time it yourself using same volume and identical vessels. At first the colder water will absorb energy faster but only until it reaches the temperature that the warm/hot water started at. At this point it will only absorb energy at the same rate as the warm/hot water from that point on. No faster.

There is an oddity though called the Mpemba effect in which under certain circumstances warm/hot water will freeze faster than cold water.


tampagirl
Posted 04 January 2007 at 11:37 am

I think it was Bill Nye the science guy who said that hot water freezes faster due to the molecules being closer together in hot water. I'm scared to post...what with all the genuis' on this site!


AKALucifer
Posted 04 January 2007 at 01:28 pm

ForestGrump said: "Damn interesting indead. I learned something new tonight. That the plant at the end of the Dennis the Meanace movie was "warm blooded"."

THAT'S THE ONE! Yes the flower that blooms for a second and then dies. Even when I was very young I thought that was a bit implausible


James
Posted 04 January 2007 at 03:09 pm

Nobody has even conclusively proven the Mpemba effect. Some have supposedly recreated it but not consistently and no one can really explain it. The circumstances under which it has been recreated are specific and again nobody seams to get very specific about that either and the time differences are negligible anyway. Let me put it this way for household purposes Cold water freezes faster than hot water. Water out of the cold side also does not go though the water heater and does not contain as much sediment and impurities so you’re better off anyway.

And how did we get on the Mpemba effect anyway. O well for what it is worth Interesting article I never would have guessed there are "warm blooded" plants


Radiatidon
Posted 04 January 2007 at 05:12 pm

James said: "Cold water freezes faster than hot water. Water out of the cold side also does not go though the water heater and does not contain as much sediment and impurities so you’re better off anyway."

Personally I fail to see the logic in freezing hot water. It degrades the performance of your freezer by making it work harder and longer to transfer the additional heat created by the hot water. Wither it works or not, it costs money to heat the water and even more money to freeze the resultant hot water.

The possibility looks to exist. The freezing process begins when the water touching the container and near the open top would lose energy forming an ice shell. This in turn could create convection flow within the warmer water core allowing a faster heat loss, whereas the cooler water would not have the core thermodynamics of the warmer water. One must realize that this is a basic thought only. Various factors must be included such as starting water temperatures, container size, isolation of vessel (free air stand support vs. sitting on shelf), purity of water, etc.

This would make a good mathematical/physics problem to kick around in one’s spare time.

James said: "And how did we get on the Mpemba effect anyway. O well for what it is worth Interesting article I never would have guessed there are "warm blooded" plants"

Part of the site’s enjoyment factor is the side branches that do relate to the article. In this case plants that create heat like mammals and mammals that cannot. This also branched into thoughts about thermodynamics and energy flow. Both branch offs that are just as mind expanding and interesting as organic plants that generate heat.


Radiatidon
Posted 04 January 2007 at 05:20 pm

tampagirl said: "I think it was Bill Nye the science guy who said that hot water freezes faster due to the molecules being closer together in hot water. I'm scared to post…what with all the genuis' on this site!"

Tampagirl thanks for the note about Bill Nye. I think I will look into his thoughts on this. Never be scared to post. Something simple to you may be very thought invoking and interesting to someone else. As that silly robot… what was that movie? L5 is alive? No… it called itself Johnny 5. Was the movie Short Circuit? Anyway as the robot kept saying “Input. Need more input!”


James
Posted 04 January 2007 at 05:36 pm

Radiatidon said: "Personally I fail to see the logic in freezing hot water...

This would make a good mathematical/physics problem to kick around in one’s spare time.

"

I guess that’s what makes the Mpemba effect interesting I has been demonstrated but never really proven and explained fully.
I agree it seams silly to freeze hot water like even if it really did save you a minute in the freezing process. It’s an old wives tile that has some scientific backing.


Silverhill
Posted 04 January 2007 at 07:42 pm

tampagirl said: "I think it was Bill Nye the science guy who said that hot water freezes faster due to the molecules being closer together in hot water."

Welcome to the fun house, Tampagirl! :-)

Bill Nye likely did address this problem (I don't get much chance to see him), but he should have said that the molecules are farther apart in hot substances. Water is exceptional in that regard, but only when comparing the densities of solid and liquid water. Warmer (liquid) water is indeed less dense than colder.

Radiatidon said: "As to that silly robot… what was that movie? L5 is alive? No… it called itself Johnny 5. Was the movie Short Circuit? Anyway as the robot kept saying “Input. Need more input!”"

Short Circuit (and Short Circuit 2) it was indeed, sir, that featured Johnny 5 . Silly, but fun....


FireDude
Posted 05 January 2007 at 10:53 am

The Mpemba effect is a very interesting study in how hard it is to create a well defined experiment (that whole scientific method bit that you probably learned in primary school). If I just say "Sometimes hot water freezes faster than cold water", then sure, drop a thimble full of boiling water into liquid nitrogen. That'll freeze it right quick. However, I sincerely doubt that if you take two sealed balloons full of the same mass of different temperature water from the same tap (so there is no evaporation and thus the mass of water stays constant) and stick them in the same freezer at the same time and at the same distance from the cooling elements, at any given time there'll be more ice in the one that started out colder (until they're both frozen). Sure the fluid flow could be complex, but in the end you still need to remove more heat from hot water to freeze it.

Oh, and water beds always feel cold for that same reason that furniture or pots feel cold - they're at the same temperature as everything else in the room, but they conduct heat better and thus you'll initially lose heat to it faster than to the air around you.

Warm-blooded plants are neat. DI.


Radiatidon
Posted 05 January 2007 at 11:56 am

FireDude said: "Oh, and water beds always feel cold for that same reason that furniture or pots feel cold - they're at the same temperature as everything else in the room."

Sorry FireDude but that is an incorrect statement. If you were to measure various items in the room you would discover variances in the temperatures. The ceiling will always be warmer than the floor in a forced air heating/cooling arrangement. But despite the heating/cooling arrangement, windows and doors will also display variances in temperature. This also includes a variance in temperature from say a couch’s back facing an outside wall to the face of said same couch.

You can also measure temperature change in any wall from the floor up to the ceiling. Even measure changes from the center of the room towards any wall be it the ceiling or the floor. I myself have measured as much as a 15 degree change in a single room.

You can confirm this by using either an infrared-gun or thermo-gun.


FireDude
Posted 06 January 2007 at 04:14 pm

Radiatidon said: "Sorry FireDude but that is an incorrect statement.

My bad. I didn't mean to imply that everything in a room is necessarily at the same temperature -- anyone who's lived in a drafty house would definitely know that -- but on a second reading it does kinda sound like that. I was trying to say is how cold (or hot) we perceive an item to be isn't strictly a function of it's temperature, but a function of the flux of heat out of (or into) our skin as a result of contact. A waterbed at 70 F will feel colder (initially) than regular mattress at the temperature.


plantsareamazing
Posted 10 January 2007 at 03:35 pm

I don't know if anyone else caught this but the article mentions "In order to generate all this energy, thermogenic plants use an entire alternate respiratory process, one that uses mitochondria and fats, neither of which is involved in normal plant respiration. " This is incorrect since normal plant respiration is centered in and around the mitochondria. Just a clarification. Here's a link that explains the process.

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/CellularRespiration.html


*looking interested*
Posted 23 January 2007 at 09:11 pm

hmmm....well how do they figure out that the plants in the tropical areas are warm blooded...i live in Australia which is sub-tropical and it is HOT here...so obviously there wont be ne snow....


cerealkiller
Posted 31 January 2007 at 11:17 pm

I am cold blooded. It can be 85 degrees outside and I will be freezing my ass off. Maybe I am part reptile....


DILover
Posted 05 February 2007 at 09:10 pm

It's amazing to think they have an animal-like metabolism, using fat and mitochondria. So many animals are cold blooded that to see a more primitive life form posess a more advanced qulaity is fascinating. I suppose the plant and warm-blooded animals must have evolved separately. It's very interesting to see these two organisms develop such similar metabolisms separately. Certainly DI! I'll be showing this link to all my friends!


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