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05 January 2009 @ 09:18 pm
Physics? Biology?  
Why does cold tomato juice feel colder than cold soda? Is it because it's thicker and the "cold content" of a given volume of liquid is greater?
Violet Tigress: darksideviolet_tigress1 on January 6th, 2009 02:47 am (UTC)
I think it's the pulp.
Barbrahirah on January 6th, 2009 02:57 am (UTC)
Weird tomato juju, if you ask me.
Jim Hetleyjhetley on January 6th, 2009 03:14 am (UTC)
"Specific heat" -- a measure of the amount of heat energy required to raise (or lower) the temperature of a material by a standard amount. Probably does relate to the solids content.

Or maybe it's all in your mind.
Adrian Turtleadrian_turtle on January 6th, 2009 03:57 am (UTC)
It might not be the "cold content" that makes it feel colder. When you touch 2 cold things at the same temperature, the one that chills your skin faster will *feel* colder. You aren't feeling the temperature of the thing you're touching; you're feeling your skin temperature when you touch it.

This seems terribly complicated, but most people know lots of physical examples. Are you familiar with wooden doors and metal doorknobs, outdoors in winter? The metal feels much colder to the skin, even though they are the same temperature after a winter night outside. (The metal feels hotter than the wood, after a summer day.)

Tomato pulp makes juice conduct heat a little better than water.
Carbonation makes soda conduct heat a little worse than water.
The difference is small. I would not expect the difference to be noticeable, when you take them out of the refrigerator and hold the glass in your hand. But a person could probably feel a difference in the sensation of cold liquid touching the inside of the mouth.
Xiphias Gladiusxiphias on January 6th, 2009 04:46 am (UTC)
Besides the other reasons given -- could the sensation of carbonation itself be a distraction from other sensations?

In other words, perhaps your nerves are just too busy sending you "things are a-poppin' in my mouth" messages to send you as many "things are cold" messages?
Bladerunnerbldrnrpdx on January 6th, 2009 06:27 am (UTC)
The carbonation is actually a separate, and therefore contributing, sensation. When I was interning at a ENT/Head & Neck clinic, one of the exercises the doctors would teach someone post-partial/hemi/full-on laryngectomy who was having trouble with safe swallowing was to gargle *vigorously* with something cold & carbonated. Preferably something like 7-Up or Sprite (less sugar and other assorted crap), but basically Cold & Carbonated. It provided all kinds of sensation to the areas that could still feel. It helped build up the sensory receptors that led to having a safer swallow again. The research (which was done by the doctors at this clinic) showed that the carbonation made a significant difference in how well (quickly and effectively) the patients learned to swallow safely again.
Janet Miles, CAP-OMjanetmiles on January 6th, 2009 04:24 pm (UTC)
That's fascinating! Thank you.
Bladerunnerbldrnrpdx on January 6th, 2009 06:29 am (UTC)
Are you tasting one directly after the other? Is there a significant time lapse between the two? Are you taking a drink of something warmer in between the two? (Have you put a thermometer in each to determine whether they actually *are* the same temperature or not?)

Fun science experiments to do in your own kitchen! Now you just need something to blow them up! (isn't that how all great science experiements end?)
gh4acws on January 6th, 2009 07:18 am (UTC)
the scientific fun kitchen !
blowing up:
egg in microwave
beans, potatoes, corn in microwave.

And pressure cooker. ( starting to boil over the moment one releases pressure )

red cabbage changing color with acidity ( vinegar/juice/wine/bicarbonate of soda )

and then there is fermentation : combining Physics, Chemistry and Biology

I know of cases where after inadvertent experiments the kitchen had to be repainted. ( set froze concentrated orange juice in tight, closed container on upper level of cupboard: forget for a few days: boom: repaint ceiling )

Note to self : need science icon
(Deleted comment)
Janet Miles, CAP-OMjanetmiles on November 2nd, 2011 06:24 pm (UTC)
If you don't mind my asking, how did you run across my journal and this nearly three-year-old post?