How Do We Tell Temperature?

This week Reactions takes a look at the science behind how we tell temperature. There's a lot of chemistry that goes into thermometers. We have a lot of confidence that we measure temperature accurately. But how do thermometers in the kitchen or doctor’s office work? Thanks to the laws of thermodynamics, thermometers respond to heat moving from hot to cold as a means of measuring temperature. Clever physical chemists and engineers have taken temperature tools from the simple, but still useful, lined glass thermometers to digital readouts. And you might be surprised to find out how Einstein took thermometers the distance.

Find us on all these places:

JD Pigs

Producer:
Elaine Seward

Writer:
Darcy Gentleman, Ph.D.
Judith Lavelle

Executive Producer:
Adam Dylewski

Scientific consultants:
Dawn Cross
Darcy Gentleman, Ph.D.
Kyle Nackers

Sources:
Fever Guidelines

EPA - Mercury in your thermometer
EPA - Mercury - Health Effects
NIST - phasing out mercury thermometer calibration

Galilean Thermometer not so Galilean (interesting, but also corroborates the event of Galileo’s invention of the thermoscope around the start of the 17th century)

Bimetallic thermometers

thermocouples [deleted content]

thermistors

IR semiconductor sensors

IR planet measurement

“Experiments in Physical Chemistry”, 6th edition. David P. Shoemaker, Carl W. Garland, Joseph W. Nibler. McGraw-Hill, 1996.
Chapter 18 “Temperature” and Chapter 19 “Instruments”

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Reactions is produced by the American Chemical Society.

[churchofclaus]

When I was in 5th grade my teacher asked us what the properties of the element mercury. I said that it expands when it's heat, as I was always told thermometers has mercury in them. She gave me a weird look and said "no it doesnt". I assumed I just misunderstood how a thermometer works. This video confirmed I was correct all those years ago.

[blackheadization]

Last week in the lab we tried to get water to it"s triple point. It was very cool to see all 3 phases at once

[MrMysticphantom]

You know.... I think you should make fun videos like this on many of the key concepts in Chemistry 1, 2 and Organic Chemistry

if people learned them for fun beforehand or outside of class.. they might dread them less, and also, actually earn them, rather than feel anxiety about them and not learn about the concept

[powerpuffherk]

What I wonder about is shade/ light and reflection. Also the energy added to a system. As far as i understand temperature is measured in the shade according to some standard rules and definitions. Within an area the temperature may vary due to surface, plant/ tree growth, many factors. So when the newsperson or weatherstation tells us the temperature, how does that work? And how do satellites do this?

[arvo-noon]

Hello, my teacher made me watch this.

[fireyoyos]

i'd love a video about triple point, i asked my chem teacher about it but he said that he flunked thermodynamics 3 times in a row in college haha

[lolpeachy]

my virtual teacher made me watch this .-.

[yes-kgnv]

I love how most of the people here are from their teachers 😂
(also I’m one of them)

[Jab_hutt]

As far as I know (I'm not medical professional), 40c does not necessarily means you need to go to ER. I had it more than once in my life. My little children had it too, but it depends on all other symptoms (or lack of those). Amiright or notatall?

[soniaaliahmad]

when heat moves from environment to thermometer then temperature of environment decreases and thermometer never gives the actual temperature of environment .How we say thermometer gives true temperature of environment ?

[SilentSnipest]

Heat can be created and destroyed, though. It just has to be converted to or from some other form of energy. Is this correct?

[suzanalkhatib]

temperature increase causes the fluid to expand can be determined by measuring the volume of the fluid it can be really hot and the person can feel it if it`s really hot

[eurosenelsuelo]

It would b interesting to know about PVT relation and its graph

[sebastiangardemeister]

Whenever i get a fever of a 41 celsius degrees i have never gone to a hospital. Ps im Swedish

[bryangodinho]

A quick Historical note- Nowadays, thermometers use ethanol instead of mercury.

[dronieguy]

POV: ur in my science lesson and are scrolling through the comments

[CharlieW]

Is it just me or did your teacher tell you to watch this

[gk]

What's the temperature for ovulation

[Thwapwhacket]

Interesting choice for a Star Trek clip, "Skin of Evil" where Tasha Yar (Denise Crosby) is murdered.

[y__h]

4:35 Half of the world under Russian control. Illuminati confirmed.