You Can Hear The Difference Between Hot and Cold Water

Tom Scott

6 Mar 201702:37

Summary

TLDRIn this video, the host introduces a guest presenter, Steve Mould, who reveals an intriguing superpower many people possess: the ability to hear temperature. Steve demonstrates this by pouring hot and cold water from identical jugs into mugs, asking viewers to guess which is which based on sound alone. He explains that the difference in sound is due to changes in water viscosity when heated. This concept, though intuitive from everyday experiences, is fascinating when understood scientifically. Viewers are encouraged to check out Steve's channel for more intriguing content.

Takeaways

🎥 The speaker is taking a month off, with guest videos from various YouTube creators.
👨‍🔬 Steve Mould, a science presenter, is the first guest to present a video.
❓ Steve's video explores a unique concept: the ability to hear temperature.
🔊 People can differentiate between hot and cold water just by the sound of it being poured.
👁 The screen is blurred in the experiment to avoid any visual cues influencing the guess.
💧 The first pour was cold water, and the second pour was hot water.
⚗️ The difference in sound is due to water's viscosity, which decreases when it's heated.
🍯 This is easier to observe in thicker liquids like honey, where warm honey is more fluid than cold.
💡 The sound difference is subtle with water, but it still affects how it splashes and the noise it makes.
🧠 People intuitively know this difference from years of experience with hot and cold drinks, even if they aren't consciously aware of it.

Q & A

What is the main topic of the video presented by Steve Mould?
-The main topic is the ability of humans to distinguish between hot and cold water by the sound it makes when poured.
What experiment does Steve Mould perform in the video?
-Steve Mould pours hot and cold water from identical jugs into identical mugs and asks the audience to identify which is which based solely on the sound.
Why does the video screen blur during the experiment?
-The screen blurs to prevent viewers from using visual cues to identify which water is hot and which is cold, allowing them to focus only on the sound.
What is the correct answer to the experiment?
-The first pour was cold water, and the second pour was hot water.
Why do hot and cold water sound different when poured?
-The difference in sound is due to the viscosity of the water. Water's viscosity decreases when heated, affecting the way it splashes and the sound it produces.
How is the change in water viscosity explained in the video?
-Steve Mould explains that when water is heated, its viscosity decreases, making it less 'thick.' This is more apparent with substances like honey, which becomes runnier when heated.
Why is this knowledge considered intuitive?
-Most people have learned to associate the sound of pouring hot and cold liquids through a lifetime of experience, even if they weren't consciously aware of this ability.
What is an example of another liquid where viscosity changes are more visible?
-Honey is given as an example. Warm honey is more runny than cold honey, making the change in viscosity easier to observe compared to water.
What other content does the host recommend on Steve Mould’s channel?
-The host recommends Steve Mould's video on a 'self-pouring liquid' as a good place to start.
What can viewers expect in the next video after this one?
-The next video will discuss 'the tale of an engineering disaster.'

Outlines

00:00

😊 Announcement of a Guest Series

The speaker announces they are taking a month off and during this period, five other YouTube creators will provide guest videos. The first guest, Steve Mould, is introduced with excitement. Although initially skeptical about the video’s topic, the speaker admits they were proven wrong and urges viewers to be kind. Steve is handed over to take the lead on the upcoming content.

🎧 You Can Hear Temperature

Steve Mould introduces a fascinating concept: humans can distinguish between hot and cold water by sound alone. He plans to demonstrate this by pouring hot and cold water from identical jugs into identical mugs while blurring the screen to remove visual cues. Viewers are invited to guess which is which based solely on the sound.

🌡️ The Answer: Cold and Hot Water Sounds

Steve reveals that the first pour was cold water and the second was hot water. The reason they sound different is due to water's viscosity—how thick or thin it is—which decreases as it gets warmer. This difference affects the way water splashes, and therefore the sound it makes when poured.

🍯 Viscosity and Fluid Dynamics

Steve explains how viscosity works using the example of honey, which is visibly more fluid when warm. Though this change is less obvious with water, the difference in viscosity when pouring water changes the sound due to complex fluid dynamics. He emphasizes that this is something people intuitively understand from everyday life experiences.

👍 Subscribe for More Science!

Steve wraps up by encouraging viewers to subscribe to his channel and recommends his video on a self-pouring liquid as a good starting point. The speaker returns, teasing an upcoming video about an engineering disaster to continue the series.

Mindmap

Keywords

💡Super power

In this context, 'super power' refers to an innate human ability that people may not realize they possess. The video suggests that people can 'hear' temperature by distinguishing between the sounds of hot and cold water, a skill developed unconsciously over time. This 'super power' is a metaphor for how we intuitively pick up information from our surroundings without being fully aware of it.

💡Viscosity

Viscosity is a measure of a fluid's resistance to flow. In the video, it explains that water's viscosity decreases as it heats up, making it flow more easily. The difference in viscosity between hot and cold water changes how each sounds when poured, which ties into the central idea that the sound of water can reveal its temperature.

💡Fluid dynamics

Fluid dynamics refers to the study of how liquids behave when they're in motion. In the video, it’s mentioned in relation to how the changes in water’s viscosity alter the way it splashes and creates sound when poured. This concept helps explain the scientific reasoning behind why hot and cold water sound different.

💡Intuition

Intuition in the video refers to a kind of unconscious knowledge developed over time through experience. The audience is told that they already know the difference between the sound of hot and cold water due to their intuitive understanding of subtle environmental cues, even though they may not be consciously aware of this ability.

💡Sound cues

Sound cues refer to the auditory signals that provide information about an object or action. In this case, the different sounds produced by hot and cold water when poured serve as cues for the temperature of the liquid. The video emphasizes that people can often make these distinctions based solely on sound.

💡Science of hearing

The science of hearing in the video highlights how the human auditory system can detect subtle differences in sound, like the ones produced by hot and cold water. It connects to the theme that everyday sounds carry more information than we consciously realize, illustrating how our hearing plays a role in perceiving the world.

💡Temperature

Temperature is a central theme in the video, specifically how it affects the physical properties of water, such as viscosity, and how these changes can be detected through sound. The audience is challenged to identify which water is hot and which is cold, demonstrating that temperature can be 'heard' in everyday situations.

💡Experience-based learning

Experience-based learning refers to the concept that knowledge and skills are acquired over time through direct interaction with the world. The video emphasizes that people have learned to distinguish between the sounds of hot and cold water simply by experiencing it repeatedly throughout their lives, without formal education on the subject.

💡Honey

Honey is used in the video as an example to explain viscosity. The video notes that cold honey is thicker and flows more slowly than warm honey, making the change in viscosity more obvious. This example helps clarify the concept of how temperature affects the viscosity of liquids, including water.

💡Guest presenter

A guest presenter refers to someone invited to present or host content on someone else’s platform. In this video, Steve Mould is the guest presenter, delivering the content about the ability to hear temperature. This highlights the collaborative nature of the video and brings attention to different YouTube creators contributing guest videos.

Highlights

The video introduces the concept of how humans can discern the temperature of water using sound.

The speaker explains that viscosity, or the thickness of water, decreases when it is heated.

A demonstration is conducted where viewers must guess whether the water is hot or cold based on the sound of pouring.

The screen is blurred during the test to prevent visual cues from influencing the audience's guesses.

The first pour in the demonstration was cold water, and the second was hot.

The difference in sound is due to the effect viscosity has on how water splashes.

Viscosity is more easily observed in substances like honey, where warm honey is runnier than cold honey.

Water’s viscosity change is less visually apparent but still affects the sound of pouring.

The change in splashing and sound is influenced by fluid dynamics, making the sound of hot and cold water different.

This phenomenon is something people know intuitively, even if they aren’t consciously aware of it.

The speaker invites viewers to leave a comment with their guess on which water was hot or cold.

The video encourages viewers to subscribe to Steve Mould’s YouTube channel.

The presenter recommends a video on a self-pouring liquid as a good follow-up to watch.

The video introduces an everyday science concept that people experience but may not think about consciously.

The upcoming video on the channel will discuss an engineering disaster.