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What State of Matter is Fire

2021-12-17 · explainer · Hank · 4:00 · watch on YouTube

Topic: Science & nature · mode: Explainer · tags: self promotion, calendar ritual

Hank tackles a question that seems easy but is not, what state of matter fire is: like a waterfall, fire is not matter but a process, and its reacting molecules, glowing soot and excited gas fit no single state; he closes by plugging the new Project for Awesome calendar.

What is said

The parts of the video and what is said in each (★ — how much it matters to the video).

00:00:00 — The two kinds of science questions Hank dislikes; this one is the most common

  • ★★ Hank says he has talked about science professionally for years and loves almost every question, but dislikes two kinds: ones he has answered many times, and ones that seem easy but are not. — 00:00:00
  • ★★ Hank says no question that seems easy but is not is more common than what state of matter fire is. — 00:00:00

00:00:29 — Why fire is hard: states of matter by their qualities, the waterfall as a process, molecules mid-reaction

  • ★★ Hank says asking Google the question gets you all wrong answers, because the answer is very far from simple. — 00:00:29 · Google
  • ★★ Hank says matter mostly exists in a few discrete states because of how atoms and molecules interact, but people remember the states by their qualities: a solid keeps its shape, a liquid its volume. — 00:00:29
  • ★★ Hank says none of those qualities of solids, liquids and gases holds true for fire. — 00:00:58
  • ★★★ Hank answers with a question: a waterfall has no state of matter because it is a process, not matter, though one can label its rock, water and air. — 00:00:58
  • ★★★ Hank says fire is harder than a waterfall because its molecules are undergoing rapid chemical reactions and, while reacting, have no state of matter. — 00:01:41

00:02:10 — The spoon and soot demonstration, glowing soot and the blue gas part of a flame

  • ★★ Hank pauses the reaction by passing a spoon through his candle flame and gets soot, which is why many people say fire is a solid. — 00:02:10
  • ★★ Hank explains that in a candle flame wax evaporates and combusts, forming many chemicals that become tiny particles glowing with their own heat while they react. — 00:02:10
  • ★★ Hank says most of the visible fire is solid soot glowing, but the blue part of the flame is excited gas atoms emitting light. — 00:02:50
  • ★★ Hank says so many reactions happen so fast in combustion that much of the matter in a flame, mid-reaction, does not behave as we think matter behaves. — 00:02:50

00:03:20 — Fire is a process, not matter; flubbed sign-off; the new Project for Awesome calendar

  • ★★★ Hank's simpler answer: fire has no state of matter because fire is not matter; it is a process. — 00:03:20

    “Fire does not have a state of matter because fire is not matter.”

  • ★★ Hank says this year's (2021) Project for Awesome calendar is available, released before the P4A so people can have it, celebrating Nerdfighteria's history with images from different eras. — 00:03:20 · Project for Awesome, Nerdfighteria

  • ★★ Hank says the matter in a flame mid-reaction is not really any state of matter, and maybe we will understand it better someday; it is a place where the usual hard lines between things break down. (hedged) — 00:03:20

In the description and comments

  • ★ The description says the question has been bugging Hank for about 20 years and still bugs him. — video description
  • ★★ The description recommends other YouTube videos on the question: It's OK to be Smart's (his favourite), a very short MinutePhysics one, and a TED-Ed video arguing fire is a process, not matter. — video description
  • ★★ The description notes Veritasium says fire is plasma; Hank does not think so, though fire clearly contains many ions from intermediate reaction species with no set state. — video description

Threads in this video

Where the stories that moved here went next

Mentioned

Central: fire · state of matter · waterfall

Also: chemical change · combustion · Google · Project for Awesome · Project for Awesome calendar · soot

Only in the description or credits: Derek Muller · Henry Reich · ion · It's Okay to Be Smart · plasma · TED-Ed

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