Why Only Earth Has Fire 

I think the societal misconceptions with what fire actually is is very overlooked, and what it and plasma and glowing-hot liquid metals are should be more clearly covered in school

Life is older than fire. That's going on the "obscure perspective-changing facts" list.

I don't give PBS enough credit for the knowledge, inspiration and entertainment they have provided to me my entire life. The countless people who have and continued to work to build PBS into the most reliable source of educational entertainment have my thanks.

It makes so much more sense now why classical elements consider fire an element. I wonder what kind of such "elements" exist out in the universe that we don't even know exist.

Uncle Iroh was right, fire really is the breath of life.

The fact that water, fire and life are so interconnected and reliant upon each other to exist on this planet feels poetic in a way. Water creates life, life creates fire, fire consumes life, water douses fire, life is reborn from the ashes of the old.

The older I get, the less common it is to come across something that truly teaches me something new. This video accomplished it. Thank you.

This is a great point. Fire needs reactive oxidiser and reactive fuel. (Pedantic nitpick: despite the name oxygen is not the only nor the most powerful oxidiser.) The problem is that reactive things, well, react and so they are never naturally available in large not yet reacted quantities. Life is the exception in that it reverses that process, it uses energy to turn less reactive compounds into more reactive ones (endothermic chemical reactions) so that it can use them as building blocks or react them back together to get the stored energy back. Photosynthesis is a pump that takes energy from the Sun's light to perform these reactions, transforming that light energy into usable chemical energy. When aerobic life burns sugar with oxygen to use that energy, the term "burns" is pretty literal. As a side effect, the surplus oxygen and unburnt fuel can result in plain old fire. Although, it might be possible for fire to exist without life. There are endothermic reactions that can occur due to heat without any organic help, so there might be planets where extreme solar radiation or internal heat affect naturally occurring compounds and result in endothermic reactions that produce oxidiser+fuel, which then burn back together, completing a cycle.

Sometimes a video tells me stuff I already knew, but recontextualizes it in a way that makes it feel brand new. This is one such video.

"Damn, this planet is fire"

As a degreed and professional forester. Thank you for this! I wish more people would fully understand this!

Why only Uranus has Gas

I've always wondered how grasslands could be the dominant biome for an area without it getting taken over by trees. This makes so much sense. I already kind of knew this, I live in an area where land burning is a seasonal phenomenon land owners do (its in a controlled setting) but I really didn't know why. And I had no clue this was an evolved adaptation to benefit the grass. Evolution is crazy and I feel like we as laymen humans forget about the plants but they do some cool stuff.

I haven't thought about this before. Goes to show you you never stop learning

This is something we are missing in modern forest management that has been a contributing factor to the intense wildfire burns we are seeing!!! It's just one piece of the puzzle of course, but the importance of regenerative burning cannot be overstated!

I really liked this one. It is obvious in retrospect that you can't have fire without life or some other ongoing process, given that chemicals that can vigorously react (burn) on geological time will find each other and react until something is completely consumed (the rusting of the Earth's crust is evidence of that); however, until someone mentions it, you don't really think about it. In other words, I liked this episode because it made me look at what I thought I knew differently.

Earth: Creates Giant Insects: Also Earth: Creates fire to deal with said giant insects.

I don't know why but watching this video makes me long to see the days before I ever existed. Not to experience or go through it, but just to observe it and just wonder and wander more.

It may not be very scientific, but I've always liked thinking of fire as an abstract form of life. So it's super interesting to learn that fire wasn't always around, and needed a specific set of circumstances to "evolve" so to speak. Really neat episode, I learned a lot!

"Fire can't exist without life" 🤯 Wow, that is something to think about. I have had thoughts about fire as a form of life recently, but I have never though fire is dependent on life. It is like we could place fire somewhere in the phylogenetic tree! Heraclitus is the best!

Those fire storms of the Carboniferous would have been a terrifying sight to behold.

2:29 i like it when the hosts enjoy the scripts that they write. gives everyone a bit more voice. Wood is rarer in this universe than Diamond, because only Earth has wood.

This is one of y'all's best videos of all time imo. Wow

But then the fire planet attacked.

This makes me wonder what other kind of things are possible on other planets. If fire is unique to our earth like conditions, what about other things? The universe is constantly amazing.

I would love to see an episode about lichens: their evolution, when the symbiont relation may have appeared, if they have made genetic studies and if they have learned something from them. I always had the idea that lichens have much to say about the emergence of life on land.

This is lowkey an anthropologist answer to religious fire and early religions too. Fire made humanity and culture as it is today from the very start. Its importance is woven into most mythologies, for better and for worse.

Fire is a chemical reaction and life is a chemical reaction.

This is one of your best presentations. Never actually thought about fire as discussed here. Very informative. Thx.

Wow, I'd never considered the fact that fire wouldn't exist without something carbon-based to burn. Thanks for expanding my horizons and helping me to reframe my understanding!

Wow. What an episode. I’m mid sixties. Why did I not know this?

I’ve watched a lot of these PBS Eons videos, and this has got to be one of the most interesting ones yet. Well done 👏 👏 👏

Wow. This episode explained one of the longest interconnected chain of events ever.

Considering Fire's role in human societies, this might also be a small step towards the Fermi Paradox

Pretty neat! I hadn’t ever really thought about this even though in hindsight, it seems very logical and obvious. Reminds me a lot of Avatar: The Last Airbender and how Firebending is actually the element of life - not destruction. Without controlled burnings of grasslands and the death of old, decaying plants, new life would never have the chance to flourish.

This was an original and interesting angle! Great job.

plants that are fire resistant are usually also more tolerant to poor nutrient deficient soils as well

Of course! Rocks can't burn. Only things that have lived can burn. It makes so much sense. Why didn't I think of that. I love your vids. I love learning this stuff. Thanks.

This was miles more interesting of a video than I thought it’d be

I love this. Not only is it interesting for children to learn about, it appealed to me and I'm 70!! Puts a whole new spin on fire; something we take for granted on our planet.

Gosh, I feel like my mental concept of fire is stuck in the medieval era! The fact that both decomposing organisms AND fire didn't exist since the dawn of life and came about far later just blows my mind!

New criteria in the search for earth-like exoplanets: signs of fire.. Edit - I correctly guessed Dimetrodon

This makes me wonder about life out there in space. Like, if their species couldn't invent fire, what could they do instead?

I didn’t expect this video to heighten my appreciation for fire and grass to this height.

I can't believe I'm learning this in my mid-forties. This should be middle school basic science knowledge 🤔

Fire simply needs fuel and oxygen, so as soon as there was a sufficient concentration in the atmosphere, it was a thing. I was a coal miner. Seams commonly have very thin 'soot' bands (actually crushed charcoal) in them where the forests burnt around 350M years ago. Unsurprising that it goes back much further.

I live in Kansas, and this is exactly why we do controlled burns of our fields and grasslands every year. The Flint Hills are my favorite. In winter all the grasses die, in the spring, we do controlled burns, and by later spring, early summer, they are the most beautiful green hills. Kansas doesn't have a lot going for it, but driving through the Flint Hills in late spring/early summer is definitely something to see. You can truly imagine native peoples living alongside the massive herds of buffalo, or imagine people traversing the seemingly neverending prarie in covered wagons.

may be biased, but this is one of the best eons videos yet! thanks for sharing the important and ancient relationship of life on earth with fire!

Nowadays iron contained in vehicles still absorbs oxygen. We call the product of this process "a beater car".

The opening bit about the sun being mostly hydrogen reminded me of this quote: "Several billion trillion tons of superhot exploding hydrogen nuclei rose slowly above the horizon and managed to look small, cold and slightly damp.” -Douglas Adams, Life, The Universe and Everything.

Thanks for such a great video. Love the idea that fire replenishes and nourishes life, especially at this cold time of year. It’s so interesting what fire does in our ecosystems.

Loving the new trivia ending to the videos!

I'd not really thought about this before. This is truly amazing. 🔥

Pretty cool. Makes sense why more ancient traditions view fire as life-giving.

I’ve been wondering my whole life why areas looking so dry and dead like this managed to sustain so many lives! Thanks Eons 😊🎉

Great episode! The story of how our atmosphere became partly oxygen is a fascinating story, requiring research from many fields, including geology, meteorology, paleontology, and biology. An absolutely great book that covers all of these is "Oxygen: the Molecule that Made the World", by Dr. Nick Lane, (professor of evolutionary biochemistry at University College London, director of UCL's Centre for Life's Origins and Evolution ....in fact, I highly recommend ALL of his books.) It is an incredibly thorough and engaging read and remarkably still up to date, even though it was published in 2002. :)

Well darn, I thought we only had fire because of Prometheus.

Damn, just opened RU-vid and new video

Oh my! Kelly, everytime you manage how to amaze me. Thank you all so much guys at EONS!

"Nucular" --- I died ☠

I think these are the type of things we should think of when answering questions like “could the non avian dinosaurs survive today” or any long ago population. Grasslands wasn’t even common 65 million years ago.

This episode is straight fire.

Wonderful video. So interesting! Thanks so much.

Great vid! I've never thought of that.

Given I live on a continent synonymous with fire, the lack of mention of the Eucalyptus family of flowering plants is bemusing.

What about chlorate reactions like in an oxygen candle? Isn't it possible to have combustion with the absence of Oxygen? Other types of combustion exist as well, like fluorine. Also magnesium/teflon/biton compositions burn without oxygen. Other halogens, such as bromine and iodine, can also act as oxidizing agents.

Thank you very much for this video. I often wondered on other planets if there were other natural processes that happened that couldn't happen here. Maybe like fog that was made out of acid or different types of natural phenomenon that we simply just couldn't imagine and I don't mean like raining glass or anything like that

I love learning. Thank you everyone at PBS. ☮

Fire needs an Oxidiser, it doesn’t have to be dioxygen, its just the easiest component and makes fire so common, here on Earth. Fire can exist without life, it would just be much rarer in the absence of life, not completely absent.

Even today we use fire to reseed the biosphere. Some examples that are at home for me is at Oak Openings in Toledo OH. It's an Oak Savanah and also where I currently live in Yamaguchi Japan. Akiyoshidai, a Karst plateau, both places use fire as a means to promote healthy growth.

In Australia the eucalyptus trees have oil in their leaves, not only is it toxic but it also makes them highly flammable. Many species have stringy bark which hangs down from the branches and is essentially ideal kindling. The trees go to all this effort to be flammable as a reproductive strategy as many species have seed pods that are highly resistant to fire but also are activated by fire

Came for the lesson on fire, but stood for the lesson on plants

You did it again: the title is enough to make me drop everything I'm doing cause now I HAVE to know 😅

Earth not only has fire, but also wind. Mainly in September ♬

"Maize: You call it corn" 😂 Seriously, it's ok to call it corn.

In the Age of Ancients the world was unformed, shrouded by fog. A land of gray crags, Archtrees and Everlasting Dragons. But then there was Fire and with fire came disparity. Heat and cold, life and death, and of course, light and dark. Then from the dark, They came, and found the Souls of Lords within the flame.

We can thank Prometheus for the gift of fire

This intro is missing Lindsey Nikole's "THAT WE KNOW OF" XD

I often think of fire poetically as sunlight, trapped within plants, to be re-released into the Universe again anywhere from months to millions of years later

This is so fascinating! I love PBS.

I've always wondered how a planet with so much oxygen back then never got it self set on fire. It really was on fire. This topic is Lit.

An overview of the evolution of plants would be a useful episode.

This is quite fascinating. I'm not exactly a scientist (which is a big reason I'm here-- to learn), but I'd actually never thought of this.

man, this episode is 🔥 (jokes aside...I now understand why it's called the CARBONiferous period!)

Never would have realized this. Love the show!

This is my new favourite eons video!

Well, this is not the place I expected to hear 'nuclear' get mispronounced.

I kind of knew fire had a archeological record But it was only up to humans discovering and using fire Maybe a bit of the dinosaur's extinction But damn I did not know if first appeared when life appeared or when plants appeared That's insane This channel always has many surprises instored

i feel like there’s gotta be planets with oxygen on them, even without life….

Excellent video. The only thing I would have said differently is "Earth is the only planet in our solar system that has fire." We don't know if any of the exoplanets (in other star systems) throughout the universe have fire.

imagine what the first fire on earth looked like. Probably a tiny, tiny flame that went out in a second.

This was so interesting, made me think of fire in a different way. I especially loved the analysis of the grassland biome, this is a useful vid for the NoLawns community. This made me wonder about the evolution of other biomes and plant communities. Cloud forests? Alpine grasslands? Temperate rainforests? Steppe?

So is it not actually fire if a different oxidizer causes something to combust?

This was the most beautiful video ever that came from this channel.

Earth is the only planet in our solar system where it rains liquid water.

Can you continue this video by talking about trees that only spread seed when submited to fire?

This gives the song "Fire in the sky" (American Space Age Anthem) a whole new meaning

Has the author visited every planet in the universe to come up with that conclusion

i understand now why fire is not only synonymous with death but also rebirth. poetic in a way.

Life emerged and existed peacefully for over a billion years. But then everything changed when the Fire Nation attacked.