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by vikramkr6 hours ago |
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upvoteby csours6 hours ago|
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It's an interesting discussion, because if you assume access to atmospheric oxygen, gasoline is MUCH more energy dense.

    TNT.....:  4 kJ/gram and  7 MJ/liter
 
    Gasoline: 43 kJ/gram and 33 MJ/liter
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upvoteby saltcured5 hours ago|
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The previous point is fair though. What is the energy density of gasoline in a stoichiometric mixture with its oxidizer and not already detonated? That's where TNT beats it by a long shot. The mixture with any chance of being stored would be some relatively low pressure gas.

Edit: Or, a fair closed-system comparison to a battery would need to include a liquid oxygen tank or similar so you have the two components stored but can control the delivery...

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upvoteby ux2664784 hours ago|
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In the context of the conversation, it doesn't actually refute the point though, which is that explosive danger is contingent on a much broader set of relations than simple energy density. Gasoline just demonstrates the disconnect. Tacking on additional conditions to make high-density batteries dangerous is exactly what the engineering goal should be.

As a stupid example, if we have a high density battery technology that never explodes unless, say, under magnetic forces only seen being produced by magnetars, that's a pretty safe battery.

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upvoteby SV_BubbleTime3 hours ago|
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Air is usually quite available though.
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upvoteby 3 hours ago|
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upvoteby ranger_danger6 hours ago|
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That's a huge assumption that won't always be the case though. A gasoline tank with a small hole in it is a lot safer than a liquid-electrolyte battery with a hole in it.
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upvoteby csours5 hours ago|
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Yes, that's what makes it interesting.

Interesting discussions about energetics are best had from a distance.

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upvoteby K0balt4 hours ago|
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I can remember several situations where “a little bit of gasoline” caused a lot of problems. It’s a relative term. You need a lot of air to make it really shine, but “a little bit of gas” goes a long way lol.
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upvoteby 5 hours ago|
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upvoteby lightedman6 hours ago|
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"Liquid gasoline does not have anywhere near the energy of TNT,"

Energy density of gasoline is approximately 44 to 45 megajoules per kilogram.

Energy density of TNT is approximately 4.184 megajoules per kilogram.

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upvoteby leonidasrup3 hours ago|
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Gasoline, when in liquid form, is not mixed with oxygen and burns, releases energy slowly. In comparison with TNT which is both the fuel and oxidizing agent releases energy very fast, it has detonation velocity of 6,900 m/s.

https://en.wikipedia.org/wiki/Table_of_explosive_detonation_...

There is a way how to use the energy density of gasoline for explosive purposes, Thermobaric weapons.

"A fuel–air explosive (FAE) device consists of a container of fuel and two separate explosive charges. After the munition is dropped or fired, the first explosive charge bursts open the container at a predetermined height and disperses the fuel in a cloud that mixes with atmospheric oxygen (the size of the cloud varies with the size of the munition). The cloud of fuel flows around objects and into structures. The second charge then detonates the cloud and creates a massive blast wave."

https://en.wikipedia.org/wiki/Thermobaric_weapon

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upvoteby K0balt4 hours ago|
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A snickers bar has nearly 5× TNT’s energy per kilogram—TNT merely has the habit of being extremely impatient about releasing it.
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upvoteby 14 minutes ago|
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upvoteby moffkalast3 hours ago|
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I'm still surprised we haven't figured out a bioreactor you can feed your scrap food and turn it into energy, methane combustion notwithstanding. Like imagine feeding a roomba some sugar and it's set for a few days lol.
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upvoteby vitally36435 hours ago|
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upvoteby lightedman5 hours ago|
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I read it all and even what is stated is mostly wrong UNTIL THE EXACT UNIT IS SPECIFIED.

And I'd know because I have to work with this IN ORBIT. I've had this conversation a dozen times in meetings with military and government.

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upvoteby 6 hours ago|
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