# So what's the difference between 10,000 tonnes of TNT and a 10 kiloton nuke?
**URL:** https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800
**Category:** Factual Questions
**Created:** [July 29, 2019, 5:49am UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800 "2019-07-29T05:49:59Z")
**Posts on this page:** 14
**Page:** 1
### Author:  [@Rayks\_Marcial](https://boards.straightdope.com/u/Rayks_Marcial)
#### Post date: [July 29, 2019, 5:49am UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/1 "2019-07-29T05:49:59Z")
Just the radiant and blast effects, ok? Let’s assume both explode just a few hundred meters above ground. Also assume there’s a reliable way to detonate 10,000 tonnes of TNT uniformly.
Will the nuke be deadlier to humans because of the heat generated? Who will have a more powerful blast wave? Actually part of this has been answered by the Halifax explosion (estimated at 2.9 kilotons force), and that Texas Harbor accident in 1947 involving 2,000 tonnes of ammonium nitrate.
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### Author:  [@Velocity](https://boards.straightdope.com/u/Velocity)
#### Post date: [July 29, 2019, 6:28am UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/2 "2019-07-29T06:28:52Z")
One difference that comes to mind is the relative brightness - supposedly, you can easily go permanently blind by looking at the fireball of a nuke that detonated, whereas I don’t think there is any light-brightness hazard with looking at a TNT explosion.
As for the heat, I believe it is the X-rays heating up air as it passes through the air and is absorbed? So I would guess that the nuke would also fry/kill people a split-second faster than the TNT.
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### Author:  [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)
#### Post date: [July 29, 2019, 10:51am UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/3 "2019-07-29T10:51:22Z")
> **[TNT equivalent | Historical derivation of the value](https://en.wikipedia.org/wiki/TNT_equivalent#Historical_derivation_of_the_value)**
>
> Alternative values for TNT equivalency can be calculated according to which property is being compared and when in the two detonation processes the values are measured.
> Where for example the comparison is by energy yield, an explosive's energy is normally expressed for chemical purposes as the thermodynamic work produced by its detonation. For TNT this has been accurately measured as 4,686 J/g from a large sample of air blast experiments, and theoretically calculated to be 4,853 J/g.
> However ev...
> [@Wikipedia](#):
>
> So, one can state that a nuclear bomb has a yield of 15 kt (63×1012 or 6.3×1013 J); but an actual explosion of a 15 000 ton pile of TNT may yield (for example) 8×1013 J due to additional carbon/hydrocarbon oxidation not present with small open-air charges.
TL,DR: 15 kt of TNT may give you a somewhat bigger bang than a 15-kt nuke.
There’s also this note related to [Operation Sailor hat](https://en.wikipedia.org/wiki/Operation_Sailor_Hat), a test that detonated 500 tons of conventional explosive to test ships’ resistance to nuclear blast effects:
> [@Wikipedia](#):
>
> Each “Sailor Hat” test at Kahoʻolawe consisted of a dome-stacked 500-short-ton (454 t) charge of TNT high explosive detonated on the shore close to the ships under test. However, since a TNT detonation releases energy more slowly than a nuclear explosion, the blast effect was equivalent to a 1 kiloton of TNT (4.2 TJ) nuclear weapon.
the kt standard is based on mechanical work done by the device on its surroundings - that is, it’s entirely related to blast effects. A nuclear bomb creates its blast effect by radiation being absorbed by the air around the bomb, which implies that any radiant energy that’s not incorporated into the resulting mechanical blast wave wouldn’t be part of that kiloton rating. Given that radiative effects can cause significant thermal damage to the target area, it would seem that a nuclear bomb has considerably more radiant effects than a conventional explosion of equivalent kt rating.
[This video](https://www.youtube.com/watch?v=ztJXZjIp8OA) of a nuclear test clearly shows the radiant effects of the detonation, creating rapid charring of target objects shortly before the blast wave arrives. As with every nuclear test clip I’ve seen, the camera exposure gets drastically reduced for many seconds after detonation so as to not overexpose the film. This is an important clue about the extreme radiant intensity of a nuclear detonation.
OTOH, [this clip of the Operation Sailor Hat test](https://www.youtube.com/watch?v=go4NO8v7Goc) remains at a constant exposure level throughout the blast footage; there is a brief instant at the moment of detonation when the brightness overwhelms the film, but it’s over in a frame or two, just as soon as the gases created by the detonation can expand and cool.
There was also [Minor Scale,](https://en.wikipedia.org/wiki/Minor_Scale) in which 4 kilotons of TNT was detonated in a single explosion. I’ve never found any video of the event, but [the still shot recorded in the microseconds after detonation is telling](https://upload.wikimedia.org/wikipedia/commons/9/9f/Minor_Scale_test_explosion.jpg): It’s a bright fireball alright (and a big one - note the F-4 parked in the foreground), but the sky around it is blue - indicating that the camera’s exposure hasn’t been reduced. IOW, not so much radiant energy as a nuclear blast of comparable size.
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### Author:  [@Gray\_Ghost](https://boards.straightdope.com/u/Gray_Ghost)
#### Post date: [July 29, 2019, 12:17pm UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/4 "2019-07-29T12:17:38Z")
Broader spectrum of radiation from the nuke as well. As you’d think when talking about X-rays emitted by the device, and Feynman’s observing the Trinity explosion without goggles, but behind automobile glass, and still retaining his vision.
Is the radiation from a nuclear explosion, in a vacuum, basically a pure black body at how ever many tens of million Kelvin? Which then couples with atmosphere to produce the rest of the radiation emitted by the fireball?
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### Author:  [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)
#### Post date: [July 29, 2019, 1:46pm UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/5 "2019-07-29T13:46:54Z")
> [@Velocity](#):
>
> One difference that comes to mind is the relative brightness - supposedly, you can easily go permanently blind by looking at the fireball of a nuke that detonated…
Blindness from looking at a nuclear blast is a very real thing. That’s why some military pilots wear [nuclear flash protection goggles](http://www.flightgear.dk/flash.htm).
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [July 29, 2019, 2:35pm UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/6 "2019-07-29T14:35:53Z")
Both will release the same amount of heat. Unless you’re doing something very careful to control it, all energy ends up as heat. And explosions are not noted for being very carefully controlled.
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### Author:  [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)
#### Post date: [July 29, 2019, 2:44pm UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/7 "2019-07-29T14:44:04Z")
> [@Chronos](#):
>
> Both will release the same amount of heat.
Not true. The kiloton standard is based on blast effects. A 10kt nuke will have blast effects approximately on par with a 10kt TNT detonation, but the nuke will also put out a lot of heat. See the video I linked to upthread, showing nuclear targets being charred by radiative heating in the moments before the blast wave arrives.
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [July 29, 2019, 7:25pm UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/8 "2019-07-29T19:25:14Z")
I thought the standard was based on the amount of energy released? Certainly, one can find conversions between kilotons and joules.
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### Author:  [@scr4](https://boards.straightdope.com/u/scr4)
#### Post date: [July 29, 2019, 7:34pm UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/9 "2019-07-29T19:34:03Z")
> [@Machine\_Elf](#):
>
> Not true. The kiloton standard is based on blast effects. A 10kt nuke will have blast effects approximately on par with a 10kt TNT detonation, but the nuke will also put out a lot of heat. See the video I linked to upthread, showing nuclear targets being charred by radiative heating in the moments before the blast wave arrives.
[TNT equivalent](https://en.wikipedia.org/wiki/TNT_equivalent) is a unit of energy, not any specific effect.
But that same wikipedia page talks about [relative effectiveness factor (RE factor)](https://en.wikipedia.org/wiki/TNT_equivalent#Relative_effectiveness_factor), and says the RE factor of a fission bomb is about 50,000. Which means the demolition power of a 10 kiloton nuclear bomb is 50,000 greater than 10,000 tons of TNT.
As for heat, target being charred by the explosion doesn’t necessarily indicate greater heat being generated. The same amount of heat being used to heat a smaller amount of matter will lead to a hotter temperature and greater radiative heating of the target.
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [July 29, 2019, 7:45pm UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/10 "2019-07-29T19:45:52Z")
> [@scr4](#):
>
> [TNT equivalent](https://en.wikipedia.org/wiki/TNT_equivalent) is a unit of energy, not any specific effect.
>
> But that same wikipedia page talks about [relative effectiveness factor (RE factor)](https://en.wikipedia.org/wiki/TNT_equivalent#Relative_effectiveness_factor), and says the RE factor of a fission bomb is about 50,000. Which means the demolition power of a 10 kiloton nuclear bomb is 50,000 greater than 10,000 tons of TNT.
>
> As for heat, target being charred by the explosion doesn’t necessarily indicate greater heat being generated. The same amount of heat being used to heat a smaller amount of matter will lead to a hotter temperature and greater radiative heating of the target.
That R.E. rating is inconsistent.
The R.E. rating for non-conventional explosives appears to be just energy/bomb mass. That’s what is giving those enormous numbers.
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### Author:  [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)
#### Post date: [July 29, 2019, 8:16pm UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/11 "2019-07-29T20:16:31Z")
> [@scr4](#):
>
> [TNT equivalent](https://en.wikipedia.org/wiki/TNT_equivalent) is a unit of energy, not any specific effect.
It is the energy delivered into a very specific effect, namely the mechanical work produced by the detonation, as clearly stated on the Wikipedia page you linked to:
> [@Wikipedia page on the TNT Equivalent](#):
>
> Where for example the comparison is by energy yield, an explosive’s energy is normally expressed for chemical purposes as the thermodynamic work produced by its detonation.
By definition, any thermal energy released that is _not_ converted to mechanical work is not considered in the kt rating of a bomb.
> [@scr4](#):
>
> But that same wikipedia page talks about [relative effectiveness factor (RE factor)](https://en.wikipedia.org/wiki/TNT_equivalent#Relative_effectiveness_factor), and says the RE factor of a fission bomb is about 50,000. Which means the demolition power of a 10 kiloton nuclear bomb is 50,000 greater than 10,000 tons of TNT.
**Beowulff’s** got it: the 50,000 RE figure means that if you built a nuclear bomb big enough to _actually weigh 10,000 tons,_ it would deliver 50,000 times as much blast work as a 10,000-ton TNT bomb.
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [July 29, 2019, 8:17pm UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/12 "2019-07-29T20:17:38Z")
Actually, I just realized it might be consistent. But, it’s just a measure of explosive power vs explosive mass. So an A-bomb has 50k Times the explosive power of the same mass of TNT.
ETA: Ninja’d on my own correction.
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### Author:  [@scr4](https://boards.straightdope.com/u/scr4)
#### Post date: [July 29, 2019, 8:31pm UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/13 "2019-07-29T20:31:13Z")
OK sorry, I think I misunderstood RE factor in that page. It’s just yield divided by mass of the bomb.
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### Author:  [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)
#### Post date: [July 30, 2019, 3:33pm UTC](https://boards.straightdope.com/t/so-whats-the-difference-between-10-000-tonnes-of-tnt-and-a-10-kiloton-nuke/837800/14 "2019-07-30T15:33:01Z")
One difference is that a nuclear detonation releases its energy much faster, producing a sharper shockwave. This means it imparts its energy quicker to a target, and produces effects like [shocked quartz](https://en.wikipedia.org/wiki/Shocked_quartz) not seen from chemical detonations. In fact shocked quartz was first discovered in the aftermath of nuclear tests.