The UNSC Nova Bomb

[kingdragon]

In the halo novel Ghosts of Onyx, the detonation of the titular bomb causes half a planet to be scorched and shatters a nearby moon.

Now look at the following conjecture from the Halo wiki.

Assumptions: the moon is 2km, and the NOVA bomb is only 5,000 km away.

Calc: Apply the Inverse Squared Law: Source Energy / (4 * Pi * R2) the radius is the distance from the source to the range.

x/ (4 * 3.14195... * 5,0002) = 4 Megatons per square kilometer to fragment a 2km moon which requires 8 Megatons to be fragmented.

x = 1.2 Petatons.

Some may find this yield hard to believe for a fusion device, but the stated effects to the planet and nearby moon require explosive power of this magnitude.

That being said, did the UNSC really make such a powerful nuke, or did Nylund have no sense of scale, if you know what I mean?

[Eviscerator]

Offhand about the only other sci-fi weapon i can recall that approaches such an level of explosive power is the Neutron S Super-Dimensional Strategic Missile

http://www.xs4all.nl/~ptn/Naval/NeutronS.html

this weapon was supposed to be a single large warhead or numerous MIRVs, the total volume of the reactant is approximately 150,000,000 cubic meters, with an expected total yield of 15 million megatons, similar to the K-T event that struck the Yucatan 65 million years ago, leading to the mass extinction of the late Cretaceous

15 million mega = 15 tera which makes the 8 Neutrons launched at earth = 120 teratons. ADM Hunter really wanted to make sure the Invid were gone from Earth .

[Eviscerator]

Back to the Nova Bomb, if the UNSC did really make such a powerful weapon, why didn't they include one or two with the penetration mission John-117 was to lead? a couple of these scattered around high charity , set to detonate at the same time and poof, no more high charity

[Ghost Rider]

And this is why arbitrary numbers without objective evidence yields completely subjective nonsense. Or...so where does it state the composition of the moon, distance(which looks completely plucked out) and the size. So yes, it tells us in the stories it's a large bomb, much like the Robotech comparison. Where can we actually find said material out beyond what might, may, could be.

[Darth Wong]

In the halo novel Ghosts of Onyx, the detonation of the titular bomb causes half a planet to be scorched and shatters a nearby moon.

That line is stupid and meaningless. To "scorch" something is merely to blacken it with heat.

Now look at the following conjecture from the Halo wiki.

Assumptions: the moon is 2km, and the NOVA bomb is only 5,000 km away.

Calc: Apply the Inverse Squared Law: Source Energy / (4 * Pi * R2) the radius is the distance from the source to the range.

x/ (4 * 3.14195... * 5,0002) = 4 Megatons per square kilometer to fragment a 2km moon which requires 8 Megatons to be fragmented.

x = 1.2 Petatons.

Some may find this yield hard to believe for a fusion device, but the stated effects to the planet and nearby moon require explosive power of this magnitude.

That being said, did the UNSC really make such a powerful nuke, or did Nylund have no sense of scale, if you know what I mean?

What the fuck kind of analysis is that? 4 megatons per square kilometre? If the bomb only "scorches" half a planet ("scorching" being a surface effect), it wouldn't be powerful enough to fragment a nearby moon unless it's a loose rubble pile, which many objects in that size range are. And what's the point of an analysis when all of the figures in it are just made up out of thin air?

Hey, let's just assume a certain size, and a certain distance, and a certain type of object, with no objective data to work with.

[Black Admiral]

The description of the one known NOVA initiation;

A battlegroup of eighteen destroyers, two cruisers, and one carrier collected in orbit over Joyous Exultation, and drew into a spherical formation around their flagship, the Incorruptible.

They shimmered blue-white and vanished into Slipspace.

A heartbeat later Vice Admiral Whitcomb's ploy of slipping the UNSC prototype Nova bomb into Covenant supplies paid off: a star ignited between Joyous Exultation and its moon.

Every ship not protected on the dark side of the planet boiled and vaporised in an instant.

The atmosphere of the planet wavered as helical spirals of luminescent particles lit both north and south poles, making curtains of blue and green ripple over the globe. As the thermonuclear pressure wave spread and butted against the thermosphere, it heated the air orange, compressed it, until it touched the ground and scorched a quarter of the world.

The tiny nearby moon Malheim cracked and shattered into a billion rocky fragments and clouds of dust.

The overpressure force subsided, and three-hundred-kilometre-an-hour winds swept over Joyous Exultation, obliterating cities and whipping tidal waves over its coastlines.

The number of Covenant ships destroyed seems to be about 140-odd, as it was earlier stated (pg. 240) that there were ~200 ships assembled over Joyous Exultation, from which must be deducted the 22 initially detached to Onyx and 32 that arrived there later.

[Darth Wong]

A "thermonuclear pressure wave" in space? I think that answers the question of whether the author was just talking out of his ass. You would get a burst of energetic particles, but you're not going to get anything resembling a "pressure wave".

[Darksider]

A "thermonuclear pressure wave" in space? I think that answers the question of whether the author was just talking out of his ass. You would get a burst of energetic particles, but you're not going to get anything resembling a "pressure wave".

The only way I can possibly think of to rationalize this is that the heat/radiation from the blast vaporize the covenant fleet, and that the "moon" is actually some sort of asteroid or artificial construct whose orbit is so close it's practically inside the atmosphere, and that's why the nuke was able to shatter it like that.

[Manus Celer Dei]

A "thermonuclear pressure wave" in space? I think that answers the question of whether the author was just talking out of his ass. You would get a burst of energetic particles, but you're not going to get anything resembling a "pressure wave".

The fact that is specifies the pressure wave hitting the thermosphere rather than just the atmosphere may indicate that what the author meant was all that energy caused rapid heating and the production of a shockwave in the exosphere which then passed to the thermosphere. However I really doubt that's likely to occur, given the density of the exosphere, and would be giving the author too much credit.

I think it was another one of Eric Nylund's Halo books that had nuclear detonations in space producing EMPs so yeah, not incredibly surprised that they also produce pressure shockwaves.

[DrStrangelove]

Halo canon feats are crazy. You either have to throw science out the window, or throw out most of the canon as the ramblings of delusional imbeciles.

[Darksider]

To be fair, Halo isn't alone with the "Massive nuclear shockwave in space" phenomenon. Naquadah enhanced nukes in SG-1 are also a frequent offender.

[Connor MacLeod]

In the halo novel Ghosts of Onyx, the detonation of the titular bomb causes half a planet to be scorched and shatters a nearby moon.

Now look at the following conjecture from the Halo wiki.

*snip the rest*

First, there's been discussio nof the GoO nova bomb before here and here so this was a tad redundant.

Secondly, the fact that its from a wiki, much less the Halo wiki, should have clued you in onto its reliability (which is to say not at all). I've browsed that Wikie enought o know that they put almost zero effort into consistent analytical approach (mindlessly repeating the Encyclopedia stats rather than attempting to address all the inconsistencies of the mass driver, to say nothing of all the other nuke entries).

Going by the moon, as Mike noted, is pointless - we dont know the distance or the properties of the moon, and starships aren't inert objects. So that leaves the planet. A Nova Bomb IIRC is basically a "planet killer" weapon, but its worth noting that the effects on the planet were nowhere near "petaton" range themselves since that would involve global firestorms hitting the planet (and that clearly isn't what we see.) so it would be teraton range at best hitting the planet - and thats all we could say - and that's not really all that helpful either.

[Blayne]

This reminds me of the various 'Darths and Droids' strips where the players from vague unreliable and exaggerated descriptions from the DM come up with something that sounds plausible within their field of study. I think that whether the author (probably not being a qualified physicist) knows or only partially knows isn't so much important as your ability to "okay if by this he actually means this then that makes sense" to the work.

I would also agree that the moon should be reasonable close to the planet for it to make sense.

[Aratech]

A "thermonuclear pressure wave" in space? I think that answers the question of whether the author was just talking out of his ass. You would get a burst of energetic particles, but you're not going to get anything resembling a "pressure wave".

In Nylund's defense, thermonuclear 'pressure waves' are something that Halo 'nukes' are established as being able to do for some time now, and the energy densities required for some of their feats (100 Shiva's inducing a super-nova at Cole's Last Stand, being powerful enough to threaten capships that can eat low end gigaton power at hundreds to thousands of kilometers, etc) exceed, IIRC, 100% efficiency AM/M reactions. The only 'logical' conclusion that I could reach from their observed effects is that these are not nukes at all, but much like Turbolasers. That is to say, they're some kind of whacky physics defying sci-fi technobabble weapon that makes a really, really big boom, and as such the term 'nuke' is a holdover from the days when nukes were actually used. Just like how Turbolasers are not actual lasers, but a whacky sci-fi technobabble weapon that makes a really big boom and the name is but a holdover from the days when those were

Of course not helping matters (and being a Halo fanboy (albeit a disillusioned one with some of their recent material) it pains me to say this) is that Bungie/Microsoft/whoever the hell is running things now has decided to screw any notions of trying to make Halo weaponry make sense and just tried to bullshit their way through this stuff. *sighs*


Addendum: Blayne, Nylund's is not a physicist, though he apparently holds a Ph.D in chemistry. He has stated, IIRC, point blank, that these weapons don't make any sense and half of them flat out ignore the known laws of physics. Especially Covenant 'plasma' weaponry.

[Connor MacLeod]

In Nylund's defense, thermonuclear 'pressure waves' are something that Halo 'nukes' are established as being able to do for some time now, and the energy densities required for some of their feats (100 Shiva's inducing a super-nova at Cole's Last Stand, being powerful enough to threaten capships that can eat low end gigaton power at hundreds to thousands of kilometers, etc) exceed, IIRC, 100% efficiency AM/M reactions.

It didn't trigger a super nova. It triggered fusion in the hydrogen of the brown dwarf star (which was already on the borderline threhshold for self-sustaining fusion) in a matter more reminisicent of a fission-boosted fusion bomb. Nova and supernova are different things entirely. That Halo nukes may not be like normal nukes is a well knonw possibility.

The only 'logical' conclusion that I could reach from their observed effects is that these are not nukes at all, but much like Turbolasers. That is to say, they're some kind of whacky physics defying sci-fi technobabble weapon that makes a really, really big boom, and as such the term 'nuke' is a holdover from the days when nukes were actually used. Just like how Turbolasers are not actual lasers, but a whacky sci-fi technobabble weapon that makes a really big boom and the name is but a holdover from the days when those were.

They specify in GoO that the "quasi atmospheric" effects are a specific modification to the nukes - they even note the "fireballs" don't really last as long as they do in the atmosphere. What I am guessing this is supposed to mean is that they're going for something akin to Project Orion and the Casaba Howitzer (basically you have a nuke vaporizing a dense material creating a sort of high velocity jet of plasma)- which isnt a bad idea. but they dont seem to focus it, so its use is debatable IMHO, so its still somewhat silly - but more of a tactically silly.

[adam_grif]

No you guys, the bomb is so powerful and awesome that it actually causes the vacuum around it to create an atmosphere for it to blow up. This is the power of SQUAWK.