General How does the explosive behaviour of TDX vary in different gravitational fields?

[l_c_jackson]

Gentlesophonts, how does the explosive behaviour of TDX vary in different gravitational fields?

TDX gravitationally polarised explosive has been a part of Traveller since at least MegaTraveller (Players Manual pg 94). It was obviously borrowed from the "Cities in Flight" novels, by James Blish. http://www.technovelgy.com/ct/content.asp?Bnum=2460

Imagine that you have an armoured test firing chamber, equipped with powerful grav plates. You place in the chamber a small charge of TDX, and a remote detonator. The chamber has a small blast-proof window, with a high-speed 3D multi-wavelength camera outside, pointing in. Your multi-species, & multi-gender research team seal the door, set the gravitational field to the desired value, and retreat behind a further blast shield. A flashing light starts and a warning klaxon sounds. After a short countdown, the camera rolls, and the charge is triggered.

In your Traveller universe, how does TDX behave differently if it is detonated in zero-gravity, or in micro-gravity? Does it detonate at all?

What happens to TDX in common planetary surface gravitational fields that happen to be slightly lower, or higher than standard? Could the explosion be slightly more, or slightly less violent?

Please share your thoughts! Thank you.

 

[McPerth]

TDX gravitationally polarised explosive has been a part of Traveller since at least MegaTraveller (Players Manual pg 94). It was obviously borrowed from the "Cities in Flight" novels, by James Blish. http://www.technovelgy.com/ct/content.asp?Bnum=2460

In fact since before, as it apeared in JTAS 1, when Traveller was just Traveller...

I'd suggest you to look at this old thread.

Not that it answered too much, though...

 

[kilemall]

I never saw the big to-do about TDX. I would care about it if I was a lumberjack or firing spring mines against giant alien races or animals, otherwise blah.


I guess if I were doing an off-the-cuff ruling, I'd say TDX has a rating for each range of G, and gets a higher or lower amount of whatever gravitically sensitive material in the explosives defines the shape of the detonation.


If a TDX charge is set off in a non-matching G-field, it would create a bowl pointed down for world heavier then rated G charges, and a bowl with edges pointed up for world lighter then rated G charges.



Hmm, now that I think on it, I'd want what I will provisionally call TDX-V, for vertical, perpendicular to the plane of gravity. That would be helpful for shearing off a cliff for resource extraction or intentional avalanche, cutting that pesky monorail, or slicing an asteroid in half.


Taking the idea further, TDX should come in little 1kg bits that a professional demolitionist would use to pack custom charges for special effects.

 

[aramis]

I never saw the big to-do about TDX. I would care about it if I was a lumberjack or firing spring mines against giant alien races or animals, otherwise blah.


I guess if I were doing an off-the-cuff ruling, I'd say TDX has a rating for each range of G, and gets a higher or lower amount of whatever gravitically sensitive material in the explosives defines the shape of the detonation.


If a TDX charge is set off in a non-matching G-field, it would create a bowl pointed down for world heavier then rated G charges, and a bowl with edges pointed up for world lighter then rated G charges.



Hmm, now that I think on it, I'd want what I will provisionally call TDX-V, for vertical. That would be helpful for shearing off a cliff for resource extraction or intentional avalanche, cutting that pesky monorail, or slicing an asteroid in half.

That would be ODX, One-dimensional explosive. Great for anti-vehicle mines, lousy for anti-infantry popups.

 

[Redcap]

My take would be yeah, it needs to be have different velocity ratings depending on the strength of the local gravitational strength.

Here comes a Rogers Rules House Rule...

PDX in different gravity fields...

PDX, or Polarised Detonation Explosives, which is the Imperial Standard Organisation (ISO) family name for TDX and OXD, is rated by most commercial sources for use in a 1-2 Gee field.

There's no point, after all, having an explosive that works fine in a 1 to 2 Gee field, if you're in a 3 to 4 gee field; the power of the blast wave (the velocity rating has a major effect on this) drops off in a shorter distance, so for higher G-ratings, you need more powerful explosives.

These are, of course, more expensive than 1-2G rated PDX.

Ratings bands are not per UWP Size rating, but by the local Gee (relative to an ISO-norm 1G) rating. Gravity ratings for PDX are listed in 2-gee brackets, thus ratings are as follows:

Gee .. Cost multiplier ... Availability
1-2 ... Normal ... ... ... Normal
3-4 ... x (1d6+2) ... ... Most tech A and above worlds
5-6 ... x (2d6+5) ... ... 30% tech A and above worlds
7-8 ... x (4d6+8) ... ... 1% tech A and above worlds ("rare as hens teeth")

Enjoy

 

[l_c_jackson]

Back to basics - proposed answers

1. TDX is an explosive, so it is chemically unstable, and detonates relatively easily.

2. It responds to the presence (or absence) of a gravitational field AFTER it detonates, and not before.

3. Thus, logically, in zero-gravity TDX must first detonate, and only then look around going "Huh - where's the gravity gone?" Like user "shield", I would operationalise that "confused" explosive as an omnidirectional blast, but of correspondingly reduced power.

4. The energy content of any known chemical explosive does not depend on the surrounding gravitational field, so why should TDX be any different? Gravity merely focusses the blast into a particular direction.

5. Thus, at a particular maximum gravity for which the explosive is designed (let's say 1g for argument) the blast effect is maximised, and disk-shaped.

6. Any higher gravity has no effect, beyond reducing the range that debris and shrapnel will travel before hitting the ground. You could operationalise that as a reduced blast radius.

7. Lower gravitational fields however will cause the blast to partially spread outside the plane of the gravitational field. That means less damage horizontally, and more damage vertically. That would be a blast radius of a different shape - more spherical, less of a disk.


I'm not going to go into ODX (great idea though). Jack Vance had something vaguely similar in his "Durdane" novels, in the form of expanding slivers of freezing crystal (in "The Brave Free Men").

Thanks all for your interesting ideas, and useful references.

 

[Condottiere]

Now that I think of it, it's a variation on a shape charge.

What mechanism creates this particular focus of force?

 

[Fovean]

It seems there needs to be a knoodling pin or gadget that initiates the gravity shape before the charge goes off. A variation of a grav belt?... It would only need to enforce the disk shape at the moment of detonation, the rest would occur naturally.

So then maybe the charges are like the flaming spouts in the ROUS's woods... there's a give-away sound or vibration (the knoodling pin creating the grav-disk) that can warn alert targets of the danger moments before the detonation.

The gadget could be tuned to operate at up to 90 degrees perpendicular to the local plane. Bonus, it would know the local gravity and adjust its force parameters accordingly, allowing consistent performance regardless of local G.

Or assume 1G sensitivity is the manufacturing norm and divide it by local G for the damage and area-of-effect multiplier.

 

[kilemall]

The thought I had behind my effects description was that the explosive itself is sensitive to the gravitational field- if it was just shaped charge the gravitics component could be ignored. So, part of that 'understanding and manipulating gravity' thing transposed onto an explosive.


If you had some sort of gravitic field emanating from a device in the center of the explosive, no need to bother with the intermediate explosive bit, just use that grav field generator as a buzzsaw.


In a sense this tech could be precursor to the PGMP/FGMPs, which after all are long-range plasma bolts that hold together their field coherently, only in a directional pointy end manner.

 

[nobby-w]

That would be ODX, One-dimensional explosive. Great for anti-vehicle mines, lousy for anti-infantry popups.

I did think about vertical TDX once but realised that you could achieve the same effect with a shaped charge.

 

[Condottiere]

Creating a force field that strictly focusses the explosion along a two dimensional plane defined by gravitation would require some form of gravity/tractor/repulsor generator, which would be a one shot device, as I would assume it would be consumed during said explosion.

 

[Fovean]

Yes. A modified grav belt seems like a strong possibility but then TDX would be so expensive no one would use it. Or use the grav belts for assault troops instead of land mines.

I'm starting to think about nano tech as opposed to gravitics. Maybe TDX is a ring of tiny cannons all facing outward. But then that's not really TDX I suppose.

 

[aramis]

I did think about vertical TDX once but realised that you could achieve the same effect with a shaped charge.

TDX is, too... a v-channel in a ring.

 

[BRover]

The thought I had behind my effects description was that the explosive itself is sensitive to the gravitational field- if it was just shaped charge the gravitics component could be ignored. So, part of that 'understanding and manipulating gravity' thing transposed onto an explosive.


If you had some sort of gravitic field emanating from a device in the center of the explosive, no need to bother with the intermediate explosive bit, just use that grav field generator as a buzzsaw.


In a sense this tech could be precursor to the PGMP/FGMPs, which after all are long-range plasma bolts that hold together their field coherently, only in a directional pointy end manner.

IIRC, Blish used it in his "Cities in Flight", book 3? He described it as an explosive with polarized atoms, so that somehow they were constrained to move only perpendicularly to gravity--hence a flat plane (TDX = Two-Dimensional eXplosive, I believe).

Blish wrote:

Miramon goggled. "Impossible. An explosion has to expand evenly in all directions that are open to it."

"Not if the explosive is a piperazohexynitrate built from polarized carbon atome. Such atoms can't move in any direction but at right angles to the gravity radius...

But--how long are they constrained? Only in the initial combustion? For a time after the burst?

 

[Redcap]

IIRC, Blish used it in his "Cities in Flight", book 3? He described it as an explosive with polarized atoms, so that somehow they were constrained to move only perpendicularly to gravity--hence a flat plane (TDX = Two-Dimensional eXplosive, I believe).

Blish wrote:


But--how long are they constrained? Only in the initial combustion? For a time after the burst?

I would say from the moment of detonation until such point where gravitational forces reduce to less than what might be called effective levels, say 0.25 standard G? That sound reasonable?

 

[BRover]

I would say from the moment of detonation until such point where gravitational forces reduce to less than what might be called effective levels, say 0.25 standard G? That sound reasonable?

Maybe. Or maybe when it goes boom (flatly), the polarized atoms go off--but after a collision, there is a chance that they depolarize, and can then be scattered anywhere? That could limit the size of the explosion--once scattering allows the blast focus to dissipate.

Does anyone have a few TDX plates so we can run some experiments . . . ?

 

[Redcap]

Maybe. Or maybe when it goes boom (flatly), the polarized atoms go off--but after a collision, there is a chance that they depolarize, and can then be scattered anywhere? That could limit the size of the explosion--once scattering allows the blast focus to dissipate.

Hmm. Interesting thought. Is there any existing science on the depolarisation of 'stuff' due to explosive projection/propulsion?

Does anyone have a few TDX plates so we can run some experiments . . . ?

Evil cackling :devil:

 

[BRover]

Redcap, I'm thinking maybe Mythbusters? If it has anything to do with cool explosions, they will know--or can figure it out . . . :smirk:

 

[Redcap]

Redcap, I'm thinking maybe Mythbusters? If it has anything to do with cool explosions, they will know--or can figure it out . . . :smirk:

Peering over spectacles with a raised eyebrow...

Young man, you are blessed indeed that I did not have a mouthful of coffee when I read that :rofl:

 

[BRover]

Peering over spectacles with a raised eyebrow...

Young man, you are blessed indeed that I did not have a mouthful of coffee when I read that :rofl:

Not exactly young--I was playing CT in college in the '70s . . . :coffeesip:

I got a fresh pot for you. :coffeegulp: