Can a lake of eternal fire be created with the spell blast of flame?

Question

Spells in the creation subschool of the conjuration school have this note:

A creation spell manipulates matter to create an object or creature in the place the spellcaster designates.... If the spell has a duration other than instantaneous, magic holds the creation together, and when the spell ends, the conjured creature or object vanishes without a trace. If the spell has an instantaneous duration, the created object or creature is merely assembled through magic. It lasts indefinitely and does not depend on magic for its existence. (PH 173)

Emphasis mine.

The 4th-level Sor/Wiz spell blast of flame [conj] (SpC 31) is in the creation subschool and has an instantaneous duration, yet it creates neither an object nor a creature.

Blast of Flame

Conjuration (Creation) [Fire]
Level: Sor/Wiz 4
Components: V, S, M
Casting Time: 1 standard action
Range: 60 ft.
Area: Cone-shaped burst
Duration: Instantaneous
Saving Throw: Reflex half
Spell Resistance: No

As you cast the spell, your hand becomes sheathed in barely perceptible yellow flames. With a roar, the flames burst from your hand in the shape of a cone, leaving your hand trailing wisps of smoke.

Flames fill the area, dealing 1d6 points of fire damage per caster level (maximum 10d6) to any creature in the area that fails its saving throw.

Material Components: A bit of wick soaked in oil.

Does the spell blast of flame create an instantaneous 60-ft. cone-shaped burst that...

1. continues indefinitely?
2. continues until naturally extinguished?
3. lasts only long enough to inflict damage to creatures in the area then dissipates?

Further, here's the 4th-level Sor/Wiz spell orb of force [conj] (SpC 151):

Orb of Force

Conjuration (Creation) [Force]
Level: Sor/Wiz 4
Components: V, S
Casting Time: 1 standard action
Range: Medium (100 ft. + 10 ft./level)
Effect: One orb of force
Duration: Instantaneous
Saving Throw: None
Spell Resistance: No

As you gather the energies of the spell, you feel against your palm a spherical weight that seems almost bonded to your skin. The sphere grows, until with a final precise movement, you release the translucent blue orb, sending it hurtling toward your intended target.

You create a globe of force 3 inches across, which streaks from your palm toward your target. You must succeed on a ranged touch attack to hit the target. The orb deals 1d6 points of damage per caster level (maximum 10d6).

Does the spell orb of force instantaneously create a 3"-across globe of force that...

1. remains indefinitely?
2. lasts only long enough to inflict damage to creatures in the area then dissipates?

Can a lake of eternal fire be created with blast of flame? Can a ball pit be filled with orbs of force created via the spell orb of force?

Answer 1

The spell creates fire and projects it away from you in a cone. The difference between this spell and, say, fireball, is that the fire is no longer magical once it's projected, and thus overcomes Spell Resistance.

Natural fires require fuel to maintain themselves for long. Once the spell is no longer maintaining the flame, it should quickly dissipate, assuming it wasn't cast into a field of dry grass or over a pool of oil. Note that lesser acid orb from Complete Arcane and Spell Compendium is also Conjuration(Creation) with an Instantaneous duration and creates neither an object nor a creature, simply a (non-magical, after leaving the caster) spell effect.

Orb of force is clearly meant to work like orb of acid, although this explanation is going to belong more on Physics.SE than RPG.SE. Force, in real world physics, is transferred between objects when they touch. Ergo, rather than "breaking" or "bouncing off", an orb composed entirely of force should be absorbed by a target (or by the ground or scenery on a miss) on impact. This is what does the damage of the spell - raw kinetic force being transferred to a relatively-stationary target.

Of course, the spell in this case probably shouldn't have the [Force] descriptor, as DnD [Force] has absolutely nothing to do with real-world force, as indicated by the fact that [Force] has full effect on incorporeal creatures and force should have none. If you (or your DM) want to rule orbs of [Force] continue to exist after striking a ghost or object, go for it. (However, both [Force] and force can be assumed to be weightless and noncorporeal, so rather than falling to the ground or filling a ball pit, they should probably keeping bouncing like that one scene in Men in Black until it escapes to outer space...)

Answer 2

The fire dissipates.

Blast of Flame is a burst. Bursts being instantaneous follows from a reading of the Emanation description.

From Spell Descriptions:

An emanation spell functions like a burst spell, except that the effect continues to radiate from the point of origin for the duration of the spell.

Which implies that bursts don't stick around.

As an aside, the description of the spell implies that the fire doesn't stick around.

"the flames burst from your hand in the shape of a cone, leaving your hand trailing wisps of smoke."

Emphasis mine.

This does not answer the more general question of what happens to the instantaneous Conjuration of energy, but this spell at least should be reasonably manageable.

Answer 3

While it would be awesome for Mr. and Mrs. Salamander's swimming pool to be filled with actual, for-reals fire and to watch the little guardinal kids play in the ball pit of orbs of electricity

No.

Although each of these spells (and other spells like them) is a "creation spell [that] manipulates matter to create an object," the cone of fire from the spell blast of flame and the orb of force from the spell orb of force have no hp (and, although unimportant, no hardness either).

Thus these objects are ruined immediately upon their creation, only remaining unruined long enough to inflict their damage because the spells themselves specifically allow them to.

However, the effects of the--for lack of a better term--energy objects remain after the energy objects are ruined (so creatures and objects may still be alight and damage inflicted will still have been inflicted), even though there's no way to make the energy objects themselves remain.