Condign volumes 1 to 3

# UNCLASSIFIED

UK RESTRICTED

OPTICAL 'THICKNESS' OF BLACK BODY RADIATORS

48. A supportable theory suggests that some balls have a coherent core which is too cool to radiate in the optical visible spectrum hence such a volume would appear totally black. The visible appearance of the phenomenon depends on optical 'thickness', where:

- If the body (of gases/particles??) is hot enough to radiate, then its intensity is uniform over the surface; independent of the angle the surface makes with the sightline of the observer.

- When the radiator is too cold to radiate a significant amount of energy in the optical region, it will completely absorb any optical radiation which falls on it and hence would be 'seen' as a totally black object.

NOTE: This later statement would seem to have a significant read-across to frequent UAP sightings where a black shape (often rectangular or triangular) is seen between visible lights at the extremities. Although, Black and grey-body radiators are respectively, 'thick' and 'thin' optical sources.

## THERMO-CHEMICAL REFRIGERATION

49. Considerable evidence exists to show that the incidence of ball lightning, especially with a longer lifetime, is higher when conditions of high humidity are present. Further, because of rapid ion motion and a higher temperature than the surrounding air, ions escaping from the plasma become hydrated and this action adds heat to the system; keeping the hydration zone (boundary) fairly hot. However, if the ions survive long enough to become hydrated by ~5 water molecules it is postulated that cooling occurs. To this thermochemical action is attributed the characteristics of the reported harmlessness of occasional human brushing contact with a ball and the reason for the cloudiness/indistinct appearance of the edges of the ball.

## SUMMARY OF BALL LIGHTNING CHARACTERISTICS

50. A survey of literature on ball and bead lightning and its relevance to UAP reports, has shown that:

- There is a near constant brightness, size and shape, which can exist from a few seconds to minutes.

- The balls/beads have considerable mobility.

- It is possible for an electronicallycharged body (possibly including ball lightning) to attach itself to an aircraft in flight; where, apparently due to a balance of fields (electrostatic/magnetic or EM), it can remain in close proximity (formation abreast or astern).

- Ball lightning can enter houses and structures including aircraft and can actually exist within closed metal structures

- Sounds and smells are present on rare occasions. These are both often described, respectively, as 'electrical' (e.g. buzzing sounds, or explosions) and smells witnesses associate with electrical equipment, such as insulators overheating or rotten eggs.

51. Near Terrestrial Events There is a tendency for ball lightning not to rise - most sightings remain at low level near the earth in a near horizontal path. This is explained, in theory, in the reasonable expectation that the balance of charges between the ball in its environment (either indoors or outdoors) is such that the postulated radially-moving negative ions form a static charge on nearby surfaces which tend to repel the negative body of the ball; keeping it at a distance. This, it is argued, is the most likely reason for the balls to reportedly try to pass through any aperture (i.e. window, door, chimney). In short, as it moves it creates a field which tends to hold the ball in position (e.g. at constant altitude outdoors, or across the centre of a room. Further, since no charge builds on the aperture, the ball can proceed - presumably sending a positive charge somewhere ahead. This may also account for