The apprehension of the last three factors of the Drake equation, fi · fc · L, is misguided or at least not very well examined. This article scrutinizes the underlying suppositions involved in the search for extraterrestrial intelligence (SETI) research. What is meant by “intelligence,” “technology,” and “civilization”? What makes them possible, and how do they evolve? The present examination a...

Elevated irradiance has a profound effect on the successful dispersal and establishment of kelp zoospores, affecting their physiology and viability. The research to date, however, has been on zoospores localized near the benthos, with little attention on the importance of vertical transportation and subsequent exposure to increased irradiance. Therefore, we wanted to investigate the effects of ...

Fiber-optic microprobes for determining irradiance and scalar irradiance were used for light measurements in sandy sediments of different particle size. Intense scattering caused a maximum integral light intensity [photon scalar ~rradiance, E"(400 to 700 nm) and Eo(700 to 880 nm)] at the sediment surface ranging from 180% of incident collimated light in the coarsest sediment (250 to 500 pm grai...

The Chicxulub impact event led to a worldwide deposition of impact materials originated from target rocks and the vaporized bolide. Relative contributions of both types of material to the K/T ejecta deposits vary with distance to the crater site. At distal sites (e.g., Agost and Caravaca in the SE of Spain) a major contribution of extraterrestrial material is indicated by different impact signa...

Carl Sagan’s words convey how the detection of an extraterrestrial form of intelligence would not just be a new discovery, it would be the beginning of a new era. Fortytwo years ago when Philip Morrison and Giuseppe Cocconi, two physicists at MIT, published the famous paper “Searching for Interstellar Communications”, they gave birth to the idea of starting a Search for ExtraTerrestrial Intelli...

Exploration of novel thin-film solar cell technologies outreaches for their application in space. For extraterrestrial tests, irradiance conditions must be well determined to extract quantitative performances. We present a new method position determination based on parallelized ambient light sensor measurements, obtained from the sounding rocket experiment Organic and Hybrid Solar Cells Space d...

A dynamic model of photosynthesis is developed, accounting for factors such as photoadaptation, photoinhibition, and the "flashing light effect." The model is shown to explain the reported photosynthesis-irradiance responses observed under various conditions (constant low light, constant intense irradiance, flashing light, diurnal variation in irradiance). As significant distinguishing features...