An exercise in communicating science results, by @neuroamanda and @RaoOfPhysics
An exercise in communicating science results, by @neuroamanda and @RaoOfPhysics
No signs of tell-tale particles despite years of data collection
We are all bathed in a constant stream of particles knows as cosmic rays1, which are produced mostly outside the Solar System. These high-energy particles were initially suspected to have Earthly origins, but Victor Hess demonstrated in 1912 that they arrive on our planet from non-terrestrial sources. For decades, the enigmatic nature of cosmic rays has captivated scientists, who have sought explanations for their origins and the energies they possess.
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Exoplanets that are too hot may be a sign of alien life
A new research paper suggests that scanning for waste heat radiating off of Earth-like planets may be important in the search for extraterrestrial intelligence. Like the radio signals emitted by Earth, heat may serve as an interstellar smoke signal indicating energy production and consumption. While this is not a new idea, the study argues that heat is a viable marker of alien civilization that should be considered in plans for building future telescopes.
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Improvement to tissue-imaging technique based on photoacoustic spectroscopy shows promise for minimally invasive radiology
Photoacoustics (PA) involves shining light (photo–) on a material to produce sound (acoustics) and using the sound for spectroscopy1. When energy from the incident light is absorbed by a material it expands slightly and when the light source is switched off the material contracts. Alternately shining and switching off the light source rapidly creates pressure differences that manifest as sound waves. Materials will vary in the sounds they produce depending on the wavelength of light shone on them. A light-vs-sound spectrum for a particular material can be prepared by “listening” to the pressure waves that various wavelengths of light make in it, allowing one to see with sound. The photoacoustic effect was discovered by Alexander Graham Bell in the late 19th century, but has found use in materials science and medicine relatively recently.
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A suggested biological color vision mechanism exploits optics
From humans to mantis shrimp, the key to seeing in color is to compare. With at least two different types of wavelength-sensitive cells in the eye, you can start to distinguish different parts of the spectrum, and thus different-colored objects in the environment. The more photoreceptor types you have, the more precisely you can interpret the incoming light, depending on how finely or evenly the photoreceptor sensitivities are spaced on the spectrum. Humans are trichromatic, with three kinds of cone cells well-tuned to the short, medium, and long wavelengths of our diurnal environment. The mantis shrimp has 16 photoreceptor types, suited to both its vibrant patchwork body coloring as well as its bright surroundings. The question then is, how many photoreceptors does the cuttlefish, a squid-like underwater chameleon, have?
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