Scientists CT Scan An Entire Whale to Study Its Ears

By Nathaniel Scharping | April 23, 2018 1:30 pm
A minke whale surfacing. (Credit: Graeme Snow/Shutterstock)

A minke whale surfacing. (Credit: Graeme Snow/Shutterstock)

How do you get inside a whale’s head? With a CT-scanner made for rocket bodies, that’s how.

Researchers from San Diego State University stuck an entire juvenile minke whale inside a computed tomography (CT) scanning machine to virtually slice and dice its anatomy with X-rays. Their goal was to get a look at the structures that allow whales to hear underwater and better understand a sense that’s vital for these underwater mammals. Read More

CATEGORIZED UNDER: Living World

Is It Time For A New Astronomical Yardstick?

By Alison Klesman | April 23, 2018 10:18 am
An illustration of the scale of our solar system. Distances here are measured in Astronomical Units (AU). (Credit: NASA)

An illustration of the scale of our solar system. Distances here are measured in astronomical units (AU). (Credit: NASA)

Click on an article about space on Discover, and you’ll likely run into a measurement in terms of light-years, solar masses, astronomical units, or arcminutes. These units are unique to astronomy, and all can be expressed in terms of other, more fundamental units, such as meters, grams, and degrees.

In a paper published April 1 in Astronomy & Geophysics, Keith Atkin, a retired associate lecturer in physics at the University of Sheffield, UK, argues that while the professional field of astronomy has moved away from the imperial units of miles, pounds, and degrees Fahrenheit, “this transition has not been complete,” according to the abstract of his paper. The use of units such as light-years (the distance light covers in a year: 5.88 trillion miles [9.5 trillion kilometers]) and astronomical units (abbreviated AU, the average Earth-Sun distance: 93 million miles [150 million km]) persists, he says, when “simpler logical units would help both within the subject and in multidisciplinary research.”

It’s true that astronomy is a bit weird, in general. Our brightness system of magnitudes, for example, is “backwards” — the smaller the number describing its magnitude, the brighter a star appears. And sometimes terms are outdated: Planetary nebulae are not planets or even associated with planets at all, but are the expanding outermost layers of stars in their late stages of life. They were originally called planetary nebulae because they often appear round, like planets, but the term remains confusing and even misleading, particularly for the public.

Proposed Replacements

In the paper, Atkin first focuses on units of distance measurement, noting not only the seemingly random and often redundant nature of units unique to the astronomical field, but sometimes their completely strange construction as well. “My bête noire is the megaparsec — a clumsy and ugly fusion of an SI prefix and a non-SI unit,” he writes.His solution? “To encourage the use of SI units of length in all astronomical work: all distances and lengths should be based on, and simply related to, the metre. The metre is defined as the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.”

Thus, he argues, all units of astronomical distance, from the AU to the parsec (equivalent to 3.26 light-years, and derived from the apparent motion of nearer stars against the background that occurs as Earth orbits the Sun), can really be expressed in meters, with the appropriate SI prefix attached.

For example, Atkin proposes that megameters (Mm, 106 m), gigameters (Gm, 109 m), and terameters (Tm, 1012 m) be used for planetary- and solar system-scale distances, making Earth’s radius 6.37 Mm and its distance from the Sun 150 Gm. For larger distances, he suggests petameters (Pm, 1015 m) and exameters (Em, 1018 m) within our galaxy, and zettameters (Zm, 1021 m) and yottameters (Ym, 1024 m) for extragalactic distances. In this regime, Proxima Centauri is about 40 Pm (instead of 4 light-years) away, the Milky Way is 1 Zm across, and Andromeda is 20 Zm away. The proto-galaxy UDFj-39546284, one of the earliest and most distant objects detected to date, would sit at a distance of 126 Ym.

aty085_fig1

Some astronomical distances using SI units. Note: Distances not to scale. (Credit: Keith Atkin, Astronomy & Geophysics)

Atkin expands his argument to other units of measurement — why use kilograms or solar masses (the Sun’s mass, 1.98 × 1030 kg, is equal to 1 solar mass, and the masses of other stars can be measured on this scale, such that Betelgeuse is almost 8 solar masses) when SI prefixes and grams will do? He suggests that the unofficial prefix besa (1033) be used, such that the Sun is 1.98 Bg and Betelgeuse is 15 Bg. Similarly, the electron volt (eV), which measures the energy of particles in both astronomy and physics, could instead be expressed in terms of attojoules (aJ, 10−18 joules).

He also argues that units such as arcminute and arcsecond should be done away with, though admits that “the degree is presumably here to stay.” Atkin proposes measuring all angles in terms of either decimal degrees or radians, rather than using degrees, arcminutes, and arcseconds, as astronomers do today.

Will Things Change?

But change is difficult, and often a slow process, to boot. In his conclusion, Atkin admits that “as a colleague recently observed: ‘Andromeda will be a good deal closer to the solar system than it is now, before we read of its distance in zettametres.’” His colleague is likely correct, especially given examples such as the public and professional pushback to the recent demotion of Pluto as a dwarf planet under the updated definition of the word planet.

It’s worth noting, too, that units such as the AU and solar mass relate distances and objects to those we understand closer to home — explaining that a star is 8 solar masses immediately makes it clear that it is eight times as massive as our Sun, while stating that Jupiter is 5.2 AU from the Sun paints the clear picture that it is five times Earth’s distance from our star. Light-years, too, are a relatively intuitive unit, even if they are unique to astronomy, and speak both to distance and the time light requires to reach us.

However, the ultimate goal of science is to understand and describe the universe around us. Scientists constantly strive to test, improve, and update their understanding, and standardizing the units that pervade astronomy, Atkin writes in closing, “will surely benefit understanding and communication within astronomical circles and between astronomy and related sciences.”

 

[This post originally appeared on Astronomy.com]

CATEGORIZED UNDER: Space & Physics
MORE ABOUT: cosmology, solar system

Your Weekly Attenborough: Sirdavidia solannona

By Nathaniel Scharping | April 20, 2018 4:35 pm
Sirdavidia solannona. (Credit: homas L.P. Couvreur (Institut de Recherche pour le Développement , Montpellier, France) - Couvreur TLP, Niangadouma R, Sonké B, Sauquet H (2015) Sirdavidia, an extraordinary new genus of Annonaceae from Gabon. PhytoKeys 46: 1-19)

Sirdavidia solannona. (Credit: Thomas L.P. Couvreur (Institut de Recherche pour le Développement , Montpellier, France) – Couvreur TLP, Niangadouma R, Sonké B, Sauquet H (2015) Sirdavidia, an extraordinary new genus of Annonaceae from Gabon. PhytoKeys 46: 1-19)

Gabon’s hottest nightclub is Sirdavidia solannona.

Located on the side of a mountain in this coastal African country, the genus of flowering plants has pulled out all stops.

It’s got everything: stamens, anthers, petals, stems, bees, three drunk porpoises trying to microwave leftover Chipotle, a human Slap Chop… Read More

CATEGORIZED UNDER: Living World

Researchers Find New Species of ‘Exploding Ants’

By Lauren Sigfusson | April 20, 2018 4:34 pm
exploding-ant-insect-suicide-kill-defensive

Step back, or I’ll explode! (Alexey Kopchinskiy/Pensoft Publishers)

Ants, social insects that live in structured communities and work around the clock to keep the colony running, really take one for the team. Elderly and terminally ill ants leave their nests to die, while others purposefully explode.

Scientists recently discovered a new species of exploding ants, which kill themselves to save their colony as a defensive behavior. Worker ants can choose to rupture their abdominal wall to ward off or kill enemies. During the fatal act, called autothysis, the reddish-brown ants secrete bright yellow sticky toxins from their mandibular gland. Read More

CATEGORIZED UNDER: Living World

Fruit Flies Sure Enjoy Ejaculating

By Carl Engelking | April 19, 2018 4:14 pm

shutterstock_134872160

Throughout history we’ve blushed and called it la petite mort, the sting of pleasure, the balsamic injection, the flood of bliss—the list continues. But let’s cut to the chase: I’m talking about ejaculation.

It’s almost seems as if some deep-seated Puritanical modesty compels us to semantically sidestep addressing this perfectly natural function. Perhaps we’re just a bit bashful that it feels really, really good. It’s not polite to discuss such scrumptious pleasures publicly. Read More

CATEGORIZED UNDER: Living World, top posts

This Organ Helps Sea Nomads Dive Deeper for Longer

By Nathaniel Scharping | April 19, 2018 4:05 pm
A Bajau diver hunting fish underwater. (Credit: Melissa Ilardo)

A Bajau diver hunting fish underwater. (Credit: Melissa Ilardo)

When we think of the organs that help humans stay alive under the water, the heart and lungs top the list. But there’s another organ that deserves recognition as well, though few of us would think to name it. It’s the spleen.

Mammals have a unique response to having our faces engulfed by water. Our heart rate slows and peripheral blood vessels constrict, shunting blood to vital organs where it’s needed most. At the same time, our spleens release a cache of red blood vessels held for this express purpose, giving our blood an increased ability to transport oxygen to vital organs. Read More

How to Bend A Diamond

By Charles Choi | April 19, 2018 1:00 pm
(Credit: The Adventurer/Shutterstock)

(Credit: The Adventurer/Shutterstock)

Diamond is the hardest natural material, but now scientists have shown that it can bend and stretch, much like rubber, and even elastically snap back into shape — even if it only happens with diamonds that are very small. Such flexibility could open up a wide new range of applications for diamond, the researchers say.

Diamond is extraordinarily hard, meaning it excels at resisting any change to its shape — that’s why a diamond can cut through softer materials and will only be scratched by another diamond. However, diamond is not especially tough — when enough force is applied to it to change its shape, it doesn’t usually bend, it breaks. Read More

CATEGORIZED UNDER: Space & Physics
MORE ABOUT: physics

At the Bottom of the Ocean, a Surprising, Gloomy Discovery

By Nathaniel Scharping | April 18, 2018 4:03 pm
17 octopods congregate on the sediment free surface of Dorado Outcrop, 16 are in the brooding posture. (Credit: Phil Torres, Dr. Geoff Wheat)

17 octopods congregate on the sediment free surface of Dorado Outcrop, 16 are in the brooding posture. (Credit: Phil Torres, Dr. Geoff Wheat)

Almost two miles below the surface of the Pacific Ocean, on a lonely outcrop of bare rock 100 miles from Costa Rica, researchers on a geological expedition found something odd. As their remotely controlled submersible sunk through the black waters toward the seafloor, they saw a collection of purple lumps dotting the rocky bottom.

As they got closer, they resolved themselves into something resembling a bowling ball with suckers. It was a group of female octopuses, of the genus Muusoctopus, guarding clutches of eggs they’d carefully attached to the cracks and crevices snaking across the seafloor. Read More

CATEGORIZED UNDER: Living World, top posts
MORE ABOUT: animals

One Simple Trick To Improve Credibility

By Bill Andrews | April 18, 2018 2:37 pm
shutterstock_586485371

(Credit: PrinceOfLove/Shutterstock)

It’s intuitive: We hear a message, think about it, and decide whether or not we believe it. We have to do it whenever we get a new piece of information in our lives, from politics to the news to gossip, so you’d think we’d be good at it by now.

But studies constantly show that our squishy human brains don’t make it quite so easy. Presenting information in different ways — whether there’s a photo included, or changing the colors of the words — affects our interpretation of it, without our even knowing it. It turns out, the same is true for how we hear information. Read More

CATEGORIZED UNDER: Mind & Brain, top posts
MORE ABOUT: psychology, Senses

No One Knows How Long the U.S. Coastline Is

By Nathaniel Scharping | April 17, 2018 4:02 pm
The coast of California. (Credit: Alizada Studios/Shutterstock)

The coast of California. (Credit: Alizada Studios/Shutterstock)

How long is the U.S. coastline? It’s a straightforward question, and one that’s important for scientists and government agencies alike. The U.S. Geological Survey could give you an answer, too, but I’m going to tell you right now that it’s wrong.

In fact, no one could give you the right answer, and if you look around, you’ll find a number of estimations that differ by seemingly improbable amounts. One government report lists the number as 12,383 miles. The same report admits that a different government agency says the figure is actually 88,612 miles. That’s an almost eight-fold disparity for a fact that seems simple to obtain. We all know how to use a ruler, right? Read More

CATEGORIZED UNDER: Environment, top posts
MORE ABOUT: earth science
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