Once Wounded, Plants Use Calcium Signals To Warn Distant Tissues Of Future Attacks.

The Andromeda Galaxy Floats Above the Dawn Clouds - May 6, 2017

Joseph Brimacombe

Earthrise, Apollo Moon Landing 

Created using still images taken by the Cassini spacecraft during it’s flyby of Jupiter and while at Saturn. Shown is Io and Europa over Jupiter’s Great Red Spot.

NASA/JPL-Caltech/SSI/CICLOPS/Kevin M. Gill

If you’ve ever watched water running down the side of the street, you’ve probably noticed that it doesn’t flow smoothly. Instead, you’ll see waves, rivulets, and disturbances that form. That’s because the simple action of flowing down an incline is unstable. Water and other viscous liquids can’t flow downhill smoothly. Any disturbances – an uneven surface, the rumble of passing cars, a pebble in the way – will create a disruption that grows, often until the entire flow is affected. This video shows some of the complex and beautiful patterns you get then. (Video and image credit: G. Lerisson et al.)

The edges of this flame are black. No camera trickery, no special effects. What’s going on here is down to some interesting science and some excited electrons.

When you burn sodium it emits a monochromatic yellow/orange light. This happens because when sodium heats up, electrons in the atom’s orbitals become excited and they jump up to a higher energy level. When they drop back down to their original energy level they release a photon of light of a specific wavelength, which for sodium is yellow/orange.

As well emitting photons, sodium atoms also absorb photons of the same wavelength. That means if you have a light source emitting the same monochromatic light (like the sodium street lamp which we have here) the sodium atoms in the flame will absorb the light making the flame look dark.

For more flame filled visuals and a more detailed explantation of this phenomenon, check out our latest video https://www.youtube.com/watch?v=Kn2OyQh6o7U

sure i guess sex is okay but have you ever closed a dozen tabs after finishing an academic paper

One of the challenges in studying tornadoes is being in the right place at the right time. In that regard, storm chaser Brandon Clement hit the jackpot earlier this week when he captured this footage of a tornado near Sulphur, Oklahoma from his drone. He was able to follow the twister for several minutes until it apparently dissipated. 

Scientists are still uncertain exactly how tornadoes form, but they’ve learned to recognize the key ingredients. A strong variation of wind speed with altitude can create a horizontally-oriented vortex, which a localized updraft of warm, moist air can lift and rotate to vertical, birthing a tornado. These storms most commonly occur in the central U.S. and Canada during springtime, and researchers are actively pursing new ways to predict and track tornadoes, including microphone arrays capable of locating them before they fully form. (Image and video credit: B. Clement; via Earther)