Veritasium: How Kodak Detected the Atomic Bomb. (YouTube, 13:19min) “Kodak detected the first atomic bomb before anyone else figured it out. Then they made a deal not to tell anyone.” He lists his sources in the video description.
Link via MetaFilter: A government secret that still slightly contaminates your body.
Physics Girl: Insanely Fun DIY Science Experiments at Home with Physics Girl. “So you know when you find yourself stuck at home with a bunch of sodium acetate in the fridge and a laser in your hand? Ugh, Mondays, am I right?”
Actually, I don’t have any sodium acetate, but other than that, I totally get it!
“Space is big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.”
Harry Evett: Universe Size Comparison 3D (YouTube, 5:07min)
morn1415: Star Size Comparison 2. (YouTube, the interesting part is between 0:41 and 5:53min; the whole video is 6:50min.)
morn1415: Star Size Comparison 3 (Vortex V1). (YouTube, 8:16min)
morn1415: Real Images from the Solar System! (YouTube, 11:22min)
Die Welt physikalisch gesehen: Schneeverlust unter dem Gefrierpunkt. Von Joachim Schlichting. “Manchmal verschwindet die Schneedecke, obwohl das Thermometer unter null Grad anzeigt. Oder aber sie schmilzt selbst bei Plusgraden kaum. Die Temperatur allein ist nicht entscheidend – bei den Vorgängen spielen weitere Kennzahlen eine wichtige Rolle.”
Spoiler: ein Psychrometer ist hier nützlich.
NPR: A New Form Of Northern Lights Discovered In Finland – By Amateur Sky Watchers.
“The group was discussing the phenomenon in the days after Palmroth’s book was published, when one member pointed out that the mysterious phenomenon was happening at that very moment, outside their windows.
So Palmroth suggested a way that the members might be able to help scientists investigate the phenomenon: by taking photographs of it from different locations around Finland, at the exact same time.
Two of the group’s photographers managed to capture pictures of the aurora at the exact same second, from locations 120 kilometers (75 miles) apart. That gave researchers in Palmroth’s group at the University of Helsinki what they needed to measure the aurora and locate it in near-Earth space.”