We are confronted by many mysteries, from the nature of dark matter and the origin of the universe to the quest for a theory of everything. These are all puzzles on the grand scale, but you can observe another enduring mystery of the physical world — equally perplexing, if not quite so grand — from the comfort of your kitchen. Simply fill a tall glass with chilled water, throw in an ice cube and leave it to stand.The fact that the ice cube floats is the first oddity. And the mystery deepens if you take a thermometer and measure the temperature of the water at various depths. At the top, near the ice cube, you'll find it to be around 0 °C, but at the bottom it should be about 4 °C. That's because water is denser at 4°C than it is at any other temperature — another strange trait that sets it apart from other liquids.
Tag Archives | Physics
Dan Koeppel writes in Popular Mechanics:
… Read the rest
You’re six miles up, alone and falling without a parachute. Though the odds are long, a small number of people have found themselves in similar situations — and lived to tell the tale.
6:59:00 AM, 35,000 Feet: You have a late night and an early flight. Not long after takeoff, you drift to sleep. Suddenly, you’re wide awake. There’s cold air rushing everywhere, and sound. Intense, horrible sound. Where am I?, you think. Where’s the plane?
You’re 6 miles up. You’re alone. You’re falling.
Things are bad. But now’s the time to focus on the good news. (Yes, it goes beyond surviving the destruction of your aircraft.) Although gravity is against you, another force is working in your favor: time. Believe it or not, you’re better off up here than if you’d slipped from the balcony of your high-rise hotel room after one too many drinks last night.
An upcoming television show explains why real life lightsabers are a physical impossibility, before building the next best thing. It's like Mythbusters but, surprisingly, made with even more awesome. According to Variety, the show, Sci-Fi Science: Physics of the Impossible, will feature Dr. Michio Kaku looking at the reality behind Star Wars' favored weapon of choice. After explaining that light can't be formed into a solid blade, Jedi-style, he then goes to work looking for alternatives, including plasma swords and carbon nano-tubes, with the help of experts in the field. As you can see from the pic, he apparently succeeds. My mind is almost so blown that I forgot to say that I really, really want to see lightsaber battles as part of the Olympics now.
Popular Science reports on scientists messing around with something that could cause the end of the world: pocket-sized laboratory-made black holes.
Unlike a regular black hole, which traps light using the gravitational pull of the dead star at its core, this simple metal disc uses the geometry of 60 concentric rings of metamaterials to lock up light…bending beams into the center of the disc, and trapping them in the etched maze-like grooves.