Scientists unearth ancient Papua New Guinea artifacts in the highlands of the island that settle a longstanding archaeological argument regarding the emergence of complex culture on the island.
About 10,000 years ago, the climate changed to better suit the planting of crops and the Neolithic revolution that brought about agriculture emerged in different parts of the world at different times. In Europe and Asia it is known that at this time cultural complexity developed as people began settling and living together on farms.
Amazon CEO Jeff Bezos and the World Health Organization’s director-general are trading ideas on how to get the COVID-19 pandemic under control, using tools ranging from Amazon Web Services’ firepower in cloud computing and artificial intelligence to distribution channels for coronavirus test kits.
Bezos recapped today’s talk with Director-General Tedros Adhanom Ghebreyesus in an Instagram post, featuring a screengrab of Bezos’ videoconference view with the billionaire’s own visage in the upper right corner of the frame:
On this episode of Anti-Aging Hacks, we discuss all about reversing aging in humans! My guest in this podcast is Dr. Greg Fahy, and he is the first scientist to reverse aging in humans. Here is what we discuss in this interview: 1. Why the Thymus is really important for Immune Function 2. How creating a combination.
I would love to see this on a long handle to grab the stuff I can’t get to. http://robohub.org/ lead me here after seeing Sabine Hauert do a talk on micro-swarms.
Parachutes are plaguing space programs. SpaceX doesn’t like Parachutes. They are difficult to design, hard to package, and easy to damage. The larger the mass of the spacecraft, the more effort to slow down. Larger, more efficient, complex parachute systems are needed. Several failures have hit the industry over the last few years, including SpaceX Crew Dragon, ESA ExoMars, Boeing CST-100, and the NASA Orion to name a few.
How do parachutes work and why are they hard?
The idea of a parachute is simple. All falling objects fall the same when under the same conditions… that is so long as no outside force is exerted on it. So two objects dropped from the same altitude, one a feather and hammer will fall equally. Don’t believe me? NASA tested it on the Moon. During Apollo 15 moon walk, Commander David Scott performed a live demonstration for the television cameras. Commander Scott did the Apollo 15 Hammer and Feather test. He held out a geologic hammer and a Falcon feather and dropped them at the same time. Because there is not an atmosphere on the Moon, they were essentially in a vacuum. With no air resistance force, the feather fell at the same rate as the hammer. Ironically, Apollo 15 had a second demonstration of falling objects when one of the parachutes failed to function as planned.
Apollo 15 parachute Failure Credit NASA
On Earth, and any other planet with an atmosphere, air acts as a resistance force for an object moving through it. We can get more air resistance force by increasing the surface area. Depending on the shape of the object, it’s orientation, and the amount of resistance will increase, and therefore slow the object down. Unbalanced and uncorrected resistance can cause the object to start to turn, twist and tumble. A parachute system is deployed to generate air resistance from the atmosphere. (note that the thicker the atmosphere the more resistance) Parachutes designed for use on Earth will not be the same as a parachute designed for Mars.