10 MAR 2017 by ideonexus
Intelligent Plant Life
On certain small planets, drenched with light and heat from a near or a great sun, evolution took a very different course from that with which we are familiar. The vegetable and animal functions were not separated into distinct organic types. Every organism was at once animal and vegetable. Many species, of course, developed predatory habits, and special organs of offense, such as muscular boughs as strong as pythons for constriction, or talons, horns, and formidable serrated pincers. In the...02 SEP 2016 by ideonexus
Teaching Temperature
Outside Temperatures. Place a thermometer outside a window so students can make daily calculations and keep a chart reporting the actual temperature and the temperature change from the previous day. Students will see that the change can be a negative number without the temperature falling below 0—an often-confusing concept that is clarified by these observations. An achievable-challenge extension could include barometers, and students who need more advanced work can learn how negative—or...30 JAN 2015 by ideonexus
The Sensation of Pressure
We feel pressure on our skin, when we place our hand over the outlet of a bicycle pump, for example, as a kind of springy push. Actually, pressure is the summed bombardments of thousands of molecules of air, whizzing about in random directions (as opposed to a wind, where the molecules predominantly flow in one particular direction). If you hold your palm up to a high wind you feel the equivalent of pressure - bombardment of molecules. The molecules in a confined space, say, the interior of a...18 NOV 2013 by ideonexus
An Example of the Joy of Hard Science Fiction
If they are going to sink below, then the pressure on the vessel is going to rise as Verne talked about in 20,000 Leagues Under the Sea. If the pressure on the vessel is going to rise, then it's going to collapse unless the pressure within the vessel rises. So the captain is slowly letting the vessel sink into the Moon dust, while the crew is not letting onto the tourists that anything is wrong, but the pressure is slowly going up. Now just as we don't typically notice the pressure go up or ...This example from a Clarke novel illustrates the fun of Hard-SF in how it leaves it up to the reader to figure things out from their scientific literacy.
16 JUL 2013 by ideonexus
Physiological Effects from Exposure to a Vaccum
Vacuum doesn’t have a temperature of its own, so space is not really that cold. It’s a great insulator too, meaning that your core body heat doesn’t get sucked away. Without an atmosphere to transfer heat away, the risk of exposure is somewhat mitigated. The saliva on your tongue may boil off, as it’s not pressurized like your blood is, and you may get some frost on your skin. Sunburn from direct contact with the sun’s ultraviolet rays is a more immediate danger than perishing from ...A good description.