|
|
When Gabriel Fahrenheit invented the first mercury thermometer, he called "zero degrees" the lowest temperature he was able to attain with a mixture of ice and salt. For the upper point of his scale, he used 96°, which he measured as normal human body temperature (we know it to be 98.6° today because of more accurate thermometers).
Looking at the sun may not only cause headache and distort your vision temporarily, but it can also cause permanent eye damage. Any exposure to sunlight adds to the cumulative effects of ultraviolet (UV) radiation on your eyes. UV exposure has been linked to eye disorders such as macular degeneration, solar retinitis, and corneal dystrophies.
If all the neurons in the human body were lined up, they would stretch more than 600 miles.
The toxic levels for lithium carbonate are close to the therapeutic levels. Signs of toxicity include fine hand tremor, polyuria, mild thirst, nausea, general discomfort, diarrhea, vomiting, drowsiness, muscular weakness, lack of coordination, ataxia, giddiness, tinnitus, and blurred vision.
Alzheimer's disease affects only about 10% of people older than 65 years of age. Most forms of decreased mental function and dementia are caused by disuse (letting the mind get lazy).
![The recent mass upheavals in Tunisia, Egypt, Libya, Yemen, and Syria gave political scientists a cha](https://biology-forums.com/gallery/47/medium_262797_12_08_15_1_33_47_221751025.png)
![The world has been horrified recently at a U.S. Congress so polarized and paralyzed that it cannot p](https://biology-forums.com/gallery/47/medium_262797_12_08_15_1_37_18_22184240.png)
![In 2013, Americans learned that the federal government massively surveys their phone calls and e-mai](https://biology-forums.com/gallery/47/medium_262797_12_08_15_1_46_35_221931656.png)