We’ve all heard them: drink eight glasses of water a day, we only use 10% of our brains, and reading in dim light causes eye damage. But what is the truth behind these old wives’ tales?
Drink eight glasses of water a day
No, you need about eight glasses of FLUID (not necessarily water) each day. Water does constitutes about 70% of our bodies, and we do need water to survive. But too much water can be just as dangerous as too little. Drinking too much water can lead to water retention, so be sure to follow your thirst as a guide. If you’re on a long flight, the weather is sweltering, or you exercise a lot, drink a little extra.
We only use 10% of our brains
Some think Albert Einstein said this, but there is no record of him ever making this statement. And modern neuroscience says we use much more than 10% of our brains. Studies have shown that no area of the brain is completely inactive or silent.
Reading in dim lights ruins your eyes
Not in the long run. You may have difficulty focusing in dim light, and it may make your eyes water, but there is no evidence that these effects persist after you stop reading. Strangely, there has actually been an increase in the prevalence of bad eyesight as we have moved from candles and lanterns to brighter electric lighting. Scientists are still trying to figure out why, but they think it might be environmental.
Hair and fingernails continue to grow after death
It might look like they do, but don’t actually continue to grow after death. After death, the body dehydrates, and this may cause the skin around the nails and hair follicles to ‘shrink’ away which makes it look like the nails and hair have grown. The actual growth of hair and nails is controlled by a complex hormonal system, which doesn’t function after death.
Sitting in hot water can have an effect on a man’s ability to father babies
Yup, you might want to rethink having a hot soak if you are planning on having children in the near future. High water temperature can affect the process of sperm foundation. Any male interested in fathering a child should avoid water temperatures greater than about 100 degrees Fahrenheit. Women though can indulge in those long, hot soaks without affecting their fertility.