A letter being auctioned in London this week adds more fuel to the long simmering debate about the Nobel prize winning physicists religious views. In the note, written the year before his death, Einstein dismissed the idea of God as the product of human weakness and the Bible as " pretty childish."

The letter, handwritten in German, is being sold by Bloomsbury Auctions and is expected to bring in between $12,000 and $ 16,000. In it, Einstein said that " the word God is for me nothing more than the expression and product of human weaknesses, the Bible a collection of honorable but still primative legends which are nevertheless pretty childish. For me the Jewish religion like all other religions is an incarnation of the most childish superstitions."

Addressing the idea that the Jews are God's chosen people, Einstein wrote that " the Jewish people to whom I gladly belong and with whose mentality I have a deep affinity have no different quality for me than all other people. As far as my experience goes, they are also no better than other human groups, although they are protected from the worst cancers by a lack of power. Otherwise I cannot see anything " chosen " about them."

Einstein's most famous legacy is the special theory of relativity, which makes the point that a large amount of energy could be released from a tiny amount of matter, as expressed in the equation E= m c 2 ( energy equals mass times the speed of light squared.)

We all want to keep our families safe and healthy, but knowing what's worth worrying about can save your nerves from fraying and help keep you healthier. Here are nine common concerns, how scary they really are, and how to protect yourself and your family.

TOILETS.
Toilets are not as likely to spread infection as you may think. That's because you don't touch a toilet seat and then your mouth or nose without washing your hands. Very few viruses or bacteria can pass through intact skin, so in order to catch something from an inanimate object, you have to spread it to your mouth, nose or eyes. The prevalent myth that sexually transmitted diseases can be picked up from a toilet seat is just not true. Sexually transmitted diseases are acquired by having sex.

GAS FUMES.
If you breathed them constantly, gas vapors and additives would certainly make you sick. The good news is that modern pumps use special nozzles that trap more than 90% of vapors during refueling. Still, have someone else pump for you if your sensitive to fumes, pregnant, or if won't be able to wash the gas residue off your hands afterward.

DOOR KNOBS.
Public restrooms are a major source of disease because of the number of dirty fingers touching the doors, sinks and paper-towel dispensers. Your own fingers become contaminated and can make you sick if you touch your mouth or other mucous membrane. The solution is to wash your hands, then open the door with your elbows or use a paper towel to turn the knob.

HAIR COLORING.
Hair dye is less dangerous for clients than for stylists, who have the greatest exposure to the chemicals. Still, the use of dark, permanent dyes for more than 25 years has been linked to a higher risk of lymphoma, a kind of blood cancer. To be on the safe side, consider using semi-permanent or Henna based dyes.

NAIL POLISH.
Polishing your nails isn't dangerous, but sitting in a nail salon can be. The chemicals in nail polish are volitile, they evaporate into the air, and you breath them in. Exposure to the three most dangerous chemicals, toluene, formaldehyde and phthalate, has been linked to cancer and birth defects. If your pregnant or nursing, you probably should keep your nails au naturel. Otherwise, look for a salon with personal ventilation hoods that remove, not recycle, contaminated air.

DIRT.
If your thinking " yuck ", think again. Dirt may be the most underrated health product around. Studies show that children who grow up dirty, for example, living with pets or older siblings, or attending daycare in the first year of life, have a lower risk of getting allergies, asthma, eczema and autoimmune diseases later in life. Let the children play in the dirt. Of course, stay away from contaminated dirt around construction sites, old homes with lead paint or garbage dumps.

MICROWAVE OVENS.
Microwave ovens do leak minimal amounts of radiation, but heating or reheating food in them is safe when done properly. Ovens made since 1971 meet FDA standards and are safe unless they are damaged in some way. Still, stand at least two inches from the door while cooking, and avoid reheating foods in plastic containers.

CELLPHONES.
Mobile phones receive and transmit radio waves very much like FM radio but at a higher frequency. Some people are concerned that this may increase the risk for cancer, but the National Cancer Institutes have found no link so far. However, a study in Sweden in 2005 showed higher risk for people using cellphones in rural areas (where phones transmit with more power, because towers are further apart) compared with urban areas. Furthermore, studies suggest that frequent cellphone use, or carrying a cellphone on your belt or in your pocket, could affect male fertility.

AIRPLANES.
You're less likely to be injured in an airplane crash than while driving, taking the train or riding a bike. But there are health risks associated with flying. The most serious is " economy class syndrome," sitting too long in a confined space can cause blood clots in the legs. People who are overweight, have joint problems, varicose veins or cancer, or who have had a revent surgery or injury are at greatest risk. Get up and walk the aisles every 90 minutes, move your legs while you sit, drink plenty of water, and ask your doctor if you should take an aspirin before a long flight.