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Have you ever wondered why shoes hanging on a power line don’t get fried? Or why natural gas flames are blue? Now you can get answers to these and all your energy-related questions. Just Ask an Expert!

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NEW! Why is the sun yellow and orange?
—Lily

Answer: Would you be surprised, Lily, to learn that the sun is not yellow or orange? It's actually white. The reason the sun appears yellow during the day, or orange to red at sunrise and sunset, is because we view it through the filter of the atmosphere. The atmosphere changes the apparent color of the sun by scattering light. The atmosphere is thicker at sunrise and sunset, and therefore the sun appears more orange and red at these times of day. The atmosphere is thinnest at midday, and that’s when the sun appears closest to its true color white, but still has a yellow tint to it. Smoke and smog can also make the atmosphere thicker, making the sun appear more orange or red.

Why can birds sit on power lines and not get electrocuted?
—Sandra

Answer: Electricity is always looking for a way to get to the ground. Small birds can sit safely on one power line: they do not touch anything in contact with the ground, so electricity stays in the power line and does not harm the birds. However, large birds with broad wingspans are more likely to touch a power line and a utility pole at the same time, which can create a path for electricity to travel down the pole to the ground. Their large wings can also bridge two power lines, creating a circuit or a path for electricity. In either situation, the birds can be electrocuted.

Can books start an electrical fire?
—Sam

Answer: Yes! Books that are in contact with a heat-producing electrical appliance could indeed catch fire. Books could also catch fire if left too close to a high-wattage light bulb. So be careful to keep your books, papers, and other flammable materials away from anything that gets hot, including irons, space heaters, toaster ovens, kitchen ranges, and light fixtures.

Is it safe to use a generator to run an electric space heater?
—Tom

Answer: You can safely use a generator to run an electric space heater, provided you take three important precautions. First and foremost, never use your generator indoors. Generator exhaust contains high levels of carbon monoxide (CO), a deadly gas. To keep CO from entering your home, you must set up your generator outdoors, away from doors, windows, and vents. Second, never try to power your home wiring by plugging the generator into a wall outlet. Instead, plug the space heater directly into the generator—or, if the heater cord is not long enough, use a heavy-duty, outdoor-rated extension cord. Make sure the extension cord is in good condition and the plug has all three prongs. Last but not least, check the wattage on your space heater and make sure your generator can accommodate it. The manufacturer’s instructions will tell you how much wattage your generator can handle.

What is cap rock?
—Rasty

Answer: Cap rock is the layer of very dense rock above reservoir rock and source rock that keeps underground natural gas from traveling to the surface. For more on this, see the “Older Than Dinosaurs” section in our Natural Gas Safety-SMART module on this site.

I stood next to two large green boxes, transformers I assume, for about 20 seconds. In that time I felt a tingle/mild heat through my body. What’s that all about, and did it hurt me?
—Jeff

Answer: Safety is our number one core value. We build and maintain our equipment to ensure that we provide safe and reliable electric service for our customers. Any time you have a safety concern, such as the green boxes you mentioned, please move safely away and call Dominion. We will investigate your concern to determine whether or not the boxes are our equipment, and take any corrective actions that may be needed. Even if the green boxes are not ours, we will ensure that the owner of the equipment is notified and your concern is appropriately addressed.

Should liquefied natural gas be exported?
—Grace

Answer: Our nation has vast reserves of natural gas, enough to easily meet domestic needs and have enough for limited sales overseas. Along with being part of the president’s plan to help the world shift to cleaner fuels, exporting liquefied natural gas will create thousands of jobs and provide a major boost to our economy.

At what depth are residential power lines normally buried?
—Cliff

Answer: Underground power lines in the Dominion service area are buried at depths specified by the National Electrical Safety Code. In general, buried power lines carrying up to 600 volts must be buried at least 24 inches deep, and lines carrying between 601 and 50,000 volts must be at least 30 inches deep, although there are variations on this rule. Landscaping or excavation work in the area can change ground conditions after a power line has been installed and alter its depth. If your family is considering a digging project, always call Miss Utility at 811 to have utilities marked before digging, to allow time for all the utilities to be marked, and to obtain a positive response from Miss Utility.

Is it possible to have an underground power line? How much does an underground power line cost?
—Jacob

Answer: Yes, underground power lines are indeed possible, and are in place all over the country. But putting power lines underground is very expensive. The cost varies according to the type of the line and the geographic location, so I can't provide an exact dollar amount.

How can lightning kill you?
—Jacob

Answer: A lightning strike can carry up to 100 million electrical volts. That's as much electricity as is contained in about 8 million car batteries. A shock of this size can disrupt the body's electrical signals, and stop the heart and brain. For tips on how to stay safe in a lightning storm, check out our site's lightning safety section here.