Ask an Expert about Electricity & Natural Gas

 

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! How often might a residential light switch need to be replaced?
—CP

Answer: Light switches are pretty durable and can last for 20 years or more. However, they can wear out over time due to repeated use or loose wire connections, so it is wise to check them periodically. If you spot any one of the signs below, you should immediately turn the light switch off.

  • If your light switch makes popping or crackling sounds when you flip it on or off.
  • If your light switch cover is loose and won’t stay level.
  • If there is a delay between when you flip the light switch on and when the light actually comes on.
  • If the light switch is warm when you touch it. This could indicate a loose wire connection and a fire hazard. Turn the light off.

Why when I touch a power line I get hurt, but a bird doesn't?
—Mikalika

How do birds not get burnt when they sit on a telephone wire?
—Akira

Answer: A little birdy told me you two have been watching us! And since birds of a feather, flock together, I shall answer both of your questions together. 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. Like large birds, you should never touch a power line, because you would be giving the electricity a path to the ground, and you would get hurt.

I once saw a pair of shoes hanging from a power line. Why didn’t the shoes get burned up by the electricity in the line?
—Will

Answer: Shoes hanging on a power line don’t get burned for the same reason that birds standing on a power line don’t get shocked: they don’t give electricity a path to the ground, so electricity stays in the line and does not go through them. But if the shoes were to touch a power line and a power pole at the same time, they would provide a path to the ground and would get blasted with electric current. It wouldn’t be pretty!

By the way, if you ever see someone throwing shoes up onto a line, tell them to stop! The shoes can damage the power line, or someone trying to get the shoes down could be seriously shocked or even killed.

Why does the flame on my stove burners look blue, but the flame of a campfire is yellow?
—Evan

Answer: A natural gas flame burns hotter than a campfire. In general, cooler flames appear yellow, orange, or red, while hotter flames look blue or white. (Flecks of orange in your gas flames are OK, but if the flame is yellow, large, and flickering, the appliance may need a safety adjustment by a qualified repair person.)

Do electric eels really create electricity?
—Elena

Answer: Yes! An electric eel uses chemicals in its body to manufacture electricity. A large electric eel can produce a charge of up to 650 volts, which is more than five times the shocking power of a household outlet.

Who discovered natural gas?
—Sela

Answer: The ancient Chinese were the first to discover underground deposits of natural gas. In 600 BC, Confucius wrote of wells 100 feet deep yielding water and natural gas along the Tibetan borer. The Chinese piped the gas to where it was needed through long, hollow bamboo stalks.

How much energy is in a bolt of lightning?
—Sophie

Answer: One lightning strike can carry 100 million to 1 billion volts. That’s the equivalent of between 8 and 80 million car batteries!

When a circuit is open, do electrons go backwards, or do they just stop?
—Alex

Answer: Neither! In the wires of an electrical circuit, the electrons are always jiggling around. When a circuit is closed to run an appliance or a light bulb, the electrons jiggle a lot and travel through the wire. When the circuit is open, all the electrons just jiggle where they are—kind of like running in place.

Why didn’t Ben Franklin get electrocuted when he tied a metal key to a kite string and flew the kite in a thunderstorm?
—Tyler

Answer: Ben Franklin probably did not do his famous kite experiment the way it is usually portrayed. (Franklin never wrote about it himself, and the only description we have of it was written by another scholar, Joseph Priestley, 15 years later.) Franklin believed lightning was a flow of electricity taking place in nature. He knew of electricity’s dangers, and would probably not have risked being struck by lightning by flying his kite during a storm. It is more likely that Franklin flew his kite before the storm occurred, and that his famous key gave off an electric spark by drawing small electrical charges from the air.