Sound waves are mechanical waves. They can travel only through matter. They cannot travel through empty space. This was demonstrated in the 1600s by a scientist named Robert Boyle. Boyle placed a ticking clock in a sealed glass jar. The clock could be heard ticking through the air and glass of the jar. Then Boyle pumped the air out of the jar. The clock was still running, but the ticking could not be heard. Thats because the sound couldnt travel without air particles to transfer the sound energy. Is there any other place where sound cannot be heard? Here is a hint: is there any other place that does not have air molecules? Thats right, in space sound cannot be transferred. So can astronauts hear each other? Yes, they can, because they are in enclosed space stations or pressurized suits.In both cases, they are surrounded by air molecules. If they left their space ship and did not use their electronics, they would not be able to hear each other. Next time you watch a science fiction movie, think about this factoid. When spaceships are destroyed by hostile alien beings, there would be no sound heard. Sound waves can travel through many kinds of matter.

Question: "How did Robert Boyle prove the properties of sound waves?"

Response: "yelling in a vacuum"

A: no

Tuesday, September 11, 2001, dawned temperate and nearly cloudless in the eastern United States. Millions of men and women readied themselves for work. Some made their way to the Twin Towers, the signature structures of the World Trade Center complex in New York City. Others went to Arlington, Virginia, to the Pentagon. Across the Potomac River, the United States Congress was back in session. At the other end of Pennsylvania Avenue, people began to line up for a White House tour. In Sarasota, Florida, President George W. Bush went for an early morning run. For those heading to an airport, weather conditions could not have been better for a safe and pleasant journey. Among the travelers were Mohamed Atta and Abdul Aziz al Omari, who arrived at the airport in Portland, Maine. Boston: American 11 and United 175. Atta and Omari boarded a 6:00 A.M. flight from Portland to Boston's Logan International Airport. When he checked in for his flight to Boston, Atta was selected by a computerized prescreening system known as CAPPS (Computer Assisted Passenger Prescreening System), created to identify passengers who should be subject to special security measures. Under security rules in place at the time, the only consequence of Atta's selection by CAPPS was that his checked bags were held off the plane until it was confirmed that he had boarded the aircraft. This did not hinder Atta's plans. Atta and Omari arrived in Boston at 6:45. Seven minutes later, Atta apparently took a call from Marwan al Shehhi, a longtime colleague who was at another terminal at Logan Airport. They spoke for three minutes. It would be their final conversation.

Question: "How long was Atta's final conversation with Marwan al Shehhi?"

Response: "2 minutes"

A: no

Once upon a time I had a dog named Toodles. He was black and white and had long floppy ears. He also had very short legs, but really big paws. Every Saturday we would go to the park and play Toodles' favorite game. Toodles loved playing fetch. One Saturday, Toodles ran over to the pond because he saw ducks swimming there. He ran all around the pond, barking at the ducks. The ducks ignored him, and kept swimming. Toodles wasn't having it! He jumped into the pond and started swimming toward the ducks, chasing around his new playmates. One of the ducks, braver than the others, poked Toodles with his beak - and then bit him right on one of his floppy ears! Toodles barked and ran out of the pond because the duck hurt his ear. Soaking wet, he ran toward where I was eating a sandwich on the grass and curled right up in my lap so I could make him feel better. After that, whenever he would see a duck, Toodles would run the other way.

Question: "Where was the pond"

Response: "In the park"

A:
yes