If the asteroid that wiped out the dinosaurs 65 million years ago had landed a thousand miles out in the ocean, would the result have been different?
Stephen C. McArthur, The Villages, Florida
Yes. The dinosaurs might well have survived. Unfortunately for them, the asteroid hit shallow crustal rock—specifically, the Yucatán Peninsula. The impact blasted a toxic combination of sulfur dioxide and carbon dioxide gases, as well as dust and soot, into the upper atmosphere, causing the dispersal of sulfuric acid aerosols and acid rain and a fatal blackout of sunlight that led to global cooling.
Brian Huber, Marine Micropaleontologist, National Museum of Natural History
How was the telegraph system powered before the development of long- distance transmission of electricity?
Donald Gruber, Clinton, Illinois
One word: batteries. Samuel Morse’s 1844 line used wet-cell batteries designed by William Grove. One of Thomas Edison’s routine chores as a telegrapher involved refilling batteries with fresh acid.
Hal Wallace, Curator of Electricity, National Museum of American History
Are probiotic supplements actually helpful for the digestive tract?
Ingrid Wild Kleckner, Riverside, Rhode Island
For humans, it’s hard to say; definitive research is scant. But at the National Zoo, we occasionally feed probiotics (such as yogurt) to tamarins and other animals whose digestion has been hindered by illness, novel foods or medicines that kill the micro-organisms normally (and usefully) present in the digestive tract.
Mike Maslanka, Head, Department of Nutrition Science, National Zoo
Couldn’t we dispose of our radioactive waste—and settle the contentious debate over where we should bury it—by launching it into outer space?
Larry Vanderleest, Oak Harbor, Washington
We could, but two big problems arise immediately. First, this would be an enormously expensive enterprise. More important is the issue of safety: The failure of any rocket launching nuclear waste into space would disperse its payload into the atmosphere and could endanger humans around the globe. That would certainly defeat the purpose of safely disposing of nuclear material.
Roger D. Launius, Curator of Space History, National Air and Space Museum
Where can I find a complete list of the names of those who bought tickets for the Titanic, even if they missed it or were barred from the ship?
Eric William Ruckman, Memphis, Tennessee
Try Debbie Beavis’ book, Who Sailed on Titanic?, or the original passenger lists on which it is based. The National Archives Northeast Region in New York City has a copy of the “Contract Ticket List,” White Star’s list of Titanic tickets sold. The National Archives in London has lists of those who boarded at Southampton and at Queenstown. Some names of ticketed passengers who did not sail appear on these lists.
Daniel Piazza, Curator of “Fire & Ice: Hindenburg and Titanic,” National Postal Museum
It's your turn to Ask Smithsonian