Journey Inside One of the Planet's Biggest Caves

Plus, learn how to throw a knife and why oceans weren't always blue. 

Happy Tuesday Happy birthday to Felix Baumgartner, the Austrian daredevil who has lived to see another birthday despite a high-flying career that's involved things like base jumping and voluntarily jumping to Earth from a helium balloon 13.5 miles (21.7 kilometers) above it. In case you missed it: For all you deal hunters out there, Home Chef is offering our newsletter readers $90 off their first four meal kits. Check it out. Vietnam's Massive Hang Sơn Đoòng Cave Has Its Own Jungles In this remote cave, stalagmites can grow to be over 246 feet (75 meters)! It's like a real-life version of Jules Verne's "Journey to the Center of the Earth." Read more >> Do People Really Die of Old Age? Most of us have had a grandparent or great-aunt who, whether suddenly or gradually, "died of old age." What does that mean? Read more >> How Knife Throwing Works Knife throwing can be a rewarding pastime. All it takes is knife balanced for throwing, a good target and lots and lots of practice. Read more >> A Tax for Frequent Flyers? All those aviation-related carbon emissions aren't so great for the climate. What if the tax on airline tickets went up with every flight taken? Read more >> We Once Had Pink Oceans It seems that ancient oceans had a rosy hue. How did that happen? Read more >> How Fish and Chips Became England's National Dish Today, there are still 10,500 "chippies" in the U.K. serving 360 million meals of fish and chips every year, the equivalent of six servings of fish and chips for every British man, woman and child. Read more >> Q: Which National Park is Your Favorite?   This week we want to know which national park is your favorite to visit! And, if you can, tell us in one sentence why it's your favorite. Reply to this email with your first name and answer so we can feature you in a future newsletter! The Results Are In ...   Last week we asked which season you love the most, and the lovely season we are currently experiencing in the Northern Hemisphere is the winner! But, fall is a very close second. Thanks for participating, everyone. Stay cool, winter lovers. Copyright © 2021 HowStuffWorks, All rights reserved. You are receiving this email because you opted in at our website howstuffworks.com Our mailing address is: HowStuffWorks 1501 Main St Suite 101 Venice, CA 90291 Want to change how you receive these promotional emails? You can update your preferences or unsubscribe from this list