Is It Possible for an Object to Escape the Influence of Gravity While on Earth?

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Is it possible for any object not to be under the influence of gravity while on Earth?C Stuart Hardwick:

No.

No object can escape the influence of gravity anywhere in the universe, as far as we know.

It is, however, possible for an object to escape certain effects of gravity under certain circumstances. Airplanes, for example, escape the acceleration of gravity by constantly expending energy to climb against it. I do it by pressing the electrons in the outer shells of the molecules of my shoe leather against those of the sidewalk.

Skydivers can do something pretty interesting by donning their wind-resistant gear and floating above a giant fan.


Mythbusters did essentially the same thing with a penny and an adjustable blower:


And of course, ships and balloons overcome the pull of gravity via buoyancy:


Astronauts escape more—but not all—effects of gravity by coasting away from the Earth in a straight line at exactly the speed they are falling toward it. This is what we call “being in orbit.” The same thing can be achieved in an aircraft by carefully diving toward the ground along at exactly the speed of acceleration due to gravity. Pulling up after a few seconds is highly recommended.

But all these remain under the influence of gravity, and would remain so even if the Earth weren’t here, because there are plenty of other objects, such as the Sun, which also originate their own far-reaching gravitational fields.

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This Course Will Teach You How to Play Guitar Like a Pro for $29

BartekSzewczyk/iStock via Getty Images
BartekSzewczyk/iStock via Getty Images

Be honest: You’ve watched a YouTube video or two in an attempt to learn how to play a song on the guitar. Whether it was through tabs or simply copying whatever you saw on the screen, the fun always ends when friends start throwing out requests for songs you have no idea how to play. So how about you actually learn how to play guitar for real this time?

It’s now possible to learn guitar from home with the Ultimate Beginner to Expert Guitar Lessons Bundle, which is currently on sale for $29. Grab that Gibson, Fender, or whatever you have handy, and learn to strum rhythms from scratch.

The strumming course will teach you how to count beats and rests to turn your hands and fingers into the perfect accompaniment for your own voice or other musicians. Then, you can take things a step further and learn advanced jamming and soloing to riff anytime, anywhere. This course will teach you to improvise across various chords and progressions so you can jump into any jam with something original. You’ll also have the chance to dive deep into the major guitar genres of bluegrass, blues, and jazz. Lessons in jam etiquette, genre history, and how to read music will separate you from a novice player.

This bundle also includes courses in ear training so you can properly identify any relative note, interval, or pitch. That way, you can play along with any song when it comes on, or even understand how to modify it into the key you’d prefer. And when the time comes to perform, be prepared with skilled hammer-ons, pull-offs, slides, bends, trills, vibrato, and fret-tapping. Not only will you learn the basic foundations of guitar, you’ll ultimately be able to develop your own style with the help of these lessons.

The Ultimate Beginner to Expert Guitar Lessons Bundle is discounted for a limited time. Act on this $29 offer now to work on those fingertip calluses and play like a pro.

 

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A Prehistoric Great White Shark Nursery Has Been Discovered in Chile

Great white sharks used prehistoric nurseries to protect their young.
Great white sharks used prehistoric nurseries to protect their young.
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Great white sharks (Carcharodon carcharias) may be one of the most formidable and frightening apex predators on the planet today, but life for them isn’t as easy as horror movies would suggest. Due to a slow growth rate and the fact that they produce few offspring, the species is listed as vulnerable to extinction.

There is a way these sharks ensure survival, and that is by creating nurseries—a designated place where great white shark babies (called pups) are protected from other predators. Now, researchers at the University of Vienna and colleagues have discovered these nurseries occurred in prehistoric times.

In a study published in the journal Scientific Reports, Jamie A. Villafaña from the university’s Institute of Palaeontology describes a fossilized nursery found in Coquimbo, Chile. Researchers were examining a collection of fossilized great white shark teeth between 5 and 2 million years old along the Pacific coast of Chile and Peru when they noticed a disproportionate number of young shark teeth in Coquimbo. There was also a total lack of sexually mature animals' teeth, which suggests the site was used primarily by pups and juveniles as a nursery.

Though modern great whites are known to guard their young in designated areas, the researchers say this is the first example of a paleo-nursery. Because the climate was much warmer when the paleo-nursery was in use, the researchers think these protective environments can deepen our understanding of how great white sharks can survive global warming trends.