3 experiments that prove the Earth is round

Celebrate Science Day 2020 by proving the Earth is not flat.

3 experiments that prove the Earth is round
Credit: NASA/sharplaninac/Adobe Stock/Big Think
  • Flat-Earthers drive rational people nuts.
  • A physicist offers three experiments to confirm it is those people who are crazy, not you.
  • The experiments, however, do require a belief in mathematics.

Happy World Science Day! It's been a rough year for ol' science, which probably hasn't been under attack by so many people since the (last) Dark Ages. Conspiracy theorists at heart, anti-maskers, anti-vaxxers, and perhaps most unbelievably of all, flat-Earthers have been loudly calling into question the pretty-much unquestionable.

In any event, physicist Steven Wooding — the guy who brought us the contactable alien civilization calculator last spring — has offered up a lovely gift for science on its special day: the Flat vs. Round Earth Calculator. It consists of three experiments that can prove to anyone who believes in math that the Earth really is round. We can probably assume, of course, that there are now people arguing that 2+2=5. For these folks we'll point out simply that if the Earth really were flat, cats would have long ago pushed everything over its edge.

Be sure to scroll down the calculator page for Wooding's entertaining treatise on why the whole flat-Earth idea is so forehead-smackingly stupid.

Experiment 1: Catch a sunset twice

Credit: Johannes Plenio/Unsplash

At the top of the calculator is the "Select an experiment" drop-down menu. Let's start with the "sunset twice" experiment.

Wooding notes that you can prove the Earth is round by standing up quickly right after the Sun goes down and getting ahead of the shadow cast by the horizon so you can see the sun set a second time. If the planet were flat, once it went over the edge from your first viewing position it would be gone.

You may want to find out the time of sunset before testing out the calculator. There are many places online to find this information. Here's one.

To use the calculator, begin by selecting a city in your time zone. Wooding has pre-entered the sunset duration for you, though you can look up the precise value online for your location.

There are three ways to increase your height, selected from the "Ideas" menu: standing up from a lying down position, taking the sky-lift elevator at the Burj Khalifa Hotel in Dubai, or sending up a drone with a camera on it. Most of us will select the first option.

Next, you enter your starting height (the default for lying down is .6562 feet), how long it will take you to stand up, and then the final standing elevation, presumably of your eyes.

What the calculator finds for you is the percentage of the second sunset you'll see. Note that for the sky-lift and drone tests, you see a lot more of that second sunset given the greater height and your accelerated ascent speed.

Experiment 2: Disappearing object

Credit: Michael Olsen/Unsplash

Thanks to the curvature of the Earth, you can make an object on a distant lake shore seem to disappear with a change in viewing height.

You'll need binoculars for this one. And, um, a lake.

The calculator will tell you how much of the object will become unobservable after you fill in the three values.

(You may also need a boat to measure the distance.)

Experiment 3: Stick shadows

Credit: Logan Radinovich/Unsplash

For this one you'll need a cooperative friend who lives at least some distance away, or a teleporter. Also two sticks and a day with enough sunlight to cast shadows in both locations.

This experiment involves measuring shadows cast at two different locations and calculating the angle between them to arrive at the Earth's circumference.

This experiment is a little advanced mathematically, and Wooding offers a help link if you're confused.

How New York's largest hospital system is predicting COVID-19 spikes

Northwell Health is using insights from website traffic to forecast COVID-19 hospitalizations two weeks in the future.

Credit: Getty Images
Sponsored by Northwell Health
  • The machine-learning algorithm works by analyzing the online behavior of visitors to the Northwell Health website and comparing that data to future COVID-19 hospitalizations.
  • The tool, which uses anonymized data, has so far predicted hospitalizations with an accuracy rate of 80 percent.
  • Machine-learning tools are helping health-care professionals worldwide better constrain and treat COVID-19.
Keep reading Show less

Listen: Scientists re-create voice of 3,000-year-old Egyptian mummy

Scientists used CT scanning and 3D-printing technology to re-create the voice of Nesyamun, an ancient Egyptian priest.

Surprising Science
  • Scientists printed a 3D replica of the vocal tract of Nesyamun, an Egyptian priest whose mummified corpse has been on display in the UK for two centuries.
  • With the help of an electronic device, the reproduced voice is able to "speak" a vowel noise.
  • The team behind the "Voices of the Past" project suggest reproducing ancient voices could make museum experiences more dynamic.
Keep reading Show less

Dark matter axions possibly found near Magnificent 7 neutron stars

A new study proposes mysterious axions may be found in X-rays coming from a cluster of neutron stars.

A rendering of the XMM-Newton (X-ray multi-mirror mission) space telescope.

Credit: D. Ducros; ESA/XMM-Newton, CC BY-SA 3.0 IGO
Surprising Science
  • A study led by Berkeley Lab suggests axions may be present near neutron stars known as the Magnificent Seven.
  • The axions, theorized fundamental particles, could be found in the high-energy X-rays emitted from the stars.
  • Axions have yet to be observed directly and may be responsible for the elusive dark matter.
  • Keep reading Show less

    Put on a happy face? “Deep acting” associated with improved work life

    New research suggests you can't fake your emotional state to improve your work life — you have to feel it.

    Credit: Columbia Pictures
    Personal Growth
  • Deep acting is the work strategy of regulating your emotions to match a desired state.
  • New research suggests that deep acting reduces fatigue, improves trust, and advances goal progress over other regulation strategies.
  • Further research suggests learning to attune our emotions for deep acting is a beneficial work-life strategy.
  • Keep reading Show less
    Surprising Science

    World's oldest work of art found in a hidden Indonesian valley

    Archaeologists discover a cave painting of a wild pig that is now the world's oldest dated work of representational art.

    Scroll down to load more…