The Brain Chemistry Behind Your Caffeine Boost

iStock
iStock

Whether it’s consumed as coffee, candy, or toothpaste, caffeine is the world’s most popular drug. If you’ve ever wondered how a shot of espresso can make your groggy head feel alert and ready for the day, TED-Ed has the answer.

Caffeine works by hijacking receptors in the brain. The stimulant is nearly the same size and shape as adenosine, an inhibitory neurotransmitter that slows down neural activity. Adenosine builds up as the day goes on, making us feel more tired as the day progresses. When caffeine enters your system, it falls into the receptors meant to catch adenosine, thus keeping you from feeling as sleepy as you would otherwise. The blocked adenosine receptors also leave room for the mood-boosting compound dopamine to settle into its receptors. Those increased dopamine levels lead to the boost in energy and mood you feel after finishing your morning coffee.

For a closer look at how this process works, check out the video below.

[h/t TED-Ed]

Amazon's Best Cyber Monday Deals on Tablets, Wireless Headphones, Kitchen Appliances, and More

Amazon
Amazon

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

Cyber Monday has arrived, and with it comes some amazing deals. This sale is the one to watch if you are looking to get low prices on the latest Echo Dot, Fire Tablet, video games, Instant Pots, or 4K TVs. Even if you already took advantage of sales during Black Friday or Small Business Saturday, Cyber Monday still has plenty to offer, especially on Amazon. We've compiled some the best deals out there on tech, computers, and kitchen appliances so you don't have to waste your time browsing.

Computers and tablets

Amazon

- Amazon Fire HD 10 Tablet 64GB; $120 (save $70)

- Amazon Fire HD 8 Tablet 64GB; $84 (save $35)

- HP Pavilion x360 14 Convertible 2-in-1 Laptop; $646 (save $114)

- HP Pavilion Desktop, 10th Gen Intel Core i3-10100 Processor; $469 (save $81)

- Acer Nitro 5 Gaming Laptop; $973 (save $177)

Headphones and speakers

Beats/Amazon

- Bose QuietComfort 35 II Wireless Bluetooth Headphones; $200 (save $100)

- Sony Bluetooth Noise-Canceling Wireless Headphones; $278 (save $72)

- JBL LIVE Wireless Headphones; $100 (save $30)

- JBL Charge 4 - Waterproof Portable Bluetooth Speaker; $120 (save $10)

- Bose SoundLink Color Bluetooth Speaker II; $79 (save $50)

- Powerbeats Pro Wireless Earphones; $200 (save $50)

Video Games

Sony

- Watch Dogs Legion; $30 (save $30)

- Marvel's Avengers; $27 (save $33)

- Ghost of Tsushima; $40 (save $20)

- The Last of Us Part II; $30 (save $30)

TECH, GADGETS, AND TVS

Samsung/Amazon

- Amazon Fire TV Stick; $30 (save $20)

- Echo Show 8; $65 (save $65)

- Nixplay Digital Picture Frame; $115 (save $65)

- eufy Smart Doorbell; $90 (save $30)

- Samsung 75-Inch Class Crystal 4K Smart TV; $898 (save $300)

home and Kitchen

Ninja/Amazon

- T-fal 17-Piece Cookware Set; $124 (save $56)

- Le Creuset Enameled Cast Iron Curved Round Chef's Oven; $180 (save $136)

- Ninja Foodi 10-in-1 Convection Toaster Oven; $195 (save $105)

- Roborock E4 Robot Vacuum Cleaner; $189 (save $111)

- Instant Pot Max Pressure Cooker 9 in 1; $80 (save $120)

- Shark IZ362H Cordless Anti-Allergen Lightweight Stick Vacuum; $170 (save $110)

Sign Up Today: Get exclusive deals, product news, reviews, and more with the Mental Floss Smart Shopping newsletter!

How Much Is the Earth Worth?

The New York Public Library, Unsplash
The New York Public Library, Unsplash

Our home planet may be the most precious place we know, but it isn't priceless. The Earth's resources and the value it offers to humans add up to some unknown, tangible cost. The species may never have to worry about buying or selling the world, but thinking of it in terms of concrete numbers can help us better understand its value. Now, as Treehugger reports, one scientist has developed a special formula that allows us to do just that.

According to the calculations of Greg Laughlin, an assistant astronomy and astrophysics professor from the University of California, Santa Cruz, the Earth is worth roughly $5 quadrillion (or $5,000,000,000,000,000). He came up with that price after gauging the planet's mass, temperature, age, and other factors that directly correlate to its ability to sustain life.

To emphasize just how valuable the Earth is, Laughlin also estimated the worth of other planets in our solar system. Our nearest neighbor Mars costs about the same as a used car at $16,000. That's a fortune compared to Venus, which he appraised at the meager value of one cent.

Laughlin doesn't expect these numbers to have applications in the real world. Rather, he hopes they will inspire people to better appreciate the only home they know. He's not the first person to put a massive, hypothetical price tag on something just for fun. The cost of the Death Star from Star Wars has been calculated at $852 quadrillion—many times Laughlin's estimate for Earth.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.