How Does E-mail Work?
Ever wondered how e-mail gets from your desktop to a friend halfway around the world? How Stuff Works author Marshall Brain explains how e-mail works.

Using an e-mail program, or client, you compose your message. Then you send it. Marshall says to think of your message as a little digital package of information. That package is sent through a cable from your computer to another computer maintained by your e-mail service provider, which is called a mail server. The mail server examines the recipient's address to decide how to route the message.

The message then travels over the Internet, arriving at the mail server of the recipient's e-mail service provider, where it is held in an electronic mailbox. When the recipient checks for new messages, their e-mail client communicates with their e-mail service provider's mail server and retrieves any new messages waiting in that electronic mailbox. In a process that typically takes less than a second—you've got mail!

How Do Televisions Work?
How does The Oprah Show end up on the television screen in your house? Marshall Brain knows! First, a video camera takes Oprah's picture and breaks it up into about a quarter of a million tiny little dots called pixels. Each one of these dots has a color and a place on the screen. The camera converts this series of dots into an electrical signal that is then sent to a satellite dish about three miles from the studio. The satellite dish converts the electrical signal into radio waves and beams them up into space to a satellite 22,000 miles away. From there, the signal can be directed to any place on the planet—from cable companies to the dish on your roof—where it's turned back into an electrical signal.

The signal is still a bunch of dots, but your TV puts them all back together to make a picture. Something called an electron gun, inside your television, sprays all those dots onto your TV screen in the same order they were originally sent out. In this way an entire picture is created.

This entire process happens 30 times a second—that's why the images seem to move!

How Do Telephones Work?
In order to make a telephone call, you pick up a telephone and release the hook switch (the piece of the phone on the receiver you press to get a dial tone or to hang up, or the ON/OFF button on cordless phones). Marshall explains that act basically tells the phone company you want to make a call. When you hear a dial tone, you dial your number.

The phone company gets the number you're calling and makes a path for it, or routes the call, to its destination. There are buildings across the globe that house telephone switching equipment, as well as fiber optic cables that flow between them. In split seconds, computers patch together a set of cables and figure out precisely how to direct your call. The moment the path is established, the phone rings and you're ready to chat.

As you speak into your telephone's microphone, the sound waves are turned into an electrical signal so that it can flow through the network along copper wires. On the other end of the line, a phone takes the signal and uses the speaker to convert the electrical signal back into sounds waves.

How Do Microwaves Work?
Once you pop in your food and hit start, Marshall Brain explains that a microwave oven has a little metal box inside of it called a magnetron. The magnetron produces the microwaves that heat your food. And microwaves, says Marshall, are really radio waves. A little metal fan inside your microwave breaks up the radio waves and spreads them throughout the oven. Some ricochet off the walls, some hit the food directly.

Marshall points out that radio waves are in the air all around us. But in the case of microwave ovens, the radio waves have a specific frequency that gives them an interesting property: they are absorbed by water, fats and sugars. Food contains those same molecules that become excited as the radio waves strike them. This excitement turns into heat, which cooks your food.

What's a Stock?
CNBC star Maria Bartiromo is here to school us on money matters. First, the basics: What's a stock?

"A stock is ownership in a company," Maria says. "You have a friend who is doing well and has a small business and decides, 'I want to take this business to the next level. I need money to do that. I'm going to go public. I want to sell part of that company to the public.' Then a banker comes, they value the business, they divvy it up—shares—and that gives individuals an opportunity to own part of that business."

Why Do Traders Yell?
Why do people who work on the trading floor yell so much?

"Information is moving so quickly and stocks are trading all day long," Maria says. "Let me give you a quick analogy. You're at home, you call your broker at [UBS] PaineWebber and you say ... 'I want to buy IBM but I'm not paying any more than $70 a share.' He's got to get over to that post before that stock changes in price. ... He's physically running over because if somebody gets in front of you and they want to buy a million shares, the next thing you know, it's $72 [per share]. Then he's got to call you and say, 'Guess what, Oprah? I couldn't buy it at $70. You paid $75.' And you're going to say, 'You're fired.'"

What Is the NASDAQ and What Does It Stand For?
"First I'm going to tell you what it is," Maria says, "before I tell you what it stands for, because when I tell you what it stands for it actually sounds a lot more complicated than what it is. All it is is an electronic computer system where brokers and dealers will buy or sell stocks. Just like you buying or selling something on eBay, you can buy or sell stocks on NASDAQ.

"What does it stand for? National Association of Securities Dealers Automated Quote System."

What Is FICA?
One audience member wants to know—"Who is FICA and why do they take so much money out of my paycheck every week?"

"Federal Insurance Contributions Act," Maria says. "[It's a] federal law that requires employees and employers to withhold back a portion of our paycheck and put it into a fund that—when we turn 65—will pay our Medicare and our Social Security benefits. So every two weeks you have to pay, as an employee, 7.65 percent of your check. Your employer will match that another 7.65 percent for a total of 15.2 percent. ... If you're self-employed, you're on the hook for the whole 15.2 percent."

When's the Best Time to Buy a House or Car?
Think "low interest rates," Maria says. But when you're thinking about purchasing a home, timing the market should not be your first consideration. "A home is your home; it's an investment. You want to buy a home when you need a home, and you want to live in a home, and [when] you find a beautiful home."

What Is a Good Stock Strategy?
Maria shares financial wizard Warren Buffet's stock-buying strategy.

"His strategy is to buy well-known quality companies," Maria says. "He calls them 'market leaders.' [These are] the Coca-Colas of the world, American Express—those are two of his big holdings."

Where Does Money Go to Die?
"When [dollar bills] get old and the quality has deteriorated, they throw it out," Maria says. At the New York Federal Reserve Bank they have bags of shredded dollars—free for the taking!

What's the Best Way to Save Money?
Maria says there are "three buckets" to savings:

  1. Savings Account or CD: "You're not going to get a great interest rate," Maria says, "but at least you know it's there and safe."
  2. 401k or IRA: "You must have a 401k," Maria says. "If your company is not offering a 401k, you must have an IRA (or Individual Retirement Account.)"
  3. Stocks: "I do believe most people should be invested in stocks," Maria says. "You want to have an investment account if you have the extra money to do so."

Money Mistakes
Maria says that spontaneous spending and "those fabulous shoes that cost way too much" can wreak havoc on your finances. What's her weakness? "I go out to dinner way too much!" she admits.

Oprah's Kind of Town
Before the show, audience members wrote down their most burning questions for Oprah!

First, why does Oprah tape in Chicago?

"I started in Chicago 20 years ago," Oprah says. "This is the audience that made it possible for this show to go national. Because of that, I always wanted to honor the people who made me who I am."

Trading Places
If Oprah could live a week in someone else's shoes, whose would they be?

"I would just live a week in my own shoes that were the right size," Oprah jokes. "I have a pretty good life. I don't want to trade my life with anybody."

Oprah for President?
Does Oprah have any political aspirations?

"No, no, never, no!" Oprah says in no uncertain terms. "I know they say, 'Never say never', but, no, no, never."

Who Was Oprah's First True Love?
Oprah doesn't reveal his name, but says that she and her beau dated in high school. "He was voted most popular; I was voted most popular," Oprah recalls with a nostalgic smile. "I ended up with a TV show; he didn't!"

Oprah's Last Day on Earth
If it were Oprah's last day on earth, how would she spend her final hours?

"I have a lovely home in California," Oprah says, "I love sitting under the oak trees. So that's what I would do."

Thong or Panties?
The person who asked this bold question is suddenly shy when asked to claim it. "Who asked that question?" Oprah says as she scans the audience for a guilty face. "I want to know!"

No one owns up to it, but Oprah answers anyway: "Neither." (Oprah wears Spanx®.)