When you go on vacation, you tell the post office to hold your mail and probably don’t think about it once. Email clients are also important for communication; popular programs include Microsoft Outlook, Gmail, Apple Mail and Mozilla Thunderbird. For teens, e-mail is the equivalent of snail mail. Researcher and blogger Danah Boyd, who studies the online habits of teens, uses the mailbox metaphor to explain young people’s preference for instant messaging (IM) over e-mail. The people who sent the e-mails are aware that it might take as long as a couple of hours or even a day to get a response. But even if you’re basking on the beach in Borneo, you might make two or three stops a day to the Internet café to check your e-mail. Which brings us to the main disadvantage of e-mail, that you might have to wait a couple of hours or even a day for a response.

With e-mail, if you compose a message and send it to your friend, you have no idea if your friend is logged onto his computer, when he’ll read your message or when or if he’ll respond. It was so innovative, in fact, that when Jerome Lemelson first submitted the idea to the patent office in 1977, it was rejected as an absurd notion. There’s no need to e-mail multiple copies of the same idea to six people and wait for them all to respond, usually in a confusing, overlapping combination of messages. The Maybach actually has six brake calipers instead of the normal four — two calipers on each front wheel. Now based on the East Coast, the Global Hawks can spend up to six hours off the coast of Africa as storms develop, or 20 hours or more as the storms approach North America. The oil industry thrived there, and millions of tons of cargo and munitions were shipped from West Coast ports. From a technical perspective, real-time communications implies that there’s a direct, open connection between the two or more parties who are talking. For IM, the Internet supplies the direct, open connection. If you send your friend an IM, there’s a much greater chance that he’ll receive the message immediately and respond quickly.

You can see in the following figure that the primary in this particular transformer uses very fine wire while the secondary uses much thicker wire. In the secondary winding the magnetic field in the core creates current. The AC current in the primary winding creates an alternating magnetic field in the iron just as it would in an electromagnet. The 120 volts comes in on the primary winding on the left. In this case the transformer converts the normal 120 volt AC current in your house down to three volts. The purpose of a transformer is to convert one AC voltage to another AC voltage. So if the primary and secondary windings have the same number of turns, the primary and secondary voltage will be the same. The other winding, known as the secondary winding wraps around the same iron core. Running down the middle of that winding (as well as around the outside) is an iron core.

They’re finding that office IM accounts, as well as collaboration tools like wikis and conferencing programs, can make online office life far more efficient. That said, IM is slowly gaining popularity with adults as well, mostly as a workplace collaboration tool. Sure, teens all have e-mail accounts, just like we adults all have mailboxes, but their real communication happens elsewhere. E-mail is fine for sending your assignment to your teacher, but real communication requires the immediacy, intimacy and ubiquity of IM. IM isn’t like e-mail, which uses a standard technological protocol for sending and receiving messages. For the recipient to receive the e-mail, she must log on to her e-mail software or webmail program and retrieve any new messages from the destination server. For this reason, e-mail is usually reserved for messages that fall within a certain window of time sensitivity. The advantage of e-mail is that recipients can read and respond to their messages at their own pace. Those old enough to remember their first e-mail account might remember how exciting it was to discover a new, easy way to correspond with people halfway across the world. So what are the main differences between IM and e-mail, and what are the factors that make someone either an IM fan or a staunch e-mail loyalist?