Google's instant messenger, Google Talk, went down for over four hours early Thursday morning, with users able to log on but not use the IM, according to Google. This comes less than a day after Google debuted its new scientific calculator feature.

At 6:40 a.m., Google posted that the issue was brought to their attention on their Apps Status page: "We're investigating reports of an issue with Google Talk. We will provide more information shortly." Ten minutes later, Google added, "The affected users are able to access Google Talk, but are seeing error messages and/or other unexpected behavior."

Google updated the page hourly, starting at 6:50 a.m. Over the next four hours Google wrote four posts saying they were investigating the issue and that they would update the page again, one hour later.

An hour later, Google posted, "Google Talk service has already been restored for some users, and we expect a resolution for all users in the near future." The post also notes that the time frame is an estimate.

Google reported that the issue was fully resolved at 11:25 am. The post assures users that, "system reliability is a top priority at Google," and suggests that anyone who is still having trouble with Google Talk contact the Google Help Center.

This unfortunate outage comes less than a day after Google added a scientific calculator to its long list utilities that accompany its popular search engine, according to PC World. The new feature displays a searched equation with the results and a full scientific calculator, rather than only giving users the equation and result.

Google's new scientific calculator

Even though Google could already solve math problems, the scientific calculator allows users to easily click the commands buttons rather than to typing them out. The calculator functions include sin, cos, tan, log, exponential calculation, and square roots, making it a complete scientific calculator.

For users with the mobile version of Google's web browser, Chrome, there is a voice feature available. If a math problem is too complex to type out, a user can say the equation to your smartphone and have it answered.

Google also has a graphing calculator feature that was added last year, though the two calculators serve different purposes. The graphing calculator is more for creating graphs, while the scientific calculator solves basic problems.

Google competitor Bing has yet to introduce their own version of this feature. The Microsoft search engine still performs mathematical calculations the way Google used to, according to PC World.