Seed a random number generator with a real random number to get real random numbers?

This is a general question, and not specific to a programming language.

If I use a random number generator (e.g. Math.Random() in Java), the Numbers are not really random. A common practice is to seed the numbers with the local system time to get random numbers every time the program is executed.

Now what if you seed with a really random number (for example from random.org). Will the numbers you get be real random numbers too?