Question

What is the origin of the continuous spectrum?

Answer 1

Continuous spectrum is result of vibrations with different frequency of electric charges (maybe free electrons) of the surface of materials which aren't in gas (or vaper) phase.

Answer 2

Are you sure this is the definition of continuous spectrum?I don't think so as I just read the chemistry text regarding this continuous spectrum.The continuous spectrum(lines) as stated there is that it consist of all the lines of all wavelength and frequency.eg.the sunlight.correct me if I was wrong.

Answer 3

It's right. all lines means all wavelengths these differences in wavelengths or frequencies are because of different frequencies of vibration of electric charges which produce an electric field and a magnetic field in the space perpendicular to each other as shown here: http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=35
It's all about classic point of view.
Generation of electromagnetic waves is also described in lecture #30 of 8.02 SC by Professor Walter Lewin.