continuous spectrum

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continuous spectrum

physics

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June 24, 2026

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In physics, a continuous spectrum refers to the full range of wavelengths or frequencies of light emitted by a source, with no apparent breaks or gaps. This type of spectrum is typically produced by incandescent solids or gases at high temperatures, such as a lamp filament, a heated piece of iron, or the Sun.123

In a continuous spectrum, all wavelengths are present. This is because the atoms in a hot, dense material are packed closely together, causing their individual energy levels to merge. This results in the emission of a broad range of light, encompassing all colors of the visible spectrum and often extending into infrared and ultraviolet radiation. This is in contrast to a line spectrum, which is emitted by gases and consists of only specific, discrete wavelengths.342

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electromagnetic radiation
Continuous spectra of electromagnetic radiation
Such spectra are emitted by any warm substance. Heat is the irregular motion of electrons, atoms, and molecules; the higher the temperature, the more rapid the motion. Since electrons are much lighter than atoms, irregular thermal motion produces irregular oscillatory…
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Such spectra are emitted by any warm substance. Heat is the irregular motion of electrons, atoms, and molecules; the higher the temperature, the more rapid the motion. Since electrons are much lighter than atoms, irregular thermal motion produces irregular oscillatory…
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spectrum
…solids is said to be continuous because all wavelengths are present. The spectrum of incandescent gases, on the other hand, is called a line spectrum because only a few wavelengths are emitted. These wavelengths appear to be a series of parallel lines because a slit is used as the light-imaging…
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…solids is said to be continuous because all wavelengths are present. The spectrum of incandescent gases, on the other hand, is called a line spectrum because only a few wavelengths are emitted. These wavelengths appear to be a series of parallel lines because a slit is used as the light-imaging…
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spectroscopy
Broadband-light sources
…then overlap and form a continuous—i.e., nondiscrete—spectrum. Similar phenomena occur in high-pressure arc lamps, in which broadening of spectral lines occurs owing to high collision rates.
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…then overlap and form a continuous—i.e., nondiscrete—spectrum. Similar phenomena occur in high-pressure arc lamps, in which broadening of spectral lines occurs owing to high collision rates.
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star
Line spectrum
The continuous (as distinct from the line) spectrum of the Sun is produced primarily by the photodissociation of negatively charged hydrogen ions (H⁻)—i.e., atoms of hydrogen to which an extra electron is loosely attached. In the Sun’s atmosphere, when H⁻ is subsequently destroyed by photodissociation, it…
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The continuous (as distinct from the line) spectrum of the Sun is produced primarily by the photodissociation of negatively charged hydrogen ions (H⁻)—i.e., atoms of hydrogen to which an extra electron is loosely attached. In the Sun’s atmosphere, when H⁻ is subsequently destroyed by photodissociation, it…
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spectroscopy
Relation to atomic structure
If the continuous spectrum from an X-ray source is passed through an absorbing material, it is found that the absorption coefficient changes sharply at X-ray wavelengths corresponding to the energy just required to remove an electron from a specific inner shell to form an ion. The sudden…
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If the continuous spectrum from an X-ray source is passed through an absorbing material, it is found that the absorption coefficient changes sharply at X-ray wavelengths corresponding to the energy just required to remove an electron from a specific inner shell to form an ion. The sudden…
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