Radiant energy is a type of energy that travels through space in the form of electromagnetic waves. It includes visible light, radio waves, microwaves, and other forms of electromagnetic radiation. Radiant energy is produced by the movement of charged particles and is essential for many natural processes, such as photosynthesis in plants and the warmth we feel from the sun. It is also used in various technologies, such as solar panels and communication devices. **

No, the luminous clock is not radioactive. The luminescence in the clock is typically achieved using a phosphorescent material that absorbs light and then slowly releases it over time. This process does not involve any radioactive materials. The glow from the clock is simply a result of this light-absorption and emission process. **

A luminous point is a theoretical concept used in physics and optics to represent a source of light that emits light in all directions. It is often used as a simplification in the study of light and its behavior, allowing for easier calculations and analysis. In reality, a luminous point does not exist as a physical object, but it is a useful tool for understanding the behavior of light in various systems. **

The luminous intensity is specified for reflector lamps because it measures the amount of light emitted in a specific direction, which is important for directional lighting applications such as spotlights and floodlights. Reflectors are designed to control and direct light in a specific direction, so specifying luminous intensity helps to ensure that the lamp is suitable for its intended purpose. Luminous flux, on the other hand, measures the total amount of visible light emitted by a source in all directions, which may not be as relevant for reflector lamps where the focus is on directing light in a specific direction. **

In physics, a self-luminous object is one that produces its own light, such as the sun or a light bulb. These objects emit light due to internal processes, such as nuclear fusion or electrical excitation. On the other hand, an externally luminous object is one that reflects light from another source, such as the moon or a mirror. These objects do not produce their own light but appear illuminated due to the light they reflect from another source. **

A non-luminous Bunsen burner flame is a type of flame produced when the air intake is adjusted to allow for complete combustion of the gas. This results in a blue, nearly invisible flame that produces a high temperature. The non-luminous flame is often used for heating and sterilization in laboratory settings because it produces minimal soot and is less likely to interfere with the observation of reactions or the color changes of substances being heated. **

Yes, there are several apps available that can brighten a photo. Some popular options include Adobe Photoshop Express, Snapseed, and VSCO. These apps offer various tools and filters that can help enhance the brightness and overall quality of a photo. Users can adjust settings such as exposure, contrast, highlights, and shadows to achieve the desired level of brightness. **

A luminous figure can be seen through the emission of light from the figure itself or from the reflection of light off the figure. Luminous figures can emit light due to bioluminescence, phosphorescence, or other chemical reactions that produce light. Additionally, a figure can appear luminous if it is illuminated by a light source, causing it to reflect and scatter light, making it appear to glow. In both cases, the human eye is able to detect the light emitted or reflected by the figure, allowing it to be seen as luminous. **