Strictly speaking, NO system can be completely closed - for example, hot liquid in the best thermos eventually cools down - but for most purposes a system can effectively be “closed”. How would you create a system which is more or less closed with respect to:
a) Heat loss?
b) Light?
c) Loss of mass?
See your post above.
To create a system that is more or less closed with respect to different factors, such as heat loss, light, and loss of mass, various approaches can be taken. Here's how you could achieve a more or less closed system for each of these factors:
a) Heat loss:
To minimize heat loss in a system, you can consider the following approaches:
1. Insulation: Use materials with low thermal conductivity to minimize heat transfer between the system and its surroundings. For instance, you can utilize materials like foam, fiber, or reflective coatings that can act as good insulators and reduce heat loss.
2. Sealing: Ensure that the system is tightly sealed to prevent the exchange of air or other medium that can transfer heat. Use seals, gaskets, or insulation tapes to close any gaps or openings.
3. Controlled environment: Place the system in a controlled environment such as a temperature-controlled room or chamber. By maintaining a consistent temperature within the environment, you can minimize heat dissipation.
b) Light:
To minimize the entry or exit of light in a system, you can consider the following approaches:
1. Light-blocking materials: Use opaque or light-blocking materials to construct the system. This can include materials like metal, thick plastic, or fabrics that are not transparent. By using these materials, you can restrict the transmission of light through the system.
2. Light shields or blinds: Install light shields or blinds around the system to block external light sources. These can be adjustable or fixed, allowing you to control the amount of light entering the system.
3. Enclosure design: Ensure that the system is designed in a way that limits the entry of light. This can involve using enclosures with no or minimal transparent surfaces or incorporating light-absorbing surfaces internally.
c) Loss of mass:
To minimize the loss of mass from a system, you can consider the following approaches:
1. Sealing: Ensure that the system is tightly sealed to prevent the escape of any mass. Use appropriate seals, closures, or fasteners to secure the openings and prevent leakage.
2. Containment measures: Implement containment measures such as barriers or physical obstructions within the system to prevent the loss of mass. For example, if the system contains a liquid, use a sealed container with a lid to prevent evaporation.
3. Monitoring and maintenance: Regularly monitor the system to identify any potential sources of mass loss, such as leaks or evaporation. Perform regular maintenance tasks, including inspections and repairs, to address any issues that may arise.
By combining these strategies, you can create a system that is more or less closed with respect to heat loss, light, and loss of mass. However, as mentioned earlier, achieving a completely closed system may not be technically possible, as there may always be some level of interaction or exchange with the surrounding environment.