Question about Closed Systems vs Isolated System

[James Cheng 3I]

For 8.1, they say that coffee in a high quality thermos bottle is isolated and not a closed system. Hypothetically, shouldn't the thermos give even a very very very small amount of heat off to the surroundings, thus making it a closed system? Could we assume this small amount of heat be so negligible that we can assume it is an isolated system?

[AlisonWong_1D]

Truly isolated systems are very difficult to create, and a thermos will give off some small amount of heat as you said. But I think for the purposes of our class and learning theory, we can consider it an isolated system since it's supposed to prevent heat (energy) and mass from entering or leaving.

As for considering a system with negligible amounts of heat exchange isolated, I'm not sure. If an ice cube was dropped into an ocean the heat change would be negligible, but this is still an open system.

[Shaye Busse 3B]

Not only is an isolated system very difficult to create, it is actually impossible to create a 100% isolated system. The reason for this is there will always be at least one part of the system in contact with something of higher or lower energy.

An example of this would be why absolute zero has not and will likely never be reached. While certain set-ups have come to withing very small fractions of a degree of absolute zero, it will probably never be reached because there ill always be a part of the system exchanging energy externally, causing the energy within the system to increase, slightly missing absolute zero.