Apparatus comprising: a spinning member; one or more heat generating components including a bearing that supports the spinning member; cooling apparatus configured to transfer heat from and cool the one or more heat generating components; the apparatus further comprising: an enclosure enclosing the spinning member in a partial vacuum maintained by the enclosure; a first heat transfer element comprising a first plurality of vanes within the enclosure and attached to the spinning member such that the first plurality of vanes will spin with the spinning member relative to the enclosure; a second heat transfer element comprising a second plurality of vanes within the enclosure fixed relative to the enclosure such that the first vanes move with respect to the second vanes, the second vanes defining gaps into which the first vanes extend so that the first and second vanes are interleaved, and wherein the first and second vanes (66, 62) are located adjacent the bearing (18, 20) that supports the spinning member, the bearing (18, 20) has an inner race (30, 32) and an outer race (26, 28), the first vanes and inner race (30, 32) are attached to the spinning member so heat flows by conduction from the inner race (30, 32) to the first vanes and from the spinning member to the first vanes, the outer race (30, 28) is attached to the enclosure, and the inner race (30, 32), spinning member, first vanes and second vanes are sized and positioned so that heat from the inner race of the bearing flows by solid conduction from the inner race (30, 32) to the spinning member and to the first vanes, by solid conduction from the spinning member to the first vanes, and primarily by gaseous conduction from the first vanes to the second vanes, and by solid conduction from the second vanes to the exterior of the enclosure. a spinning member; one or more heat generating components including a bearing that supports the spinning member; cooling apparatus configured to transfer heat from and cool the one or more heat generating components; the apparatus further comprising: an enclosure enclosing the spinning member in a partial vacuum maintained by the enclosure; a first heat transfer element comprising a first plurality of vanes within the enclosure and attached to the spinning member such that the first plurality of vanes will spin with the spinning member relative to the enclosure; a second heat transfer element comprising a second plurality of vanes within the enclosure fixed relative to the enclosure such that the first vanes move with respect to the second vanes, the second vanes defining gaps into which the first vanes extend so that the first and second vanes are interleaved, and wherein the first and second vanes (66, 62) are located adjacent the bearing (18, 20) that supports the spinning member, the bearing (18, 20) has an inner race (30, 32) and an outer race (26, 28), the first vanes and inner race (30, 32) are attached to the spinning member so heat flows by conduction from the inner race (30, 32) to the first vanes and from the spinning member to the first vanes, the outer race (30, 28) is attached to the enclosure, and the inner race (30, 32), spinning member, first vanes and second vanes are sized and positioned so that heat from the inner race of the bearing flows by solid conduction from the inner race (30, 32) to the spinning member and to the first vanes, by solid conduction from the spinning member to the first vanes, and primarily by gaseous conduction from the first vanes to the second vanes, and by solid conduction from the second vanes to the exterior of the enclosure. an enclosure enclosing the spinning member in a partial vacuum maintained by the enclosure; a first heat transfer element comprising a first plurality of vanes within the enclosure and attached to the spinning member such that the first plurality of vanes will spin with the spinning member relative to the enclosure; a second heat transfer element comprising a second plurality of vanes within the enclosure fixed relative to the enclosure such that the first vanes move with respect to the second vanes, the second vanes defining gaps into which the first vanes extend so that the first and second vanes are interleaved, and wherein the first and second vanes (66, 62) are located adjacent the bearing (18, 20) that supports the spinning member, the bearing (18, 20) has an inner race (30, 32) and an outer race (26, 28), the first vanes and inner race (30, 32) are attached to the spinning member so heat flows by conduction from the inner race (30, 32) to the first vanes and from the spinning member to the first vanes, the outer race (30, 28) is attached to the enclosure, and the inner race (30, 32), spinning member, first vanes and second vanes are sized and positioned so that heat from the inner race of the bearing flows by solid conduction from the inner race (30, 32) to the spinning member and to the first vanes, by solid conduction from the spinning member to the first vanes, and primarily by gaseous conduction from the first vanes to the second vanes, and by solid conduction from the second vanes to the exterior of the enclosure.