Final answer:
The presence of symmetry in the laws of motion results in the fact that a baby at rest in a crib can sleep just as well as an Apollo astronaut hurtling through space at high speed.
Step-by-step explanation:
The presence of symmetry in the fundamental laws of motion is responsible for the fact that a baby at rest in a crib can sleep just as well as an Apollo astronaut hurtling through space at 24,000 mph. This is related to the principle of equivalence in physics, which states that the effects of gravity can be completely compensated by the right acceleration. In both scenarios, the objects experience a state of weightlessness or zero apparent weight.
For example, the astronaut in space is falling freely towards Earth, which cancels out the effect of gravity. Similarly, the baby in a crib experiences an upward force from the crib that counteracts the force of gravity. These symmetries, such as time symmetry, space symmetry, and directional symmetry, result in conservation laws like conservation of energy, momentum, and angular momentum respectively. Therefore, it is the presence of these symmetries in the laws of motion that allows both the baby and the astronaut to experience a state of weightlessness.