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Yes. A full circular rainbow can be visible from an elevated viewpoint when sunlight and water droplets align. From the ground, we usually see only part of the circle.
No. The second is still defined using caesium-133. The new lutetium clock is a research advance that could contribute to a future redefinition.
No. Goldfish can learn feeding schedules and spatial tasks. Experiments contradict a three-second memory limit, but do not establish one universal memory duration.
Yes. Researchers observed cell division at 63°C. Recovery after brief exposure to 70°C is a separate result and does not demonstrate reproduction at that temperature.
No. Bats have functional eyes and can see. Their visual abilities vary between species, so limited detail vision should not be confused with blindness.
Yes. Researchers say the insect had been misidentified for decades. Recognising it as a new species does not mean it had never been observed before.
No. Diamonds resist scratching extremely well, but a hard impact can chip or fracture them. Hardness and resistance to breaking are different properties.
No. Sirius is the brightest star in the night sky. Polaris is useful for finding north because of its position near the north celestial pole.