Some see 5.0 seconds a possibility. Because 6' 5 Usian Bolt broke the mathematical model that had fit 100-meter record data for almost a century, his incredible performance has reset the bar for how fast researchers believe humans ultimately can run.
Lobsters may eat other lobsters in captivity, but this has not been observed in the wild. It takes an American lobster 6-7 years to get to an edible size, but that is just the beginning. Lobsters are long-lived animals, and are thought to be capable of living over 100 years.
Lobsters do not age as we do. They do not die of the debility of old age. They are killed, eaten and they may die of infection just as humans do. Lobsters continue to absorb nutrition throughout life, while humans gradually seem to lose the ability to absorb specific nutrition.