Cleland and Chyba argue that it is not, taking it to imply that explorers, let us say on Mars, would need to observe a possible life form for years, waiting for it to evolve before they could be certain that it is life.
Memorably, he recalls sending a frigate into San Carlos Water prior to the landings to see if there were any minefields - without minesweepers in the fleet, the only way he could be certain it was clear was if the ship returned intact.
Grant Butler of The Oregonian gave the machine's trumpet fanfare as one of three examples of ways in which people could be certain it was noon in Portland.
Christopher Bartle, who lives on the Upper East Side and works in Midtown, said he was willing to pay higher fares if he could be certain that it would shorten his wait for a cab during rush hour.
Some Resistance May Be Reasonable It could be that certain family members are resistant for legitimate reasons, like overwhelming schedules or their own financial troubles.
Similarly, it could be that certain complex target diseases for vaccines require a greater number of human subjects in order to prove safety and efficacy.
