Although scientists generally agree our universe was born in a Big Bang 13.8 million years ago, most Americans say they have some doubts about the concept, a poll has found.
In an Associated Press-GfK survey asking people to express their level of confidence in a number of statements concerning medicine and science, respondents gave answers ranging from complete certainty to serious doubt.
They're secure in accepting that we are who we are as the result of a genetic code, and they've become certain smoking can cause cancer, but in some questions on bigger issues and those of a longer time span, they're not so sure.
Many in the survey expressed doubts over the existence of global warming, evolution, the age of our planet and the concept of a Big Bang beginning everything.
About 40 percent of survey respondents said they're unsure or outright disbelieving that man-made greenhouse gases are causing the climate to warm up.
A similar percentage said they don't accept the world's age at 4.5 billion years, or that the planet's life has evolved through natural selection.
But the most doubt -- at 51 percent -- was reserved for the theory of the universe's birth in a Big Bang.
That's a result that disappointed some scientists, including Nobel Prize winners, many of whom argue the issues in the survey should be considered settled facts of science.
"Science ignorance is pervasive in our society, and these attitudes are reinforced when some of our leaders are openly antagonistic to established facts," says Randy Schekman of the University of California, Berkeley, a 2013 winner of the Nobel Prize for medicine.
When it comes to public perception, "most often values and beliefs trump science" when there's a conflict among them, say Alan Leshner, head of the American Association for the Advancement of Science, the largest scientific society in the world.
There was a political difference among survey respondents, the poll's researchers said, with Democrats being more likely to say they were confident in the questions about the Big Bang, evolution, climate change and the Earth's age than Republicans were.
That changed when religious values came into play, the poll found, as those expressing a faith in the existence of a supreme being saying they had less confidence in those same issues.
The AP-GfK Poll was conducted online from March 20-24 among 1,012 adults with a margin of sampling error of plus or minus 3.4 percentage points.
