Science - time

Apr

2013

2:53pm, EDT

Physicist argues, controversially, that time is real

Brian Snyder / Reuters

Is time real? Peter Shugrue probably hoped so as he checked four custom clocks destined for installation in Kansas City, Mo, at the Electric Time Co. factory in Medfield, Mass. on March 8.

By Clara Moskowitz
LiveScience

NEW YORK — Is time real, or the ultimate illusion?

Most physicists would say the latter, but Lee Smolin challenges this orthodoxy in his new book, "Time Reborn" (Houghton Mifflin Harcourt, April 2013), which he discussed here Wednesday at the Rubin Museum of Art.

In a conversation with Duke University neuroscientist Warren Meck, theoretical physicist Smolin, who's based at Canada's Perimeter Institute for Theoretical Physics, argued for the controversial idea that time is real. "Time is paramount," he said, "and the experience we all have of reality being in the present moment is not an illusion, but the deepest clue we have to the fundamental nature of reality." [Album: The World's Most Beautiful Equations]

Smolin said he hadn't come to this concept lightly. He started out thinking, as most physicists do, that time is subjective and illusory. According to Albert Einstein's theory of general relativity, time is just another dimension in space, traversable in either direction, and our human perception of moments passing steadily and sequentially is all in our heads.

Over time, though, Smolin became convinced not only that time was real, but that this notion could be the key to understanding the laws of nature.

"If laws are outside of time, then they're inexplicable," he said. "If law just simply is, there's no explanation. If we want to understand law … then law must evolve, law must change, law must be subject to time. Law then emerges from time and is subject to time rather than the reverse."

Smolin admitted there are objections to this idea, especially what he calls "the meta-law dilemma:" If physical laws are subject to time, and evolve over time, then there must be some larger law that guides their evolution. But wouldn't this law, then, have to be beyond time, to determine how the other laws change with time? Other physicists have cited this objection in reaction to Smolin's work.

"The problem I see with the argument for laws that evolve in time is one that you yourself identify in the book: what you call the 'meta-laws dilemma,'" Columbia University physicist Peter Woit wrote on his blog Not Even Wrong. "You speculate a bit in the book on ways to resolve this, but I don't see a convincing answer to the criticism that whatever explanation you come up with for what determines how laws evolve, I’m free to characterize that as just another law."

Smolin admitted this is currently a sticking point, but maintained that there are possible solutions.

"I believe you can resolve the meta-law dilemma," Smolin said at the Rubin event. "I think the direction of 21st-century cosmology will depend on the right way to resolve the meta-law dilemma."

Smolin and Meck discussed the consequences of his idea, including what it means for our understanding of human consciousness and free will. One implication of the idea that time is an illusion is the notion that the future is just as decided as the past.

"If I think the future's already written, then the things that are most valuable about being human are illusions along with time," Smolin said. "We still aspire to make choices in life. That is a precious part of our humanity. If the real metaphysical picture is that there are just atoms moving in the void, then nothing is ever new and nothing's ever surprising — it's just the rearrangement of atoms. There's a loss of responsibility as well as a loss of human dignity."

Follow Clara Moskowitz on Twitter and Google+. Follow us @livescience, Facebook and Google+. Original article on LiveScience.com.

Mar

2013

4:35pm, EST

Spring into daylight science time

Brian Snyder / Reuters

Peter Shugrue checks four custom-made clocks, destined for installation in Kansas City, Mo, at the Electric Time Company factory in Medfield, Mass. Daylight saving time begins in the United States at 2 a.m. Sunday.

By David Ropeik and Alan Boyle, NBC News

It's that time of year, when most Americans lose an hour's sleep setting their clocks ahead. (Remember? Spring forward, fall back.) So here are answers to questions about the time switch and about sleep.

In most of the United States, we'll be moving our clocks ahead for daylight saving time in the wee hours of Sunday morning. The official switch comes at 2 a.m. Sunday, which instantly becomes 3 a.m. Most people, however, move their clocks ahead just before going to bed Saturday night or just after getting up Sunday morning.

The day of the big switch used to be the first Sunday of April, but in 2005, Congress changed the rule to make it the second Sunday in March, as an energy-saving measure.

What's the rationale?
As the year progresses toward the June solstice, the Northern Hemisphere gets longer periods of sunlight. Timekeepers came up with daylight saving time — or summer time, as it’s known in other parts of the world — to shift some of that extra sun time from the early morning (when timekeepers need their shut-eye) to the evening (when they play softball).

The idea is that having the extra evening sunlight will cut down on the demand for lighting, and hence cut down on electricity consumption — and that few people will miss having it a little darker at, say, 6 o'clock in the morning. At least that's how the theory goes.

Who's in on the switch?
Not everybody goes along with the plan. Arizona sticks with Mountain Standard Time, which turns out to be the same as Pacific Daylight Time. (The Navajo Nation, however, goes along with the summertime switch.) Hawaii and U.S. possessions such as American Samoa, Guam, Puerto Rico and the Virgin Islands are also staying on standard time.

Most European countries don't switch to summer time until the last weekend in March. That means the usual time difference will be out of sync for three weeks. For example, when it's noon in New York, it'll be 4 p.m. in London. But starting March 31, the five-hour difference between the two cities' clocks will be back in force.

Some countries in the Southern Hemisphere move their clocks back an hour at this time of year. In Brazil, for example, the switch from daylight saving time to standard time took place in mid-February.

How can we cope?
If you’re in the “spring forward” mode, don’t lose any sleep over the hour you’re losing. But do try to get back into your regular sleep routine. Rosalind Cartwright, a sleep expert at Rush Medical Center in Chicago, says that if you lose too much sleep, even a couple of hours for just two or three days, your immune system will suffer and you'll be more susceptible to colds and viral infections.

A couple of small-scale studies have suggested that heart attack rates go up during the switch to daylight saving time, perhaps because of the sleep-cycle disruption. But the evidence is too meager to make a solid connection to that issue or other purported health effects of the time change.

Generally speaking, if you get to sleep too late, or get up too early, your body will find a way to get the deep sleep it needs for rest. But Cartwright says you lose the stage of sleep during which you dream, which is important for mood. Which explains why you might feel groggy and grumpy after we "spring forward" to daylight saving time.

More about the time changeover:

David Ropeik is a consultant and author specializing in risk perception and risk communication. Alan Boyle is NBCNews.com's science editor. This is an updated version of a report originally published in March 2000.