Thursday, July 26, 2007

9 Great Family Getaways


Bike along Connemara's white-sand beaches, tour the ruins of a 17th-century fort, and see a falconry demonstration. There's also storytelling and dance performances for the kids, whiskey tasting and golfing for the adults, and sing-a-longs for all in the pubs. July 30-Aug. 4; $5,996; includes all meals, lodging, equipment and admission to events. Minimum age: 8.


Cycle on car-free bike paths, pedal past rolling farmland and build sand castles at Katama Beach. Highlights include a sunset cruise on Nantucket Harbor and visits to the Black Dog Bakery. July 22-26; $1,980; includes meals, lodging at historic inns and bike rental. Minimum age: 6.


After a day of cycling through forests, orchards and sunflower fields, retreat to a chateau. Kids can try ropes courses, horseback riding and fencing, and adults can enjoy a wine tasting and a sumptuous dinner. July 29-Aug. 4; $5,495; includes lodging, concierge services, most meals, all wine and bike rental. Minimum age: 5.


Cycle past dude ranches, ride a gondola and take a dip in natural hot springs. Pizza parties for kids, candlelight dinners for adults. Aug. 12-17; $2,198/$1,758 (under 15); includes all meals, lodging, bike equipment, and all taxes. Minimum age: 7.


Cycle past windmills, tulip fields and beaches, then board a houseboat, which takes you to the start of the next day's journey while you sleep. Aug. 18-Sept. 1; $867; includes meals, bike rental and lodging. All ages.


Pedal past lighthouses, visit a colony of seals or go to an old-fashioned amusement park. Aug. 5-10; $2,798-$3,098; includes all meals, lodging, bike equipment and trail-a-bikes. Minimum age: 3 to attend, 6 to ride own bike.


Visit Northern California's most remote beaches, bike along the Coastal Trail--closed to cars--and see the Redwood Forest's 350-foot trees. Tours from mid-June to mid-Aug.; $975/$875 (under 14); includes meals, excursions and camp gear. Extra: Bike equipment and sleeping-bag rental. All ages.


Between ferry rides, crafts and visits to a whale museum, bike on nearly traffic-free roads. Aug. 5-9; $1,358, with kid discounts available; includes meals and camping equipment. Extra: Bike rental. All ages; minimum age for kayaking: 6.


Canyonlands National Park offers some of the best mountain biking in the United States. This trip is timed for spring break, and is structured so you and your teen can enjoy biking down switchbacks together or with your individual peer groups. April 2008; $865/$764 (under 14); includes all meals, excursions and camp equipment. Extra: Bike equipment and sleeping-bag rental.

By Jennifer Mack

Friday, July 20, 2007

6 ways to tone up, trim down, and get some Me Time, too.

We've rounded up and tested out six sensational get-moving destinations--some far-flung, some close to home--to help you get a jump-start on fitness. So whether you're on a budget or set for a splurge, turn the page and get ready to have a great time getting fit.

Get a boot-camp boost

Splurge: If you want a fitness jump-start that burns a ton of calories, there's nothing better than a boot camp. Put some exotic spice into your basic training at Amansala Eco Chic Resort's Bikini Boot Camp in Tulum, Mexico (a 2-hour drive south of Cancun). Your daily power walk won't be around the block--it'll be through the Yucatan jungle. In the morning, your body-sculpting class will be on the beach. In the afternoon, you'll bike to a freshwater swimming hole. And your cross-training will be flamenco and salsa dance lessons. A week in a beachfront cabana won't hurt either. Six-night boot camp ($1,842 per person, double occupancy) includes accommodations, meals, fitness classes, kayaking, two bike excursions, and three spa services.

On a budget: Get the boot camp experience closer to home with classes at a local gym. National-chain clubs Equinox Fitness and 24-Hour Fitness, for example, have several cool camps to choose from. Get all wet at Equinox's Aqua Boot Camp and bikini ready in its Boot Camp Intervals class.

Stretch out

Splurge: At the Aspen Club and Spa in Aspen, Colorado, your own wellness guru will create a 1- to 3-day getaway that includes a daily dose of two private yoga or Pilates sessions, lunch at the spa, and an 80-minute spa treatment. Offered year-round, the $450-per-day rate doesn't include lodging, but the spa is a short walk from several downtown Aspen hotels.

On a budget: Many yoga centers offer free or reduced-price, first-time classes, and many Pilates instructors will give you an introductory session gratis. To find yoga classes close to home. For local Pilates classes, see

Take a hike

Splurge: Put hiking center-stage at Jimmy LeSage's New Life Hiking Spa. Take a low-key ramble along country roads or a climb up one of Vermont's highest peaks in the Green Mountains. To fill out your day, try a before-breakfast stretch class, an afternoon core-training or yoga class, and an evening massage or facial. New Life's 2- to 4-day Mini Vacation ($229 per person per night, double occupancy) in the charming Inn of the Six Mountains in Killington includes all meals and fitness activities, plus one massage or facial per 3-night stay.

On a budget: Keep your trek local by using Take advantage of its free 14-day trial to find reviews of more than 30,000 trails nationwide, along with all the information you'll need to get out there (including maps and campground sites, if you're planning an overnight). Start at the site's "Top 100 Trails" for inspiration, and you'll be lacing up your lightweight hikers in no time.

By Tracey Minkin

Monday, June 11, 2007

A trip to Antarctica reveals some completely new life under the ice

The icebreaker Polarstern arrived in Antarctica last December packed with 52 scientists and a remotely operated submersible called Cherokee. The mission: to survey the ocean life under the former Larsen B ice shelf, the 720-billion-ton mass of ice that disintegrated in 2002. After 17 dives as deep as 2,800 feet by Cherokee, the scientists had observed approximately 1,000 marine species, many of them recent arrivals to the newly uncovered ecosystem and some completely new to science. "The only species that were able to make a living under that much ice were those typically found in the deep sea," says Terry Collins of the Census of Antarctic Marine Life. "They're still there, but you can see the signs of colonizing species as well." The trip was the first of 14 Antarctic voyages aiming to document how climate change is affecting the poles.

By Kalee Thompson

Wednesday, May 30, 2007

Got big travel plans? Here's how to stay in shape and feel great over the long haul.

One of the best things about a vacation in a far off locale is that it whisks you away and lets you forget the daily grind. For a few blissful days, you don't have to think about wake-up times, workout schedules and what to eat or drink… or do you?

Turns out that break from routine is the very thing that can leave you with postholiday regrets. Recuperating from travel fatigue and getting enough exercise often takes a backseat to fun--after all, who wants to be at the gym doing crunches or lifting weights when you can be sitting in the sun lifting Mojitos? Add a few rich restaurant dinners and the gotta-get-energized jetlag munchies to lack of exercise, and you could end up wishing you'd never left when you trade in that elastic-waist grass skirt for fitted pants once again.

The solution? A few easy, preventive measures that can help you feel fit and well rested both during and after your grand getaway.



Doing some cardio exercises every third day burns a few of those cocktail-hour calories and keeps stamina at pre-vacation levels. "You can retain a relatively high level of both aerobic power and strength with just two exercise sessions per week," says William J. Stone, EdD, professor in the department of exercise and wellness at Arizona State University. Shorten the workout time if you want--for example, if you normally jog for 45 minutes, you can scale back to 30 minutes--but don't slack off on the intensity. Another good way to get your heart pumping is to integrate aerobic exercise into your vacation fun. Rent a bike for one or two afternoons and pedal as you sightsee. Try swimming a few laps each time you cool off in the pool, or turn your saunter down the sand into a 10-minute jog. Bring along a jump rope and do three to four two-minute sets, advises Los Angeles-based personal trainer Alison Copeland. "You can jump anywhere, and it's an amazing way to get your heart rate up in a short time," she says. "Plus, I don't know anyone who can't find room in a suitcase for a jump rope."


Got a weight-training program going at the gym? Practice it once a week while you're away. "Strength gains, in the form of stronger muscles, last a bit longer than cardio fitness, but you can lose an appreciable amount in eight to ten weeks," explains John J. Duncan, PhD, CEO and founder of Texas-based Via Scan, a preventive wellness and heart-health center.

If you have a personal trainer, ask him or her to design a travel fitness program using rubber tubing. These giant, stretchy bands are inexpensive, weigh just a few ounces, fold up like belts, are available in a variety of resistances and can be found in the fitness section of most sporting good stores. (Note: if you don't have a trainer-designed regimen to take along, the tubing comes with exercise examples that are safe for most workouts.) Tubing also gives you the freedom to work out in your pj's in your hotel room instead of having to put on fitness gear and go to a gym. Another option is a set of Aqua Bells, collapsible plastic dumbbells and ankle weights that offer up to 15 lbs. of resistance when filled with water (dumbbell and ankle weight set, $80; Or just grab a couple of full one-liter water bottles and use them---one liter of water weighs 2.2 lbs.


Even if you end up taking a break from exercise during your time away, try to avoid letting your vacation be an excuse to allow your regular fitness routine to slip. Return to your schedule the first week you get back so you won't lose strength or endurance. "Ten percent of your cardiovascular stamina is lost after two weeks of not exercising, and after four to eight weeks, you're starting over," explains Duncan. In other words, if you trained for 20 years and then take off one to two months, your aerobic fitness goes back to what it was 21 years ago.



Because the body functions on a 24-hour time frame (called circadian rhythms), small alterations in your sleep schedule can reduce the effects of changing time zones. "Making big changes in sleep cycles is like jamming on the brakes when you're on the freeway. It's much better to switch speeds gently," says Vicki Rackner, MD, one of the authors for Chicken Soup for the Soul Healthy Living Series. "I begin adjusting my schedule days before I actually have to leave." For example, if you plan to travel east, start going to bed an hour earlier every day and getting up an hour earlier to sync up with the time zone. Rackner also recommends avoiding red-eye flights. "Quality of sleep on a plane is never as good," she explains. You may think you gain a day, but you could end up losing more because of exhaustion.


Sure, you've been told a million times to down eight to ten glasses of water a day, but it's more important than ever if you're getting on a plane to travel long distances. "Staying hydrated while flying is important because dehydration may be linked to jet lag," says Rackner. But consuming your fill of fluids doesn't mean you have to forgo a glass of juice or even a cocktail when the beverage cart comes by. Just ask for a glass of water and whatever beverage you'd like to have. On longer flights make a point of taking water breaks. Water is always available at galley stations in the plane and pouring yourself a glass or two is a good excuse to get up and stretch your legs. Try to drink one cup of water for every hour in the air.


As tempting as it is to hit the ground running at your destination, allow yourself a couple of days to acclimate to a new time zone. It typically takes 24 hours or more to recover for each time zone crossed and you'll enjoy the scenery more if you're not feeling sleepy. Plan busy mornings of sightseeing and long day trips toward the middle or the end of the trip rather than in the first days. To keep from waking up at 3 a.m. (long before you can hit the beach or even order breakfast) and dozing off right after dinner, help your system adjust with melatonin supplements. "Melatonin is produced naturally by the body and regulates sleep patterns without the hangover side effects some sleeping pills may have," explains Vibhuti Arya, PharmD. She recommends taking 0.5mg to 5mg melatonin for two to five days.

Whether your dream vacation centers around tiki lights and tropical destinations or sightseeing in foreign lands, take along these fitness and fatigue-fighting schemes. They'll ensure you get the most out of your great escape and make re-entry into the real world a bit easier to take.


When choosing a carry-on bag, check handle height. Handles that are too short to pull at a comfortable angle put undue strain on shoulders and back.

Is airport anxiety creating extra travel stress? Anne McAlpin, packing expert and founder of, offers the following tips:

Protect your privacy. Use your work address instead of your home address on your luggage tag.

Share the load. If you're traveling with someone, put a few of each other's clothes in both suitcases in case one gets lost.

Double-check travel sizes You can carry on all your toiletries as long as each bottle is 3 oz. or smaller and all items fit into a 1-quart resealable plastic bag.

Wear socks Flip flops may seem like the right choice for an island escape, but they leave your feet exposed to the bare floor when passing through security. Comfy, easy-to-remove shoes with socks are your best bet.

Pack snacks Nuts, granola bars and healthy nibbles are allowed through security and help avoid overpriced fast food and nonveg airline offerings.

Stay informed For up-to-the minute security information, log on to


Sure, ab exercises are great and your belly can always use an extra crunch or two, but traveling takes its toll on multiple body zones, especially your feet, neck and torso. Here are a few exercises you can do anywhere (even sitting at the gate in the airport!) to help keep them limbered up and tension free.


Toe curls Sit with legs forward, heels resting on the floor. Flex toes, then curl tightly and hold 5 seconds. Release; repeat 5 to 10 times.

Ankle circles Sit with legs forward, heels 12 inches off floor. Point toes, flex and rotate feet clockwise 5 times, then counterclockwise 5 times. Repeat 3 times.


Head tilts Let arms hang loosely at sides. Tilt head to one side until you feel a stretch in opposite side of neck. Hold 10 seconds, then tilt neck to other side. Repeat 3 to 5 times.

Shoulder stretches Extend right arm across body so it crosses left shoulder. Crook left arm under right arm next to elbow, and pull to feel stretch in shoulder blades and upper back. Hold 10 seconds, then repeat with left arm.


Low-back stretch Sit with legs slightly apart. Place head between knees, wrap arms around legs and gently hug calves. Hold 10 to 20 seconds. Rest 5 seconds, then repeat.


Chest stretch Stand or sit up straight. Reach arms behind your back. Clasp hands together, and push arms down and back. Hold 10 to 20 seconds. Rest 5 seconds, then repeat.

By Linda Melone

Sunday, April 22, 2007

The inhospitable side of the galaxy?

The solar system's periodic visits to the northern side of the Milky Way expose life on Earth to extra cosmic rays that have caused catastrophic mass extinctions, two astrophysicists propose.

Biodiversity has had well-known ups and downs over the eons, with major extinctions followed by rebounds. In a 2005 study, Robert Rohde and Richard Muller of Lawrence Berkeley (Calif.) National Laboratory found that these swings were surprisingly regular, most of them taking place at intervals of about 62 million years. The researchers reached their conclusion after examining one of the most comprehensive long-term biodiversity surveys, a compilation of fossil data that charted the number of marine-life genera over the past 500 million years.

The extraordinary dinosaur kill 65 million years ago doesn't fit in the cyclic pattern, and experts widely blame it on the impact of a large asteroid.

To explain the cyclic pattern of mass extinctions, Rohde and Muller considered a phenomenon that has just about the right periodicity. As the solar system orbits around the galaxy, it swings from one side to the other of the galactic plane every 63 million years. Gravity from the rest of the galaxy's mass pulls the solar system back each time.

Perhaps when the sun is at the maximum distance from the galactic plane, Earth's biodiversity is at greatest risk, Rohde and Muller speculated. But that would put mass extinctions every 31.5 million years, not every 63 million. It wasn't clear why one side of the galaxy's plane would be more dangerous to life than the other.

Mikhail Medvedev and his colleagues of the University of Kansas in Lawrence now propose an explanation that rests on variations in the number of high-energy particles, known as cosmic rays, that strike Earth from space. They argue that because the galaxy is moving toward a large cluster of galaxies in the direction of the Virgo constellation, cosmic rays would be more abundant on the galaxy's north side-according to the view from Earth.

A particle flow similar to the solar wind emanates from the Milky Way as a whole, and as the galaxy moves, that wind runs into the tenuous medium that pervades intergalactic space. The collision creates a shock wave. The Kansas team calculates that when electrically charged particles rebound within the shock wave, they gain enough energy to turn into cosmic rays.

When a cosmic ray hits the upper layers of the atmosphere, it triggers a shower of millions of energetic electrons and other particles, some of which can penetrate to land and into the oceans. The particles have a variety of effects. For example, they may alter cloud coverage or damage DNA, with potentially fatal consequences for entire species.

"Drops in biodiversity correspond to peaks in cosmic rays," Medvedev says. However, he and his colleagues stress that they haven't identified the mechanism linking cosmic rays and extinctions.

"I was stunned when I learned that [Medvedev's team] had succeeded where we had failed" at explaining the 62-million-year cycle, Muller says.

Charles Dermer, an astrophysicist at the Naval Research Laboratory in Washington, D.C., says that the new explanation is "very tantalizing" but that it rests on Rohde and Muller's biodiversity cycles, which are not firmly established.

Medvedev and his colleagues say that the cosmic ray bombardments would also increase gamma rays from the north side of the galaxy, a prediction that new gamma-ray observatories may test in the next few years.

The researchers presented their work this week, in Jacksonville, Fla., at a meeting of the American Physical Society. The report is also due to appear in Astrophysical Journal.

By Davide Castelvecchi

Friday, March 30, 2007

Gassing Up With Hydrogen

Researchers are working on ways for fuel-cell vehicles to hold the hydrogen gas they need for long-distance travel

On a late summer day in Paris in 1783, Jacques Charles did something astonishing. He soared 3,000 feet above the ground in a balloon of rubber-coated silk bags filled with lighter-than-air hydrogen gas. Terrified peasants destroyed the balloon soon after it returned to earth, but Charles had launched a quest that researchers two centuries later are still pursuing: to harness the power of hydrogen, the lightest element in the universe, for transportation.

Burned or used in fuel cells, hydrogen is an appealing option for powering future automotive vehicles for several reasons. Domestic industries can make it from a range of chemical feedstocks and energy sources (for instance, from renewable, nuclear and fossil-fuel sources), and the nontoxic gas could serve as a virtually pollution-free energy carrier for machines of many kinds. When it burns, it releases no carbon dioxide, a potent greenhouse gas. And if hydrogen is fed into a fuel-cell stack--a battery-like device that generates electricity from hydrogen and oxygen--it can propel an electric car or truck with only water and heat as by-products [see "On the Road to Fuel-Cell Cars," by Steven Ashley; Scientific American, March 2005]. Fuel-cell-powered vehicles could offer more than twice the efficiency of today's autos. Hydrogen could therefore help ease pressing environmental and societal problems, including air pollution and its health hazards, global climate change and dependence on foreign oil imports.

Yet barriers to gassing up cars with hydrogen are significant. Kilogram for kilogram, hydrogen contains three times the energy of gasoline, but today it is impossible to store hydrogen gas as compactly and simply as the conventional liquid fuel. One of the most challenging technical issues is how to efficiently and safely store enough hydrogen onboard to provide the driving range and performance that motorists demand. Researchers must find the "Goldilocks" storage solutions that are "just right." Storage devices should hold sufficient hydrogen to support today's minimum acceptable travel range--300 miles--on a tank of fuel in a volume of space that does not compromise passenger or luggage room. They should release it at the required flow rates for acceleration on the highway and operate at practical temperatures. They should be refilled or recharged in a few minutes and come with a competitive price tag. Current hydrogen storage technologies fall far short of these goals.

Researchers worldwide in the auto industry, government and academia are expending considerable effort to overcome these limitations. The International Energy Agency's Hydrogen Implementing Agreement, signed in 1977, is now the largest international group focusing on hydrogen storage, with more than 35 researchers from 13 countries. The International Partnership for the Hydrogen Economy, formed in 2003, now includes 17 governments committed to advancing hydrogen and fuel-cell technologies. And in 2005 the U.S. Department of Energy set up a National Hydrogen Storage Project with three Centers of Excellence and many industry, university and federal laboratory efforts in both basic and applied research. Last year alone this project provided more than $30 million to fund about 80 research projects.

Infrastructural Hurdles

One obstacle to the wide adoption of hydrogen fuel-cell cars and trucks is the sheer size of the problem. U.S. vehicles alone consume 383 million gallons of gasoline a day (about 140 billion gallons annually), which accounts for about two thirds of the total national oil consumption. More than half of that petroleum comes from overseas. Clearly, the nation would need to invest considerable capital to convert today's domestic auto industry to fuel-cell vehicle production and the nation's extensive gasoline refining and distribution network to one that handles vast quantities of hydrogen. The fuel-cell vehicles themselves would have to become cheap and durable enough to compete with current technology while offering equivalent performance. They also must address safety concerns and a lingering negative public perception--people still remember the 1937 Hindenburg airship tragedy and associate it with hydrogen, despite some credible evidence that the airship's flammable skin was the crucial factor in the ignition of the blaze.

Why is it so difficult to store enough hydrogen onboard a vehicle? At room temperature and atmospheric pressure (one atmosphere is about 14.5 pounds per square inch, or psi), hydrogen exists as a gas with an energy density about 1/3,000 that of liquid gasoline. A 20-gallon tank containing hydrogen gas at atmospheric pressure would propel a standard car only about 500 feet. So engineers must increase the density of stored hydrogen in any useful onboard hydrogen containment system.

A 300-mile minimum driving range is one of the principal operational aims of an industry-government effort--the FreedomCAR and Fuel Partnership--to develop advanced technology for future automobiles. Engineers employ a useful rule of thumb in making such calculations: a gallon of gasoline is equal, on an energy basis, to one kilogram (2.2 pounds) of hydrogen. Whereas today's average automobile needs about 20 gallons of gasoline to travel at least 300 miles, the typical fuel-cell vehicle would need only about eight kilograms of hydrogen because of its greater operational efficiency. Depending on the vehicle type and size, some models would require less hydrogen to go that far, some more. Tests of about 60 hydrogen-fueled prototypes from several automakers have so far demonstrated driving ranges of 100 to 190 miles.

Aiming for a practical goal that could be achievable by 2010 (when some companies expect the first production fuel-cell cars to hit the road), researchers compare the performance of various storage technologies against the "6 weight percent" benchmark. That is, a fuel storage system in which 6 percent of its total weight is hydrogen. For a system weighing a total of 100 kilograms (a reasonable size for a vehicle), six kilograms would be stored hydrogen. Although 6 percent may not seem like much, achieving that level will be extremely tough; less than 2 percent is the best possible today--using storage materials that operate at relatively low pressures. Further, keeping the system's total volume to about that of a standard automotive gasoline tank will be even more difficult, given that much of its allotted space will be taken up by the tanks, valves, tubing, regulators, sensors, insulation and anything else that is required to hold the six kilograms of hydrogen. Finally, a useful system must release hydrogen at rates fast enough for the fuel-cell and electric motor combination to provide the power and acceleration that drivers expect.

Containing Hydrogen

At present, most of the several hundred prototype fuel-cell vehicles store hydrogen gas in high-pressure cylinders, similar to scuba tanks. Advanced filament-wound, carbon-fiber composite technology has yielded strong, lightweight tanks that can safely contain hydrogen at pressures of 5,000 psi (350 times atmospheric pressure) to 10,000 psi (700 times atmospheric pressure) [see box above]. Simply raising the pressure does not proportionally increase the hydrogen density, however. Even at 10,000 psi, the best achievable energy density with current high-pressure tanks (39 grams per liter) is about 15 percent of the energy content of gasoline in the same given volume. Today's high-pressure tanks can contain only about 3.5 to 4.5 percent of hydrogen by weight. Ford recently introduced a prototype "crossover SUV" called Edge that is powered by a combination plug-in hybrid/fuel-cell system that stores 4.5 kilograms of hydrogen fuel in a 5,000-psi tank to achieve a total maximum range of 200 miles.

High-pressure tanks would be acceptable in certain transportation applications, such as transit buses and other large vehicles that have the physical size necessary to accommodate storage for sufficient hydrogen, but it would be difficult to manage in cars. Also, the current cost of such tanks is 10 or more times higher than what is competitive for autos.

Liquefying stored hydrogen can improve its energy density, packing the most hydrogen into a given volume of any existing option. Like any gas, hydrogen that is cooled sufficiently condenses into a liquid, which at atmospheric pressure occurs around –253 degrees Celsius. Liquid hydrogen exhibits a density of 71 grams per liter, or about 30 percent of the energy density of gasoline. The hydrogen weight densities achievable by these systems depend on the containment and insulation equipment they use.

Liquefied hydrogen has important drawbacks, though. First, its very low boiling point necessitates cryogenic equipment and special precautions for safe handling. In addition, because it operates at low temperature, the containers have to be insulated extremely well. Finally, liquefying hydrogen takes more energy than compressing the gas to high pressures. This requirement drives up the cost of the fuel and reduces the overall energy efficiency of the cryocooling process.

Nevertheless, one carmaker is pushing this technology onto the road. BMW plans to introduce a vehicle this year called Hydrogen 7, which will incorporate an internal-combustion engine capable of running on either gasoline (for 300 miles) or on liquid hydrogen for 125 miles. Hydrogen 7 will be sold on a limited basis to selected customers in the U.S. and other countries with local access to hydrogen refueling stations.

Chemical Compaction

Searching for promising ways to raise energy density, scientists may be able to take advantage of the chemistry of hydrogen itself. In their pure gas and liquid phases, hydrogen molecules contain two bound atoms each. But when hydrogen atoms are chemically bound to certain other elements, they can be packed even closer together than in liquid hydrogen. The principal aim of hydrogen storage research now is finding the materials that can pull off this trick.

Some researchers are focusing on a class of substances called reversible metal hydrides, which were discovered by accident in 1969 at the Philips Eindhoven Labs in the Netherlands. Investigators found that a samarium-cobalt alloy exposed to pressurized hydrogen gas would absorb hydrogen, somewhat like a sponge soaks up water. When the pressure was then removed, the hydrogen within the alloy reemerged; in other words, the process was reversible.

Intensive research followed this discovery. In the U.S., scientists James Reilly of Brookhaven National Laboratory and Gary Sandrock of Inco Research and Development Center in Suffern, N.Y., pioneered the development of hydride alloys with finely tuned hydrogen absorption properties. This early work formed the basis for today's widely used nickel–metal hydride batteries. The density of hydrogen in these alloys can be very high: 150 percent more than liquid hydrogen, because the hydrogen atoms are constrained between the metal atoms in their crystal lattices.

Many properties of metal hydrides are well suited to automobiles. Densities surpassing that of liquid hydrogen can be achieved at relatively low pressures, in the range of 10 to 100 times atmospheric pressure. Metal hydrides are also inherently stable, so they require no extra energy to maintain storage, although heat is required to release the stored gas. But their Achilles' heel is mass. They weigh too much for practical onboard storage. Metal hydride researchers have so far attained a maximum hydrogen capacity of 2 percent of the total material weight (2 weight percent). This level translates into a 1,000-pound hydrogen storage system (for a 300-mile driving range), which is clearly too heavy for today's 3,000-pound car.

Metal hydride studies currently concentrate on materials with inherently high hydrogen content, which researchers then modify to meet the hydrogen storage system requirements of operating temperatures in the neighborhood of 100 degrees C, pressures from 10 to 100 atmospheres and delivery rates sufficient to support rapid vehicle acceleration. In many cases, materials that contain useful proportions of hydrogen are a bit too stable in that they require substantially higher temperatures to release the hydrogen. Magnesium, for example, forms magnesium hydride with 7.6 weight percent hydrogen but must be heated to above 300 degrees C for release to occur. If a practical system is to rely on waste heat from a fuel-cell stack (about 80 degrees C) to serve as the "switch" to liberate hydrogen from a metal hydride, then the trigger temperature must be lower.

Destabilized Hydrides

Chemists John J. Vajo and Gregory L. Olson of HRL Laboratories in Malibu, Calif., as well as researchers elsewhere are exploring a clever approach to overcoming the temperature problem. Their "destabilized hydrides" combine several substances to alter the reaction pathway so that the resulting compounds release the gas at lower temperatures.

Destabilized hydrides are part of a class of hydrogen-containing materials called complex hydrides. Chemists long thought that many of these compounds were not optimal for refueling a vehicle, because they were irreversible--once the hydrogen was freed by decomposition of the compounds, the materials would require reprocessing to return them to a hydrogenated state. Chemists Borislav Bogdanovic and Manfred Schwickardi of the Max Planck Institute of Coal Research in Mülheim, Germany, however, stunned the hydride research community in 1996 when they demonstrated that the complex hydride sodium alanate becomes reversible when a small amount of titanium is added. This work triggered a flurry of activity during the past decade. HRL's lithium borohydride destabilized with magnesium hydride, for example, holds around 9 percent of hydrogen by weight reversibly and features a 200 degree C operating temperature. This improvement is notable, but its operating temperature is still too high and its hydrogen release rate too slow for automotive applications. Nevertheless, the work is promising.

Although current metal hydrides have limitations, many automakers see them as the most viable low-pressure approach in the near- to mid-term. Toyota and Honda engineers, for example, are planning a so-called hybrid approach in a system that combines a solid metal hydride with moderate pressure (significantly lower than 10,000 psi), which they predict could achieve a driving range of more than 300 miles. General Motors has teams of storage experts, including Scott Jorgensen, who are supporting research on a wide range of metal hydride systems worldwide (including in Russia, Canada and Singapore). GM is also collaborating with Sandia National Laboratories on a four-year, $10-million effort to produce a prototype complex metal hydride system.

Hydrogen Carriers

Other hydrogen storage options have the potential to work well in cars, but they suffer a penalty in the refueling step. In general, these chemical hydride substances need industrial processing to reconstitute the spent material. The step requires off-board regeneration; that is, once hydrogen stored onboard a vehicle is released, a leftover by-product must be reclaimed at a service station and regenerated in a chemical plant.

More than 20 years ago Japanese researchers studied this approach using, for example, the decalin-naphthalene system. When decalin (C10H18) is heated, it converts chemically to naphthalene (a pungent-smelling compound with the formula C10H8) by changing the nature of its chemical bonds, which liberates five hydrogen molecules. Hydrogen gas thus bubbles out of the liquid decalin as it transforms into naphthalene. Exposing naphthalene to moderate hydrogen gas pressures reverses the process; it absorbs hydrogen and changes back to decalin (6.2 weight percent for the material alone). Research chemists Alan Cooper and Guido Pez of Air Products and Chemicals in Allentown, Pa., are investigating a similar technique using organic (hydrocarbon-based) liquids. Other scientists, including S. Thomas Autrey and his co-workers at the Pacific Northwest National Laboratory and chemistry professor Larry G. Sneddon of the University of Pennsylvania, are working on new liquid carriers, such as aminoboranes, that can store large amounts of hydrogen and release it at moderate temperatures.

Designer Materials

Yet another approach to the hydrogen storage problem centers on lightweight materials with very high surface areas to which hydrogen molecules stick (or adsorb). As one might expect, the amount of hydrogen retained on any surface correlates with the material's surface area. Recent developments in nanoscale engineering have yielded a host of new high-surface-area materials, some with more than 5,000 square meters of surface area per gram of material. (This amount equates to about three acres of surface area within just a teaspoon of powder.) Carbon-based materials are particularly interesting because they are lightweight, can be low cost and can form a variety of nanosize structures: carbon nanotubes, nanohorns (hornlike tubes), fullerenes (ball-shaped molecules) and aerogels (ultraporous solids). One relatively cheap material, activated carbon, can store up to about 5 weight percent hydrogen.

These carbon structures all share a common limitation, however. Hydrogen molecules bond very weakly with the carbon atoms, which means that the high-surface-area materials must be kept at or near the temperature of liquid nitrogen, –196 degrees C. In contrast to hydride research, in which scientists are struggling to lower the hydrogen binding energy, carbon researchers are exploring ways to raise the binding energy by modifying the surfaces of materials or by adding metal dopants that may alter their properties. These investigators employ theoretical modeling of carbon structures to discover promising systems for further study.

Beyond the carbon-based approaches, another fascinating nanoscale engineering concept is a category of substances called metal-organic materials. A few years ago Omar Yaghi, then a chemistry professor at the University of Michigan at Ann Arbor and now at the University of California, Los Angeles, invented these so-called metal-organic frameworks, or MOFs. Yaghi and his co-workers showed that this new class of highly porous, crystalline materials could be produced by linking inorganic compounds together with organic "struts" [see box at right]. The resulting MOFs are synthetic compounds with elegant-looking structures and physical characteristics that can be controlled to provide various desired functions. These heterogeneous structures can have very large surface areas (as high as 5,500 square meters per gram), and researchers can tailor chemical sites on them for optimal binding to hydrogen. To date, investigators have demonstrated MOFs that exhibit hydrogen capacities of 7 weight percent at –196 degrees C. They continue to work on boosting this performance.

Although current progress on hydrogen storage methods is encouraging, finding the "just right" approach may take time, requiring sustained, innovative research and development efforts. Over the centuries, the basic promise--and challenge--of using hydrogen for transportation has remained fundamentally unchanged: Holding onto hydrogen in a practical, lightweight container allowed Jacques Charles to travel across the sky in his balloon during the last decades of the 18th century. Finding a similarly suitable container to store hydrogen in automobiles will permit people to travel across the globe in the coming decades of the 21st century without fouling the sky above.

Overview/Hydrogen Storage

• One of the biggest obstacles to future fuel-cell vehicles is how engineers will manage to stuff enough hydrogen onboard to provide the 300-mile minimum driving range that motorists demand.

• Typically hydrogen is stored in pressurized tanks as a highly compressed gas at ambient temperature, but the tanks do not hold enough gas. Liquid-hydrogen systems, which operate at cryogenic temperatures, also suffer from significant drawbacks.

• Several alternative high-density storage technologies are under development, but none is yet up to the challenge.


The Hydrogen Economy: Opportunities, Costs, Barriers, and R&D Needs. National Research Council and National Academy of Engineering. National Academies Press, 2004

Hydrogen Program: 2006 Annual Merit Review Proceedings. U.S. Department of Energy

United States Council for Automotive Research

International Energy Agency's Hydrogen Implementing Agreement

International Partnership for the Hydrogen Economy

By Sunita Satyapal; John Petrovic and George Thomas

Saturday, February 03, 2007

Mother of All Paradoxes

The notorious mother paradox (sometimes formulated using other familial relationships) arises when people or objects can travel backward in time and alter the past. A simplified version involves billiard balls. A billiard ball passes through a wormhole time machine. When it emerges, it hits its earlier self, thereby preventing it from ever entering the wormhole.

Resolution of the paradox proceeds from a simple realization: the billiard ball cannot do something that is inconsistent with logic or with the laws of physics. It cannot pass through the wormhole in such a way that will prevent it from passing through the wormhole. But nothing stops it from passing through the wormhole in an infinity of other ways.

A Wormhole Time Machine in Three Not So Easy Steps

1. Find or build a wormhole -- a tunnel connecting two different locations in space. Large wormholes might exist naturally in deep space, a relic of the big, bang. Otherwise we would have to make do with subatomic wormholes, either natural ones (which are thought to be winking in and out of existence all around us) or artificial ones (produced by particle accelerators, as imagined here). These smaller wormholes would have to be enlarged to a useful size, perhaps using energy fields like those that caused space to inflate shortly after the big bang.

2. Stabilize the wormhole. An infusion of negative energy, produced by quantum means such as the so-called Casimir effect, would allow a signal or object to pass safely through the wormhole. Negative energy counteracts the tendency of the wormhole to pinch off into a point of infinite or near-infinite density. In other words, it prevents the wormhole from becoming a black hole.

3. Tow the wormhole. A spaceship, presumably of highly advanced technology, would separate the mouths of the wormhole. One mouth might be positioned near the surface of a neutron star, an extremely dense star with a strong gravitational field. The intense gravity causes time to pass more slowly. Because time passes more quickly at the other wormhole mouth, the two mouths become separated not only in space but also in time.

Friday, February 02, 2007

How To Build A Time Machine

Time travel has been a popular science-fiction theme since H. G. Wells wrote his celebrated novel The Time Machine in 1895. But can it really be done? Is it possible to build a machine that would transport a human being into the past or future?

For decades, time travel lay beyond the fringe of respectable science. In recent years, however, the topic has become something of a cottage industry among theoretical physicists. The motivation has been partly recreational--time travel is fun to think about. But this research has a serious side, too. Understanding the relation between cause and effect is a key part of attempts to construct a unified theory of physics. If unrestricted time travel were possible, even in principle, the nature of such a unified theory could be drastically affected.

Our best understanding of time comes from Einstein's theories of relativity. Prior to these theories, time was widely regarded as absolute and universal, the same for everyone no matter what their physical circumstances were. In his special theory of relativity, Einstein proposed that the measured interval between two events depends on how the observer is moving. Crucially, two observers who move differently will experience different durations between the same two events.

The effect is often described using the "twin paradox." Suppose that Sally and Sam are twins. Sally boards a rocket ship and travels at high speed to a nearby star, turns around and flies back to Earth, while Sam stays at home. For Sally the duration of the journey might be, say, one year, but when she returns and steps out of the spaceship, she finds that 10 years have elapsed on Earth. Her brother is now nine years older than she is. Sally and Sam are no longer the same age, despite the fact that they were born on the same day. This example illustrates a limited type of time travel. In effect, Sally has leaped nine years into Earth's future.

Jet Lag

THE EFFECT, KNOWN AS time dilation, occurs whenever two observers move relative to each other. In daily life we don't notice weird time warps, because the effect becomes dramatic only when the motion occurs at close to the speed of light. Even at aircraft speeds, the time dilation in a typical journey amounts to just a few nanoseconds--hardly an adventure of Wellsian proportions. Nevertheless, atomic clocks are accurate enough to record the shift and confirm that time really is stretched by motion. So travel into the future is a proved fact, even if it has so far been in rather unexciting amounts.

To observe really dramatic time warps, one has to look beyond the realm of ordinary experience. Subatomic particles can be propelled at nearly the speed of light in large accelerator machines. Some of these particles, such as muons, have a built-in clock because they decay with a definite half-life; in accordance with Einstein's theory, fast-moving muons inside accelerators are observed to decay in slow motion. Some cosmic rays also experience spectacular time warps. These particles move so close to the speed of light that, from their point of view, they cross the galaxy in minutes, even though in Earth's frame of reference they seem to take tens of thousands of years. If time dilation did not occur, those particles would never make it here.

Speed is one way to jump ahead in time. Gravity is another. In his general theory of relativity, Einstein predicted that gravity slows time. Clocks run a bit faster in the attic than in the basement, which is closer to the center of Earth and therefore deeper down in a gravitational field. Similarly, clocks run faster in space than on the ground. Once again the effect is minuscule, but it has been directly measured using accurate clocks. Indeed, these time-warping effects have to be taken into account in the Global Positioning System. If they weren't, sailors, taxi drivers and cruise missiles could find themselves many kilometers off course.

At the surface of a neutron star, gravity is so strong that time is slowed by about 30 percent relative to Earth time. Viewed from such a star, events here would resemble a fast-forwarded video. A black hole represents the ultimate time warp; at the surface of the hole, time stands still relative to Earth. This means that if you fell into a black hole from nearby, in the brief interval it took you to reach the surface, all of eternity would pass by in the wider universe. The region within the black hole is therefore beyond the end of time, as far as the outside universe is concerned. If an astronaut could zoom very close to a black hole and return unscathed--admittedly a fanciful, not to mention foolhardy, prospect--he could leap far into the future.

My Head Is Spinning

SO FAR I HAVE DISCUSSED travel forward in time. What about going backward? This is much more problematic. In 1948 Kurt Gödel of the Institute for Advanced Study in Princeton, N.J., produced a solution of Einstein's gravitational field equations that described a rotating universe. In this universe, an astronaut could travel through space so as to reach his own past. This comes about because of the way gravity affects light. The rotation of the universe would drag light (and thus the causal relations between objects) around with it, enabling a material object to travel in a closed loop in space that is also a closed loop in time, without at any stage exceeding the speed of light in the immediate neighborhood of the particle. Gödel's solution was shrugged aside as a mathematical curiosity--after all, observations show no sign that the universe as a whole is spinning. His result served nonetheless to demonstrate that going back in time was not forbidden by the theory of relativity. Indeed, Einstein confessed that he was troubled by the thought that his theory might permit travel into the past under some circumstances.

Other scenarios have been found to permit travel into the past. For example, in 1974 Frank J. Tipler of Tulane University calculated that a massive, infinitely long cylinder spinning on its axis at near the speed of light could let astronauts visit their own past, again by dragging light around the cylinder into a loop. In 1991 J. Richard Gott of Princeton University predicted that cosmic strings--structures that cosmologists think were created in the early stages of the big bang--could produce similar results. But in the mid-1980s the most realistic scenario for a time machine emerged, based on the concept of a wormhole.

In science fiction, wormholes are sometimes called star-gates; they offer a shortcut between two widely separated points in space. Jump through a hypothetical wormhole, and you might come out moments later on the other side of the galaxy. Wormholes naturally fit into the general theory of relativity, whereby gravity warps not only time but also space. The theory allows the analogue of alternative road and tunnel routes connecting two points in space. Mathematicians refer to such a space as multiply connected. Just as a tunnel passing under a hill can be shorter than the surface street, a wormhole may be shorter than the usual route through ordinary space.

The wormhole was used as a fictional device by Carl Sagan in his 1985 novel Contact. Prompted by Sagan, Kip S. Thorne and his co-workers at the California Institute of Technology set out to find whether wormholes were consistent with known physics. Their starting point was that a wormhole would resemble a black hole in being an object with fearsome gravity. But unlike a black hole, which offers a one-way journey to nowhere, a wormhole would have an exit as well as an entrance.

In the Loop

FOR THE WORMHOLE to be traversable, it must contain what Thorne termed exotic matter. In effect, this is something that will generate antigravity to combat the natural tendency of a massive system to implode into a black hole under its intense weight. Antigravity, or gravitational repulsion, can be generated by negative energy or pressure. Negative-energy states are known to exist in certain quantum systems, which suggests that Thorne's exotic matter is not ruled out by the laws of physics, although it is unclear whether enough antigravitating stuff can be assembled to stabilize a wormhole.

Soon Thorne and his colleagues realized that if a stable wormhole could be created, then it could readily be turned into a time machine. An astronaut who passed through one might come out not only somewhere else in the universe but somewhen else, too--in either the future or the past.

To adapt the wormhole for time travel, one of its mouths could be towed to a neutron star and placed close to its surface. The gravity of the star would slow time near that wormhole mouth, so that a time difference between the ends of the wormhole would gradually accumulate. If both mouths were then parked at a convenient place in space, this time difference would remain frozen in.

Suppose the difference were 10 years. An astronaut passing through the wormhole in one direction would jump 10 years into the future, whereas an astronaut passing in the other direction would jump 10 years into the past. By returning to his starting point at high speed across ordinary space, the second astronaut might get back home before he left. In other words, a closed loop in space could become a loop in time as well. The one restriction is that the astronaut could not return to a time before the wormhole was first built.

A formidable problem that stands in the way of making a wormhole time machine is the creation of the wormhole in the first place. Possibly space is threaded with such structures naturally--relics of the big bang. If so, a supercivilization might commandeer one. Alternatively, wormholes might naturally come into existence on tiny scales, the so-called Planck length, about 20 factors of 10 as small as an atomic nucleus. In principle, such a minute wormhole could be stabilized by a pulse of energy and then somehow inflated to usable dimensions.


ASSUMING THAT the engineering problems could be overcome, the production of a time machine could open up a Pandora's box of causal paradoxes. Consider, for example, the time traveler who visits the past and murders his mother when she was a young girl. How do we make sense of this? If the girl dies, she cannot become the time traveler's mother. But if the time traveler was never born, he could not go back and murder his mother.

Paradoxes of this kind arise when the time traveler tries to change the past, which is obviously impossible. But that does not prevent someone from being a part of the past. Suppose the time traveler goes back and rescues a young girl from murder, and this girl grows up to become his mother. The causal loop is now self-consistent and no longer paradoxical. Causal consistency might impose restrictions on what a time traveler is able to do, but it does not rule out time travel per se.

Even if time travel isn't strictly paradoxical, it is certainly weird. Consider the time traveler who leaps ahead a year and reads about a new mathematical theorem in a future edition of Scientific American. He notes the details, returns to his own time and teaches the theorem to a student, who then writes it up for Scientific American. The article is, of course, the very one that the time traveler read. The question then arises: Where did the information about the theorem come from? Not from the time traveler, because he read it, but not from the student either, who learned it from the time traveler. The information seemingly came into existence from nowhere, reasonlessly.

The bizarre consequences of time travel have led some scientists to reject the notion outright. Stephen Hawking of the University of Cambridge has proposed a "chronology protection conjecture," which would outlaw causal loops. Because the theory of relativity is known to permit causal loops, chronology protection would require some other factor to intercede to prevent travel into the past. What might this factor be? One suggestion is that quantum processes will come to the rescue. The existence of a time machine would allow particles to loop into their own past. Calculations hint that the ensuing disturbance would become self-reinforcing, creating a runaway surge of energy that would wreck the wormhole.

Chronology protection is still just a conjecture, so time travel remains a possibility. A final resolution of the matter may have to await the successful union of quantum mechanics and gravitation, perhaps through a theory such as string theory or its extension, so-called M-theory. It is even conceivable that the next generation of particle accelerators will be able to create subatomic wormholes that survive long enough for nearby particles to execute fleeting causal loops. This would be a far cry from Wells's vision of a time machine, but it would forever change our picture of physical reality.

Overview Time Travel

* Traveling forward in time is easy enough. If you move close to the speed of light or sit in a strong gravitational field, you experience time more slowly than other people do--another way of saying that you travel into their future.

* Traveling into the past is rather trickier. Relativity theory allows it in certain spacetime configurations: a rotating universe, a rotating cylinder and, most famously, a wormhole--a tunnel through space and time.


Time Machines: Time Travel in Physics, Metaphysics, and Science Fiction. Paul J. Nahin. American Institute of Physics, 1993.

The Quantum Physics of Time Travel. David Deutsch and Michael Lockwood in Scientific American, Vol. 270, No. 3, pages 68-74; March 1994.

Black Holes and Time Warps: Einstein's Outrageous Legacy. Kip S. Thorne. W. W. Norton, 1994.

Time Travel in Einstein's Universe: The Physical Possibilities of Travel through Time. J. Richard Gott III. Houghton Mifflin, 2001.

How to Build a Time Machine. Paul Davies. Viking, 2002.
Existing Forms of Forward Travel

By Paul Davies

Tuesday, January 30, 2007

50, 100, 150 Years Ago


BOREDOM --"In this age of semi-automation, when not only military personnel but also many industrial workers have little to do but keep a constant watch on instruments, the problem of human behavior in monotonous situations is becoming acute. In 1951 McGill University psychologist Donald O. Hebb obtained a grant from the Defense Research Board of Canada to make a systematic study. Prolonged exposure to a monotonous environment has definitely deleterious effects. The individual's thinking is impaired; he shows childish emotional responses; his visual perception becomes disturbed; he suffers from hallucinations; his brain-wave pattern changes."

ANXIETY --"In the past year and a half prescription sales of the tranquilizing drug meprobamate, better known as Miltown and Equanil, have jumped to the rate of $32.5 million a year. More than a billion tablets have been sold, and the monthly production of 50 tons falls far short of the demand. Some California druggists herald each new shipment with colored window streamers reading, 'Yes, we have Miltown today!'"


AUTO CHIC --"The improved appearance of this year's cars is largely aided by the considerable increase in the wheel base which, in the case of some of the heavier machines, is now as great as 123 inches. Furthermore, the use of six-cylinder motors has brought with it a considerable increase in the length of the bonnet, and this also adds to the generally rakish and smart appearance of the up-to-date machine. By a judicious attention to these principles, the builders of even the low-powered and low-priced machines have succeeded in giving to their output a style which was altogether lacking in the earlier models."

FLYING FOR SPORT AND WAR --"With mechanical aeroplane flight an accomplished fact, we may now look for a diversion of interest from the dirigible balloon to the aeroplane proper. Its field of usefulness will be found chiefly in military service, where it will be invaluable for reconnoitering purposes and for the conveyance of swift dispatches. In all probability its chief development ultimately will be in the field of sport, where it should enjoy a popularity equal to that of the automobile."

TEA MONEY --"The queerest use to which brick-tea (tea leaves compressed into a block) has ever been put in the Orient is in the capacity of money. It is still in circulation as a medium of exchange in the far-inland Chinese towns and central Asian marts and bazaars. Between the Mongolian town of Urga and the Siberian town of Kiakta, there is as much as half a million taels (say $600,000) of this money in circulation. At the latter place it ceases to be used as currency, and enters into the regular brick-tea trade of Siberia and Russia, where it is largely used in the Russian army, by surveying engineers, touring theatrical companies, and tourists in general."


REALITY THEATER --"A severe test of the strength of the suspension bridge at Niagara Falls was afforded by the gale on the evening of the 13th of last month, when the toll gatherers deserted their posts at either end, and crowds assembled to see it fall, but it stood like a rock."

DR. LIVINGSTONE'S TALES --"The celebrated traveler Dr. Livingstone has been lecturing since his return to England. During his unprecedented march, alone among savages, to whom a white face was a miracle, Dr. Livingstone was compelled to struggle through indescribable hardships--he conquered the hostility of the natives by his intimate knowledge of their character and the Bechuana tongue. He waded rivers and slept in the sponge and ooze of marshes, being often so drenched as to be compelled to turn his arm-pit into a watch-pocket. Lions were numerous, being worshiped by many of the tribes as the receptacles of the departed souls of their chiefs; however, he thinks the fear of African wild beasts greater in England than in Africa."

Scientific American, Jan2007

Monday, January 29, 2007

Happier holidays -- in 5 easy steps

Ditch those obligatory get-togethers for new traditions with folks who really matter.

Last year, my girlfriend Betsy and I decided to set the holiday craziness aside and spend an impromptu few hours celebrating Christmas Eve together. No big dinner, no fancy gifts, no huge crowd--just us, our kids, and our husbands, enjoying store-bought hors d'oeuvres, desserts, and eggnog, swapping traditions, and rediscovering why we adore one another. It was a celebration full of sweet memories we won't soon forget.

If only all holiday connections were as low-key and hassle-free. Unfortunately, with all the party-hopping and the pressure to cook, decorate, and find the perfect gift, celebrations can end up feeling more like The Nightmare Before Christmas than It's a Wonderful Life. In fact, the National Mental Health Institute says that worrying, partying, stressing, and clinging to unrealistic expectations--all in an overcommercialized atmosphere--can lead to a case of the holiday blues, a condition that can cause insomnia, headaches, fatigue, and even depression.

"People focus on the holidays by saying, 'Can I just get through it?' instead of recognizing this as a time to connect with family, reflect on the previous year, and look forward to the New Year," says life coach Valorie Burton, author of Listen to Your Life.

It doesn't have to be that way, though. Get more out of this holiday season by saying no to irrelevant obligations and finding more meaningful ways to connect with those most important to you. Here are a few tips to get you started.

1 Instead of assembling and wrapping gifts into the wee hours to keep the kids from hearing your tools and the distinct sound of tape ripping …

Take an afternoon off from work and invite a few buddies over for a gift-wrapping party, while the kids are at school. "Put on your holiday music, have cake and tea, talk and laugh--and connect," Burton suggests.

2 Instead of packing the whole family into the minivan and driving 6 hours across four states to see your parents (or worse, spending thousands of dollars in airfare) …

Send Mom and Dad tickets so they can visit you during the holidays. "It'll cost you a few hundred bucks. But it's an awfully wonderful trade, compared with what it would take for you to get there and the disruption it would cause," says Jeff Davidson, author of Breathing Space: Living and Working at a Comfortable Pace in a Sped-Up Society. "The gesture alone speaks volumes."

3 Instead of attending multiple Hanukkah or Kwanzaa parties to celebrate these weeklong holidays …

Host a small gathering of friends on one of the days, and enjoy the others with just your immediate family. You can even make your party more special by inviting people whose religions and traditions differ from your own. Cecelia Cancellaro and Eric Zinner, of Maplewood, New Jersey, let their 7- and 4-year-old daughters invite friends over to play dreidels, eat latkes, and participate in lighting the menorah as part of their annual Hanukkah party. It gives her daughters a sense of pride when they share their tradition with friends, Cancellaro says. "It helps all the children feel more connected to one anther."

4 Instead of schlepping the kids to the mall to wait (and wait) in an excruciatingly long line to get pricey-but-not-so-great holiday portraits …

Whip out your home video camera and have your children sing, dance, and share their New Year's resolutions. Then when the holidays arrive, pop some popcorn, pour the eggnog, dim the lights, and sit everyone down to enjoy your own musical. The kids will love seeing themselves, you'll capture priceless memories, and the entire family will enjoy your new holiday tradition. Plan to make it an annual event. And next year, this year's video will be even more fun.

5 Instead of going to the annual neighborhood-association holiday potluck …

Help your kids bake a batch of cookies, and then take the treats to your favorite neighbors' homes with handwritten holiday greetings. "These days, people don't connect much with their neighbors," Burton says. "This is a great way to get the kids involved and do something that you wouldn't normally do. It's an inexpensive and extremely thoughtful gesture."

Already dreading the holidays? Ease your stress with our Holiday Survival Guide at

By Denene Millner