The size of our Milky Way

 

The disk of the Milky Way Galaxy disk may actually be rippled. (Image credit: Heidi Newberg)

Two ringlike structures of stars wrapping around the Milky Way's outer disk now appear to belong to the disk itself.

The results, outlined in a new study, show that the disk is about 60 percent larger than previously thought. Not only do the results extend the size of the Milky Way, they also reveal a rippling pattern, which raises intriguing questions about what sent wavelike fluctuations rippling through the disk.

The researchers said the likely culprit was a dwarf galaxy. It might have plunged through the Milky Way's center long ago, sparking the rippling patterns astronomers have now detected for the first time.

Roughly 15 years ago, Heidi Newberg, an astronomer at the Rensselaer Polytechnic Institute in New York, and her colleagues found a group of stars beyond the disk's outermost edge. The so-called Monoceros Ring is about 60,000 light-years from the galactic center (just beyond where the disk was thought to end at 50,000 light-years). Over the years, astronomers were divided into two camps regarding the origins of the ring. Some argued that it was simply a tidal stream: The debris of a dwarf galaxy that fell into the Milky Way and was stretched in the process. Others argued that the ring is a part of the disk. The issue, however, is that the ring is slightly above the plane of the disk. So astronomers in the latter camp attributed that to the fact that the disk flares up toward the edge. Enter Yan Xu, an astronomer at the National Astronomical Observatories of China. Xu, Newberg and colleagues took a second look at the problem using data from the Sloan Digital Sky Survey. With improved data compared to previous studies, they found four total structures in and just outside what is currently considered the Milky Way's outer disk. The third structure was the highly debated Monoceros ring, and the fourth structure was the Triangulum Andromeda Stream, located 70,000 light-years from the galactic center. All four structures alternated with respect to the disk. They went from above it, to below it, to above it, to below it. Newberg, who was in the tidal stream camp, was surprised that the ring and three other structures were actually a part of an oscillating disk.

"We didn't know how a disk could go up and down," said Newberg. Luckily, computer simulations by various teams showed that a dwarf galaxy falling into the Milky Way might create a similar pattern. "When it goes through, it can disturb the disk just like a pebble disturbs water in a puddle," said Newberg. "And that wave can propagate through the disk from that event."

This new picture makes sense, said Newberg. It even matches observations of the gases in the disk, which have long been observed as rippled. But the implications extend far beyond a corrugated disk.

"If it's true that the Monoceros Ring and the Triangulum Andromeda structure are part of this oscillatory pattern, then the stellar disk goes out way further than the textbook tells us it ought to be," said Newberg. Instead of extending nearly 100,000 light-years from one side to the other, it would be more like 160,000 light-years wide.

This brings the Milky Way's size up to that of Andromeda. The Milky Way's small radius in comparison to Andromeda's larger radius has always puzzled astronomers, because the two galaxies have roughly the same mass. The team plans to further map the rippled disk of Earth's galaxy and better match their results to models. The study was detailed in the March 10 edition of the Astrophysical Journal.

Shannon Hall

https://tinyurl.com/bdhhaxs9

The Milky Way is a vast, flat, barred spiral galaxy approximately 100,000 light-years in diameter and about 1,000 light-years thick. Our Solar System is located in one of its spiral arms, about 27,000 light-years from the center, which means we are unable to take a direct picture of the entire disk. 

• If the Sun were a tiny grain of sand, the entire Milky Way's stellar disk would still be an immense 100,000 miles across.
• Compared to the nearby Andromeda Galaxy (our closest large neighbor), which is 2.5 million light-years away, the Milky Way's diameter is roughly 1/20th of that distance.
• The entire observable universe is estimated to be approximately 930,000 Milky Way diameters across, making our galaxy a tiny speck in the grand scheme of the cosmos. 

Contemplate the incredible vastness of space with this visualization of the size of our Milky Way galaxy

: NASA/JPL-Caltech

The sizes of satellites

 

Visualization comparing sizes of the Universe

 

Black holes

 

A black hole is an astronomical object with a gravitational pull so strong that nothing, not even light, can escape it. A black hole’s “surface,” called its event horizon, defines the boundary where the velocity needed to escape exceeds the speed of light, which is the speed limit of the cosmos. Matter and radiation fall in, but they can’t get out.

 

Two of the main classes of black holes have been extensively observed out of four classified.

 

Stellar-mass black holes with six to dozens of times the Sun’s mass are spread throughout our Milky Way galaxy, while supermassive monsters weighing 100,000 to billions of solar masses are found in the centers of most big galaxies, ours included.

 

Astronomers had long suspected an in-between class called intermediate-mass black holes, weighing 100 to more than 10,000 solar masses. While a handful of candidates have been identified with indirect evidence, the most convincing example to date came on May 21, 2019, when the National Science Foundation’s Laser Interferometer Gravitational-wave Observatory (LIGO), located in Livingston, Louisiana, and Hanford, Washington, detected gravitational waves from a merger of two stellar-mass black holes. This event, dubbed GW190521, resulted in a black hole weighing 142 Suns.

 

A stellar-mass black hole forms when a star with more than 20 solar masses exhausts the nuclear fuel in its core and collapses under its own weight. The collapse triggers a supernova explosion that blows off the star’s outer layers. But if the crushed core contains more than about three times the Sun’s mass, no known force can stop its collapse to a black hole. The origin of supermassive black holes is poorly understood, but we know they exist from the very earliest days of a galaxy’s lifetime.

 

Once born, black holes can grow by accreting matter that falls into them, including gas stripped from neighboring stars and even other black holes.

 

These videos are generated with the help of MidJourney AI.

 

Video credits: @zataylor

DM For removal.

NASA released this sound coming from a Black Hole

The sound waves are rippling out of a supermassive black hole, located 250 million light-years away.

The black hole is at the center of the Perseus cluster of galaxies, and the acoustic waves coming from it have been transposed up 57 and 58 octaves so they're audible to human hearing.

The sound waves were extracted radially, or outwards from the supermassive black hole at the center of the Perseus cluster, and played in an anti-clockwise direction from the center, so that we can hear the sounds in all directions from the supermassive black hole at pitches 144 quadrillion and 288 quadrillion times higher than their original frequency.

The result is an eerie one, like many of the waves recorded from space and transposed into audio frequencies.

Follow @spacestrikes if you are ready to explore space!🚀

1-2nd video credit: @eawnnn
3rd video credit: Black Hole at the Center of the Perseus Galaxy Cluster (X-ray)

The Big Bang Future

 

What happens when the sun burns out?

 

It won't go quietly into the night.

BY RAHUL RAO 

There’s perhaps nothing more ancient and unchanging than the sun, a yellow dwarf star that has illuminated Earth for over 4 billion years.

But our star, too, shall pass. And scientists are actually pretty certain about what will happen when it does.

The sun powers itself by fusing, or combining, extremely hot hydrogen atoms inside its core. That creates helium and a lot of energy. But just as a music box will wind itself out, the hydrogen in the sun’s core will run dry. When that happens, in around 5 billion years, the sun will have to find a new power source. 

At first, that’s not a problem. Today, fusing hydrogen also lets the sun’s core push back against the outer layers pressing down. When the core can no longer hold out, hydrogen from those outer layers will flood in and heat up—giving the sun more fuel to fuse. All will seem well.

But this will come at a cost. The side effects of these events will cause the sun to redden, cool, and inflate to more than a hundred times its current size, swallowing the orbits of Mercury, Venus, and even Earth. The sun will transform into a red giant, just like the stars Arcturus or Aldebaran that we can see in our sky.

It’s all for a fix of hydrogen that will only buy the sun an extra billion years of life. When that, too, runs out, the sun will be forced to reach for the next best thing: that helium it’s produced all this time.

When the sun begins to fuse helium, it might seem a return to normal. The helium will partly rebuild the ruins of the core, and the bloated star will lose much of its size. Astronomers call this the helium flash. But there’s a catch: The flash will burn off nearly a tenth of the sun’s perfectly good helium in mere minutes.

Afterwards, the increasingly geriatric sun faces a fatal problem: As fuel, helium just doesn’t compare to hydrogen. Fusing helium isn’t nearly as energy-efficient as fusing hydrogen, and it produces carbon and oxygen. It’s possible to fuse those, but it’s far more difficult and far more inefficient.

The remaining helium will only buy the sun another 100 million years or so.

When the sun can no longer fuse helium, it will enter another troubled time. It’ll puff back up, desperately flailing for any pockets of hydrogen or helium it can fuse. Even as the core starts to collapse, the star might push its outer rim ever farther away, maybe all the way past the asteroid belt.

This can only go on for so long. In the end, the sun will throw off all of its outer layers. Observers in the next star system might see a spectacular display, like a bright halo. For the sun we recognize, these 10,000 years are its moment of death.

It will leave behind a sort of celestial tombstone called a planetary nebula, even though planets aren’t involved—unless the dark, dead husks of what were once Jupiter, Saturn, Uranus, and Neptune manage to stop themselves from being blown away.

But for the sun, death is not the end. While about half its mass will flood out, the rest will crush together at the very center of the planetary nebula. This will turn into a tiny, bright, ultra-dense ember of the sun’s core, no larger than the Earth. This kind of smoldering remnant is called a white dwarf star.

So begins the sun’s long, last, lonely form. Over trillions of years, over a time that’s hundreds of times longer than the current age of the universe, that white dwarf will—very, very slowly—lose its remaining heat and fade to black.

https://bit.ly/3i4zFRe

FAVORITE IMAGES OF THE WEEK - 8

NASA/CampoAlto/V. Robles

Mars On Earth

Chile's Atacama Desert contains Earth's closest Mars-like conditions: It's extremely dry with high UV radiation from the sun. So naturally, NASA has made the area it's go-to practice facility for tests and experiments that they may one day perform on the red planet. Recently, scientists from NASA’s Atacama Rover Astrobiology Drilling Studies completed their second season of tests. The tested KREX-2 rover was able to rove, drill, and detect life signs all at the same time. Such multi-tasking robotic rovers could ultimately help scientists to figure out if there was (or still is) microbial life forms under Mars' surface.

Image courtesy of UW–Madison

A Simulated Tornado

Believe it or not, it’s springtime. And with it comes Tornado season—and tornado simulations. By modeling real data with a supercomputer, a team led by Leigh Orf at the University of Wisconsin–Madison has re-created this tornado-producing supercell that spawned several strong tornadoes in May 2011, including the EF-5 that touched down near El Reno, Oklahoma and caused a 63-mile path of destruction. These simulators can help us better understand the formation and structure of this extreme weather form.

NASA/Chris Gunn

NASA's Ghosts

It takes some artistic tricks to see ghosts around a space telescope. A NASA photographer recently captured this amazing and freaky picture during a lights-out inspection on the James Webb Space Telescope at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Because the special flashlights used for testing worked better in the dark, the engineers kept the lights off. To combat the dim (or nonexistent) light, the photographer used a longer than normal exposure, making the moving technicians look like blurred ghosts.

X-ray: NASA/CXC/University of Alberta/A.Bahramian et al.; Illustration: NASA/CXC/M.Weiss

A Black Hole Meets A White Dwarf Star

In a new study out this week in the journal, Monthly Notices of the Royal Astronomical Society, researchers found a white dwarf star orbiting around a black hole. It's a pretty rare find. Only a handful of binary systems like this one have been found in such dense globular star clusters. The researchers hope to learn more about this star-and-black-hole pair in future, and space-based gravitational wave observatories could be the key to its secrets.

Internet In Spaaaaaaaaace!

FAVORITE IMAGES OF THE WEEK - 2

NASA

Hurricane Tracker

A NASA mission called the Cyclone Global Navigation Satellite System (CYGNSS), which includes eight small satellites, launched this week. Its goal is to better understand how hurricanes form in order to more accurately predict how and when they will occur. One advantage of this system is that it will focus only on areas around the tropics, where most hurricanes form.

XPRIZE

Patient, Diagnose Thyself

In many ways, the tricorder in Star Trek is the ultimate piece of medical technology: A handheld device that can diagnose any disease in the body. In 2012, tech company Qualcomm created an XPRIZE competition to challenge engineers and doctors to create a device similar to the fictional tool. We took a first look at the two finalists' prototypes, which show us that our future doctor might simply be a tiny, high-tech medical box.

Joshua Stevens/NASA Earth Observatory

Snow Light

The weather these past two weeks has been rough for communities around the Great Lakes. Last week, the region was smothered with several feet of snow, and this week, an arctic air mass piled a few more feet on top. The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite, which can detect even extremely dim light sources, took this image above. The white areas show where the full moon is reflecting off of large piles of snow.

Department of Transportation

Talking Cars

Behind the wheel, humans make mistakes and cause accidents. That's mostly because we have bad communication skills (among other reasons). To make roads safer, the U.S. Department of Transportation wants cars to "talk" to each other. New technology that forces cars to broadcast their surroundings to other vehicles might prevent many accidents in the future.

NASA/JPL-Caltech/Univ. of Arizona

Dry Ice Bubbles

These crazy land formations, which look more like human intestines, can only be found on the south pole of Mars. They form when dry ice (carbon dioxide), which makes up the pole, is punctuated with holes. Over time, air slowly leaks in and puffs up the surface.

T.H. Prettyman and N. Yamashita, Planetary Science Institute

Ceres On Ice

Scientists are pretty sure that Ceres, the dwarf planet between Mars and Jupiter, holds water. But a new paper out this week suggests that it might contain more than liquid H2O: A portion of its surface, particularly near the poles, could be coated in a thin layer of ice. Studying how it built up there will help researchers understand how ice forms all over our solar system.

3-D Map of the Universe’s Galaxies is Largest Ever

A slice of the researchers’ map showing about 1/20th of the sky. Each dot represents the position of a galaxy 6 billion years into the past. Color indicates distance from Earth, ranging from yellow on the near side of the slice to purple on the far side. There are 48,741 galaxies in this picture, only about 3 percent of the total surveyed. (Credit: Daniel Eisenstein and SDSS-III)

By Jordan Rice

In the quest for dark energy, astronomers have created an unprecedented 3-D map of galaxies in a volume of about 650 cubic billion light years.

Hundreds of astronomers from the Sloan Digital Sky Survey III (SDSS-III) and the Max Planck Institutes for Extraterrestrial Physics (MPE) and for Astrophysics (MPA) contributed to this map. The astronomers found that the map agrees with the current cosmological model (the Lambda Cold Dark Matter model) and confirmed that dark energy is a cosmological constant.

Insights Into Dark Energy

Understanding how dark energy interacts and affects our universe is crucial to unraveling how the universe came to be and how it may end. Dark energy is believed to be what contradicts the force of gravity and is what is accelerating the expansion of the universe. These findings were submitted to the Monthly Notices of the Royal Astronomical Society (MNRAS) as a collection of papers.

“We have spent a decade collecting measurements of 1.2 million galaxies over one quarter of the sky to map out the structure of the universe over a volume of 650 cubic billion light-years,” says Dr. Jeremy Tinker of New York University in a press release.

The Baryon Oscillation Spectroscopic Survey (BOSS) of the SDSS-III carried out the precise measurements found. By studying the tugs between dark energy and dark matter, the scientists were able to determine the Baryonic Acoustic Oscillation (BAO) between the galaxies in the map to measure the expansion rate of the universe.

Frozen Waves

The normal BAO size is found from pressure waves that traveled throughout the universe when it was only 400,000 years old (the universe is currently 13.8 billion years old). The distribution of matter throughout the galaxy represents a frozen image of the life of these waves. All galaxies are therefore separated preferentially by a characteristic distance in what is called the BAO scale.

Using observations from the cosmic microwave background (CMB), the size of the acoustic scale at the universe’s current age can be determined. This is because the light that is emitted corresponds to when the pressure waves became frozen. Seeing how the distribution of galaxies has changed since then can give astronomers clues to how dark energy and dark matter have battled over the expansion rate of the universe. Ariel Sanchez, from MPE, was the astronomer who led the search to find the total amounts of dark energy and dark matter in the universe.

“Measuring the acoustic scale across cosmic history gives a direct ruler with which to measure the universe’s expansion rate,” says Sanchez in the same press release. “ With BOSS, we have traced the BAO’s subtle imprint on the distribution of galaxies spanning a range of time from 2 to 7 billion years ago.”

An illustration showing how a 2-dimensional image of the sky was transformed into a 3-D map of the universe. (Credit: Jeremy Tinker and SDSS-III)

How Far Away?

These very precise measurements had to be analyzed many times, in particular the distances from Earth to the galaxies in the map. Using a spectrometer, the light from a galaxy appears red-shifted as it is moving away from us. The red-shift in light is how the astronomers were able to correlate the galaxy’s distance from Earth; the farther a galaxy is, the faster it moves and therefore the more it is red-shifted. Dr. Shun Saito from MPA contributed models to the BOSS data analysis.

“However, galaxies also have peculiar motions and the peculiar velocity component along the line-of-sight leads to the so-called redshift space distortion,” says Saito in the same press release. “This makes the galaxy distribution anisotropic because the line-of-sight direction is now special — only along this direction the distance is measured through a redshift, which is contaminated by peculiar velocity. In other words, the characteristic anisotropic pattern allows us to measure the peculiar velocity of galaxies — and because the motion of galaxies is governed by gravity, we can use this measurement to constrain to what level Einstein’s general relativity is correct at cosmological scales. In order to properly interpret the data, we have developed a refined model to describe the galaxy distribution.”

Another possible approach is to use the angular positions of the galaxies in the sky rather than the 3-D physical positions in the universe.

“This method uses only observables,” says Dr. Salvador Salazar, a junior MPE researcher, in the same press release. “We make no prior assumptions about the cosmological model.”

Many approaches have been used to try and analyze the huge BOSS data set. “We now have seven measurements, which are slightly different, but highly correlated,” Sanchez says in a separate press release. “To extract the most information about the cosmological parameters, we had to find not only the best methods and models for data analysis but also the optimal combination of these measurements.”

Upholds Theory

Their strenuous efforts have paid off as the BOSS data show that dark energy is causing the expansion of the universe with an error of only 5 percent in the cosmological constant found. The cosmological constant is called Lambda, as coined by Albert Einstein as a repellant effect in the universe. These findings are still consistent with the relatively young theory of the cosmological model.

The map also reveals that galaxies tend to move to areas with more matter, staying true to the laws of gravity as well as the infall of material following the laws of general relativity. This suggests that the idea of the expansion of the universe is caused by a phenomenon like dark energy that works on large cosmic scales and dismisses the notion that our laws of gravity are breaking down.

This post originally appeared on Astronomy.com.

FAVORITE IMAGES OF THE WEEK

Anna Redmond/Facebook

Exposed Seawall

This bizarre mass of rocks and seaweed is the result of a 7.8-magnitude earthquake that hit New Zealand last week, thrusting the seawall up and out from the water. The movement of the planet's plates isn't uncommon at all. It's what formed Mount Everest and why South America and Africa fit so nicely together. But while tectonic plates usually move from side to side, the earthquake pushed them up and down instead, exposing this rather alien-looking seawall.

Photograph by Brian Klutch

Buy Your Own Paper Microscope

When Stanford physicist Manu Prakash invented his pocket-sized foldable microscope, called Foldscope, a few years back, his main goal was to make them widely available for any child (or adult) who wanted one. Now he's launched a kickstarter campaign where anyone can reserve a Foldscope of their own for $15. While the cost to create the device is only around 57 to 97 cents, the extra dollars will go toward donating millions of Foldscopes to schools and communities around the world.

ESA/Hubble & NASA, D. Calzetti

Oh Hey Spiral Galaxy NGC 3274

NASA's Hubble telescope snapped this image of a spiral galaxy more than 20 million light years away from Earth. The image is a combination of five different filters, incorporating ultraviolet, infrared, and visible light into one shot. If you look closely you can see another galaxy—PGC 213714—in the upper right corner.

NASA

Silver Linings

Astronauts above the Philippine Sea took this shot from aboard the International Space Station. They actually aimed their camera toward the sun, which emphasizes the clouds' shadows and produces a dramatic 3D effect.

Screenshot by author, from YouTube

The Most Luxurious Private Jet

Boeing’s 787 Dreamliner is designed to carry 280 people across oceans and between continents. But one special model has been converted to a private plane, complete with a master bedroom and five bathrooms. It's slightly smaller than the average U.S. home, but nearly 100 times the price.

Our Favorite Science Images of the Week

Lego NASA Women on Facebook

Women Of NASA, As Legos

When we think about astronauts that have paved the way for NASA to advance forward, the people that come to mind first--Buzz, Neil, Gus--are all male. That is leaving out so many women who have been essential members of many NASA missions. The Women Of NASA project, which was submitted to Lego Ideas aims to put leading women astronauts into the spotlight. The project highlights five women astronauts--Sally Ride, Margaret Hamilton, Katherine Johnson, Mae Jemison, and Nancy Grace Roman--by giving them the highest honor in the Lego world: their own figurine.

NASA/Magellan

Venus' Surface Revealed

For a long time, the surface of Venus remained a mystery to scientists. The planet's unusually thick atmosphere prevented researchers from being able to see what was underneath. But in a recent paperpublished in the Journal of Geophysical Research, researchers took advantage of this handicap by using infrared light and radar to penetrate through the surface and see beneath. They found that Venus' surface, as seen in the image above, is similar to Earth with mountains, canyons, valleys, and plains. And like Earth, these features influence its unique weather patterns.

H/T Gizmodo

Victoria Webster, via Case Western Reserve University

Powered By Sea Slugs

No one typically thinks that much of a sea slug. But researchers at Case Western Reserve University were curious to see what the little guys could amount to. So they created a biohybrid slugbot by 3-D printing a shell around a sea-slug's mouth muscle. Compared to most other muscles, sea slugs fair better in rapidly changing environments, which could make them a good candidate for biohybrid bots.

Matthew F. Glasser, David C. Van Essen

The Map Of the Brain Gets An Update

The cerebral cortex of the brain is a mysterious place. Until now, neuroscientists have relied on a map that broke the brain's cerebral cortex up into 80 different sections in each hemisphere. But in a paper released this past week in Nature, researchers released a brand new and updated map of the brain, including 100 new regions in each hemisphere.

To create the new map, researchers combined three different imaging techniques as well as a machine learning system. As seen above, the different colors represent what sensory input that area is connected to: Red for hearing, green for touch, and blue for vision. When two senses had overlap, mixed colors were displayed.

NASA

JunoCam Releases Its First Picture

Since Juno made it to Jupiter earlier this month, some of us have been anxiously awaiting the first picture of the largest planet in our solar system. Earlier this week, NASA finally released the first batch of unprocessed images. The image above is probably the best or most detailed of the set. As we pointed out in our original post, we have been incredibly spoiled by the high resolution images taken by near-Earth equipment like the Hubble. Given the obstacles that Juno is working with, that image above is pretty great.

Facebook

Facebook's Internet Beaming Drone Takes To The Sky

Facebook wants to make the internet accessible to the entire world. To do that, they are trying to employ a network of drones that would beam the internet down from the sky. This week, Facebook announced that it flew its first test flight of the internet beaming drone. At a steady pace of 25 mph, the drone, named Aquila, flew for 96 minutes, much longer than engineers had anticipated. The company's next goal is to have it fly for much longer.

U.S. Geological Survey

A Skylight View Of A Volcano

Until they explode with molten rock, what lies beneath volcanoes are not typically on our minds. But this image, taken last month by the U.S. Geological Survey atop the Puʻu ʻŌʻō crater at Kīlauea​ on the main island of Hawaii shows a glimpse of molten rock just beneath the surface.

H/T America's Great Outdoors

NASA/ESA/STScI/J. de Wit (MIT)

Distant Planets

In this image shown above taken by the Hubble Space Telescope, two planets called TRAPPIST-1b and TRAPPIST-1c can be seen as they pass across their sun. While the two planets are about 40 light-years away from Earth, they may have atmospheres that are capable of supporting life, unlike most gaseous planets. In the future, scientists plan to search for signs of life on these planets, such as carbon dioxide or water vapor, as well as figure out what the temperature and pressure are like on their surfaces.

NASA

Toning Up On Your Way To Mars

The astronauts that plan to make the big trek to Mars need to stay fit on their six to nine month journey. But how can that happen while inside a 316-cubic-foot capsule? NASA's Exploration Exercise Equipment project may have found a solution in its recently developed Resistive Overload Combined with Kinetic Yo-Yo (ROCKY for short). The device is a compact yet multifunctional exercise machine the size of a large shoebox that can be opened up into a rowing type machine, as seen above, as well as a strength training machine.

Courtesy of Hannu Makarainen

Zuckerberg's AI Toaster

In an interview with The Verge, Facebook CEO Mark Zuckerberg revealed that he has a goal of making his entire home run on AI technology, including his toaster. The real challenge, he says, is making the AI aware of when to actually make the toast. Once it effectively learns his exercise, meeting, and eating habits, it will know what time of the day he's in need of some toasted bread.

By Claire Maldarelli