Showing posts with label Arizona State University. Show all posts
Showing posts with label Arizona State University. Show all posts

Thursday, January 26

Multiverse Theory


Multiverse theory suggests that our universe, with all its hundreds of billions of galaxies and almost countless stars, spanning tens of billions of light-years, may not be the only one. Instead, there may be an entirely different universe, distantly separated from ours — and another, and another. 

Indeed, there may be an infinity of universes, all with their own laws of physics, their own collections of stars and galaxies (if stars and galaxies can exist in those universes), and maybe even their own intelligent civilizations.

It could be that our universe is just one member of a much grander, much larger multitude of universes: a multiverse.  The concept of the multiverse arises in a few areas of physics (and philosophy), but the most prominent example comes from something called inflation theory. 

Inflation theory describes a hypothetical event that occurred when our universe was very young — less than a second old. In an incredibly brief amount of time, the universe underwent a period of rapid expansion, "inflating" to become many orders of magnitude larger than its previous size, according to NASA.

Inflation of our universe is thought to have ended about 14 billion years ago, said Heling Deng, a cosmologist at Arizona State University and an expert in multiverse theory. "However, inflation does not end everywhere at the same time," Deng told Live Science in an email. "It is possible that as inflation ends in some region, it continues in others."

Thus, while inflation ended in our universe, there may have been other, much more distant regions where inflation continued — and continues even today. Individual universes can "pinch off" of larger inflating, expanding universes, creating an infinite sea of eternal inflation, filled with numerous individual universes.

In this eternal inflation scenario, each universe would emerge with its own laws of physics, its own collection of particles, its own arrangement of forces and its own values of fundamental constants. This might explain why our universe has the properties it does — particularly the properties that are hard to explain with fundamental physics, such as dark matter or the cosmological constant, Deng said.

"If there is a multiverse, then we would have random cosmological constants in different universes, and it is simply a coincidence that the one we have in our universe takes the value that we observed," he said.   READ MORE...

Thursday, July 7

Moon's Permanent Shadows

Original story reprinted with permission from Quanta Magazine, an editorially independent publication of the Simons Foundation whose mission is to enhance public understanding of science by covering research develop­ments and trends in mathe­matics and the physical and life sciences.



ON OCTOBER 9, 2009, a 2-ton rocket smashed into the moon traveling at 9,000 kilometers per hour. As it exploded in a shower of dust and heated the lunar surface to hundreds of degrees Celsius, the jet-black crater into which it plummeted, called Cabeus, briefly filled with light for the first time in billions of years.

The crash was no accident. NASA’s Lunar Crater Observation and Sensing Satellite (LCROSS) mission aimed to see what would be kicked up from the lunar shadows by the impact. A spacecraft trailing the rocket flew through the dust plume to sample it, while NASA’s Lunar Reconnaissance Orbiter observed from afar. The results of the experiment were astonishing: Scientists detected 155 kilograms of water vapor mixed into the dust plume. They had, for the first time, found water on the moon. “It was absolutely definitive,” said Anthony Colaprete of NASA’s Ames Research Center, the principal investigator of LCROSS.

The moon isn’t an obvious reservoir of water. “It’s really weird when you stop to think about it,” said Mark Robinson, a planetary scientist at Arizona State University. Its lack of atmosphere and extreme temperatures should cause any water to almost instantly evaporate. Yet about 25 years ago, spacecraft began to detect signatures of hydrogen around the moon’s poles, hinting that water might be trapped there as ice. LCROSS proved this theory. Scientists now think there’s not just a bit of water ice on the moon; there are 6 trillion kilograms of it.  READ MORE...

Thursday, May 5

The Beginning of Outer Space


When mountaineers climb Mount Everest, they routinely carry oxygen cylinders, devices that allow them to breathe freely at high altitudes. This is necessary because the closer you get to the edge of Earth's atmosphere, the less oxygen there is available compared with the plentiful amounts found at sea level.

This is just one example of how variable Earth's atmosphere is and showcases the elemental makeup of its layers, from the troposphere, near sea level, to the exosphere, in its outermost regions. Where each layer ends and begins is defined by four key traits, according to the National Weather Service: temperature change, chemical composition, density and the movement of the gases within it.

So, with this in mind, where does Earth's atmosphere actually end? And where does space begin?

Each of the atmosphere's layers plays a role in ensuring our planet can host all manner of life, doing everything from blocking cancer-causing cosmic radiation to creating the pressure required to produce water, according to NASA.

"As you get farther from Earth, the atmosphere becomes less dense," Katrina Bossert, a space physicist at Arizona State University, told Live Science in an email. "The composition also changes, and lighter atoms and molecules begin to dominate, while heavy molecules remain closer to the Earth's surface."

As you move up in the atmosphere, the pressure, or the weight of the atmosphere above you, weakens rapidly. Even though commercial planes have pressurized cabins, rapid changes in altitude can affect the slim eustachian tubes connecting the ear with the nose and throat. "This is why your ears may pop during takeoff in an airplane," said Matthew Igel, an adjunct professor of atmospheric science at the University of California, Davis.  READ MORE...

Wednesday, March 2

Controlling the Moon


Photo Illustration by Elizabeth Brockway and Luis G. Rendon/The Daily Beast/Getty


In 1961, U.S. President John F. Kennedy declared that his nation would be the first to land a man on the moon. That ambitious goal would later be fulfilled as two NASA astronauts took wobbly steps across the lunar surface on July 20, 1969, much to the dismay of Russia’s own space program leaders.

More than 60 years later, a new space race to the moon has begun, albeit with much higher stakes and brand new players ready to make the 238,855-mile journey. This time, the race to the moon is about much more than just planting a flag on its dusty surface. Getting to the moon first could also mean calling dibs on its limited resources, and controlling a permanent gateway to take humans to Mars—and beyond.

Whether it’s NASA, China, Russia, or a consortium of private companies that end up dominating the moon, laying claim to the lunar surface isn’t really about the moon anyway—it’s about who gets easier access to the rest of the solar system.

Everyone’s Got an Agenda

James Rice, a senior scientist at the School of Earth and Space Exploration at Arizona State University, remembers growing up with the Apollo program and getting bitten by the space bug as he watched the 1969 moon landing unfold on television.

“As a kid, I saw that happening and I wanted to be a part of it,” Rice told The Daily Beast. “That’s basically why I’m in this career today.”

As Rice reflected on the current space race, he recognized some key differences. “Things have really changed dramatically in terms of the technology and the players that are out there,” he said. “This is not the moon we thought of during the Apollo days.” Scientists have learned so much more about the moon through more detailed analysis of lunar samples, as well as several missions that have probed exactly what might be sitting on the moon’s surface and remain hidden deep underground.  READ MORE...

Tuesday, January 25

Multiple Universes



If the multiverse exists, there could be another you somewhere out there, doing exactly what you're doing now. (Image credit: Getty Images)

The multiverse is a hypothetical group of multiple universes. Together, these universes comprise everything that exists: the entirety of space, time, matter, energy, information, and the physical laws and constants that describe them. The different universes within the multiverse are called "parallel universes", "other universes", "alternate universes", or "many worlds".  SOURCE:  Wikipedia


Multiverse Theory 
...suggests that our universe, with all its hundreds of billions of galaxies and almost countless stars, spanning tens of billions of light-years, may not be the only one. Instead, there may be an entirely different universe, distantly separated from ours — and another, and another. Indeed, there may be an infinity of universes, all with their own laws of physics, their own collections of stars and galaxies (if stars and galaxies can exist in those universes), and maybe even their own intelligent civilizations.

It could be that our universe is just one member of a much grander, much larger multitude of universes: a multiverse.

The concept of the multiverse arises in a few areas of physics (and philosophy), but the most prominent example comes from something called inflation theory. Inflation theory describes a hypothetical event that occurred when our universe was very young — less than a second old. In an incredibly brief amount of time, the universe underwent a period of rapid expansion, "inflating" to become many orders of magnitude larger than its previous size, according to NASA.

Inflation of our universe is thought to have ended about 14 billion years ago, said Heling Deng, a cosmologist at Arizona State University and an expert in multiverse theory. "However, inflation does not end everywhere at the same time," Deng told Live Science in an email. "It is possible that as inflation ends in some region, it continues in others."

Thus, while inflation ended in our universe, there may have been other, much more distant regions where inflation continued — and continues even today. Individual universes can "pinch off" of larger inflating, expanding universes, creating an infinite sea of eternal inflation, filled with numerous individual universes.  READ MORE...