Uncategorized

Read e-book The 4 Percent Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality

Free download. Book file PDF easily for everyone and every device. You can download and read online The 4 Percent Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality file PDF Book only if you are registered here. And also you can download or read online all Book PDF file that related with The 4 Percent Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality book. Happy reading The 4 Percent Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality Bookeveryone. Download file Free Book PDF The 4 Percent Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality at Complete PDF Library. This Book have some digital formats such us :paperbook, ebook, kindle, epub, fb2 and another formats. Here is The CompletePDF Book Library. It's free to register here to get Book file PDF The 4 Percent Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality Pocket Guide.

What is Kobo Super Points?

Yet Rubin's observations found no drop-off at all in the stars' velocities further out in a galaxy. Instead, she found that all stars in a galaxy seem to circle the center at roughly the same speed. But research by other astronomers confirmed the odd finding. Ultimately, based on observations and computer models, scientists concluded that there must be much more matter in galaxies than what's obvious to us. If the stars and gas that we can see inside galaxies are only a small portion of their total mass, then the velocities make sense.

Astronomers nicknamed this unseen mass dark matter. Yet, in the nearly 40 years that followed, researchers still haven't been able to figure out what dark matter is made of. A popular hypothesis is that dark matter is formed by exotic particles that don't interact with regular matter, or even light, and so are invisible. Yet their mass exerts a gravitational pull, just like normal matter, which is why they affect the velocities of stars and other phenomena in the universe.

However, try as hard as they might, scientists have yet to detect any of these particles, even with tests designed specifically to target their predicted properties.


  • BOOKS ON SPACE:?
  • Stanford Libraries.
  • Trypanosomatid Diseases: Molecular Routes to Drug Discovery.
  • Mossbauer Effect in Lattice Dynamics: Experimental Techniques and Applications.
  • Growth, Distribution, and Social Change: Essays on the Economy of the Republic of China;

Still, many hold out hope that we're getting close and that experiments such as the newly built Large Hadron Collider particle accelerator in Geneva may finally solve the puzzle. Dark energy is possibly even more baffling than dark matter. It's a relatively more recent discovery, and it's one that scientists have even less of a chance of understanding anytime soon. It all started in the mids, when two teams of researchers were trying to figure out how fast the universe was expanding, in order to predict whether it would keep spreading out forever, or if it would eventually crumple back in on itself in a "Big Crunch.

To do this, scientists used special tricks to determine the distances of many exploded stars, called supernovas, throughout the universe. They then measured their velocities to determine how fast they were moving away from us.

THE 4 PERCENT UNIVERSE by Richard Panek | Kirkus Reviews

When we view very distant stars, we are viewing an earlier time in the history of the universe, because those stars' light has taken millions and billions of light-years to travel to us. Thus, looking at the speeds of stars at various distances tells us how fast the universe was expanding at various points in its lifetime. Astronomers predicted two possibilities: either the universe has been expanding at roughly the same rate throughout time, or that the universe has been slowing in its expansion as it gets older.

Shockingly, the researchers observed neither possibility. Instead, the universe appeared to be accelerating in its expansion. That fact could not be explained based on what we knew of the universe at that time. Yet, in the nearly 40 years that followed, researchers still haven't been able to figure out what dark matter is made of.


  1. Regionalisierung der Strukturpolitik in Nordrhein-Westfalen.
  2. On the Air Resistance of Projectiles;
  3. The Lessons of Rancière.
  4. A popular hypothesis is that dark matter is formed by exotic particles that don't interact with regular matter, or even light, and so are invisible. Yet their mass exerts a gravitational pull, just like normal matter, which is why they affect the velocities of stars and other phenomena in the universe.

    However, try as hard as they might, scientists have yet to detect any of these particles, even with tests designed specifically to target their predicted properties. Still, many hold out hope that we're getting close and that experiments such as the newly built Large Hadron Collider particle accelerator in Geneva may finally solve the puzzle.

    Dark energy is possibly even more baffling than dark matter. It's a relatively more recent discovery, and it's one that scientists have even less of a chance of understanding anytime soon. It all started in the mids, when two teams of researchers were trying to figure out how fast the universe was expanding, in order to predict whether it would keep spreading out forever, or if it would eventually crumple back in on itself in a "Big Crunch.

    Wake up with the smartest email in your inbox.

    To do this, scientists used special tricks to determine the distances of many exploded stars, called supernovas, throughout the universe. They then measured their velocities to determine how fast they were moving away from us.


    • The 4-Percent Universe?
    • Building PHP Applications with Symfony, CakePHP, and Zend Framework.
    • Principles of Pharmacology: The Pathophysiologic Basis of Drug Therapy?

    When we view very distant stars, we are viewing an earlier time in the history of the universe, because those stars' light has taken millions and billions of light-years to travel to us. Thus, looking at the speeds of stars at various distances tells us how fast the universe was expanding at various points in its lifetime. Astronomers predicted two possibilities: either the universe has been expanding at roughly the same rate throughout time, or that the universe has been slowing in its expansion as it gets older.

    The 4% Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality

    Shockingly, the researchers observed neither possibility. Instead, the universe appeared to be accelerating in its expansion.

    You are here

    That fact could not be explained based on what we knew of the universe at that time. All the gravity of all the mass in the cosmos should have been pulling the universe back inward, just as gravity pulls a ball back down to Earth after it's been thrown into the air.

    Reward Yourself

    Scientists named this mysterious force dark energy. Though no one has a good idea of what dark energy is, or why it exists, it is the force that appears to be counteracting gravity and causing the universe to accelerate in its expansion. The lack of a good explanation for dark energy hasn't seemed to dampen scientists' enthusiasm for it. Overall, dark energy is thought to contribute 73 percent of all the mass and energy in the universe. Another 23 percent is dark matter, which leaves only 4 percent of the universe composed of regular matter, such as stars, planets and people.