Nothingness of Space Could Illuminate the Theory of Everything

Could the vacuum contain dark energy, gravity particles, and frictionless gears?

When the next revolution rocks physics, chances are it will be about nothing—the vacuum, that endless infinite void. In a discipline where the stretching of time and the warping of space are routine working assumptions, the vacuum remains a sort of cosmic koan. And as in the rest of physics, its nature has turned out to be mind-bendingly weird: Empty space is not really empty because nothing contains something, seething with energy and particles that flit into and out of existence. Physicists have known that much for decades, ever since the birth of quantum mechanics. But only in the last 10 years has the vacuum taken center stage as a font of confounding mysteries like the nature of dark enery and matter; only recently has the void turned into a tantalizing beacon for cranks. As one blond celebrity heiress and embodiment of emptiness might say, nothing is hot.

To investigate the mysteries of the void, some physicists are using the biggest scientific instrument ever built—the just-completed Large Hadron Çollider, a huge particle accelerator straddling the French-Swiss border. Others are designing tabletop experiments to see if they can plumb the vacuum for ways to power strange new nanotech devices. “The vacuum is one of the places where our knowledge fizzles out and we’re left with all sorts of crazy-sounding ideas,” says John Baez, a mathematical physicist at the University of California at Riverside. Whether in the visionary search for the engine of cosmic expansion or the near-fruitless quest for perpetual free energy, the vacuum is where it’s happening. By mining the vacuum’s riches, a true theory of everything may yet emerge.

Empty space wasn’t always so mystifying. Until the 1920s physicists viewed the vacuum much as the rest of us still do: as a featureless nothingness, a true void. That all changed with the birth of quantum mechanics. According to that theory, the space around a particle is filled with countless “virtual” particles rapidly bursting into and out of existence like an invisible fireworks display.

Those virtual quantum particles are more than a theoretical abstraction. Sixty years ago a Dutch physicist named Hendrik Casimir suggested a simple experiment to show that virtual particles can move objects in the real world. What would happen, he asked, to two metal plates placed very close together in a complete vacuum? In the days before quantum mechanics, physicists would have said that the plates would just sit there. But Casimir realized that the net pressure of all the virtual particles—the stuff of empty space—outside the plates should exert a minuscule force, a nudge from nothing that would push the plates together.

Physicists tried for decades to measure the Casimir force with great precision, but it wasn’t until 1997 that technology caught up with theory. In that year, physicist Steve Lasmoreux now at Yale, managed to detect the feeble Casimir force on two small surfaces separated by a few thousandths of a millimeter. Its strength was about equal to the force that would be exerted against the palm of one’s hand by the weight of a single red blood cell.

At first most physicists regarded the Casimir force as a quantum oddity, something of no practical value. Now that has changed: Forward thinkers see it as an important energizer for the tiniest of machines, devices on the nano scale, and a few labs are working on ways to use the force to defy the conventional limitations of mechanical design. Federico Capasso, a physicist at Harvard, leads a small team that is trying to create a repulsive Casimir force by tinkering with the shapes of plates or with the coatings used to cover them. His entire set of experiments fits on a desktop, and the objects he works with are so small that most of them cannot be seen without a microscope.

“Once you have a repulsive force between two plates, you should be able to eliminate static friction,” Capasso says. That could lead to a host of useful applications, including tiny frictionless bearings or nanogears that spin without touching. “But the experiments are enormously difficult, so I cannot tell you when and how.”

For all its strangeness, the Casimir force may be the one property of empty space that does not baffle today’s physicists. It is garden-variety quantum mechanics, weird but not unexpected. The same can’t be said about dark energy, a truly astonishing discovery made by astronomers a decade ago while observing distant exploding stars.

Extracted from:

Discover Magazine

http://discovermagazine.com/2008/aug/18-nothingness-of-space-theory-of-everything

Author: Tim Folger

In space, loneliness has many zeros

Human beings possess a terrestrial dimension of loneliness. The Antarctic, the great deserts, the less populated forests, the great oceans, are all environments in which it is possible to be in solitude, far from other people, from towns and cities.

In all these places, the distances that separate isolated individuals from populated areas are only a few hundred kilometers, perhaps thousands.

A similar loneliness but related to the technical difficulties to arrive and to return are felt in the satellite terrestrial orbits. Astronauts are not too far from the surface of our planet (barely 300 or 400 kilometers), although it seems to be much more because of the risks involved in the ascent and descent of orbital levels.

Traveling to the moon adds new elements of loneliness. The lunar astronauts were all the time at a distance of 350,000 kilometers from their homes, with a single fragile vehicle available to return, to which it was added the vulnerability of the lunar environment, without significant atmosphere and temperatures that can range from 130 degrees Celsius at noon until 150 degrees below zero at night (1 lunar day lasts 29 Earth days):

The moon is close when compared to Mars, where many probes have been sent and some still remain active on the Martian surface.

The distance to Mars varies due to the respective orbital movements of Mars and Earth. At the moment they are closer, they are distant about 60,000,000 kilometers and when they are further away, the distance is 400,000,000 kilometers.

If one thinks of the distances to the greater planets, one must keep adding zeros. At Jupiter the distance can vary between 800,000,000 and 1,100,000,000 km. In Saturn, it is 1,200,000,000 km when it is closest and 1,700,000,000 when it is farther away. Uranus is even more remote: 2,600,000,000 km when it is near, 2,900,000,000 km when it is far away. The last greater planet, Neptune is 4,300,000,000 and 4,700,000,000 km and finally the planet today classified as "dwarf planet", Pluto, is 4,280,000,000 kilometers when it is "close" and 7,500,000,000 kilometers at its maximum distance.

Of course, these are just numbers. It is difficult to imagine the feeling of loneliness in these great distances simply with these numbers.

Perhaps it helps to perceive what loneliness means is when one examines the story of the New Horizons probe that made the trip to Pluto from Earth in recent years.

Launched from our planet on January 19, 2006, it had to travel more than 9 years to approach Pluto where it arrived on July 17, 2015.

These were 9 years in the solitude and emptiness of space. At a high speed of 30,000 to 50,000 km per hour it took New Horizons more than 9 years to arrive.

The distance traveled was not rectilinear, so it traveled for 12,500,000,000 kilometers.

During his trip he was subjected to extreme temperatures that dropped to 240-250 degrees below zero or even less (on Pluto, the surface temperature varies between -220 and -230).

Even so it was communicated with the Earth in the moments that were required, sending for several months very rich information that is still being evaluated.

The probe continues its space navigation towards a small planetary object of about 100 kilometers in diameter called 2014 MU69 for which it needs to travel another 1,500,000,000 kilometers at a slightly reduced speed of 15,000 km / hour in the cold close to absolute zero and the indescribable loneliness, to get to 2014 MU69.

And throughout this journey he will continue to communicate with the base of operations on Earth.

It will arrive at the indicated object on January 1, 2019, At that date it will collect the information that is planned and continue your space drift sending the data for several months, losing contact in the year 2023 or 2024. Its trip will continue, it will leave the solar system, and it will digress in interstellar space by several thousands, tens of thousands, millions of years.

It will probably pass close to a star that is about 10 light years away, within 100,000 years.

Then, the distance to our planet will be 100,000,000,000,000 kilometers.

Maybe at that moment humanity and even the human species itself could have disappeared.

Or traveled to even greater distances.

Coldness and loneliness of spece
D. Anton

Absolute zero, also called zero Kelvin, occurs when the particles that constitute matter have no motion. Measured in degrees Celsius 0 Kelvin takes place at -273.15 (degrees Celsius below zero).
The average temperature at the Earth's surface is 287 degrees Kelvin or 14 degrees Celsius above zero. The average temperature at the surface of Mars is 213 degrees Kelvin or minus 60 degrees Celsius. Pluto, which is much further away, shows very low temperatures of 44 degrees Kelvin or 229 degrees Celsius below zero.
The Horizons probe that was sent to Pluto had to cross enormous distances. In them, without internal heating systems, the temperature of the probe would have dropped to 270 degrees centigrade below zero or about 3 degrees above the absolute 0.
So the interplanetary space is cold, VERY COLD.
But in addition to being cold, it is fundamentally empty space, VERY EMPTY. A spacecraft, such as New Horizons, destined for the planet Pluto (about 6,000 million km away from Earth) traveled 9 years (yes, more than 3,300 days) at a speed of 30,000 to 15,000 kilometers per hour, without finding any particles of visible dimensions . Only the loneliness of space. THE GREAT LONELINESS OF SPACE.
It only came to Pluto because it was directed in that direction. In any other direction I would have followed long into interstellar space.
But the New Horizons story did not end there.
From Pluto, the spacecraft was redirected to a small asteroid a hundred kilometers of diameter, distant about 2,000 million kilometers from Pluto, which will arrive in about three more years, continuing its march through the empty space.
Cold and empty. The greatest of the solitudes. Only the faint light of distant stars.
Incomprehensible to us, little human beings, on this hospitable planet, accompanied only by ourselves.

Cold and lonely. Such is the universe.