Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Testing Einstein's E=mc2 in Outer Space

09.01.2013
UA physicist Andrei Lebed has stirred the physics community with an intriguing idea yet to be tested experimentally: The world's most iconic equation, Albert Einstein's E=mc2, may be correct or not depending on where you are in space.
With the first explosions of atomic bombs, the world became witness to one of the most important and consequential principles in physics: Energy and mass, fundamentally speaking, are the same thing and can, in fact, be converted into each other.

This was first demonstrated by Albert Einstein’s Theory of Special Relativity and famously expressed in his iconic equation, E=mc2, where E stands for energy, m for mass and c for the speed of light (squared).

Although physicists have since validated Einstein’s equation in countless experiments and calculations, and many technologies including mobile phones and GPS navigation depend on it, University of Arizona physics professor Andrei Lebed has stirred the physics community by suggesting that E=mc2 may not hold up in certain circumstances.

The key to Lebed’s argument lies in the very concept of mass itself. According to accepted paradigm, there is no difference between the mass of a moving object that can be defined in terms of its inertia, and the mass bestowed on that object by a gravitational field. In simple terms, the former, also called inertial mass, is what causes a car’s fender to bend upon impact of another vehicle, while the latter, called gravitational mass, is commonly referred to as “weight.”

This equivalence principle between the inertial and gravitational masses, introduced in classical physics by Galileo Galilei and in modern physics by Albert Einstein, has been confirmed with a very high level of accuracy. “But my calculations show that beyond a certain probability, there is a very small but real chance the equation breaks down for a gravitational mass,” Lebed said.

If one measures the weight of quantum objects, such as a hydrogen atom, often enough, the result will be the same in the vast majority of cases, but a tiny portion of those measurements give a different reading, in apparent violation of E=mc2. This has physicists puzzled, but it could be explained if gravitational mass was not the same as inertial mass, which is a paradigm in physics.

“Most physicists disagree with this because they believe that gravitational mass exactly equals inertial mass,” Lebed said. “But my point is that gravitational mass may not be equal to inertial mass due to some quantum effects in General Relativity, which is Einstein’s theory of gravitation. To the best of my knowledge, nobody has ever proposed this before.”

Lebed presented his calculations and their ramifications at the Marcel Grossmann Meeting in Stockholm last summer, where the community greeted them with equal amounts of skepticism and curiosity. Held every three years and attended by about 1,000 scientists from around the world, the conference focuses on theoretical and experimental General Relativity, astrophysics and relativistic field theories. Lebed’s results will be published in the conference proceedings in February.

In the meantime, Lebed has invited his peers to evaluate his calculations and suggested an experiment to test his conclusions, which he published in the world's largest collection of preprints at Cornell University Library (see Extra Info).

“The most important problem in physics is the Unifying Theory of Everything – a theory that can describe all forces observed in nature,” said Lebed. “The main problem toward such a theory is how to unite relativistic quantum mechanics and gravity. I try to make a connection between quantum objects and General Relativity.”

The key to understand Lebed’s reasoning is gravitation. On paper at least, he showed that while E=mc2 always holds true for inertial mass, it doesn’t always for gravitational mass.

“What this probably means is that gravitational mass is not the same as inertial,” he said.

According to Einstein, gravitation is a result of a curvature in space itself. Think of a mattress on which several objects have been laid out, say, a ping pong ball, a baseball and a bowling ball. The ping pong ball will make no visible dent, the baseball will make a very small one and the bowling ball will sink into the foam. Stars and planets do the same thing to space. The larger an object’s mass, the larger of a dent it will make into the fabric of space.

In other words, the more mass, the stronger the gravitational pull. In this conceptual model of gravitation, it is easy to see how a small object, like an asteroid wandering through space, eventually would get caught in the depression of a planet, trapped in its gravitational field.

“Space has a curvature,” Lebed said, “and when you move a mass in space, this curvature disturbs this motion.”

According to the UA physicist, the curvature of space is what makes gravitational mass different from inertial mass.

Lebed suggested to test his idea by measuring the weight of the simplest quantum object: a single hydrogen atom, which only consists of a nucleus, a single proton and a lone electron orbiting the nucleus.

Because he expects the effect to be extremely small, lots of hydrogen atoms would be needed.

Here is the idea:

On a rare occasion, the electron whizzing around the atom’s nucleus jumps to a higher energy level, which can roughly be thought of as a wider orbit. Within a short time, the electron falls back onto its previous energy level. According to E=mc2, the hydrogen atom’s mass will change along with the change in energy level.

So far, so good. But what would happen if we moved that same atom away from Earth, where space is no longer curved, but flat?

You guessed it: The electron could not jump to higher energy levels because in flat space it would be confined to its primary energy level. There is no jumping around in flat space.

“In this case, the electron can occupy only the first level of the hydrogen atom,” Lebed explained. “It doesn't feel the curvature of gravitation.”

“Then we move it close to Earth’s gravitational field, and because of the curvature of space, there is a probability of that electron jumping from the first level to the second. And now the mass will be different.”

“People have done calculations of energy levels here on Earth, but that gives you nothing because the curvature stays the same, so there is no perturbation,” Lebed said. “But what they didn't take into account before that opportunity of that electron to jump from the first to the second level because the curvature disturbs the atom.”

“Instead of measuring weight directly, we would detect these energy switching events, which would make themselves known as emitted photons – essentially, light,” he explained.

Lebed suggested the following experiment to test his hypothesis: Send a small spacecraft with a tank of hydrogen and a sensitive photo detector onto a journey into space.

In outer space, the relationship between mass and energy is the same for the atom, but only because the flat space doesn’t permit the electron to change energy levels.

“When we're close to Earth, the curvature of space disturbs the atom, and there is a probability for the electron to jump, thereby emitting a photon that is registered by the detector,” he said.

Depending on the energy level, the relationship between mass and energy is no longer fixed under the influence of a gravitational field.

Lebed said the spacecraft would not have to go very far.

“We’d have to send the probe out two or three times the radius of Earth, and it will work.”

According to Lebed, his work is the first proposition to test the combination of quantum mechanics and Einstein’s theory of gravity in the solar system.

“There are no direct tests on the marriage of those two theories,” he said. “ It is important not only from the point of view that gravitational mass is not equal to inertial mass, but also because many see this marriage as some kind of monster. I would like to test this marriage. I want to see whether it works or not.”

Daniel Stolte | EurekAlert!
Further information:
http://www.arizona.edu
http://uanews.org/story/testing-einsteins-emc2-outer-space

More articles from Physics and Astronomy:

nachricht Squeezed quantum cats
27.05.2015 | ETH Zurich

nachricht Supernovas help 'clean' galaxies
27.05.2015 | Michigan State University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Advance in regenerative medicine

The only professorship in Germany to date, one master's programme, one laboratory with worldwide unique equipment and the corresponding research results: The University of Würzburg is leading in the field of biofabrication.

Paul Dalton is presently the only professor of biofabrication in Germany. About a year ago, the Australian researcher relocated to the Würzburg department for...

Im Focus: Basel Physicists Develop Efficient Method of Signal Transmission from Nanocomponents

Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.

Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...

Im Focus: IoT-based Advanced Automobile Parking Navigation System

Development and implementation of an advanced automobile parking navigation platform for parking services

To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...

Im Focus: First electrical car ferry in the world in operation in Norway now

  • Siemens delivers electric propulsion system and charging stations with lithium-ion batteries charged from hydro power
  • Ferry only uses 150 kilowatt hours (kWh) per route and reduces cost of fuel by 60 percent
  • Milestone on the road to operating emission-free ferries

The world's first electrical car and passenger ferry powered by batteries has entered service in Norway. The ferry only uses 150 kWh per route, which...

Im Focus: Into the ice – RV Polarstern opens the arctic season by setting course for Spitsbergen

On Tuesday, 19 May 2015 the research icebreaker Polarstern will leave its home port in Bremerhaven, setting a course for the Arctic. Led by Dr Ilka Peeken from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) a team of 53 researchers from 11 countries will investigate the effects of climate change in the Arctic, from the surface ice floes down to the seafloor.

RV Polarstern will enter the sea-ice zone north of Spitsbergen. Covering two shallow regions on their way to deeper waters, the scientists on board will focus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International symposium: trends in spatial analysis and modelling for a more sustainable land use

20.05.2015 | Event News

15th conference of the International Association of Colloid and Interface Scientists

18.05.2015 | Event News

EHFG 2015: Securing health in Europe. Balancing priorities, sharing responsibilities

12.05.2015 | Event News

 
Latest News

Researchers develop intelligent handheld robots

27.05.2015 | Power and Electrical Engineering

"Hidden" fragrance compound can cause contact allergy

27.05.2015 | Health and Medicine

Supernovas help 'clean' galaxies

27.05.2015 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>