Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ESA to look for the missing link in gravity

12.09.2002


Although you can never be certain of predicting future developments in science, there is a good chance of a fundamental breakthrough in physics soon. With a series of unique experiments and missions designed to test our understanding of gravity, the European Space Agency (ESA) hopes to get to the very bottom of it.

Scientists will study space phenomena that do not seem to conform to our perceived understanding of gravity. In this way, they hope to develop a greater comprehension of the Universe.
Gravity is one of the four fundamental forces of nature. It shapes the Universe around us, allowing planets, stars and galaxies to form. However, the more scientists study gravity and its effects on celestial objects, the more mysteries they seem to uncover. One example is the so-called `Pioneer anomaly`, named after the NASA space probes Pioneer 10 and 11, on which the effect was first noticed. The anomaly was revealed when a number of spacecraft were seen to be affected by an unknown force that slowed them down. The same behaviour has now been detected on NASA`s Galileo and the joint ESA-NASA Ulysses spacecraft.


Scientists have known for a long time that there appears to be `too much` gravity in the Universe. They can observe the effects of gravitational forces at work, but the origin of these forces cannot be identified. This `excess` of gravity is usually referred to as `the missing mass problem`, since scientists assume that only matter can create gravity. It is therefore supposed that the Universe is filled with large quantities of `dark matter` that has yet to be detected. What if that assumption is wrong?

Some theories suggest that gravity might pull a little harder at extreme distances than had previously been considered, so the concept of dark matter may not even be necessary. Alternatively, the anomalies may be the result of a fifth force of nature: one that is very weak and only shows up in the remotest regions of space. Space is an ideal testing ground to examine the existing theories. In the apparent weightlessness of space, scientists can detect the most delicate of forces and can measure them with extreme accuracy.

Developing an ambitious series of space experiments and missions, ESA is focusing its efforts on testing Albert Einstein`s Theory of General Relativity, the most advanced description of gravity ever formulated. One of the first objectives is the detection of gravitational waves. General Relativity has predicted their existence but, so far, they remain undetected. These waves should travel through space like ripples on a pond. LISA, a joint ESA-NASA mission, will be the first space mission to attempt to detect such gravitational waves. Finding them would be the ultimate test of General Relativity.

A second objective, to be tested by the ESA Gaia and BepiColombo missions, will be to measure precisely how matter distorts space, searching for any deviation in the amount predicted by General Relativity. Microscope, an ESA mission carried out in coordination with the French National Space Agency (CNES), is designed to test a concept from General Relativity called The Principle of Equivalence. According to this, objects are accelerated by gravity in the same way, independent of their mass and chemical composition. If Microscope detects a violation of this principle, it could be the clearest sign yet of a new dimension to gravity, known as quantum gravity.

Quantum gravity is a much-sought-after theory. Its purpose is to reconcile Einstein`s General Relativity with quantum physics, the most advanced theory describing the fundamental forces in Nature, with the exception of gravity. Quantum gravity supposes that space is granular on the smallest of scales. In a similar way, for example, a beach appears smooth from a distance but is actually composed of individual pieces of sand. Hyper, a mission currently under study at ESA would attempt to detect the quantum granularity of space, as one of its investigations into gravity. Looking further into the future, ESA has taken the first steps in defining a mission which would examine directly the Pioneer anomaly.

With this series of missions, ESA will carry out a unique investigation into the very nature of gravity. This may well provide the next fundamental breakthrough in our understanding of the Universe.

Dr Michael Perryman | alfa
Further information:
http://www.esa.int

More articles from Physics and Astronomy:

nachricht UNLV study unlocks clues to how planets form
13.12.2018 | University of Nevada, Las Vegas

nachricht Unprecedented Views of the Birth of Planets
13.12.2018 | Universität Heidelberg

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: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Magic number colloidal clusters

13.12.2018 | Life Sciences

UNLV study unlocks clues to how planets form

13.12.2018 | Physics and Astronomy

Live from the ocean research vessel Atlantis

13.12.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>