This page contains basic information and FAQs about the force we call gravity. Gravity plays an important role in our universe. Scientists still have a tough time understanding what this force is.This remains one of the greatest challenges of 21st Century science.
My book, Exploring Quantum Space also explains some of the exciting, and mysterious, aspects of the nature of gravity.
Ten Amazing Things about Gravity!
- It travels at the speed of light
- It is not a true force in nature
- It is the weakest ‘force’ in the universe
- It is only attractive and never repulsive
- It is produced by both matter and energy
- It only exists in 3-dimensional space
- It can warp the geometry of empty space
- It is the ultimate source of energy in the universe
- Space and time are created by it
- Its ultimate origin is completely unknown
My Blogs about Gravity and Space
- How do you visualize space?
- How do you think about ‘nothing’?
- What is space itself?
- What does the Planck Era tell us about the Nature of Space?
- What is Quantum Gravity all about?
- How does the brain think about space?
Since The Astronomy Cafe opened for business in 1995, its Ask The Astronomer resource has answered over 4000 questions about space and physics. Here are the most popular ones about gravity have generated more than 1 million views, which were also used by NASA’s Gravity Probe B mission!
- What exactly is a sub-atomic particles structure like?
- Do we really know how gravity and magnetism operate?
- Is anti-gravity possible?
- Is the empty space inside particles the same kind as there is inside atoms?
- Do other dimensions exist?
- Does the physical vacuum produce a pressure that can be measured?
- What prevents densities higher than the Planck Limit from happening?
- How does a magnetic field differ from a gravitational field?
- Can gravity be simulated using electromagnetic forces?
- How are electromagnetic fields and space-time related, and can electromagnetic fields exert a force on space -time?
- If the force of gravity were reduced 50 percent, how would this change stars and the universe?
- How much of a charge excess would be needed in the universe to produce detectable non-gravitational motions?
- Does anyone really understand general relativity well enough to have an intuitive grasp of the universe?
- How do you really know that general relativity stops working inside black holes?
- If nothing can travel faster than light, why does gravity take affect instantly?
- Are we gravitationally affected by where an object is now, or where it was when the light we see started its journey to us?
- Can gravity alter the speed of light?
- When light falls in a gravitational well, does its speed exceed 300,000 km/sec?
- Is light conducted by space, or does it travel through it?
- Can you go faster than the speed of light by altering space in some way?
- What are the ’10 dimensions’ that physicists are always talking about?
- What is the simplest evidence that there are more than 4 dimensions?
- Where does the energy come from that produces virtual particles?
- Is there a ‘smallest possible size’ to space beyond which it cannot be further divided?
- What is a space anomaly?
- What binary star is producing gravity waves?
- Are there any other astronomical systems where general relativity can be tested other than the Hulse-Taylor binary pulsar?
- Don’t objects steadily evaporate over time by emitting gravity waves?
- What does the equation look like that shows how gravitational radiation is lost from the binary pulsar system?
- Does the star DI Herculis prove that general relativity is breaking down?
- Do we really know how gravity and magnetism operate?
- Does the physical vacuum produce a pressure that can be measured?
- How do you reconcile quantum mechanics with general relativity?
- Are there alternatives to General Relativity?
- What is the substance of gravity?