Simulating gravity

News: Recently, the Orbital Assembly Corporation announced a plan to develop a space business park (hotel) which will be made operational by 2025. The hotel will be equipped with artificial gravity.

Benefits of artificial gravity

It would keep astronauts healthy on long trips, prevent loss of bone density and muscle atrophy. For example, in microgravity, the fluids in the body shift upward to the head. This put pressure on the eyes and causes vision problems. This worsens humans’ physical and mental health.

Further, the creation of artificial gravity can help humanity to settle on celestial bodies beyond Earth.

What are the proposals to create artificial gravity?

The first and considered most feasible is making a spaceship rotate. The inertia or the pseudo “centrifugal force” in such a scenario would be the basis of the solution to artificial gravity as was in the movie 2001: A Space Odyssey.

– The centrifuge solution is worth considering when looked at for setting up space colonies. It is called the O’Neill system. In fact, the space company Blue Origin has shown interest in building O’Neill cylinders.

– Similarly, centripetal acceleration could be used and a person on board would feel the outer hull of a spaceship pushing him/her towards the centre.

Second, another approach could be to use electricity and magnetism to substitute for gravity. The electricity will be run in circles to produce magnetism. This will result in a magnetic field. Astronauts would wear metal boots and the magnetic attraction should allow them to walk on the floor.

Third, the scientists could also harness real gravity. Everything with mass has gravity. Therefore, the scientists can go for creating a planet which will have enough gravity. The key might be to get a lot of mass into a very small area. For instance: A teaspoon of neutron-star material might be enough to give us gravity, or a tiny pencil prick of a black hole. Both of these are neither feasible nor possible currently.

Fourth, another idea is making gravity generators. A Russian engineer named Eugene Podkletnov has claimed to have designed and demonstrated gravitomagnetic devices. These devices consisted of rotating discs constructed from ceramic superconducting materials.

The string theory does predict that gravity and electromagnetism could be unified in hidden dimensions. This can act as a way to “generate” gravity in the future.

What are the issues with these ideas?

At present, there is no confirmed technology that can simulate gravity, other than actual mass or acceleration. All the above-mentioned solutions are in the realms of concept and the fictions.

In case of centrifugal approach, there is an issue of size. With rotating spacecraft, the radius of rotation grows with the square of the orbital period. The delivery of materials to space is very expensive. Such a concept was envisioned in the epic science fiction movie 2001: A Space Odyssey released in 1968.

The electricity and magnetic approach would require a lot of power supply which is very difficult due to limited resources.

Creating a planet is easier said than done.

The claim of gravity generators has not been verified by third parties. In 2006, another research group created a similar device but the gravity created was very small. The process wasn’t replicated.

Source: The post is based on an article “Simulating gravity” published in the Business Standard on 20^th May 2022.