NASA chief warns of Chinese military presence in space

China is bolstering its space capabilities and is using its civilian program to mask its military objectives, the head of the US space agency NASA said Wednesday, warning that Washington must remain vigilant.

Astronauts to patch up NASA's NICER telescope

NASA is planning to repair NICER (Neutron star Interior Composition Explorer), an X-ray telescope on the International Space Station, during a spacewalk later this year. It will be the fourth science observatory in orbit ...

NASA's Roman space telescope's 'eyes' pass first vision test

Engineers at L3Harris Technologies in Rochester, New York, have combined all 10 mirrors for NASA's Nancy Grace Roman Space Telescope. Preliminary tests show the newly aligned optics, collectively called the IOA (Imaging Optics ...

'Tube map' around planets and moons made possible by knot theory

Just as sat-nav did away with the need to argue over the best route home, scientists from the University of Surrey have developed a new method to find the optimal routes for future space missions without the need to waste ...

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Space

Space is the boundless, three-dimensional extent in which objects and events occur and have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of the boundless four-dimensional continuum known as spacetime. In mathematics spaces with different numbers of dimensions and with different underlying structures can be examined. The concept of space is considered to be of fundamental importance to an understanding of the universe although disagreement continues between philosophers over whether it is itself an entity, a relationship between entities, or part of a conceptual framework.

Many of the philosophical questions arose in the 17th century, during the early development of classical mechanics. In Isaac Newton's view, space was absolute - in the sense that it existed permanently and independently of whether there were any matter in the space. Other natural philosophers, notably Gottfried Leibniz, thought instead that space was a collection of relations between objects, given by their distance and direction from one another. In the 18th century, Immanuel Kant described space and time as elements of a systematic framework which humans use to structure their experience.

In the 19th and 20th centuries mathematicians began to examine non-Euclidean geometries, in which space can be said to be curved, rather than flat. According to Albert Einstein's theory of general relativity, space around gravitational fields deviates from Euclidean space. Experimental tests of general relativity have confirmed that non-Euclidean space provides a better model for explaining the existing laws of mechanics and optics.

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