Bending of travelling path of a photon or spacecraft.

Summary: A photon exchanges momentum as it bypasses a large gravitational well during transit. The photon experiences a change in momentum and its path is bent as it interacts with the gravitational field. A photon simultaneously gains and loses momentum (p) from a gravitational interaction with a massive object. However, a photon maintains its relative path with speed c and covers the same distance (d) as compared to its constant speed. The curvature of the photon's path is understood in terms of the exchange of momentum experienced by the photon.

Relevant equations: p = E/c, constant = c = 299792458 m/s, distance = (speed x time) = (c m/s * s)

Bending of the travelling path of a body when its speed is unchanged: - photon, spacecraft:

The bending of photon's path is due to it's constant speed @c but it's increased energy and frequency corresponding to the increased gravitational influence on it. 

Since photons speed is constant, an incremental change in it's energy and/or frequency makes the photon change it's path bent. 

It's like gravity assist (sling shot) by a massive planetary body to a bypassing spacecraft in a condition when the speed of the spacecraft remains unchanged but its path bends as its kinetic energy increases.

What happens in the background:

When the photon maintains a constant speed @c, and increases its Energy, it is bound to increase its frequency too. Such increased frequency, at its constant speed, does not allow the photon to maintain a straight path anymore, as the gained frequency deviates the photon path from its apparent straight path to a bent path until the the photon reaches its earlier frequency.

The gain of its energy is temporary - temporarily synchronised. Photon frequency synchronised with gravitational field - transfers energy to the photon.

The Planck's Equation: E=hf ----> E'=hf'  when E'>E (Temporary).
So (E'-E) deviates the path of the photon and bends, since the photon cannot increase it's constant speed, it bends.

Note: The momentum of a photon is directly proportional to its frequency and inversely proportional to its wavelength. Photons momentum is given by p=hλ, where λ is the photon wavelength. Photon energy and momentum are related by p=Ec , where E=hf=hcλ for a photon

#gravityassist #slingshot #increadedenergy #increasedfrequency

The Universe (13.8 billion years) - unobservable (23 trillion ly.) and observable (46.5 billion ly.)

Beyond the visible universe, the invisible or the unobservable universe must be at least 23 trillion light years in diameter, and contain a volume of space that's over 15 million times as large as the volume we can observe. So that no signal can travel faster than light, hence there is a maximum distance beyond which nothing can be detected, as the signals could not have reached us yet. 

The visible universe is observable universe and it's physical limit created by the speed of light itself. This means a sphere with a radius of 13.7 billion light years centered around the Earth, and we can only observe 13.7 billion light years of the universe. Because the electromagnetic radiation from these objects has had time to reach the Solar System and Earth since the beginning of the cosmological expansion. The visible universe contains 4.9% ordinary matter (baryonic), 26.8% Dark matter and 68.3% Dark energy. Only five percent (5%) of the universe is visible and its radius is 46.5 billion light years.