Calculate the wavelength at which an astronaut's radio must be tuned to sense signals from electrons From level 273 = n to level 272 = n.?

The satellite's controllers are attempting to establish contact with the satellite, which is about 480 kilometers from Earth's surface. What is the gravitational redshift if they transmit at 100 MHz?

In accordance with Einstein’s theory of relativity, calculate the mass of the matter needed to be destroyed to produce an energy of 1.75×10^15 W-hr.

What is an algebraic expression for the Lorentz factor γ (gamma)? Why is never less than 1 ?

Why Does Gravity Have No Quantum Properties?

In the context of relativity, what is an "event"?  Give a specific example of an event and provide the coordinates necessary to specify the event.

On Dec 5, 2022, scientific history was made at the Lawrence Livermore National Laboratory (LLNL) in Livermore, California when nuclear fusion was achieved when the 192 lasers deposited about 2 Megajoules (MJ) of energy into a frozen pea sized deuterium-tritium pellet and ignited the pellet through nuclear fusion to release 3 MJ of energy. The metric prefix mega means million (10^6). a) How much mass (kg) would be required to release 1 MJ of energy?

Describe the Einstein’s Postulates?

The Planck time is the unique interval of time that can be built out of G, c, and h.  Some physicists think that time intervals shorter than the Planck time have no meaning.  Using G = 6.7 x 10-11 kg-1 m3 s-2, c = 3 x 108 m s-1, and h = 6.6 x 10-34 kg m2 s-1, calculate the Planck time, in units of 10-43 s.