 Another relativistic effect at play here is called relativistic beaming. To illustrate, consider an inertial reference frame moving to the right at relativistic speeds with respect to an aligned reference frame on the right. A particle emits a photon at an angle alpha from the line of motion. The angle measured in the frame on the right can be computed using the Lorentz transformation. Using M87C1's velocity as the velocity and 60 degrees as a sample angle, we see that the observed angle alpha prime is considerably smaller at only 8.2 degrees. A synchrotron radiating electron moving at speeds far smaller than the speed of light will emit radiation in all directions. Distant observers would see just the portion of the light radiated in their direction. As the speed of the electron increases, these light rays shift in the direction of the emitting object's motion. As the velocity of the emitting particle approaches the speed of light, the observed angle approaches zero. The light is beamed ahead of the emitter in the direction of the emitter's movement. This is the case, no matter what the emitted angle is, in its own frame of reference. For trillions of continually emitting particles, like the electrons in the M87 jet, this beaming effect increases the photon density in the direction of the movement, causing the jet's luminosity to increase. This explains why the jet looks so bright. And because the jet moving in the opposite direction will have their photons beamed away from the observer, the jet becomes invisible. This explains why we see only one jet in M87. Our last relevant effect is called relativistic Doppler shift. Due to space contraction, when we apply the Lorentz transformation against the frequency of a photon emitted in the same fashion as we just covered, we find that the frequency observed is greater than the frequency transmitted. This explains why the M87 jet is so blue.