Gamma-ray detection:

Gamma ray sources are notable on Earth, mostly from thunderstorms, nuclear explosions, and radioactive decay.

However, detection of gamma rays from galaxies is very rare, and even if the Fermi Space Telescope does not detect any of them, this does not mean that galaxies do not emit gamma rays.

In support of the first detection of gamma rays from galaxies, I quote from NASA articles titled, "Gamma-ray Astronomy - Imagine the Universe!"

Gamma-ray detection is quoted below,

"The first detection of significant gamma-ray emission from our galaxy was made in 1967 by the the gamma-ray detector aboard the OSO-3 satellite. In fact, OSO-3 also detected the first gamma-rays from outside our galaxy! All told, it detected 621 cosmic gamma rays."

#detectionofgammaray #gammaray

#gammarayburst

Wavelength that electron microscope can see at best:

The entire electromagnetic wave force is carried by photons, and visible light is a small part of the electromagnetic spectrum, also at much lower frequencies, below gamma rays, X-rays, and ultraviolet radiation.

Visible light occupies only frequencies above infrared, microwave and radio waves - the lowest in the electromagnetic spectrum.

Therefore, electron microscopes, if at all, can only see wave frequencies higher than visible light, somewhere in the ultraviolet or, at best, the frequency range with wavelengths of about 10^-10 m.

Whereas, the wavelength of maximum frequency of gamma rays will be about 1.24 x 10^-20 m,

Therefore, the wavelength of gamma rays at the maximum possible frequency is about 10^-10 meters shorter than what most sensitive electron microscopes can see.

However, with no known gamma ray microscope, we see that gamma rays emitted in the early years of the Big Bang are converted to longer wavelengths upon reception, which are detected by Earth-based receivers/antennas or space telescopes. 

Gamma rays can be produced on Earth for experiments, moreover, gamma waves are produced by nuclear explosions, lightning, and less dramatic activity of radioactive decay on Earth.

#electronmicroscope #gamnaray #wavelength