Why do we see a gravitational redshift in the spectrum of the sun?
a) spacetime curvature allows red photons of light to escape the sun more easily than blue photons, leading to an apparent redshift. b) because of gravity, the sun is always moving away from us, so we see a redshift. c) time runs slower on the sun than on earth, making lines in the solar spectrum have lower frequency and hence longer wavelength than normal. d) gravity makes light heavy, causing it to appear redder.

Time runs slower on the Sun than on Earth, making lines in the solar spectrum have lower frequency and hence longer wavelength than normal

Explanation:

When we talk about the visible electromagnetic spectrum, we know it starts in violet-blue and ends in red.  

In this context the astronomer Edwin Powell Hubble observed several celestial bodies, and when obtaining the spectra of distant galaxies he observed that the spectral lines were displaced towards the red one (red shift), whereas the nearby stars showed a spectrum displaced to the blue one.  

From there, it was deduced that the farther a body in the universe is, the more redshifted it is in its spectrum.

Now, the Sun is a massive star and the Earth is at certain distance from it, therefore time passes slower in the Sun than on Earth. This causes the spectrum of the Sun to present lines with a lower frequency or longer wavelength than normal, that is, more towards red.

it would be kevlar ^^

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia