It's a bird! It's a plane! It's Superman! In 1938, Action Comics #1 released the first Superman comic book to the public. Superman, also known as Kal El, has demonstrated many different powers since his debut in 1938. This article will discuss various topics regarding four of his main powers and explain why they are all impossible to achieve in real life. The four major powers of Superman that will be discussed in this article are x-ray vision, the ability to fly, super strength, and invulnerability. X-rays were first discovered in 1895 by a German physicist named WC Roentgen (“The Discovery”). . WC Roentgen was working in his laboratory one day in 1895 and decided to send a high electric current through a cathode ray filled with special gas. He realized that a faint green light was being produced and decided to hold the cathode ray just above his wife's hand. In doing so, he observed that the light was able to penetrate human skin, but left all bones visible. Below is a photo of an x-ray of WC Roentgen's wife's hand ("The Discovery"). He named it X-ray because he did not know the identity of what type of ray it was. He just named it X, because of its use to solve unknowns in algebraic equations (“The Discovery”). However, there are certain limits to this power of Superman, both in the laws of physics and the laws of the human body. The first restriction is that in an x-ray, tiny rays will pass through any atoms that do not have enough mass to stop the rays (Inglis-Arkell). Indeed, when an atom absorbs a photon (ray), one of the atom's electrons must jump from a space close to the atom to a space further away using a precise amount of energy (Inglis- Arkell). However, an electron does...... middle of paper...... Orlando, Florida: Holt, Rinehart and Winston, 2009. 35. Print.13. Preston, Raymond. “Definitions of relative wind, lift, weight, drag, thrust and lateral force.” Definition of aerodynamic terms. Np, and Web. February 18, 2014.14. “Watery humor.” Vision Eye Institute Cataract Retina Lasik and Laser Eye Surgery. Np, and Web. February 18, 2014. .15. “The discovery of X-rays.” The discovery of X-rays. Np, and Web. February 17, 2014. .16. “The physics of flight.” Flight. Np, and Web. February 18, 2014.17. Walk, Father. Edward. “How to calculate mass.” Honor to physics. Du Bois Area Catholic School. Du Bois Area Catholic School, Du Bois. December 2, 2013. Lecture.