At its core, the Marvel Universe has always been built around science. From the early experiments that created Captain America to the Atomic Age stories that saw the characters created by Stan Lee, Jack Kirby, Steve Ditko and other '60s creators come into full bloom. And in 2014, a Stanford biologist theorized the scientific explanations for some classic Marvel heroes' origin stories, including the Hulk.

In his report, Stanford biologist Sebastian Alvarado wrote that he believed the transformations of both Captain America and Hulk were possibly realistic when considering cutting-edge genome-editing techniques. Not only does the biologist believe Hulk's transformation could have a scientific explanation, but Hulk's history in comics also plays into the theory.

RELATED: Marvel's Newest 'Hulk' Inherited Bruce Banner's Creepiest Power

When the gamma radiation hit Bruce Banner's DNA, it broke the molecule's helix via chromothripsis. A person's body can repair a few breaks without loss of significant function. But ecause they broke in a severe explosion, Banner's DNA was reassembled and included "switches," as the theory states. This is what causes Banner to transform into the giant, green Hulk. As Alvarado explains, "Bruce Banner's transformation into the Hulk would be incredibly traumatic to his body, and maybe his green skin is the result of a whole-body bruise."

Avengers Mad Hulk.

This also ties in well with Bruce Banner's origin story outside of the gamma explosion. The change is traumatic for Banner's psyche as much as it is for his body. The reason Banner became the rampaging Hulk wasn't due to the transformation, as She-Hulk and Red-Hulk proved they could change and keep their intellect and control. However, Banner faced traumatic situations as a child when his father, Brian, abused him and killed Bruce's mother. For years, this led to Bruce blocking his childhood memories and famously losing control as an adult anytime he Hulked out.

RELATED: Forget the Professor - Marvel's NEW Merged Hulk Is Its Most Dangerous Yet

Bruce Banner is an individual with a unique life of experience, memories and traumas, so it makes sense that his changes into Hulk would only emphasize those aspects of his mind in the same way it supersizes his muscles. The recent Immortal Hulk series has really delved into the broken psyche of Bruce Banner by bringing out his multiple personalities and even the childlike innocence he recently exhibited while merged with the Joe Fixit personality. His body has almost grotesquely changed recently, and the colors have also changed into various changes of green, potentially revealing the true depth of how he's been scarred.

Immortal Hulk Is An Alternative Version Of Hulk

This theory plays well into the grey Hulk, both when he first changed after the explosion and later when he became Joe Fixit. The color of grey also looks like bruising, although not quite as traumatic. The original Hulk, who was not completely raged out, and the version of Joe Fixit, who he didn't get angry and stayed mostly calm, never faced the same level of rage as the green Hulk, which might be why they never bruised bad enough to turn completely green.

This theory could also explain the skin color of Red Hulk and Red She-Hulk, and those colors don't play into the bruising explanation. Those colors are likely based on the cosmic radiation compared to Hulk's gamma radiation. With that said, the red colors could reveal an even more severe reaction to the change. It also plays into the idea of the damaged psyche. While Hulk is damaged and loses control with a bruised psyche, both General Ross and Betty were always full of rage when they changed, and the color of red plays into those feelings. The color of all the Hulk's plays into the type of radiation they experienced. The tones could represent the traumatic damage to their bodies during the transformation, and the bruised colors, and the red showcase what these characters are experiencing inside.

KEEP READING: Wolverine and the Hulk Have the EXACT Same Secret