no-way
Explanation
This comic plays on the contrast between a physicist's calibrated sense of what is "surprising" versus a normal person's.
In the first panel, a physicist (the red-haired woman, a recurring SMBC character) explains a genuinely mind-bending fact: you can slow down time with speed, reduce yourself to an equation, send information faster than light using quantum entanglement (or similar phenomena), and that the universe can expand faster than light. She notes: "Everyone knows that stuff."
In the second panel, she mentions something from biology: that two mushroom species are genetically similar enough to hybridize, and asks: "Can you hybridize them?"
Her companion responds with shock: "No way!!! That's impossible!"
The caption reads: "Being a physics nerd has completely warped my sense of what's surprising."
The joke is about how immersion in physics -- where reality-defying concepts like time dilation, wave-particle duality, and quantum mechanics are everyday fare -- recalibrates your intuitions so dramatically that genuinely exotic physics seems mundane, while a relatively straightforward biological fact (mushroom hybridization) seems shocking. It's a commentary on how expertise in one domain can distort your baseline for what counts as "weird." The comic also gently mocks the tendency of physics enthusiasts to treat their field's discoveries as obviously normal while being blown away by basic facts from other sciences.