Gizmodo is 20 years old! To celebrate the anniversary, we're looking back at some of the most significant ways our lives have been thrown for a loop by our digital tools. Like so many others after 9/11, I felt spiritually and existentially lost. It's hard to believe now, but I was a regular churchgoer at the time. Watching those planes smash into the World Trade Center woke me from my extended cerebral slumber and I haven't set foot in a church since, aside from the occasional wedding or baptism. I didn't realize it at the time, but that godawful day triggered an intrapersonal renaissance in which my passion for science and philosophy was resuscitated. My marriage didn't survive this mental reboot and return to form, but it did lead me to some very positive places, resulting in my adoption of secular Buddhism, meditation, and a decade-long stint with vegetarianism.

On Friday, Elon Musk's company Neuralink introduced the world to three pigs who seemed indistinguishable. Yet Gertrude, who was both shy and stubborn, had a secret: Two months prior, her brain had been implanted with Neuralink's newest version of a brain-computer interface, or BCI. She looked just like another pig with no such device and a third who had had a similar device in and then removed. As Gertrude walked around doing pig things, viewers saw a display of her real-time brain activity. "If the device is lasting in the pig, as it lasted in there for two months and going strong, then that's a good sign the device is robust for people," Musk said.

If Facebook and Elon Musk's ambitions to directly connect human brains to machines are any indication, it seems we will become increasingly dependent on smart devices. Less bombastic than this proposal, but already widespread, are more mundane forms of augmentation – neural prostheses allow brains to control replacement body parts, artificial organs can be designed to specific bodies, and embedded devices like insulin pumps can intelligently support their hosts. With this is mind, we asked six experts the following question: How will technologically augmenting humans affect sustainability? The implications of human augmentation are so complex that it is difficult to succinctly assess what their implications will be for sustainability. There are, of course, potential benefits.

At the World Government Summit in Dubai in February, Tesla and SpaceX chief executive Elon Musk said that people would need to become cyborgs to be relevant in an artificial intelligence age. He said that a "merger of biological intelligence and machine intelligence" would be necessary to ensure we stay economically valuable. Soon afterwards, the serial entrepreneur created Neuralink, with the intention of connecting computers directly to human brains. He wants to do this using "neural lace" technology – implanting tiny electrodes into the brain for direct computing capabilities. Various forms of BCI are already available, from ones that sit on top of your head and measure brain signals to devices that are implanted into your brain tissue.

"Now after wearing it on and off for so long, I do feel like it is an extension of my hand," says Dani Clode, a Royal College of Art student who created a "third thumb" as part of her MA dissertation project. "This is a similar kind of feeling to driving, or using a sewing machine. You don't think about putting your foot down after a while, you think about moving forward and your foot just goes down." Completed earlier this summer, the Third Thumb Project consists of a 3D-printed prosthetic thumb, which is attached to the user's hand, while a bracelet receives signals from a bluetooth device that detects movements in the wearer's foot. To operate the thumb, the wearer just has to press down with one of their feet.

For Bryan Johnson, the founder and CEO of neuroscience startup Kernel, the question is when, not if, we all have computer chips inside of our brains. Kernel, founded last fall with more than $100 million of Johnson's own money, is trying to better understand the human brain, so that we may one day program it to improve. The company is focusing first on medical applications, to gain a deeper understanding of the diverse and complex ways the brain can fail. Eventually, Johnson would like to move toward augmenting the organ to make us smarter and healthier and pave the way for interfacing directly with computing devices. Johnson, who made his fortune selling his payments company Braintree to PayPal for $800 million in 2013, doesn't have past experience in neuroscience.

Science is slowly inching its way to discovering the secret to immortality. Human enhancement, as defined by transhumanists, is everything that "encompasses a range of approaches that may be used to improve aspects of human function." Human enhancement is currently being researched in institutions such as Stanford University, which has recently devised a mathematical algorithm, called ReFIT, that can decipher neurological signals in the brain that convey movement, speed and accuracy. While the public justification of the study is to improve "prosthetic system performance and robustness in paralyzed people," its implications are far-reaching. The FDA has approved ReFIT for human clinical trials as researchers work to create neuroprosthetics for mind–controlled robotic limbs.