Sadly I don't own Star Trek, but if I did then there would be a mix of the optimism Gene Roddenberry viewed the future, as if his vision would whitewash the sides of humanity he didn't want to view, but are in fact a reality every single day of the week. The mix would be Roddenberry grade optimism and Babylon 5's grittiness.
There are videos on Youtube showing time travel has changed history, some of it is subtle and other changes not so subtle. Enjoy.
Shockwaves of time meddling.
Time meddling. Have you ever had one of those really long glass fish tanks which are long enough to cover a long trestle table and filled it with fish? Did you ever drop something like a stone in the tank, and seen it disturb the fishes inside while ripples radiate outwards in increasingly large circles, disturbing anything near the surface of the tank?
Now think of time travel. Imagine the tank is in fact the universe and the timeline from the beginning of the universe to the end of the universe, and the fish and plants inside the tank are planets and civilisations. Every single time you stick your hand inside the tank, disturbing the fish or taking one of them out of their environment, dropping something in the tank, you are changing history.
Ever since the 19th century, time travel had been changing the progress of technological and scientific development. In a hotel room in San Francisco, one of the bellboys found a strange collection of gadgets with a beam of blue light, described by him to a scientist whom he'd sold the device to as a "mini bolt of lightning."
However, it was in the 20th century that things really changed. Not only was transparent aluminium a sudden invention, but the computer revolution unleashed upon the world by Henry Starling's work before he suddenly vanished despite rumours surrounding him, rumours of him flying some strange new kind of stealth plane only to blow up because of engine trouble, or how a competitor had paid one of Starling's workers exceedingly well to sabotage the plane, was the thing that really showed how far time meddling was going.
Rumours from Roswell reported a strange alien ship had been taken in, but nobody was willing to admit the aliens had somehow managed to escape by flying straight into a nuclear explosion.
However, scientists did take a great deal of data of the ship; it would be decades before human technology advanced to the point where the data would make any headway.
Strange badges and equipment found in the 21st century helped provide breakthroughs allowing subspace to be studied, and with access to subspace being unlocked a few years earlier, humanity's understanding of physics leapfrogged. But the biggest act of time meddling in the 21st century was purely unintentional when Zefram Cochrane showed crude but later extremely detailed sketches and designs for warp ships without allowing any kind of research where starships were constructed with Coleopteric warp engines mimicking those used by the Vulcans. Instead, starships were conceived as having a saucer-shaped primary hull, a secondary hull joined underneath, and two warp nacelles stretched away from the ship like the wings of a bird in flight rather than the traditional bulky shaped ships designed more for function than aesthetics.
The 22nd century was one of the biggest battlegrounds of the Temporal Cold War; the factions knew the 22nd century was the point in history where the future of the galaxy was shaped, the seed of the United Federation of Planets would be planted. Many of the factions either journeyed back in time or communicated with the past, appearing before various races, giving them advanced science and technology in the hopes it would create a disruption which would have a strong effect on history while Federation temporal agents likewise journeyed back and prevented the worst of the meddling taking place, although some of them carelessly left behind pieces of their technology and some of their knowledge.
The former's best examples of the races manipulated by the factions are the Suliban Cabal, who in the primary timeline was not seen as a threat at all and yet, someone from the future provided them with knowledge and technology, manipulating them into becoming a threat to the future Federation. Another example is the Tholians, who had a strong presence in the future anyway, but their role in the Cold War was minimum. By far one of the biggest groups were the trans-dimensional beings who manipulated the Xindi into destroying Earth, changing the future of the galaxy forever. The aliens had spent centuries manipulating the space in the region known as the Delphic Expanse with the long-term plan of transforming the space special spherical stations located within cloaking barriers to prevent local races from discovering their activities into a trans-dimensional wasteland.
Appearing before the Xindi after manipulating the Xindi Reptilians and the Xindi Insectoids into destroying their own world in a turbulent war, these aliens guided the Xindi to new worlds, providing them with new propulsion technologies which prevented their ships from being affected by the damage inflicted on space by the spheres. As the years passed, the aliens gave them knowledge of how humanity would destroy their world in the future, and the only way to prevent it was to destroy them in a pre-emptive strike.
While the Xindi were following the Guardian's recommendations and were engaged in a decade long plan to design, build, and deploy a planet-killer using the knowledge of the physics needed to reduce a planet to rubble provided by the Guardians, the NX-01 was launched and made her mark on history without anyone realising the NX-01 was never meant to exist in the first place.
It was a launch that, like so many other things taking place during the same time, was not meant to happen. Originally the United Earth Space-Probe Agency's earliest expeditions would have given humanity a greater understanding of warp drive either from their own experimental experiences or by meeting other receptive warp-capable species, resulting in many advances which would eventually result in a revolution of starship design. It never happened in this timeline, and as a result, first contacts which were never meant to be made until much later were made early, laying down the groundwork for the foundation of the United Federation of Planets. New discoveries were made…it resulted in many minor ripples in the timeline.
However, the NX-01 crew and United Earth encountered many instances of the Temporal Cold War almost immediately before launch when they stumbled upon a plan by the Suliban cabal to instigate a civil war which was never meant to happen within the Klingon Empire. The Suliban would then secretly provide both sides with intelligence and knowledge aimed at expanding the Empire, while at the same time give the neighbouring powers time to prepare for their own defences. This whole plan would have destabilised that region of the Alpha Quadrant, changing history for good. Whether or not it would result in a Federation or not, is unknown.
Two instances occurred before the Xindi attack which had a great impact on the growth of United Earth and that of the Alpha Quadrant. An expedition was sent to the Arctic where they discovered a group of cybernetic creatures near the debris of a ship destroyed a century before, the cybernetic creatures were later suspected to be the same beings Zefram Cochrane was believed to be exaggerating or spinning a tale about. But the tale was real. Although the cybernetic aliens were destroyed along with the people they had transformed into creatures such as themselves, Starfleet gained a great deal of biometric data on them and their nanotechnology. Within a few decades, breakthroughs in medicines and computer technology were made, and advances in nanotechnology allowed breakthroughs into robotic technologies.
The second instance before the Xindi attack on Earth, sparking off the Xindi-Earth war, of time meddling involved the Time Agent Daniels. Daniels was one of many agents scattered through time. Getting himself a position on the NX-01 allowed him a position where he could monitor and report on any Temporal activity and relay it to his superiors. Unfortunately, he got himself killed and left his technology left behind, and although he was revived, he never once expressed any kind of desire to return for the Temporal Observatory he had left on the NX-01. Whether this was deliberate or a careless oversight is unknown.
Captain Jonathan Archer, made aware of Daniels' true nature, had the Observatory locked in the cabin Daniels had shared with a genuine member of 22nd-century stock. Only himself and Lieutenant Reed had access to it, but at the time Archer had no idea Reed had been a member of Section 31, a clandestine organisation dedicated to the protection of United Earth, and later the Federation, and acting as judge, jury and executioner.
With his access and his opinion that the United Earth was at risk from dangerous time travellers and possessing none of his captain's opinion and view the observatory be quietly buried, Lieutenant Reed spent months studying the technology and experimenting with it. In a matter of months, Reed developed crude holographic systems, experimental forcefield generators, and many other systems. However, what Reed did not know was Commander Trip Tucker, chief engineer, had seen the advantage of the futuristic technology, and while he shared some views of time travel as his captain and friend did, Tucker believed they may as well make use of it to ensure they were ready for the next temporal intervention. Secretly, Tucker used information from the observatory to augment the ships' engines and systems without being noticed. His modifications would be passed on to Starfleet R&D for analysis. Since Tucker regularly made tests and improvements subsequently on the engines, they checked them and added them to the current fleet and the ships yet to be produced.
The Xindi war, however, was perhaps the biggest instance of temporal intervention during the entire 22nd century. Not only did it see the mass-murder of seven million people who were not even meant to die in an attack which was never meant to happen in the first place, but it also pushed United Earth into various directions which would and could have had major effects on the timeline; a major example of this is the Terra Prime movement, an organisation which would never have lasted, considering the good relations with aliens, but thanks to the seven million deaths, gained a lot of credibility and membership. The deaths of the seven million people and the subsequent search for the Xindi weapon brought many changes for Earth, not just technologically, but socially as well.
By the 23rd century, Starfleet and the Federation possessed many new technologies and they had formed alliances with races the original timeline had never made contact with, while their ships were technologically more effective. Featuring advanced forcefields, holographic mirrors and holographic communication, as well as the dimensional drive which was classified and referred to as a spore drive, however instead of using spores to enable a kind of quantum entanglement, the drive instead created a brief wormhole through subspace, but it was extremely hazardous and its use was soon banned and classified.
But the damage to the timeline had been done.
History had been irrevocably altered, and the shockwaves were rippling throughout the timeline forever.