Those who believe in UFOs are stigmatized and ridiculed in so many ways thus this subject has become too dangerous to touch for reasonable people. Has it? I have recently heard that renowned professor Stephen Hawking and Yuri Milner granted $135 million Australian dollars in searching for alien life in vast spaces of the Universe. There is a little number of scientist who may deny that the Universe does not have other forms of life.
But why we are in denial of the UFOs. The main argument for is that there is no single reliable evidence that can serve as proof of existence of UFOs and aliens’ interactions with the humans. In many ways the UFO deniers are right. Many of findings have been examined and found that there is no scientific evidence, “but pseudoscientific speculation”  . And indeed, when we examine some evidence, we may wonder, how those primitive so called depicted devices could have utilized for a civilization that achieved such a high level of development. Take a look at alleged helicopter picture found in the temple of Seti. Many UFO enthusiasts try to interpret the image as a helicopter hieroglyph based on superficial resemblance between the picture and a real helicopter.
If we imagine that the aliens visited our planet, then we have to grant them that they had way superior level in technology and machinery than we currently do and an aircraft like a helicopter would have been merely obsolete for them. The idea of a helicopter is a merely our projection of the level of our knowledge and attribution to them not more.
Let’s take a look at another example:
Even though this figurine bears an undeniably remarkable resemblance with modern aircraft, we need to ask ourselves whether a highly developed civilization would have used such a primitive aircraft on Earth when they were able to achieve capability for interstellar traveling. No, I do not think so.
Such evidence creates a false proof that aliens have already come to our planet. This hypothesis failed to prove existence of UFOs, and then it gives the UFO deniers an argument that aliens have never been here on the Earth.
When we started to make first cars, they looked more like wains or wagons in many ways than the modern cars do nowadays. When the Wright brothers built the first airplane, it looked more like a kite than a modern aircraft at all. When Alexander Bell invented telephone, its microphone resembled an ear and was way bigger than its modern descendants. As we continue to project our past and present experiences into any imagination for the future inventions and their developments, then we can elaborate an idea how aliens’ technology, machinery and devices would have looked like. We usually draw our imagination from the nature or mankind experience.
Take for instance, a following well-known picture that intrigued our contemporaries:
Many people consider that the woman in the middle is holding a cell phone whereas the picture was taken in 1938.
Our fantasy and conventional perception of holding an object in such a manner immediately tell us that it is a cell phone. Not so fast! First of all, that woman could not speak on the cell phone because there was no infrastructure that could support this device. And that “cell phone” in the picture is a pretty darn big one as if it was manufactured in 1980s! But what if the people found the way to time traveling, would they use cell phones at all then? I think in those distant times when the people travel in time, if they would do it at all, the phones would be a rarity of the past centuries if not millennia. Look at the evolution of our cell phones. They hardly remind old fashioned cell phones: they have become computers, mini TVs, digital cameras, game devices, image scanners, means of banking, lab instruments and many things all in one though we still call them phones. And I think in a distant future they will be supplanted by other means of communications more effective and versatile in applications and usages.
If we think they do time travel, then we need to adjust our imagination to the same settings of time traveling.
The theory of relativity is comprehensive and time is also relative in terms of going to infinite ages ago. If such a time machine were invented, then any advanced civilization would have utilized this tool to its own advantage and would have annihilated its rivals or outpaced its contenders in any development. So this kind of luxury does not exist and it will be a subject of science fiction for many thousands years.
Many times our so called proof of UFO existence comes up against objections that range from offhand dismissal of any arguments to vituperation without thoughtful consideration of evidence. Such a treatment partially derived from the above mentioned or similar examples has some merits, however, we give way too much credit to the mankind, and hence we get into analogous position when the most people thought that the Earth was a center of the Universe. In the other words, we are too human centric.
One of the reasons for these doubts is that some people probably seek some sort of fame and they insist that they have met aliens who conducted medical procedures and experiments on their bodies. But some witnesses are so genuine, therefore there is no doubt that they have seen UFOs indeed. You might probably have seen UFOs yourself or heard about it from the other persons who you trust.
Take a look at this witness at John Lennon’s UFO sighting.
Hardly may you blame John Lennon’s explanation of seeing a UFO in order to get some fame. You may dismiss him as a witness on the ground he took it wrong, but never on the notion that he was looking some publicity.
Some of the images are so jarring that require us to think anew on UFOs. Take a look at a NASA telescope record of the image which many UFO enthusiasts put it as a refueling space ship:
Some of people suggest that was a birth of a planet, however that opinion contradicts the theory of gravitation. The object disconnected the sun creating a turbulence on the sun’s surface. The video is very consistent with the future advanced technology that the aliens may possess.
One thing, for instance, I am sure about that, is the alien visitors somehow have already discovered or invented anti-gravity and therefore they can travel interstellar, or universally without wasting so much energy on overcoming gravitation and or they can utilize this technology in conjunction with for spacecraft propulsion, hence their space vehicles or aircraft would look rather than discs, cubes and balloons or something close to those shape in order to make some room inside the spacecrafts and not waste valuable spaces for wings, bulky rocket engines, solar panels and etc. Therefore they would rather look like in those shape than our planes or rockets do because their spacecrafts would not need wings or rocket engines.
The logic dictates that their vehicles need to generate their own gravitational field. Therefore, our imagination that their vehicles would look like rockets, planes, helicopters or drones does not match with the future technological advancements. I suppose that their spacecrafts would generate inner artificial gravity due to many reasons for their usage. And the NASA video on the object that connected to the Sun via “an umbilical cord” is most likely serves as evidence that the aliens can easily harness pure energy from the Sun without building a power station at all!
The latter can give us an idea, that the aliens do not need much our planet for the energy, since they can plug in their ships and get it directly from stars. Indeed the energy for any civilization is the most important source for survival and prosperity. That is how they are able to travel interstellar reaching farthest corners of the Universe we have never even imagined.
As we know our solar system is not the oldest one and it is about 4.6 billion years old. The Universe is considered 13.7 billion years old and it is older than our solar system almost 3 times. Our galaxy, the Milky Way, was born 13.2 billion years ago and it is much older than the solar system. According to Wikipedia the Milky Way comprises 100 – 400 billion stars and some astronomers think 1 trillion stars and at least 100 billion planets.  According to space.com site, our galaxy alone has about 60 billion alien planets that can sustain life
It is not a science fiction anymore that absolute majority of scientists thinks that there is intelligent life in the Universe and the Milky Way and it takes time for us to discover it.
If we take into consideration those facts and mull them over in order to connect the dots, we may arrive at a conclusion that we might have already been discovered by some other civilizations, and, according to their experiences in dealing with extra alien civilizations (us from their point of view in this instance), it is not the best course of action to interact or comingle with us or to proclaim that they have already come, otherwise it does not make any sense that in the span of billion years our planet has not been discovered by the extraterrestrials yet. We may also assume that our planet might has been discovered by several extra terrestrial civilizations and we could be a subject of their close monitoring or contentions or accords on how to deal with us.
If we take the mankind evolution in the context of how we have advanced in our development in a relatively short period of time. Maybe a 100, 000 years ago our civilization sprang out from drafty and smoke filled caves and now it operates orbital space stations and launches spacecrafts in the deep Universe to explore not only our solar system, but also the Milky Way. Any other civilization would be extremely anxious of our future advancements given good consideration on our experiences in treatments to the other humans, animals and our planet the Earth, in killings our own kinds and eliminating many species nonchalantly, our perpetuate wars and ingenuous creativity in inventing more sophisticated arms up to weapons of mass destruction, unending social injustice, lingering poverty and insatiable lust for wealth and power, inequality, dubious income distribution, genocide, pollution, destruction of environment and many other things. And take this evolution in conjunction with accelerated pace of our advancement in science, technology, industry and expansion to new territories in the last two centuries; you may be paying a very good attention to what we have been doing.
Would you be worried about your well being by watching the same development in other civilizations? Would you judge them and define their true nature by their deeds not declarations? Would you put yourself in hands of the aliens if they conduct their lives in the same way as we do?
I think any other civilization would weigh our realities by underpinning their judgment based on our history and so would we do. And from this prospective Stephen Hawking is more than right. But what about the same yard stick we apply to a completely different civilization, that has developed for more than millions if not billions years. In historic perspective we are still soiling our pants, whereas they outlived that baby clothes many millions years ago and reached the heights of technological and humanitarian (in extraterrestrial sense) progress that takes us hundreds if not thousands or even millions years. Why on earth, we need to draw analogy between our treatment to native Americans by Europeans in Columbus times and an extraterrestrial civilization to us? After all, for 500 years we have changed a lot.
There are scientists who do think that the logic of Stephen Hawking is flawed by application of our own experiences and the humanized standards to this conclusion.
Dr. Neil Tysson said:
” I think his [Hawking’s] fear about aliens is reflection of his actual knowledge about humans how humans treat each other, not real knowledge about how actual aliens will treat us.” 
Let me imagine what we would have done if we had discovered an extraterrestrial civilization. At that stage of development, I do not think we would conquer or seize their planet in order to exploit their riches and/ or natural resources because we could have discovered them on uninhabitable planets. We would not do such things like in the Avatar movie. But I am absolutely sure that we going to exchange and borrow from each other in science, technology and the way how we live and will be coexisting with each other in the future.
And one more point. The extraterrestrials might have been very much interested in our planet as a unique source for harvesting biological materials and DNAs rather than natural resources. The latter are so abundant on the other planets, therefore they have no real incentives to conquer us. Our biology and life diversities might have had a priceless value for them for infinite usages, applications and developments. That is why they might be more interested in our preservation than subjugation. And in that sense their unannounced presence on the Earth is a practical and pragmatic approach.
 Wikipedia at https://en.wikipedia.org/wiki/Ancient_astronaut_hypothesis, accessed 09/02/2015
 Picture from http://in5d.com/wp-content/uploads/2015/06/sun-orb-refueling-ufo.jpg, accessed on 01/31/2016.
 http://space.com/21800-alien-planets-60-billion-habitable-exoplanets.html , accessed on 09/19/2015.