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Extra-terrestrial visitors Have they visited … are they here now? Are we that special?

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Presentation on theme: "Extra-terrestrial visitors Have they visited … are they here now? Are we that special?"— Presentation transcript:

1 Extra-terrestrial visitors Have they visited … are they here now? Are we that special?

2 Evidence Extra-ordinary claims require extra-ordinary evidence. Do we see aliens in the street? Do we have any (verified) alien artifacts? Do we have photographs or spectroscopic evidence of alien spacecraft? UFOs … unidentified flying objects

3 We are scanning the skies with a huge array of instruments … yet this type of photograph is yet to be seen.

4 UFO reports Interestingly, such reports abound since 1947, the close of the second World War and the commencement of the Cold War Is this a coincidence? Aircraft had suddenly become common as had air transportation for people. How accurate are the claims? Essential to be skeptical.

5 UFOs become IFOs By definition, something is unidentified until it becomes identified. The process requires a collection of information and an evaluation of the known facts as assembled. Regardless of what you might like the outcome to determine, an objective evaluation is needed.

6 The Scientific Method Make an observation Devise a hypothesis that accounts for the observation Test the hypothesis (usually with an experiment) Evaluate the test results and decide if they support the hypothesis. If necessary, modify or reject the hypothesis.

7 The Small Angle Formula D = linear size of object a = angular size of object (in arcsec) d = distance to the object

8 Consider … Look at the Moon … how big is it? … how far away is it?

9 Answer … The Moon has a real diameter of 3,476 km The Moon is (on average) 384,400 km from the Earth At this distance, the Moon subtends an angle of about 0.5 degrees (equivalent to 30 minutes of arc or 1800 seconds of arc). Note that the Moon is about 100 times further away than it is wide.

10 A UFO? A 1 meter diameter grey coloured balloon at a distance of 100 metres would appear to be exactly the same size as the Moon!

11 How fast is it moving? To determine a speed of an object, what do you need to know? You can say how many degrees in how many minutes (seconds) the object moved. You observe a point of light move 15 degrees in 1 minute … how fast is it really traveling?

12 Answer … If the object was 1 km away, its speed was 16 km per hour. If the object was 100 km away, its sped was 1600 km per hour! So if all you saw was a light at night, was a person riding a bike or a distant jet plane?

13 Possible confusions Meteors entering the Earth’s atmosphere can break up and be very bright indeed (bolides) shedding material as they travel.

14 What do you see?

15 De-orbiting satellites Space junk abounds in orbit above the Earth … 10,000 satellites roughly. Bits and pieces from rockets also remain in orbit for small periods of time. Re-entry, heating to incandescence and disintegration (hopefully) is happening all the time. For example, Skylab and Mir space stations.

16 Venus By far the brightest object in our skies (apart from the Moon and the Sun). Often seen very low to the horizon and can cast shadows. Often reported to ‘follow’ people around. Can be seen in conjunction with other planets.

17 Venus images …

18 Human perception All too often, we see what we want to see … believe what we want to believe. Opportunity also plays a role … if you are outside more often, the chances of observing ‘something’ increase. For the record, nearly 50% of all Canadian UFO sightings happen in BC … clearer skies, warmer temperatures (and best marijuana growing!)

19 Percival Lowell and Mars Despite logic, Lowell assumed markings on Mars were ‘canals’ forming an irrigation system on the planet surface.

20 The Face on Mars From Viking in 1976 until Mars Global Surveyor in 2001, the ‘face’ has changed!

21 The modern UFO era June 24, 1947, pilot Kennith Arnold reports an observation near Mt Rainier, Washington State. Arnold described the objects as moving "like a saucer would if you skipped it across the water.". Bill Bequette, a reporter with the East Oregonian newspaper, reworked the phrase "saucer-like" and gave the phenomenon a name: "flying saucers” 650 reports in the continental US by July 31 1947!

22 J Allen Hynek classification scheme Nocturnal lights Daylight disks Radar-visual sightings Close encounters of the first kind Close encounters of the second kind Close encounters of the third kind

23 Countless reports Hynek investigated 1,000s of UFO reports. He noted that less unusual events correlate with reliable reports and that more bizarre claims come from less credible witnesses. While many observations remain unexplained (a VERY tiny fraction of all reports), this does not imply an ET explanation. Rather it suggests a lack of information.

24 Consensus As appealing as it may be to believe that UFOs are alien spacecraft, no solid evidence exists. There is the question of ‘why would they come and be so secretive?’ Even assuming that a civilization was close-by and knew we were here, the expenditure of time and energy is significant … why come all this way and ‘scare cows’?

25 Cover up? … Conspiracy? When all else fails to convince you, reach for the expression Government cover up … they are hiding the truth about aliens from us. Note that ALL Governments around the world are in unison, covering up the information … UFOs are seen everywhere.

26 Reality check Government have difficulty keeping secrets … covering up UFOs and aliens for decades seems highly unlikely. Scientists are ‘in on it’ (me too?) … but why? Further, the number of people who would now have to ‘keep the secret’ is enormous … very unlikely.

27 Erik Von Daniken Very popular books (and TV shows) … Chariots of the Gods, Gold of the Gods, etc. Opportunistic is a word that springs to mind, not to mention denying the ingenuity of our ancestors. Careful scrutiny of his claims reveal amazing inconsistencies and hopeful exaggerations.

28 The Egyptian Pyramids The pyramid at Khufu at Giza took 10,000s of workers to complete but has been chronicled in history. An amazing undertaking to be sure but definitively human.

29 The Nazca Plains of Peru The various drawings on the Nazca Plains are associated with the Incan culture from nearly 2,000 years ago.

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