By Frank WarrenFor centuries the “faith” instilled in men of so-called science has weighed heavily on those who’ve looked towards the stars in regards to the existence of extra-solar planets. The cognition of heavenly bodies within our own solar system precipitated the “belief” there also exists what we call planets outside our solar neighborhood.
Ironically, at present just exactly “what a planet is” has come under scrutiny. The International Astronomers Union (IAU) is recognized as the world body in regards to resolving such matters; they state that the definition of a planet is “a body that orbits the Sun, it is large enough for its own gravity to make it round, and has 'cleared its neighborhood' of smaller objects.”
Paradoxically, by this definition alone there can be no extra-solar planets! This of course changes our astronomical history as Pluto does not fall under this definition.
Noteworthy “allegations” of exoplanets began in the 19th century; in 1855 Capt. W. S. Jacob of the Madras Observatory observed a binary star system, 70 Ophiuchi, to which he claimed it's orbit showed an anomaly, and it was "highly probable" that there was a planetary body in connection with this system. Moreover decade’s later, other prominent astronomers concurred with Jacob.
One hundred years later similar claims were made in regards to Barnard’s Star; today, current contemporaries have laid most of these “allegations” to the wayside.
At present “exoplanet believers” state that they have proof of the existence of over 200 extra-solar Jupiter sized planets; however, as Carl Sagan said, “extraordinary claims require extraordinary evidence!”
In addition, akin to what skeptic Dr. Michael Shermer has pointed out in regards to other alleged phenomenon, “science is open to that, but just being open to it and what we would like to be true, does not make it true.”
It’s important to note that “exoplanet believers” have no direct evidence for their claims, save one—a blurry picture of an “alleged planet.” Given today’s computer technology e.g., Photoshop etc., one has to wonder about the origins of the photograph. Perhaps the European astronomers who first made the claim and presented the image were looking for notoriety, and or monetary rewards.
Even if the photograph of the distant light is genuine, “other exoplanet believers” are hesitant to jump on board! Its been pointed out that the distant light (or alleged exoplanet) "can’t be confirmed in having a gravitational connection to what’s thought to be it’s host star.”
What that leaves is “circumstantial allusions” in support of the exoplanet believer’s theorems. The bulk of the exoplanets which are alleged to be in existence by “believers” have “not been seen by anyone, or photographed (excepting the a fore mentioned “blurry photograph” of a distant light); they haven’t been traveled to, or physically investigated in any way; there is absolutely no physical evidence. Additionally, there isn’t anecdotal, eyewitness and or documental evidence of any past proof of the existence of exoplanets.
What believers are left with for the most part is a detection method for a star’s wobble, wherein the “conjecture” is made by “believers” that an exoplanet’s gravity is causing a slight pull on it’s host star. This method is called Doppler Spectroscopy—the observation of Doppler shifts in the spectrum of the star around which the planet orbits.
From the onset of this methodology, as well as the “believer’s” first claim of the existence of exoplanets—there has been controversy within their own camp.
One of the early stars purported to host an exoplanet was “51 Peg”; Dr. David Gray (Univ. Western Ontario) published a paper back in '97 suggesting that some undulations or oscillations of the star, are responsible for the Doppler shifts, rather than an orbiting planet—this polarized the astronomical community, and although Gray’s position may be overlooked today, it hasn’t been rebutted in any definitive manner; henceforth the exoplanet believer’s methodology is arguably flawed.
Admittedly, there are other "indirect schemes" in regards to the stars which “believers” imagine may host exoplanets; however, these are also indirect contrivances.
In the end like Seth Shostak of SETI says, “The burden of proof is on those making the claims, not those who find the data dubious.” Finally, Michael Shermer concurs: [regarding science] “the default assumption is that whatever the claim is, it's not true until it's proved. So the burden of proof is on the person making the claim.”