A new Goldilocks zone

We are familiar with the Goldilocks zone, considered necessary for the emergence of life in a planetary system. It is the region where the surface temperature of the planet allows for the existence of liquid water, which is generally considered essential for life as we know it, although in science fiction literature (remember Fred Hoyle's The Black Cloud) there are life forms that might not require this condition.

Planets very close to their star would have a temperature too high for the existence of liquid water; all the water would vaporize, and in some cases escape the planet's gravitational pull. On very distant planets, the temperature would be too low, and all the water would be in a solid state (ice). In both cases, it is thought that the emergence of life would not be possible.

Probability of the existence of extraterrestrial life

In a previous post I talked about the probability of the existence of extraterrestrial intelligence and mentioned the difficulty of its calculation, as we don’t know of any planet where they exist, apart from Earth, and to calculate the probability of an event one must know the number of favorable cases and the number of possible cases. For extraterrestrial life, we ​​don’t know either.

In another post I detailed the conditions that should be necessary if life similar to ours were to be possible on a planet similar to Earth. These conditions are many, which reduces the probability that we will find life on some extrasolar planet located in our vicinity. In fact, among the almost 10,000 planets detected so far (of which just over half have been confirmed), 65 are at a distance from their star that could be favorable for life (the Goldilocks zone), but only three of them orbit around stars similar to the Sun (of the stellar class G).

Science or imagination?

A large part of the "scientific" research currently being developed, rather than being science, is just an exercise of the imagination of "scientists." It seems that we must consider as scientists all those who do mathematical speculations that have little or nothing to do with reality. And naturally, everything a scientist does is “science”. At least, scientific journals and high-profile media consider it as such.

The weak anthropic principle: Are we alone in the galaxy?

Allen Telescope Array in the SETI project

In its initial formulation, the weak anthropic principle says that, although the appearance of intelligent life on a planet may be very unlikely, the Earth must meet all the conditions, since we exist. We know that the Milky Way contains about 10¹¹ stars. At least one (the sun) has a planet populated by intelligent life. It looks like the probability of this happening should be equal to or greater than 10^-11. Note that the weak anthropic principle does not say what the value of that probability might be.

Media manipulation: the Nobel Prizes and religion

James Peebles

The 2019 Nobel Prize in Physics has been assigned to cosmology and divided among three scientists: James Peebles, a Canadian, who receives half the prize for his theoretical work; and Michel Mayor and Didier Queloz, who have shared the other half for having discovered the first planet outside the solar system that revolves around a star in the main sequence.

The theory of the Big Bang was proposed in 1931 by George Lemaître, as a consequence of the extension to the past of the Hubble-Lemaître law. In 1948, Ralph Alpher and Robert Herman predicted that, if the Big Bang theory is correct, there must be a cosmic background radiation with a temperature close to 5 Kelvin. In 1965 Arno Penzias and Robert Wilson discovered the existence of such cosmic radiation, whose temperature turned out to be close to 3 Kelvin. That same year, Robert Dicke, James Peebles and other collaborators reasoned that the radiation discovered by Penzias and Wilson is precisely the signature of the Big Bang predicted by Alpher and Herman. During the 70s, Peebles was one of the leading theoretical cosmologists who studied the field of the formation of the great cosmic structures (galaxies and groups of galaxies). For these works he has now been awarded the Nobel Prize.