« It is absolutely possible that beyond what our senses perceive, hide unsuspected worlds. » Albert Einstein (1879-1955).
Behind Einstein's quote, we perceive the great scientific revolutions to come. The emergence of new concepts will eventually approach of the observable facts, then will be replaced by other concepts. Indeed the great scientific revolutions emerge when they go against our senses and our emotions to the point where appear to us wrong. Our senses enable us to approach reality and feel the world around us.
« Nothing ever becomes real as we did not feel. » John Keats (1795-1821), english romantic poet.
But if our senses show us the contours of the world, they also confine us the reality, we see that the region of the nectary, the one that interests us most.
The concepts of gravity, space, time, vacuum, mass, life, are major concepts that seem still mysterious. It would not be surprising that they correspond to anything other than what our senses tell us about them.
On Earth gravity causes all bodies fall at the same speed regardless of their mass, this law of falling bodies goes against what our senses tell us. Earth is not the center of the universe, it goes against what our senses tell us. The Earth rotates on itself to 1 674 km/h while moving at 107 200 km/h around the Sun it, travel 792 000 km/h, yet our senses tell us anything about these movements (see nota).
The space that we consider as a passive vacuum, can bend, twist and curl in the presence of masses, and even worse it can also shrink.
We thought the time was absolute, then Einstein showed us that it roll on more slowly, as the space can contract. Space and time are relative and yet in our daily life we live with the Newtonian picture of space and time, we do not feel the flexibility of space-time. But if it was traveling at the speed of light, would see the time to adjust to the space, so that the contracting speed of light remains constant. This great idea linking space and time by the speed of light is really brilliant because the concept goes against what we said our senses.
We know now that the time is space and the space is time. Indeed in astronomy, the two concepts are related, long ago we described a distance with time. When we say "this star is located 100 light-years," we think well at a distance, while we talk about time and speed of light.
The concept of vacuum that we consider as absence of matter is even more amazing. The vacuum is not nothing, on the contrary according to physicists, he spends a lot of things, virtual particles expect the energy to materially appear. In quantum mechanics, empty space is not really empty, it is a chaotic and hot place. Waves through the void vary the electromagnetic field, i.e. energy, so the vacuum does not exist, there is everywhere a fossil radiation, cosmic microwave background.
The mass is another concept equally mysterious. Billions of dollars have been invested to bring up the famous Higgs boson, among all possible energy windows. The Higgs field is the one that gives mass to particles. And the Higgs mechanism fills the entire universe and everything in space, molasses, boson fields, which means that the matter is matter. More particles have trouble crossing this fields and more they acquire mass. However is hard to imagine a massless material, the relationship between the mass and the material is very strong in our minds, indeed, what is a massless object?
Yet since 2012 (discovery of the Higgs boson), the mass is not an intrinsic property of matter, it is the result of an interaction of matter with the vacuum, since it is moving the objects acquire mass.
And what about the concept of life is one that interests us most. Our egocentric sense tell us that we come from a miraculous creation, but are we really alone in the universe?
This question running through the minds of our astronomers for a long time and to answer this question they invented the technology that will allow us to see other planets in other worlds. There are no long to wait because the images of exoplanets are promised for the years 2020-2030. Again, our anthropocentric worldview may be undermined if biosignatures are found in the atmospheres of other planets. It was then that this beautiful Einstein quote will become fully meaningful.
NB: Why we do not feel the different speeds of movement of the Earth in space? Forces and accelerations exerted on us are too low compared to the main force, gravity, which keeps us on the surface of the Earth. Centrifugal and centripetal forces that may shake us are far too weak to be felt, our senses tell us nothing about the movements of the Earth.
Image: There a few years ago we could not imagine seeing an exoplanet and scientists today we promise these images to the 2020s.
Transit (periodic micro-eclipse) occurs each time the planet passes between the star and the observer, at this moment, the planet obscures some of the light from the star, producing a detectable periodic dimming. This remarkable idea is used to detect the planet and directly determine its size and orbit. The diameter of Jupiter is 10 times smaller than the Sun, Jupiter therefore mask 1% of the luminosity of the Sun as it passes to a distant observer. Earth it is 100 times smaller than the Sun, it therefore mask 1/10, 000th of its luminosity is 0.01% as it passes between the Sun and the observer. But what we see is a signal of brightness decrease and not the planet.
With the DARWIN space mission and the two telescopes JWST and EELT, we see the world or rather its atmosphere that reflects light from its star extinguished by an interferometric coronagraph. Any light that is perfectly aligned with the telescopes (that of the Star) will be off and so the planet can be seen without being dazzled by the nearby star.