Physicists say that even in a perfect vacuum can be friction

One of the fundamental postulates of modern physics States that in the environment a perfect vacuum is space that does not contain any matter can not exist such a process, as friction, because completely empty space cannot act this force on objects passing through it.

Despite this common belief, physicists from the UK found that the decaying atom being a complete vacuum, will be exposed to frictional forces. Moreover, scientists were able to figure out that this phenomenon is rather reinforces rather than refutes the General theory of relativity.

"We spent a lot of time searching for possible errors in calculations and even more, by studying other strange inconsistencies, not yet found, rather obvious solutions", — said Phys.org Matthias Sonnleitner from the University of Glasgow.

In the calculations for predicting the behavior of the decaying atom moving through a perfect vacuum, Sonnleitner and his colleagues have discovered something strange. Physicists have long known that a perfect vacuum can not exert any forces on the atoms, but still able in a special way to interact with them.

To date, scientists are not able to create the conditions of a perfect vacuum, because there is no level reviewer is not able to ensure the purity of the experiment, creating the confidence that any atom will not seep into this space. However, the calculations predict that the theoretical perfect vacuum will indeed be filled with his own special energy and "virtual" pairs of particles-antiparticles that have the ability to suddenly appear and as suddenly disappear.

This description of the ideal "empty but not empty" vacuum is derived from the aspect of quantum mechanics called the Heisenberg uncertainty principle, which tells of the countless theoretical virtual particles, appearing and disappearing in a vacuum at a random point in time. These quantum shifts create random fluctuating electric fields, and calculations of the team of Glasgow describe how these fields can interact with atoms moving at this point, through space vacuum, absorbing energy and moving to an excited state.

Inasmuch as in a state of excitation, the atom will decay to a lower energy state, it will be capable of in a random direction emit photon (particle of light). The researchers calculated that when the moving atom will emit a photon in the opposite to its movement direction, in this moment will create a friction force that appears in the form of reducing the speed of movement of this atom. If in practice this is true, it would contradict the principle of relativity, because in this case it will be assumed that the observer, depending on where it will be relative to this atom, will have to see an atom moving with different speeds.

Sonnleitner said that his team "spent weeks to find the right answer", and the solution is reduced to an unexpectedly simple formula E = mc². Scientists realized that the decaying atom at the time of the motion and radiation of a photon in a random direction would be to lose a small amount of energy and mass. This amount of mass is called the mass defect, and this value is so insignificant that is never measured in that context before.

"This is the same mass in the famous equation E = mc² Einstein that describes the amount of energy required to separate the nucleus into its constituent protons and neutrons. It is also called the binding energy of the nucleus. The term is widely used in nuclear physics that deals with large binding energy, but generally are considered minor in atomic optics because it supports a very small energy values".

When the researchers framed the value of the mass defect in his calculations and used the formula E = mc² for the solution, they found that the loss of insignificant weight, in the decay of the atom is actually losing momentum rather than speed.

The relationship between friction, momentum, and speed, where friction would be regarded as the result of the change of momentum due to loss of speed, the scientists see the loss of momentum as a result of changes in the mass of the atom. Its speed remains constant, as it should. Thus, the presence of friction in vacuum does not violate the theory of relativity. In fact, similar behavior is predicted in the special theory of relativity, which says that mass loss can cause a barely noticeable loss of momentum.

"by Your calculations, we've shown that the decaying atom really faced with a force that has the similarity with the friction. However, this force is represented in the form of change of momentum due to changes in the internal values of the mass and energy of the atom, and it is not connected with his slowing."

Now the researchers want to test whether to show this phenomenon, if the atom will absorb, but not emit a photon. And perhaps this information can be used to explain the results of another study, which also hinted at the presence of friction in a perfect vacuum. In 2011, physicists have assumed that the vacuum can indeed be friction if a large amount located in it a "virtual" particles will move in the opposite direction in this physical object.

To Prove it in real conditions yet, but one thing is known for sure right now: strange things sometimes happen in complete vacuum.