Is there a life form larger than a planet?

Among the many science fiction works, the visually stunning "interstellar beast" is one of the favorites. This subversive creature has the size of a planet and can shake several star systems on its own.

Even in some exaggerated depictions of science fiction, the size of such giants is directly comparable to the huge stars, their unimaginable mass and volume make their bodies inside a violent nuclear fusion reaction, and this is the root of their powerful destructive power.

These exaggerated depictions give people a feeling of pleasure, and in the enjoyment of this feeling at the same time, many people's hearts inevitably doubt: the actual universe there is no such subversive perception of life forms?

In fact., the heart of such a doubt is very normal, because the universe is vast, in 13.8 billion years of time scale, and 93 billion light-years observable distance scale, there are a lot of subversive and even beyond the human cognitive things.

For example, a black hole codenamed "SDSS J140821.67+025733.2", this black hole is the largest black hole discovered by mankind, its mass is 196 billion times that of the sun, and the apparent radius reached a staggering 116.88 billion kilometers, such a huge distance scale even light has to go 45 days if an ordinary civil airliner needs to go about 148,006 years.

Just 93 billion light-years observable universe has huge so subversive celestial bodies, not to mention 93 billion light-years is not the real size of the universe, in that eternal darkness of the unobservable region, there must be hidden extremely many secrets and unknown.

So according to normal thinking, the unknown region that mankind has not understood, if there are any ordinary planets or even ordinary stars about the size of a life form seems not without possibility. But if we look at this issue from a scientific point of view, what volume of such a huge life form will exist?

To explore this issue, we must first know what is life, after all, the universe is vast, if we do not even know what is life, then we simply cannot define those things that are even difficult to observe as not life.

Fortunately, scientists have long thought about this issue, although we still can not make a definitive conclusion on the origin of life, "what is considered life" but a logical and factual way to identify it, and this method is proposed by physicist Erwin Schrödinger.

Many people may be surprised that the question of life is a biological issue, why would a physicist propose its most essential concept?

Physics and biology are not opposing disciplines, but rather they have a close relationship and promote each other's role, and any problem as long at the most essential level, it will eventually return to the perspective of physics to find the answer, and physics is already closely linked to biology is certainly no exception.

The main thing is that the question of life is not a single field of study that can be completed, which involves a very large number of different disciplines, and fields of study, so physicists' study is not surprising.

In his later years, after studying the nature of life, Schrödinger presented his two views on how to judge life and non-life in his book "What is Life".

The first is to use the "entropy (shāng) value" to make a judgment. Schrödinger pointed out that life can spontaneously develop in the direction of "negative entropy", while non-life can not do so.

What is "entropy"? It is to describe the degree of disorder in an isolated system, the higher the entropy value, the higher the degree of disorder, such as rusting iron, and broken glass is the embodiment of a higher entropy value, their disorder has increased.

In the entire universe, the entropy value increases are irreversible, once the entropy reaches the maximum, then the universe will usher in "thermal silence", all energy will be converted into heat, and the universe will be no energy required for life activities, life will completely disappear from the universe.

And life is different from other things, it can spontaneously reduce its own "entropy", so that the disorder becomes orderly, such as rubbing the skin to restore the first, eating to replenish more energy, etc.

It is important to note that the single satisfaction of this point is not sure that a thing is a living organism, just like humans with irregular clay can burn paper out of regular porcelain, which is also the process of disorder to order, but the porcelain is certainly not our understanding of life.

At this point Schrödinger's second method of judgment comes in handy, he believes that life also has an extremely important feature - the continuation of genetic information.

Simply put, the essence of the continuation of life is the continuation of information, no matter how large or how small life is, the meaning and purpose of its existence are the same, which is to ensure that the genetic information in the body can be safely passed on.

Returning to the opening question, is there a life form in the universe that is as large as an ordinary celestial body? From a scientific point of view, it is possible, but the conditions for their existence are destined to be extremely demanding because the first challenge facing a large size is the transmission of neural signals.

If these creatures have a human sense of "hands", then they may raise a hand and need to think for a long, long time because the speed of light in the universe is the upper limit of information transmission, once the size of the huge speed of light is delayed, then the response is bound to slow a situation.

It is worth mentioning that in recent years, the University of London, a team of observers in the observation of deep space objects, accidentally found an "interstellar existence", which is very consistent with Schrödinger's definition of life.

The team has found that this "interstellar being" has a spontaneously ordered interior, which is one of the most basic characteristics of life. In addition, they also found that its internal material shows vague conformity to the symbolism, which is consistent with the second point proposed by Schrödinger.

There are only two reasons for this observation. The first is that it is itself a massive life form, and the second is that there is alien intelligent life in it that is transforming the living environment.

In general, human understanding of the universe and life is certainly far from enough, perhaps with the continuous progress and development of science and technology, the human perception of the universe and life will change, or even completely overturn is not without any possibility.