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One is the ultimate celestial body that engulfs everything in the universe, and the other is the ultimate weapon of 100% mass-energy conversion. If these two guys meet each other, who will be more brave?

Black holes probably do not need to be introduced too much, we are already familiar with it, and the concept of antimatter has been introduced in detail in the quantum series before. Some friends often confuse antimatter with dark matter, and they are two completely different things. At present, dark matter is only a kind of hypothetical matter, it only has the gravitational effect. Because we do not participate in electromagnetic and other interactions, dark matter cannot be detected in the form of electromagnetic waves, so we cannot study it directly like ordinary matter, so we know very little about dark matter.

Antimatter is nothing new, and it has been predicted and discovered by theory as early as the 1930s. So we can say that we already know a lot about antimatter compared to dark matter.

We know that antimatter is a substance with the opposite state of normal matter. For example, if an electron that should be negatively charged is positively charged, it is called a positron, that is, an antielectron. Antielectrons are also the first antimatter discovered by human beings. By the same token, if a proton that should be positively charged is negatively charged, then it is an antiproton. And if antielectrons and antiprotons can come together, then we get the real antimatter-antihydrogen atoms.

Well, this thing is not a pipe dream, and now humans do have the ability to make antimatter, though only at the particle level of antihydrogen atoms.

Many people know that the greatest characteristic of antimatter is that once it meets positive matter, it will immediately annihilate, and the mass of both will be completely converted into energy, with a mass-energy conversion rate of 100%. Perhaps it can be said that this is the ultimate energy in the absolute sense. Fusion, by contrast, is like a toy: whether it's controllable fusion or an uncontrollable hydrogen bomb, the mass-energy conversion rate of the fusion reaction is less than 1%.

What is the concept of 100% conversion rate of annihilation reaction? We can simply take a look at Einstein's mass-energy formula.

E = MC ^ 2

The formula is so simple that we can see at a glance that there is a very large number in it: the square of the speed of light! So even if there is only a small mass, when it is multiplied by the square of the speed of light, the resulting energy will be unusually large.

How powerful is this energy? According to the old rule, if the Hiroshima atomic bomb is used as a unit of measurement, 1g of antimatter and 1g of positive matter will be annihilated enough to blow Hiroshima three times. So it's really appropriate to use antimatter as a bomb.

But the problem is: at present, artificial antimatter usually requires particle accelerators, and the cost of preparation is very high. In 1995, for example, researchers prepared antiprotons through accelerators and then allowed antiprotons to react with xenon nuclei to produce a pair of positive and negative electrons. If the positron happens to be captured by other antiprotons, it is possible to get an antihydrogen atom. It can be seen that the probability of the final synthesis of antihydrogen atoms in the whole process is very low and requires a lot of energy.

In addition to the high cost of preparation, antimatter storage is also a big problem. If you think about it, almost all the matter in nature is positive matter, and it is not easy to create some antimatter, which may be annihilated without paying attention. So antimatter bombs still exist only in science fiction.

If we ignore the technical feasibility and assume that we build an antimatter bomb through more advanced technology or regardless of cost, what happens if we throw it into a black hole?

First of all, it is necessary to make clear the question of whether an antimatter bomb is made up entirely of antimatter or a bomb made up of both antimatter and positive matter. If it has only antimatter, it is equivalent to that the whole bomb is a piece of antimatter, and when it encounters positive matter, it will annihilate itself and release energy. If we just throw such an antimatter in, it may react with some interstellar matter on the way to the black hole, which is obviously not what we want. So suppose our bomb is made up of both antimatter and positive matter, so that its explosion timing is more controllable. Later, you will find that in fact, there is no difference between the two ways for black holes. )

All right, now that the timing of the explosion is controllable, let's set it to detonate after it comes into contact with the black hole. But what is contact with a black hole? You might say: it's not easy, isn't it contact with the visual interface? Hey, is that really the case? Think carefully about what the visual interface of a black hole is.

According to Einstein's field equation, the event horizon of a black hole is only a space-time boundary. Because of the distorted space-time and the speed of light, any event within this line can never affect the outside world, so it is also called the event horizon. According to the field equation, all the mass of the black hole should be concentrated on the internal singularity (or singular ring), which is theoretically empty from the singularity to the middle part of the event horizon. So although the "contact horizon" does come into contact with the black hole, it may not really touch the matter inside the black hole.

Attention, why should I add "possible" here? Because we are only speculating about the distribution of matter in black holes based on existing theories. According to general relativity, there are two perspectives from which matter falls into a black hole: one is matter itself, and the other is an external observer. The conjecture that matter collapses to a singularity is considered more from the point of view of the matter that falls into the black hole. But from an external observer's point of view, there may be another result of the matter in the black hole: it will be wrapped like an onion. This is because for external observers, the matter that falls into the black hole will always rest at the event horizon, or, to be exact, the infinite redshift.

One is to go straight to the singularity without looking back, and the other is to rest forever on the horizon. Which of the two contradictory results is the truth? Well, this is the frozen star paradox mentioned earlier.

Today we are not going to talk about it, you can temporarily think that from a relativistic point of view, because the reference frame is different, both results are true. But today we are talking about blowing up black holes with antimatter bombs, so it should be considered more from the perspective of external observers.

For external observers, because matter will always freeze at the moment it falls into the black hole, the distribution of matter inside the black hole may be like an uneven onion, retaining the "trajectory" of the previous matter falling into the black hole. So in this case, from our point of view, the antimatter bomb may never detonate because it will rest on the event horizon.

To say the least, even if it does enter the black hole, or even reach the singularity, and successfully detonate, there is no way for us to know. Because it all happened within the event horizon, that is to say, it will never enter our cone of light. So whether the antimatter bomb explodes directly, or the antimatter annihilates with the matter in the black hole, in the eyes of our observers, the black hole swallows it, which is no different from swallowing normal matter.

On the other hand, for a black hole, once matter enters, it no longer has a normal material structure. Because according to the black hole hairless theorem (No Hair Theorem), a black hole has and only three physical quantities: mass, angular momentum, charge, and all other information is lost. So whether you go into positive matter, antimatter, or even dark matter that we don't know yet, they are all the same to black holes.

And according to Hawking's black hole area theorem (the event horizon area of a classical black hole does not decrease with the passage of time), even if an antimatter black hole composed entirely of antimatter collides with an ordinary positive matter black hole, in the end, the two black holes will not annihilate and disappear, but will result in a new black hole that merges into one.

So even science fiction antimatter weapons can be helpless in the face of black holes, the most extreme celestial bodies in the universe.

This article comes from the official account of Wechat: Linvo says ID:linvo001, author: Linvo

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