It is found that one m-bacteria can self replicate while killing the virus. It is known that one m-bacteria can kill a virus and split into two m-bacteria. What is the maximum number of m-bacteria that can be produced by one m-bacteria and 2047 viruses_______ My answer is 2 * 2047 = 4094. What's wrong,

In fact, from the overall point of view, every change process is m + n - → m + m, that is, changing a virus N into an M;
Now there are 2047 virus N, which will eventually become 2047 m, so the total number of M is 1 + 2047 = 2048

C35 (3 is superscript, 5 is subscript). What is the mathematical problem? Is it permutation?

It is a permutation and combination. It means: divide the factorial of the subscript by the factorial of the superscript, and then divide by the following table minus the factorial of the superscript
C35=5!/3!/2!=10
Ca↑b↓=b!/a!/（b-a）!
Where "!" is the factorial, a! = 1 * 2 * 3 *... * (A-2) * (A-1) * a

What formula is the superscript x and subscript 20 of the letter C in mathematics

This is a combination formula in permutation and combination
It means that in 20 numbers (not necessarily numbers, can be 20 things), arbitrarily select x numbers (and the order of the X numbers is not considered)
The superscript x of C, the subscript 20 = (20!) / ((x!) times ((20-x)!), where! Is the factorial, such as 3! = 3 times 2 times 1

How to classify primary school scientific animals

1. Invertebrates include: protozoa, flat animal, coelenterate, echinoderm, arthropod, mollusc, Annelida and linear animal
2. Vertebrates include fish, amphibians, reptiles, birds and mammals

What do general relativity and special relativity mean
Simple and clear answers-#

General relativity is also called space-time geometric dynamics, that is to say, gravity is attributed to the geometric characteristics of space-time. Special relativity. This theory points out that the only constant in the universe is the speed of light in a vacuum, and everything else - speed, length, mass and passing time - changes with the observer's reference frame (specific observation)

Animal's -- and -- are important standards for scientists to classify animals
Thank you later

The (morphological) and (physiological) characteristics of animals
Morphology: bones and teeth are important criteria for fossil species
Physiological characteristics: it is often compared that there are still biological characteristics, especially reproductive physiological characteristics!

Who invented special relativity and general relativity?

First of all, as a theory, relativity can not be said who invented it. It can only be said that it was first put forward by German physicist Einstein (Jew). It is only a theory, not a theorem or axiom. It needs to be proved
secondly,
Relativity is divided into general relativity and special relativity
The basic concept of general relativity is explained as follows
General relativity is the theory of relativity of gravitational field put forward by Einstein in 1913 after special relativity. This theory is completely different from Newton's theory of gravitation. It attributes the gravitational field to the bending of space-time around the object, and the motion of the object under the action of gravitation to the free motion of the object along the geodesic line in the bending space-time, General relativity, also known as spatiotemporal geometric dynamics, attributes gravity to the geometric properties of space-time
How to understand the space-time curvature of general relativity? Here we use a model analogy to explain. If there are two steel balls with large mass, according to Newton's view, they will be close to each other because of the mutual attraction of universal gravitation. Einstein's general relativity does not think that there is an attraction between the two steel balls. The reason why they are close to each other is that they are close to each other, The reason is that when there is no steel ball, the surrounding space-time is like a flattened net. Now two steel balls bend the net, so the two steel balls roll together along the curved net. This is equivalent to the movement of objects along the geodesic due to the bending of space-time. Therefore, Einstein's general theory of relativity is a theory of gravity without "gravity"
Furthermore, the theory is based on the two basic hypotheses of equivalence principle and generalized covariance principle. The equivalence principle is based on the fact that the mass of inertia and gravity of an object are equal. It is considered that gravity and inertial force in acceleration system are equivalent, and they are indistinguishable in principle. The generalized covariance principle can be regarded as a mathematical expression of the equivalence principle, That is to say, all the differential equations reflecting the laws of physics should keep the same form in all the reference frames. It can also be said that all the reference frames are equal, thus breaking the special status of inertial frame in special relativity. Because of the arbitrariness of the selection of reference frame, it is named general relativity
We know that Newton's law of universal gravitation holds that all objects with mass attract each other, which is a static over distance action
In general relativity, the law of gravitational field produced by matter is expressed by Einstein's field equation. The gravitational action reflected by it is dynamic and transmitted by the speed of light
General relativity is a more general theory than Newton's theory of gravitation. Newton's theory of gravitation is only the weak field approximation of general relativity. The so-called weak field means that the gravitational energy of an object in the gravitational field is far less than the inherent energy, and the difference between the two is shown in the force field. At this time, general relativity must be applied to correctly deal with the problem of gravitation
After the establishment of general relativity in 1915, Einstein proposed that its correctness can be tested from three aspects, namely, the so-called three major experimental verifications. These are the deflection of light near the sun, the precession of mercury perihelion and the frequency shift of spectral lines in the gravitational field. These were soon confirmed by the experimental observations at that time. Later, someone designed the radar echo time delay experiment, In the 1960s, a series of new discoveries in astronomy, such as 3K microwave background radiation, pulsars, quasars, X-ray sources and other new astrophysical observations, strongly supported general relativity, thus making people's interest in general relativity turn from cold to hot, It has become a hot frontier in physics
Einstein always regarded general relativity as the most important scientific achievement in his life. He said, "if I didn't find special relativity, someone else would find it. The problem is mature. But I think general relativity is different." indeed, general relativity contains more profound ideas than special relativity, This brand-new theory of gravity is still the best theory of gravity. Without bold spirit of innovation, indomitable perseverance, keen theoretical intuition and solid mathematical foundation, it is impossible to establish general relativity. The great scientist Thomson once called general relativity one of the greatest achievements in human history
Special relativity is
Special relativity is a theory based on the four-dimensional space-time view. To understand the content of relativity, we need to have a general understanding of the space-time view of relativity. In mathematics, there are various multi-dimensional spaces, but so far, the physical world we know is only four-dimensional, that is, three-dimensional space plus one-dimensional time, There is no discussion here
Four dimensional space-time is the lowest dimension of the real world. Our world happens to be four-dimensional. As for the high-dimensional real space, at least now we can't perceive it. A ruler rotates in three-dimensional space (excluding time), its length remains unchanged, but when it rotates, its coordinate values change, and there is a connection between the coordinates. The meaning of four-dimensional space-time is that time is the fourth dimensional coordinate, It is related to space coordinate, that is to say, space-time is a unified and indivisible whole
In four-dimensional space-time, mass (or energy) is actually the fourth dimension component of four-dimensional momentum. Momentum is the quantity describing the motion of matter, In addition, in the four-dimensional space-time, four-dimensional velocity, four-dimensional acceleration, four-dimensional force and four-dimensional form of electromagnetic field equations are also defined. It is worth mentioning that the four-dimensional form of electromagnetic field equations is more perfect, completely unifying electricity and magnetism, The electric field and magnetic field are described by a unified electromagnetic field tensor. The physical law of four-dimensional space-time is much more perfect than the three-dimensional law, which shows that our world is indeed four-dimensional. It can be said that at least it is much more perfect than Newton's mechanics. At least because of its perfection, we can't doubt it
In the theory of relativity, time and space form an inseparable whole - four-dimensional space-time, and energy and momentum form an inseparable whole - four-dimensional momentum. This shows that there may be a profound connection between some seemingly unrelated quantities in nature, There is also a deep connection between space-time and the four vectors of energy and momentum
There is no matter that does not move and no matter that does not move in the interaction. Because matter moves in the interaction, it is necessary to describe the motion in the relationship of matter, not in isolation. That is to say, there must be a reference for motion, which is the reference system
Galileo once pointed out that the motion of a moving ship is indistinguishable from that of a stationary ship. That is to say, when you are in a closed cabin and completely isolated from the outside world, even if you have the most developed mind and the most advanced instruments, you can not perceive whether your ship is moving at a constant speed or still at a standstill. What's more, you can not perceive the speed because there is no reference, We don't know the whole motion state of our universe, because the universe is closed. Einstein cited it as the first basic principle of special relativity: the principle of special relativity. Its content is that inertial frames are completely equivalent and indistinguishable
The famous Michelson Morey experiment completely negates the ether theory of light and concludes that light has nothing to do with the reference frame. That is to say, whether you stand on the ground or on a running train, the measured speed of light is the same. This is the second basic principle of special relativity, the principle of constant speed of light
From these two basic principles, we can directly deduce all the contents of special relativity, such as the coordinate transformation and speed transformation. For example, the change of speed is contrary to the traditional law, but it is proved to be correct in practice. For example, the speed of a train is 10m / s, the speed of a person on the car is 10m / s, and the speed of a person on the ground is not 20m / s, It's about (20-10 ^ (- 15)) m / s. under normal circumstances, this relativistic effect can be completely ignored, but when approaching the speed of light, this effect increases significantly. For example, the speed of a train is 0.99 times the speed of light, and the speed of a person is 0.99 times the speed of light, so the ground observer's conclusion is not 1.98 times the speed of light, but 0.999949 times the speed of light, For him, it is also the speed of light. Therefore, in this sense, the speed of light can not be surpassed, because no matter in that reference frame, the speed of light is constant. The speed transformation has been proved by numerous experiments of particle physics, which is impeccable. Because of this unique property of light, it is selected as the only ruler of four-dimensional space-time. We need to be rigorous in dealing with science!

What is the meaning of "modify" in English, and how adverbs modify adjectives, please give examples!

For example, a big apple app