Genady

For communication. We are irrational inside our heads, but to communicate successfully we need a rational representation of our thoughts. E.g. you've asked the question and I'm trying my best to give a rational answer. If communication is not rational, it is broken. (There are examples of such in some recent threads...)

In the very recent textbook from the University of Pennsylvania, Physical Models of Living Systems: Probability, Simulation, Dynamics by Philip Nelson, November 2021, there is a little section in the introduction for students, which I have attached below. My questions for the discussions are: Do you agree with these limitations of computers? Are they temporary or fundamental?

To me, the most interesting part of the article was not about the new viruses - they looked in a new environment, they found a new stuff, not very surprising - but rather about the RdRp gene: "They examined genetic sequences extracted from small aquatic organisms known as plankton, which are common hosts for RNA viruses, the researchers said. They homed in on sequences belonging to RNA viruses by looking for an ancient gene called RdRp, which is found in all RNA viruses but is absent from other viruses and cells." "RdRp gene is billions of years old" "Understanding how the RdRp gene diverged over time could lead to a better understanding of how early life evolved on Earth, the authors said." "RdRp is supposed to be one of the most ancient genes — it existed before there was a need for DNA" "So we’re not just tracing the origins of viruses, but also tracing the origins of life."

I see now. Thank you, I've misinterpreted. BTW, I think that only very few particular behaviors can be traced to a molecular basis. Esp. if they are not disorders.

Imagine that the electromagnet was here on Earth while the permanent magnet was on a planet in Alpha Centauri. If your answer were correct, this arrangement would allow for an instantaneous, faster than light communication between the Earth and the planet in Alpha Centauri. We know that this is impossible, that no signal can travel faster than light. Thus, they would not start moving simultaneously, as per your suggestion.

OK. I think TheVat's comment above, which I'm going to +1 now, closes the topic nicely.

I don't understand this. Yes, of course. "Molecular bases" was brought up in a joigus' comment above. That it has no special role here, is my point.

Specific cases of any selection can only be considered in specific contexts. General mechanisms can be considered under general conditions. Sexual selection comes in two forms: intersexual preferences and intrasexual competition. Sexual dimorphism can result from sexual or from natural selection. In any case, AFAIK, both forms of selection work on phenotypes, while underlying molecular mechanisms are the same. On top of this, human behavior can be driven by cultural factors too short to have an effect on biological evolution.

What I don't understand is, in what way sexual selection would be "special" on a molecular level. Isn't molecular process behind evolution the same? Doesn't selection work rather on phenotypes?

What do you mean by this?

How do we know that this is the same missile in the picture? How do we know that the other numbers are true?

You're welcome. See you later. +1

The factors pointed in the comments above are possible, and informative, explanations for why such a difference between sexes exists, if it exists. I just don't think it does.

You said that the field moves, but I said it first, and that leads to misunderstanding. That's why I said, you are correct - because I was wrong first Now , to the subject. It is correct only about massive bodies, that "when something moves to the right that is a positive momentum ... etc." This does not apply to EM wave. It does apply to a moving massive body because its momentum is mv, so the momentum has the same direction as the velocity. But the momentum of a wave has nothing to do with mv. Anyway, the wave doesn't move to the right, but is radiated away from the source. The momentum of the wave is not moving from electromagnet toward the permanent magnet. The wave radiating from the electromagnet has a total momentum [-p] (not a typo.) When the permanent magnet moves, its EM field is changing in a wave radiating from it. That wave has a total momentum [+p] (not a typo.) Does this explanation clarify what I mean?

Here is a trick. Select the text and it comes out: Regarding the topic itself, every part is questionable: is it indeed so? why the chance of passing it on should be the same? why the effect should be equal?

I assume they don't want us to read what they wrote.

You are correct, it was not accurate to say that "the field is moving to the right". The EM field is there all the time. Before the electromagnet is turned on, the field is that of the permanent magnet. After the electromagnet is turned on, the field starts changing. What moves is the change, the EM wave. This wave is carrying the total momentum [-p]. The wave never slows down - being EM wave, it always travels with the speed of light. When the wave reaches the permanent magnet and interacts with it, the permanent magnet starts moving with the momentum [-p]. This causes another change in the field, making a new wave. This wave carries momentum [+p]. The stages of the process are like this: 1. Electromagnet at rest, permanent magnet at rest, no waves. Every component and the system have momentum 0. 2. Electromagnet moves to the right, momentum [+p]. Wave 1 goes out, momentum [-p]. Permanent magnet at rest. 3. Electromagnet moves to the right, momentum [+p]. Wave 1 goes out, momentum [-p]. Permanent magnet moves to the left, momentum [-p]. Wave 2 goes out, momentum[+p]. Does it make sense?

I'm not sure I follow. Let's make the discussion simpler by using symbols rather than pictures (simpler for me, anyway). Here is my scenario. As soon as the electromagnet is turned on, it gets a momentum [+p] and the EM field goes off toward the permanent magnet carrying the momentum [-p]. After the specified time, the field reached the permanent magnet and interacts with it. As a result of this interaction, the field looses the momentum but the permanent magnet gets the momentum [-p]. The total momentum is 0 all the time, isn't it?

What kind of new particle would have this effect, a boson or a fermion?

The government of Ukraine tells civilians in the east and the south to evacuate immediately. Not to help Russian army, but to save their lives.

I don't know "who" has defined this word. I don't think it matters. That's what the word means.

Definition of "rational".

" is it irrational to want/hope " (dimreepr) Yes, it is. By definition.

"For the Kiev regime, they are traitors, because they do not want to be a human shield for the armed forces of Ukraine." This is a lie. It's already several days Ukraine government urges people in the east to run for their lives. They specifically say, evacuate now!

A new most distant galaxy has been found as well: Astronomers discover the most distant galaxy yet | Astronomy.com