Question — topics and discussions

❓ Question / 🌍 Science and World

elena_w Автор статьи

📅 26.06.2026 11:06

Where have all the trijet airplanes gone?

Find out where the triple-engine aircraft disappeared: the reasons for their disappearance, changes in technology, and the latest aviation trends.

Иллюстрация с древними символами для обсуждения — Медиа-вопрос о древних символах и возможных инструкциях

A Brief History from the Aviation World.

In the 1970s, airlines wanted to operate long-haul flights over the ocean, but twin-engine aircraft were largely not permitted to do so.

The regulations at the time required that for flights far from alternate airports, the aircraft must have at least three engines. It was believed that if one engine failed, the remaining two could safely complete the flight.

This led to the development of aircraft like Boeing 727, McDonnell Douglas DC-10, McDonnell Douglas MD-11, and the famous Lockheed L-1011 TriStar. The third engine was placed in the tail section of the fuselage — at the base of the vertical stabilizer.

Over time, however, jet engines became so reliable that the regulations changed.

Thus, the ETOPS standard was introduced. It allowed twin-engine aircraft to perform long flights over the ocean, flying hundreds of minutes away from alternate airports.

The two modern engines provided the same thrust as three engines did previously, while consuming less fuel and being significantly cheaper to maintain.

Three-engine aircraft did not become any worse — twin-engine ones simply became better.

The last three-engine passenger airliner was produced in 2000. Since then, new passenger aircraft have only been manufactured with two or four engines.

Have you ever flown on a three-engine aircraft? Share in the comments.

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❓ Question / 🧠 Psychology

max_future Автор статьи

📅 24.06.2026 03:55

How to fight laziness?

Tired of laziness? Discover effective strategies and tips to overcome procrastination, boost productivity, and achieve your goals. Start taking action today!

All people are lazy in themselves, and there's nothing you can do about it. Yes, there are workaholics who seem to be not lazy at all, but they also feel that way. They just get going while working and can't stop. But as soon as they slow down a bit — it will also be hard for them to return to the work rhythm.

I want to tell you about an absurd method of fighting laziness that works almost 100%, and that not many people know about.

When a person is too lazy to do something, no matter how absurd it sounds, they're still doing something. 🙂 They're watching TV, lying on the couch, drinking beer, or doing something else. Nevertheless, they are occupied with something. And that's a paradox. Because it seems to us that laziness is when you do nothing. In fact, laziness is when you're doing a lot of things, just not what you need to do for work or important household chores.

Now, let's talk about the most effective method of fighting laziness.

You might be a little surprised by this method, but I suggest that before criticizing, you should try it yourself. Moreover, it will only take you 5 minutes, and your laziness will disappear.

The method is quite simple and absurd: to defeat laziness, you need to... do nothing.

Doing nothing means literally nothing. Well, almost nothing. That is, you shouldn't lie on the couch, you shouldn't watch TV, and so on. You just need to stand in the middle of the room and stand. Just stand, doing nothing but standing.

And believe me, after 5–10 minutes of such standing, you will gather your thoughts, remember important tasks, and you will desperately want to stop standing and start working on them.

So that's the perfectly simple method for combating laziness that works 100%.

So, tell me, did it work for you?

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❓ Question / 💻 Technology

lucky Автор статьи

📅 21.06.2026 09:59

Methods of UAV Detection in the Modern World

Learn about modern methods of detecting unmanned aerial vehicles (UAVs), including radar technologies, optical systems, acoustic methods, and the use of sensors to enhance security and improve monitoring efficiency.

We all see that wars in the world have taken on a new character. While tanks, airplanes, missiles, and other equipment played a major role in the past, UAVs are becoming increasingly important now. They can be produced and launched in large numbers relatively cheaply. Due to the high number of such devices, detection and interception are becoming increasingly difficult tasks.

Currently, two main types of UAVs can be identified that are actively used in military conflicts:

small quadcopters and hexacopters with a short flight range;
airplane-type UAVs, which have a longer range and can carry a significant payload.

These devices typically fly very low. As a result, many modern air defense systems cannot detect them from a great distance. Because of this, UAVs can penetrate deep into the rear, covering large distances and bypassing existing detection systems.

So what should one do if they are so difficult to detect? Let's try to think of possible solutions.

In my opinion, there are things here that may seem somewhat absurd at first glance.

1. Acoustic systems that "listen" to the sky

UAVs, especially airplane-type ones, produce a quite noticeable engine noise. They can often be heard well even without special means.

If several acoustic posts are used simultaneously, then by the time difference of sound arrival, one can not only detect the device but also approximately determine its location and direction of movement.

This is a rather old technology, which is rarely remembered today, but under current conditions, it could prove to be quite effective.

2. Aerostats

Aerostats are quite easy to deploy in almost any terrain, including forested areas. They can host regular cameras, thermal imagers, and other observation tools.

Deploying a network of such aerostats would not pose a major problem for many countries. The remaining question is data processing. Modern computer vision systems and AI can automatically analyze images and identify flying objects.

In my opinion, this could significantly enhance the effectiveness of detecting low-flying UAVs.

As for EW

Personally, I do not consider EW systems to be a universal solution. Many drones are capable of flying to pre-defined coordinates and do not require constant communication with an operator.

If the device is flying autonomously, there is simply nothing to suppress in terms of the control channel. Therefore, it is unlikely that the problem can be solved with only electronic warfare means.

Conclusion

So far, acoustic systems and aerostats seem to me to be the most interesting options for solving the problem of detecting UAVs.

Perhaps I am missing something, so I am curious to learn the opinions of others.

What methods of UAV detection would you suggest?

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❓ Question / 🏠 Life and Advice

veronika_rubleva Автор статьи

📅 21.06.2026 07:52

The car battery is discharging

Learn why your car battery drains and how to prevent this issue. Tips for battery maintenance and troubleshooting the causes of discharge for guaranteed reliability of your vehicle.

Hello everyone. I have a very strange situation that cannot be resolved.

I have a 2012 Chevrolet Cruze, and the battery started to discharge. At first, I thought it was the battery itself, so I put a new one in, but it still discharges. When it became clear that the problem is not with the battery, I went to an auto service. They checked everything and said that everything is fine, but the battery continued to discharge.

I went to another service. There, they told me that I need to replace the BCM block ("brains"), but they cannot replace and reflash it themselves, so they sent me to another service.

In the next service, they removed the BCM block, opened it, and discovered that it was indeed severely oxidized inside and needed replacement. They replaced the block, reflashed it, and installed a new one. But this did not solve the problem — the battery is still discharging.

After that, I went to another car service. There, after two days, they told me that the reason is very simple: the light bulb in the glove compartment does not turn off, and it constantly consumes power. They replaced some spring and said that now everything works fine and the light turns off. But this also did not solve the problem.

Then they told me that despite having a new battery, I need an EFB battery, which is better suited for vehicles with a Start-Stop system. Since I have an aftermarket alarm system installed, they recommended this type of battery specifically. By the way, I forgot to mention: I also replaced the alarm with a new one because they said the cause might be it. They installed the new EFB battery, but the problem still did not go away.

As a result, three auto services cannot find the cause and see no current leaks. What could this be? Where else can I turn and what should I check? Maybe someone has encountered a similar situation and can provide advice?

Thank you all in advance!

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❓ Question / 🧠 Psychology

Diamond Автор статьи

📅 21.06.2026 04:42

Why do we sometimes dream the same dream throughout our lives?

Discover the reasons behind recurring dreams — from psychological aspects to symbolism and the influence of life events. Why do some dreams haunt us throughout our lives? Explore the factors affecting dreams and methods of their interpretation.

I've always been curious why some dreams repeat. I have one dream that has been recurring throughout my life — at different times and with varying frequency. Sometimes it happens once a month, sometimes once a year, and there were times when it didn't occur for several years. I feel like there must be some reason for such a dream, but I still can't understand it.

The dream is always roughly the same: I am walking through a forest to a cave. But every time the path is different. Sometimes I cross a river, sometimes I navigate through thickets — everything is constantly changing. With each new dream, I seem to remember the path better. I already know where I can take shortcuts, where to go faster, and the next time I walk more confidently, as if I have really been there before.

But there's one odd thing: as soon as I approach the cave, which is near a clearing, the dream always ends.

I'm curious, what do you think such recurring dreams mean? Have you experienced anything similar? Maybe you’ve dreamt of the same person you don’t even know, or a place that continuously appears in your dreams?

Let me know, I’m very interested to read.

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