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Physics, Astronomy & Cosmology / Spinning a cassette player with a rope: same sound?

« on: 07/04/2023 11:34:55 »

I am asking this because I have never tried, it's hard to find a cassette player now. But I was thinking that when we were playing a cassette inside a fast moving car, the speed of the tape would be considered faster only for those outside the car, but for those inside the car the speed of the casstte would be totally normal and the speed of sound would be totally normal because the air is contained and travelling within the car. The same could be said for any spinning things, examples, a drill, a fan or a turntable inside the ISS for us on Earth would be spinning much faster, because we add the speed of the ISS to it, but for those inside the ISS the drill speed is  normal, and the turntable speed is the same normal speed, with a normal sound. But let's say I am in my room, I have a cassette player (I don't... ) with blue tooth speakers (so the speakers are not moving), and I spin the cassette around me with a rope: in this case, should I add the rope speed to the cassette speed, should I hear a different sound, or will I hear a normal sound without any acceleration?

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Technology / Has anyone exploited the balancing half-sphere for electricity production?

« on: 04/02/2023 00:08:08 »

Can this idea be useful? A pole wobbling on a huge concrete half-sphere? Can this become some sort of "wave power" at home?

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Physics, Astronomy & Cosmology / Electrons made of photons?

« on: 27/12/2021 13:25:27 »

Curious about it, we can't "see" travelling photons in action when they travel in a straight line, or when they carry electric and magnetic fields that oscillate at a certain frequency, the so called wavelength (how can they travel straight and oscillate at the same time by the way? Are they particles or not?). I have also read that two photons sometimes could combine to produce an electron. So is it possible that electrons are just well packed photons? What do you think? Difficult stuff, speak your mind as freely as you can.

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Technology / soundproofing in a 3d printed house?

« on: 01/05/2021 20:27:38 »

Soundproofing can be easier maybe in the near future. No more blankets, carpets, thick panels on the walls, ceiling, floor. 3D printed houses don't leave gaps, but if they leave just a few mm of space between the wall, ceiling, floor, it could be vacuum pump easily later, if the tenant needs to.

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Physics, Astronomy & Cosmology / speed of projectiles inside a free falling vacuum chamber

« on: 13/04/2021 09:38:29 »

As a result of the previous thread I tried to google about speed of arrows-bullets inside a free falling vacuum chamber. And I haven't found any, can you help me?? How can this be even possible? I know they did experiments in a static vacuum chamber on the ground, but I haven't found anything about projectiles inside a free falling vacuum chamber. It could be done easily on the ISS. Example, they could assemble a long vacuum chamber/tube/channel. Inside the vacuum tube, at the end of each side (A and B), they put an automatic crossbows or gun. Then calculate if the projectile fired from A to B (travel direction of the ISS) would be slower than the projectile fired from B to A (opposite the travel direction).
Or, they could easily do the same experiment by dropping a long vacuum chamber from the sky.

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Physics, Astronomy & Cosmology / Watching, hearing, playing in a spaceship travelling near speed of light

« on: 12/04/2021 18:23:01 »

Let’s say there are two tv playing the same movie, one screen is in front of you (direction of spaceship travel), the other screen is behind you (opposite the travel direction). I suppose the movie played by the screen in front of you will appear and reach your eyes as if the movie was played at higher speed than normal. The movie played by the screen behind you will appear and reach your eyes as if the movie was played at slower speed than normal.
The sounds will reach your ears in the same way from both tv speakers, and they will both sound normal, like on Earth. But they will be both out of sync with the images: the sounds coming from the screen in front of you will reach your ears after the images, and the sounds coming from the screen behind will reach your ears before the images.
Playing tennis inside the spaceship. Seeing and feeling will be out of sync. Actually let’s make it easier than tennis. There are two guys throwing a tennis ball to hit your head. Like for the tv case, one guy is in front of you (direction of spaceship travel), the other guy is behind you (opposite the travel direction). When the guy in front of you throws the ball, you will feel as if the ball is hitting your head after it reaches you. When the guy behind you throws the ball, you will feel as if the ball hits your head before the ball reaches you.
What do you think?

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Technology / Can we use convection to move desalinated seawater inland?

« on: 08/04/2021 12:41:23 »

For a river or aqueduct it’s simple to carry water, gravity is all is needed. But let’s say you want to transport desalinated water from the sea to the desert. If you follow the elevation map, you can basically transport desalinated water from the sea to virtually anywhere. They can use mirrors in a coastal area to heat the seawater, which will evaporate reaching high areas. Make huge funnels to collect the evaporation. And let gravity do the rest. If the pipelines are following the elevation map, water can easily travel anywhere, from Veracruz (Mexico) to Amarillo, from Guelmim area (Morocco) to Agadez (Niger), from Qabilat (Libya) to Ennedi area (Chad), etc., the possibilities are endless.

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Technology / Is it possible to tow a rocket into space from space?

« on: 12/08/2020 20:42:38 »

Rocket "a" pulls rocket "b", both on earth, with a shortish cable. If Rocket "a" is on space, apart from the extremely long chain/cable, would it be easier to pull rocket "b"? Would it save any fuel?

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Technology / Can a spinning solar plane produce energy?

« on: 09/04/2020 01:17:08 »

As solar planes are becoming more efficient and popular, is it possible for a solar plane to spin like a two blade wind turbine, and collect more energy while flying? Basically it would become like a flying wind turbine.

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Technology / Can choppers or drones suck the smoke and blow it back to the wildfires?

« on: 04/01/2020 16:56:43 »

Instead of using water they use the smoke, right on the place. A U pipe system, one metal pipe suck the smoke, the other pipe blow it back to the flames.

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Physics, Astronomy & Cosmology / Can gravitational waves be detected with electron microscopes?

« on: 20/10/2018 12:28:26 »

Can they try to detect gravitational waves with powerful microscopes? They could use them everywhere on the planet, isolating them like the LIGO, hanging them from pendulums. The advantage would be that no long pipes are needed. They record footages 24 hours a day, then they analyse the footage, playing back at the exact same moment the GR has been detected by LIGO.

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The Environment / Bring seawater to the desert?

« on: 04/09/2018 13:39:54 »

Has it being tried? You connct seawater through a pipe system, take the seawater to the hottest flattest area of the desert, keep the level of the water always constant, 1 cm deep, so the water will evaporate very quickly. The salt left, can be collected by robots, and be sold later. The flat area must be rocky surface, so the water doesn't penetrate, or it can be manmade using cement. The bigger the pool, the bigger the evaporation. What do you think?

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Technology / Should all houses be prefab like lego?

« on: 29/07/2018 12:59:07 »

I think it would be great if all the houses were prefabricated and then just assembled like lego. I know it's impossible to transport an entire house or an entire room on a truck. But they could transport a section of a room on a truck, and then assemble all the other sections. What do you think?

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Physics, Astronomy & Cosmology / Who decided North was up on maps?

« on: 28/04/2018 20:13:24 »

Let's say we conquer in the future a new planet in a far galaxy. How to decide where is north and south in the maps? And how this was decided on our planet maps? If we put our maps upside down after all, it wouldn't make any difference.

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The Environment / Can you stop a hurricane with a giant inflatable balloon?

« on: 06/09/2017 16:26:50 »

I don't know if this question has been asked before. But I am surprised they never found solutions to stop a hurricane, considering the economic damages it could prevent. If ice cubes or missiles are too expensive, why not to send submarines underneath the hurrcane, inflate giant balloons (anchored to the submarine). The balloons can float and splash into the waves, but could they survive the wind?