For the photon, no time would have passed at all. What that means in practice is that photons can't change as they travel. The photons we receive are exactly the same as the ones that were sent.

Here's another example. Back in the 80's, it was thought that neutrinos were massless, and traveled at the speed of light. Neutrinos are extremely light particles that are emitted from some nuclear reactions - and they come in three "favours".

Also, back in the 80's, careful measurements had been done of the number of neutrinos coming from the sun, and the figure was only about 1/3 of what it should have been.

There were a few ideas proposed to explain that. One was that the sun had switched off and we would all freeze to death within 10000 years or so, but another was that some of the neutrinos from the sun were transmuting into the other forms, and we were only detecting the 1/3 that stayed in their original form. However, if neutrinos were traveling at c, that couldn't happen - if, for the neutrino, no time had passed, then it couldn't transmute, since change needs a passage of time, and for objects at c, no time passes.

Since then, we have confirmed that, in fact, neutrinos do have mass, and don't travel at c, and so time does pass for them on their journey to us from the sun, so we aren't doomed to an icy future. This was very exciting for the physics world, and probably won (or will win) someone a Nobel Prize.

However, for light itself, we know it travels at c, and therefore no time passes for the photons as they cross the 8 light-minutes between the sun and us. (For them, it also seems like no distance has been traversed).

What does ETOPS have to do with engine placement on the stab vs. under-wing? I don’t think you answered the question (which is about placement, not quantity).

Are you asking about something travelling through space?

Photons, and anything else moving at c, don't really have a perspective.

An object moving at near c would experience almost no time at all during the journey. The distance between Earth and the Sun would, from its perspective, contract such that its near light speed movement allowed it to cross the distance much faster.

The whole truck isn't moving through the medium of dirt though so it's apples to oranges in this case.

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You've never called a gunship on Shipment in Call of Duty? Super effective. Check and mate (/s)

You can build systems where unused power can be returned to the power source - take regenerative braking in EVs for example. This helps prevent the unnecessary loss of power, and can substantially reduce consumption.

However, you will never return 100% of the energy you extracted back to the power source. The energy used for work can't be returned because you just transferred it somewhere else! Plus, you'll lose energy to heat.

The top speed has become a selling point.

Edward Leedskalnin - Homestead Florida.

Take a look, the wheel spins and spins and spins, constantly alternating the current for his solenoid. It’s not perpetual motion, it’s a machine that returns energy back into its source and does work.

No, f=ma. No squared term.

Lmao dude.

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There are some lights that use a weight to slowly pull a cord through an alternator and create electricity. They are testing huge versions that will use abandoned mine shafts and they will generate loads more power. https://deciwatt.global/gravitylight

Oddly enough not all 4 cylinders fire evenly. There were some Yamaha race bikes that used a 13-24-0-0 firing order. Increased low end torque to assist acceleration out of corners. I wonder what they sounded like.

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There hasn't been a model designed with an engine on the vertical stabilizer since like the 70s/80s.

As for why, it has to do with reliability and the ability to make an emergency landing if 1 engine fails. Modern jet engines are reliable enough that only 2 of them are needed for the vast majority of airline flights. In the past, 3-engine or 4-engine designs would be used for airline routes that fly over oceans or over isolated areas where the nearest available airport in case of emergency is very far away. For further information about this, search for "ETOPS" (which is what the regulation is called). "4 engines 4 long haul" was also a phrase used in the past by certain airlines which preferred flying 4-engine planes, and by Airbus to market the A340 against competitors such as the Boeing 777.

And of course, with a 3-engine design, the only place to mount the center engine and still be balanced, is the vertical stabilizer.

How about, perpetual motion could be possible one day, if only through harnessing gravity of the sun or other drastically more distant force, In terms of our local universe it would be considered perpetual motion, free energy etc.

The freezer is generally a lot colder than outdoor temps even in the winter and amount of water in the lake is significantly greater than what you’re going to freeze in a freezer.

Also water in a freezer is being cooled on all sides. A lake is only freezing because of cold air over the water. There’s no cold air around or below the water

Because is not in contact with the ground, or any warmer/insulated surface. In other words, the water in the freezer is loosing heat all around, not just the top.

Human think he very special. But human just big ape.

They are easier accessible for maintenance under the wings. But the noise is less when they are mounted in the back of the plane.

Because different airplanes are designed differently to account for amount and location of weight, payload, thrust, control, and other flight characteristics to achieve different goals or make different trade-offs, just like how everything is designed.

Why doesn't every car look the same, have the same engine, and use the same tire size?

Wankel enters the chat

Resistance increases exponentially in relation to speed. Kinetic energy is 1/2 M*V^2