> To get a single-cell battery

Strictly speaking, a "single-cell battery" is an oxymoron. The word "battery" means a group of things working together so, while a 9V battery is a battery of six cells, a AA is one (electrolytic) cell and not a battery.

The word originally comes from batteries of guns which were used to batter down fortifications.

Radiation is a severe problem for the Galilean moons except for Callisto. You could probably live metres underground on Ganymede to be adequately shielded but you'd have to arrive and leave very quickly. Only a few days on the surface, or in transit on a spacecraft, would result in a fatal dose of radiation. That's not the kind of problem that you can work around with genetic engineering. Even on Callisto, radiation is over ten times higher than on earth but at least its gravity is 0.13 G.

The non-Galilean moons are all tiny—at least four orders of magnitude less massive—with the surface gravity on Himalia only 0.006 G. Better to choose one of the dozens of larger asteroids which avoid the complications of Jupiter's gravity well.

Another amazing technology that helped beat the kamakazi attacks was the proximity fuse. Without that, you have to set your AA shells to explode at some fixed time from firing which is hard to get right against incoming aircraft. Proximity-fused shells would automatically explode when they got near something—a huge advantage—but it involved having vacuum tubes survive being fired from a gun.

> Can lunar gravitational forces affect the inner ear?

Technically yes, because gravity reaches infinitely far. Practically no; the moon is 80 times less massive and 60 times farther away than the earth, meaning it affects us 300 000 times less strongly. That's far beyond the sensitivity limit of the human saccule and utricle.

The more photosites, the higher the resolution. The bigger the photosites, the more sensitive they are and therefore the less noisy they are. It's up to the designers to balance resolution and sensitivity for their designs.

It's possible to take a high resolution image and reduce the noise by averaging neighbouring pixels which also reduces resolution. So, to some extent, you can do the trade off in software. You still lose out with very small photosites because the borders between sites are a fixed width, meaning a bigger percentage of the sensor isn't detecting light. Also, reading out more pixels takes longer which can limit camera frame rates and use more power, causing issues with overheating for video applications.

> the lunar schedule of 13 months of 28 days which is 364 days

Except that synodic months actually last 30 days, not 28, and there are nearer 12 of them per year than 13.

Car brakes are good enough these days to apply maximum braking force short of locking up in almost any situation. ABS then means you can just stomp on the brakes for the best result. The exception would be if your brakes were failing due to overuse, say on a long steep descent. In that case you should have been changing down gears to use engine braking to prevent the brakes from overheating in the first place. You can do that even with an automatic gearbox. In an emergency stopping situation, even the best driver is going to struggle to shift down fast enough to help, short of real flappy paddle gear changing and/or extremely high speeds.

If the speed doubles and the force required quadruples, then the power goes up by a factor of eight. This is because power is proportional to force times speed.

The above is true for air resistance and water resistance, where drag is proportional to speed squared. I found a publication linked in this thread that says the same is true of plowing, but another commenter found a paper with experimental results showing the force required increasing much more slowly with speed. If so, plowing is not like fluid resistance and the power required increases even less than the square of the speed.

Looks like you're right, in fact it shows closer to a power of 0.33 than 1, and far from 2. Neither document goes into the physics involved.

Note that air resistance is only proportional to the square of the speed, so the heading of the linked article is incorrect. Resistance is a force. It's power that goes with the cube, because it's proportional to force multiplied by speed.

As plowing speed increases, draft also goes up, but usually varies as the square of ground speed. In practical terms this means that by doubling the ground speed, say from two to four miles per hour, the draft increases four times.

Objects being out of focus is due to them being viewed from multiple locations, i.e., by all the points on the surface of the lens. Pinhole cameras, which have just one tiny hole instead of a lens, see everything as being in focus but, of course, the image is extremely dim. You need a lens to gather more light but then you need to choose the distance to focus on. The bigger the lens, the smaller the range of distances that are in focus at once. Photographers call this range of distances the "depth of field" and they know that adjusting the "aperture" of their lens (the size of the hole in the lens) will control the depth of field.

This is also why focusing is easier for people in bright sunlight, because then their pupils shrink down to a small hole. In dim light with large pupils, focusing needs to be more accurate.

Horsepower is the actual power of the engine. Torque is the twisting force. Multiply torque by RPM then by a conversion constant and you get horsepower.

> horsepower is a measure of work done

Horsepower is a unit of power. You need to multiply it by time to get a unit of work (AKA energy).

If pulling a plow requires 1 ton of force at 10 mph then the same plow in the same ground is going to need around 4 tons of force at 20 mph. This means that doubling the speed requires eight times the power.

So made between the German surrender in 1945 and the formation of West Germany (from the US, UK and French occupation zones) in 1949.

Mostly conduction, meaning the particles of the hot gases of the flame are moving very fast and keep bumping into the steel particles.

Static (stationary) friction is stronger than kinetic (sliding) friction. In other words, once two objects start sliding past each other, the friction between them is less than before. Also, once motion has begun there is momentum which will tend to keep it going.

Digits are usually represented by their ASCII code, with '0' having code 48 (binary 00110000) and '9' having code 57 (binary 00111001). So for a single digit the first step is to simply subtract 48. That would convert your '4' to binary 00000100.

For multi-digit whole numbers, the computer works from the first (leftmost) digit. For each ASCII digit it subtracts 48. If there's another digit following it multiplies its current answer by ten then continues, adding future digits to the total.

So, for '1234' (ASCII 49, 50, 51, 52) it goes:

• 49 − 48 = 1
• ×10 = 10 (binary 1010)
• add 50 − 48 = 12 (binary 1100)
• ×10 = 120 (binary 1111000)
• add 51 − 48 = 123 (binary 1111011)
• ×10 = (binary 100110011110)
• add 52 − 48 = 1234 (binary 10011010010)
• No more digits so we stop there.

And The Rings of Power went all the way to 2.39:1. Is that a first for a TV show?

Movies now are generally 2.39:1 or 1.85:1 whereas the 16:9 used for TVs is 1.78:1. So TVs are actually very close to one of the common cinema aspect ratios; the movies are only 4% wider.

The amount of data being transmitted is tiny so the communication speed is not an issue. Contactless wins because you just have to position the card reasonably close to the reader. For contactless you have to align the card in a slot and insert which takes longer.

The brightest rainbow always has the same colour order, with red on the outside, but in ideal conditions a secondary rainbow can become visible outside the primary. The colour order of the secondary rainbow has the red on the inside, the opposite to that of the primary.

The reason for the difference is that the secondary rainbow involves the light being bent through more than 180°, i.e., it's bent back on itself.

This is a great point. If they're going to quote miles per gallon as a fuel efficiency figure then they also need to prominently display the battery capacity in gallons. Multiplying the two numbers should give you the range in miles.

At some point it will make sense to change to kW-hours but not while the great majority of cars still run on gas. It's the same with light bulbs where people know how bright a 60W incandescent bulb is but still don't know that that's about 800 lumens. Some LED bulbs are marketed with incandescent-equivalent wattage more prominent that actual wattage.

Adding to the other comments, tidal forces follow an inverse cube law, not an inverse square law. The reason is that they're caused by differences in gravity, not just gravity itself.

As evidence of the cube law, we feel tides from both the moon and the sun, but those due to the moon are about twice as strong. The sun is almost 400 times farther away than the moon but its mass is 27 million times greater, i.e., roughly half of 400^(3).