Tugging on ropes just without the diesel engines

A small maneuverable boat pulling a slow unwieldy ship goes back a long ways

Age of sail ships used their ships boats for fine maneuvering. They'd drop the boats over the side, tie a rope to them, then some poor schmucks would have go to out and row and slowly pull the ship out of the harbor or back into its specific dock. Age of sail ships were slowwww anyway so if they could only do 1 knot being pulled by 4 dudes rowing that wasn't bad considering HMS Victory was fast with an 11 knot top speed

Another option was called [warping or kedging](https://en.wikipedia.org/wiki/Warping_(sailing)). Schmucks in the ships boat again but this time they're carrying the anchor out, dropping it, and the guys on the ship are pulling the line tight which pulls the ship to the anchor and then raising the anchor so the boat can take it out again.

Once you're near the dock you throw lines to dudes on the ground who have to pull them tight to pull the ship up tight against the dock

>Is this because we are using AC rather than DC, which creates far more and continuous emr and is capable of much greater induction?

You've misunderstood something somewhere along the way. You're throwing out words in ways that don't make sense

First, why are you discussing Electromagnetic radiation(assuming that's what EMR is since its uncommon to discuss) instead of electric field strength?

DC creates a static magnetic field and a static electric field. The strength of the magnetic field is proportional to the current and the strength of the electric field is proportional to the voltage

AC creates a changing magnetic and electric field but the strength of the magnetic field is still proportional to the current and the strength of the electric field is still proportional to the voltage

Inductance refers to how much energy is stored in the magnetic field and is a property of the windings and magnetic core, not the electricity being fed to it

Since the electric field is proportional to the voltage then the AC and DC ones will have the same average field. The AC will start a breakover a bit sooner due to the higher peak voltage, but if it breaks over the DC line won't stop arcing because the voltage never drops to zero. Its actually a lot harder to get DC to stop ionizing the air.

You compromise the spacing

High voltage wires are relying on the fact that air isn't that conductive and takes a lot of voltage to breakdown and let a lightning bolt pass

If you get too close to them then instead of the electricity needing to jump through air all the way to the ground it only needs to jump through to air to you then pass through your far more conductive body and make the final hop to ground.

Air will block about 3,000,000 volts per meter of air. We don't run it close to that limit but you might find a 300 kV line with a meter of clearance, but if you get less than 10 centimeters from the wire you're now close enough that it can blow through the air and hop to you just like lightning hopping from the cloud to the ground.

Normally voltages you encounter are low enough that it can't arc more than a millimeter, but transmission lines can get up to hundreds of thousands of volts which is enough for some sizable arcs

Generally they look at both and publish both

Food and Energy are generally impacted by different factors than consumer goods, but a spike in one of those two could mask the behavior in consumer goods so most inflation charts actually look at 4 things

All items

Food

Energy

All items not including food and energy

If food costs start to climb 9.5% due to a specific set of circumstances but the rest of things are only growing at 5.5% then how much is inflation impacting people? It depends what percentage of their budget is food. The standard weighting for "All items" has inflation at 6% but that really masks the impact that high food costs have on lower incomes and the less significant impact they have on higher incomes.

Its also important to track energy separate because energy costs feed into other goods. If electricity costs increase 10% then that cost gets passed forward in the cost of other products since they now cost more to make so its important to be able to see it as both an input cost and as an end impact on the prices

We know theory and practice don't precisely align in semiconductors. They live on the finnicky edge of quantum physics

Semiconductor devices books will have two charts next to each other. One telling you what the equation says the values should be and one showing you what the actual measured values tend to be. They can be off by >20% at times because exactly where in the silicon crystal that phosphorous atom landed matters a lot

Its a lot easier to fix one problem at a time than 10 problems at the same time

You get up in the morning and your car won't start. You run through the quick checklist. Fuel in the tank? Yup. Key in the ignition? Yup. Battery charged? Nope

So you jump the battery and the car starts and you're off

This is what happens when they slowly go through the process nodes. Each node has a new quirk that needs to be identified, triaged, and fixed and once that's done they can start getting product

Its a lot harder if your car just went through a wild science experiment and won't start. If your battery is dead, ignition switch is broken, fuel pump is missing, and spark plugs are bad its going to be a whole lot harder to troubleshoot that car and get it going since you have to identify and fix all problems before you get any results

It doesn't make business sense to go from 90% yield and then hop to a node with 2% yield that slowly ramps up to 90% over the next decade. Take a sequence of small steps that each have a small step rather than a giant leap that either works or utterly bankrupts the company

>Is there a scientific explanation for why the two are separated in lifestock feed advertising or is it just marketing?

Because they're wildly different in appearance and nutritional content

Grass and Hay are both very bulky but not very nutrient rich, that's why cows have 4 stomachs to help them break down grass and get the nutrients

Grain is wayyy denser in nutrients. A pound of grass hay has about 900 calories for the cow but a pound of feed corn has about 1500 calories, and corn is about 3x denser than hay so the same volume of corn contains about 5x the amount of calories making it a lot easier to fatten up a cow off grains like corn than just grass

The cow is going to eat until its stomach feels full. If you're feeding it grain then its going to eat a lot more calories and pack on a lot more fat than if you were just feeding it low density hay

Siberian tigers only technically live in Siberia

Sibera is all of Russia west of the Ural mountains which is like 80% of Russia's area and like 4000 miles wide

The Siberian Tiger's range is Korea and the edges of China and Russia near there. Technically that part of Russia is Siberia but Scandinavia is closer to New England than the tigers range in Russia

All nukes are meant to be set as airburst, it increases their effectiveness significantly

All nukes also create an EMP but in the thicker parts of the atmosphere it doesn't travel as far and the shockwave greatly exceeds it so it's ignored

High altitude nuclear detonations (100km+ up) create a more wide ranging EMP but if you go up too high it weakens

The nuclear blast fires off gamma rays. These Gamma rays hit air particles in the upper atmosphere and rip electrons off them and send the electrons flying. The electrons then spiral down the magnetic field lines of the Earth creating a very strong very fast moving current that can cover a large distance

In the lower atmosphere the air is thicker so while the electrons still get ripped off they'll pretty quickly bump into another atom and get slowed back down

The contact wires aren't exposed on the wall plug, they're protected inside the outlet

The plug that you're putting in isn't supposed to be energized until its mostly inserted and difficult to touch so the fact that its exposed metal normally is fine. Basically the reason male-male AC plugs are bad is because the violate the rule of keeping energized surfaces out of reach

Small interior pins that lay on pads struggle to carry any significant amount of current without overheating. For anything that you need to pump >8A through you really want a very firm connection which is generally a pin or equivalent with springy metal bits pushing on it from each side to ensure good contact

We do this with wall plugs, the prong slides between two bits of springy metal that ensure contact. High power test equipment uses similar pins that slide into spring contacts.

Time and talent

Just because you're good at acting doesn't mean you're good at business arrangements, negotiation, scheduling, and finding opportunities. And once you start getting jobs you won't have time to look for the next one which could need to be lined up months out

The whole job of the agent is to look for and make arrangements for jobs. They have time dedicated to that task since they aren't trying to shuffle between doing the thing that makes money(acting) and lining up the next job, the thing that makes money for the agent is lining up the next job. They're also going to have the right network for it, again because its what they do. Agencies will also represent multiple people so while Client A isn't the right guy for every job they can still land jobs for Client A and use Clients B-Z for the other openings they're better suited for

Generalists aren't great at any task, this is why we tend towards specialists

They go at pretty slow speeds so the engines are built around high torque and long term reliability

At low speeds, power scales linearly with speed so pulling a plow that takes 1 ton of force at 10 mph requires half as much power as pulling the same plow at 20 mph. If you're only ever going to pull that plow at 10 mph you don't need a huge amount of power, lots of farming equipment doesn't work if you pull it too fast.

Cars and trucks need to get up to highway speeds over a relatively short distance, this is really why we put 100+ horse power in everything these days. You only need about 30 hp to cruise on the highway but doing 30-70 on a short onramp to get up to a safe speed requires quite a lot more power.

When you run a current through a wire it creates a magnetic field. Flip that current on and off real quick and you'll get a vibrating wire. Coil that wire up real tight to make an inductor and now you've got a thing vibrating at a high frequency and possibly having an audible frequency getting kicked off

Coils vibrate, it's just what they do. Normally they're running at hundreds of kilohertz to megahertz so it's way beyond audible range but sometimes it makes the core rattle at an audible frequency, but it's hard to fix by winding differently

Common solutions are a big dollop of hot glue(yeah, just normal hot glue, it's cheap) or dipping the coil/transformer in varnish (clear nail polish). Both solutions just bind things together better so they can't move/vibrate as well

They're not the same reactions

Normal decay is random. A U-235 decays and then nothing else happens, there's no chain reaction

In nuclear reactors the fuel is refined and set up in the reactor so it'll be critical so each atom that splits causes one other atom to split. Now you're not waiting for each one to randomly breakdown by instead trigging a chain reaction that works its way through the fuel fairly rapidly splitting the available atoms into smaller ones. If they need more power from the reactor they briefly adjust the control rods so each split triggers more than one other split to get up to a higher power level then reduce it back to 1-1 to hold at that level. The more power you need to pull from the reactor the faster you need to burn through the fuel

They also don't burn through all the fuel of the fuel rod, but it starts building up byproducts that muck with the power you can get out of it so they have to swap it out. Unfortunately the byproducts are wayyy less stable than the starting uranium/plutonium so now the random decay is occurring at a much faster rate creating a lot more radiation but less useful kinetic energy(heat) from the process. The really angry byproducts are mostly cleared out after a year because they decay that rapidly

The IRS wants their cut, they always want their cut

In general though they don't send the feds after you because laws vary and its a question of what you did and what juridiction and they really don't care. The 5th amendment also protects you from having to say what you did to get that income.

But they can use failure to report illegal income as a way to get organized crime leaders like Al Capone. Some people clearly have significant income coming in yet only a small official income statement filed, the IRS wants their percentage off the rest of that pie

>Tires shocks and brakes all of these other things are usually repaired within a certain cycle of mileage, but the major indicator trying to figure out if a 50,000 mi which car versus 150,000 mileage car, could be incredibly different if I lived in a very urban area and perhaps sat in my car with the engine running for several hours. I'm just confused why this never was taken into account but it seems like from one of the answers that this is kind of just been the de facto standard and hasn't really ever been updated.

Highway miles are easier but only a little and it still depends on soo much. A car with 60k miles driven on a nice highway may be in better condition than one with 50k driven in the city but one with 50k driven on crappy bumpy highways may be in worse shape than the one with 60k city miles in a place with nice roads and no salt. A car with 100k highway miles is still wayyy closer to the end of its life than one with 50k miles of any variety

Each bump, vibration, start, and stop stresses various systems. Highway speeds are easier on the engine and transmission because they're staying in their happy zone but higher speed bumps are harsher on the body and suspension.

The mileage is just a guideline as higher mile cars are in general closer to the end of their life, but you really can't capture all the little differences which is why there's also a quality grade for the condition of the vehicle and you should get it checked out.

You fundamentally cannot make a perfectly accurate pricing tool for cars, there are wayyy too many variables for someone to punch in which is why you generally get a price range and there's a qualitative assessment after that.

Two main things impact phone battery life. First is what charge level it is sitting at, it lasts longest hanging out around 50% state of charge(actual charge level not displayed) and wears out a bit quicker the further from that you get. Second and wayyy more important is charge cycles, your battery has a fixed number of times it can get charged up and down. Using 10% and then charging it back up counts for 1/10th of a charge cycle. Using 40% is 4/10ths of a charge cycle.

Your phone shows you the usable range and not the actual charge state of the battery

0% is closer to 20% charge state and 100% is closer to 80% charge state to leave room for battery degradation, prevent over charging, and extend the lifespan a little. Batteries also charge significantly faster in the middle of their range than at the high end so there's a bit of marketing there.

If your phone has a setting to only charge until 80% then you can use that and it'll charge up and hold it there. It will mildly extend your battery life as charge cycles have a significantly greater impact

If your phone doesn't have this feature then manually removing it from the charger at 80% will just increase your charge cycles causing it to wear out faster. When your phone hits full charge it just runs itself off the charger and the battery sits there full, if you're constantly unplugging it when it hits 80% and doing 3% extra of charge cycles every night because of this then after a year you'll have added another 11 full charge cycles and made things significantly more complicated in your life

You, and most other multicellular creatures, have a heart that pumps blood around your body. This heart is made up of lots of heart cells that can contract when electricity is applied but also make a small amount of their own. A collection of heart cells will sync up and start beating in unison

If electricity flows through your heart it can muck up the signals causing the cells not to beat in the right sequence and either beat erratically or just stop it. This results in no blood flowing around your body and kills you

Small things don't have a heart, they're just a little fluid sack. You could hit them with enough electricity to break down their proteins but you'll have boiled the water inside them first and killed them that way

We have defined it precisely for ease of convention and discussion but its really fuzzy

FAI (International Aeronautical Federation) defines it as 100 km up above mean sea level. NASA and the US Armed Forces use 80 km above sea level.

These are just round convenient numbers to have a threshold. The atmosphere thins steadily as you get higher and higher up so there's no magic line where you're definitely in atmosphere below it and definitely in space above it. The 100 km definition for space comes from an estimate that above that height you'd need to be traveling at orbital velocities to generate enough lift to stay aloft so at that point you're orbiting not flying through the air so its a spacecraft not an airplane.

Aside from a couple test planes like the X-15, most things either operate well under that level (U2 and SR71 could hit about 25km) or well over that level (Low Earth orbit is generally 300-2000km)

Fighting a war on multiple fronts is bad, like if it happens you're probably going to lose bad

Its not considered going to war because considering it going to war is worse for the opponent

If you're Germany (or Russia) and the US is supplying weapons to the UK (or Ukraine) and you decide "that means war!" then congrats, you've overcome America's isolationism and you're now fighting yet another enemy who will commit significantly more weapons and manpower to the fight and speed up your demise. Oh, and its an opponent who had enough economic might they had military equipment to spare

Basically, its not considered going to war because that doesn't help the person who isn't receiving the weapons

We don't need to know the exact values which is nice

If you have a diesel engine or similar putting mechanical energy into a spinning generator and then you increase the electrical draw on that generator, it'll slow down. You can either accept the slower generator which changes the frequency or increase the power being supplied to the generator by the diesel engine. If you reduce the electrical load then there's less push back and the generator will speed up.

Thanks to this you don't actually need to know how much mechanical energy is being put into the generator or how much electrical energy is being drawn from it. You only need to make sure its spinning at 3600 rpm (60 Hz for North America, its 3k rpm for Europe and 50 Hz systems). If it spins too fast then put less fuel into the systems that are powering the generator. If it spins to slow then increase the mechanical energy you're supplying.

The generators can only tolerate a fairly small change in frequency (<0.5 Hz) so overall production and overall demand needs to be pretty similar, but you can figure out how much was consumed later as long as you add fuel now to manage the slowdown of the generator.

Its a measure of efficiency to allow people to compare the energy consumption, they're rated in MPGe (Miles Per Gallon equivalent)

Why list it as Miles per Gallon instead of kWh/mile or miles/kWh? Because they did some surveying and determined people don't know what a kWh means in terms of their car and found MPG less confusing and consistent with the existing markings

121/91 MPGe city means the Leaf used 0.278 kWh/mile on the city driving test and 0.370 kWh/mile on the highway test

It doesn't directly compare to the costs/CO2 emissions of a gasoline powered vehicle because it doesn't deal with the upstream power generator efficiency but its a start and allows for comparisons of efficiency between electric cars beyond just the stated range which is heavily influenced by overall battery capacity

The rocket equation is a butt and as mass/gravity scale up you start needing a rocket the size of the Saturn V just to put Sputnik into orbit

Earth having a 50% greater diameter means it has 3.375x the mass because mass scales with volume and that results in a surface gravity about 50% higher (~14.7 m/s^2 )

That higher gravity means that you need stronger(heavier) rocket engines since a rocket needs a Thrust to Weight ratio of at least 1 to leave Earth and if we still with Earth weights it'd need a TWR of 1.5 to leave the bigger Earth. The Saturn V rocket had a TWR of 1.02 at launch so it'd never make it, and the Falcon 9 is pretty zippy off the pad today but it only has a TWR of 1.4 so it would also never make it.

This then pairs with the tyranny of the rocket equation where the higher gravity means we need to go faster which means we need more fuel which needs to be lifted with more fuel and you need to lift that fuel with more fuel. Today the ISS orbits at a speed of 7.66 km/s, but around our new Earth even at the same 400 km up it'd need to be going 11.6 km/s and it'd take a bit more to get to orbit

Today it takes about 10 km/s of DeltaV(how much a rocket can change its speed, basically range) to get from the surface to the ISS, that means lifting 1 ton requires 29 tons of fuel so the rocket is 96.66% fuel. If you need to get up to 14 km/s then the rocket needs to have 115 tons of fuel(99.1% of overall mass)

So we start needing more fuel just to get to orbit and stronger rocket engines which require yet more fuel which means stronger heavier engines and more fuel and more fuel for the fuel....

The threshold is that there's less than X% chance this occurred due to random events unless we mucked something up

Replication is critical for showing that something weird actually is happening and there isn't a quirk in the setup.

If you're testing say a sweet electrically powered EmDrive that could be used on spaceships and your test measures something well above the noise floor of the system then the drive works! Right? Mmmm but what if those big ol' power cables happen to be interacting with the Earth's magnetic field? Whoops! Drive is garbage, and the setup had a parameter that wasn't accounted for!

Or maybe you measure some neutrinos traveling faster than the speed of light! But you forgot to account for the time to sync the clock on the surface with the one underground resulting in all of your time measurements on just one end being offset

Just because you can do something once doesn't mean you did what you intended to do. There are plenty of experiments that have produced the desired result because that's what people wanted to happen but were unintentionally setup incorrectly or had quirks which made it look like the desired result was real even though it was something unrelated

New elements are unlikely. We've already filled the periodic table for everything with 118 protons and below. As far as we can tell all the heavy elements are crazy unstable so its unlikely you could craft anything useful out of them. We haven't made anything over 100 that has a half life over a year so whatever you create will be extremely radioactive and change its properties very quickly

That said, new compounds/alloys/chemicals are found/created/designed fairly regularly. Alloys of steel with various quantities of nickel, chromium, molybdenum, and other metals are created all the time with slight to significant changes in the properties either making it harder or more flexible or more durable or better tensile strength or more corrosion resistance

There are a ton of different ways to create crystal structures out of atoms, we haven't created anywhere near most of them yet so there are still some oddballs out there with fun properties