You're supposed to lean against the wall to try and point it downward as much as possible before you force it out, doesn't get in the eyes this way.

Thank You! Makes packing a lot easier

> Great read but ain’t no five-year old gonna understand that!

Good thing the sub's rules explicitly say that's not what it's for then.

Thank you so much!

The first letter, U, in USB stands for universal. As in, it can take power from anywhere.

I've traveled to France, Malaysia, Hong Kong, Japan, etc and all USB plugs are the same and I can draw the exact same amount of power from them. You might want to buy a travel plug adapter, but what comes out the rectangular USB side is the same

Yes, the USB cable is carrying 5 (or 9/12/15/20) volts direct current. Thr job of the charging brick plugged between the USB cable and the wall is to regulate AC power down to direct current for USB

So USB has its own voltage and the 120/230 v doesn’t matter so much with USB?

The AC side voltage/frequency doesn't matter as long as you have a wall adapter that works for that situation. The device being charged sees a USB power source and doesn't care what's driving that.

(Also note that many, but not all, common wall-plug USB power supplies are natively designed to work under both voltages. It's usually just matter of having the appropriate plug adapter to connect the pins from whatever sockets are used abroad)

And it makes my eyes water

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

After ejaculation, the body undergoes a refractory period. During this time, the penis will become flaccid and the body will release a chemical known as prolactin to help suppress sexual arousal.

When trying to urinate immediately after ejaculation, the muscles that control urine flow are still under the influence of the refractory period and may not be able to fully relax. This can make it more difficult to urinate, and in some cases, it may result in urine being expelled with less force or in smaller quantities than normal.

Big boom makes zappies move better higher up

Great read but ain’t no five-year old gonna understand that!

Seriously though, I can’t see how this could possibly be explained at a five-year old’s level.

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The explosion itself isn't the source of the EMP. Its immediate aftermath is.

The high-energy gamma rays emitted by the explosion strike electrons in the gas molecules in the air. (And any molecules on the ground, too, but the air will be what's relevant for our purposes.) This briefly turns the air into a plasma, with free electrons moving at high speeds from the huge kick they got from absorbing a highly energetic gamma ray.

In the lower atmosphere, the air is dense enough that these free electrons cannot travel very far. But in the upper atmosphere, their mean free path (the average distance they can travel without colliding and recombining with an atom) is rather long, on the order of a hundred meters or so. That's far enough that the electrons can interact with the Earth's magnetic field.

As the electrons travel, they start to move in loops under the influence of the magnetic field, as any charged particle would. Since the electrons are traveling at relativistic speeds, this produces synchrotron radiation, in much the same way that a boat speeding through the water creates ripples. This radiation is spread out at all wavelengths of light, and radiates outward from the moving electrons until they recombine. Since the electrons are traveling at relativistic speeds with a mean free path of ~100 meters, this recombination happens in on the order of a microsecond.

Since the electrons emit all their radiation within such a brief time, and since this is happening on the shock front of the original emitted gamma rays, the radiation from the electrons closest to the blast travels essentially along with the shock front (since they're only nanoseconds behind the gamma rays that weren't absorbed). As the gamma rays continue to travel, they knock more electrons free, and the synchrotron radiation from those electrons stacks on top of the synchrotron radiation from the previous ones.

All this radiation adds up, forming a shock wave of light at all parts of the spectrum - that's your EMP. (Or rather, it's the first and most damaging of a couple of unrelated EMPs.)

In a ground-level or lower-atmospheric blast, however, there are two differences:

• All the gamma rays are quickly absorbed by nearby air, within a few kilometers. That means essentially all the gamma rays are absorbed near the ground, where the air is dense. The mean free path for electrons in such dense air is much shorter, so they have much less time to emit synchrotron radiation.

• What radiation is emitted only hits targets within line of sight of the immediate shock wave, i.e., within line of sight of a few kilometers above ground zero. The horizon from a few kilometers up is not that far away, so the effects of the original blast tend to be more important than the EMP at that range.

But if you detonate a nuclear weapon at high altitude, ~half of its gamma rays will be absorbed in the upper atmosphere (since the Earth occupies ~half of its lines of sight, just as the ground and sky occupy half on the ground). Those electrons all get the nice long mean free path, and the EMP is emitted at such a high altitude that the horizon is hundreds if not thousands of kilometers away. You generate a potentially massive EMP that can affect an entire continent, which is far beyond the direct blast range of even the largest nuclear weapons.

> That is one of the questions where you say, "that is just how it is.".

It's not so much "how it is" as that it's a specific choice of coordinates. The electric field is simply the part that, in a particular choice of coordinates, does not depend on motion. Changes in coordinates to a moving observer will "mix" the electric field into the magnetic and vice-versa.

You can do electromagnetism with fields other than the electric and magnetic fields and get the same result. In fact, if you're a moving observer, electric fields will start to generate magnetic fields and vice-versa.

In reality, electric and magnetic fields are underlying manifestations of the same (coordinate-independent) underlying "thing". This thing, electromagnetism as a unified object, is more properly described by the four-potential, of which the electric and magnetic fields are parts. We call the part that doesn't care whether you're moving "electric" and the part that does "magnetic". But that is only a choice of coordinates, in the same way that you can do your linear algebra with <1,1> and <1,2> as basis vectors rather than <1,0> and <0,1> and everything will work out fine.

It turns out that you can, in a sense, decompose any (non-changing) vector field this way into an "electric-like" field and a "magnetic-like field", in the sense that these fields share some of the important mathematical properties of the electric and magnetic fields respectively.

> To (over)simplify the math, the curl of a thing is perpendicular to the thing

That is not true.

For example, if F is the vector field sin(x) i + 3 k, we have:

• curl(F) = cos(x) k
• F dot curl(F) = 3cos(x) != 0.

Nonzero dot product -> not perpendicular.

They aren't, unless you're talking about an electromagnetic wave in vacuum. For the case of a wave, the magnetic field comes from the changing electric field, and the electric field comes from the changing magnetic field. Maxwell's equations tell us then that the curl of E looks like the changing magnetic field, and the curl of B looks like the changing electric field. To (over)simplify the math, the curl of a thing is perpendicular to the thing, so that's why the magnetic and electric fields are perpendicular in a wave.

Coming from an employee perspective, I would much rather work for a company that views me as a whole person, with a life outside of work, than a company that sees and treats me as just another cog on the gears of the machine.

Sometimes its also about making a profit for as long as possible, which means giving up a little profit now to keep the business operating for a longer period of time. Look at something like FTX vs say, Wells Fargo. The owners of FTX made an absolute shitload of money, but it is all gone, with basically no hope of ever recovering it. Wells Fargo over the same time period may have made less profit, but they are still open and conducting business. The owners of Wells Fargo are currently making quite a bit more profit than the former owners of FTX.

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