How are hexadecimal color codes formed?

One of the ways computers store color information is Red, Green, Blue (RGB) format. What the computer does is it stores a value from 0 - 255 for each of those three colors. Some examples:

0,0,0 = Black

255,255,255 = White

255,0,0 = Pure Red

0,255,0 = Pure Green

0,0,255 = Pure Blue

And all the various combinations of colors in between. As we know, computers operate in 1's and 0's. Bits and bytes. In memory and on disk, it isn't storing numbers from 0 to 255, it's storing a single byte, from 00000000 to 11111111.

Writing out all the bits of a byte can be cumbersome, so hexadecimal is often used, because you can represent four bits with a single hex character, or 2 hex characters to represent a single byte. To show the difference, take a look at some of our previous examples in binary and hex:

Black = 00000000,00000000,00000000 or 0x000000

White = 11111111,11111111,11111111 or 0xFFFFFF

Red = 11111111,00000000,00000000 or 0xFF0000

Much more compact and simpler and easy for computers to read and interpret.

In short, when you see a hex color code, the first two characters represent the amount of red, the second two represent the amount of green, and last two represent the amount of blue.

What would happen if air bubbles from a syringe are not removed?

The main risk with leaving an air bubble in a syringe is inaccurate dosing. With the syringe partly full of air, the amount of liquid won't be accurate to the markings on the syringe.

Getting air into a vein isn't a significant hazard unless it's a huge amount - like a whole drip tube full or someone squeezes a drip bag in, including the large air bubble.

The air will circulate in the veins and reach the lungs where it will lodge and get removed in a few minutes. The lungs will filter out the air so it can't travel to the brain except where there is also a "hole in the heart".

Why do lithium-ion batteries lose their ability to maintain charge after many cycles of charging?

It is due to several things.

The most important is physical. During charging/discharging lithium atoms move from one electrode to the other. The lithium goes into tiny pores in a sponge like electrode, but when this happens the sponge swells up. Repeated swelling and shrinking eventually causes cracking and fractures in the electrode, degrading it.

The other main effect is chemical reaction in the electrolyte. During charging, tiny amounts of electrolyte material undergo unwanted chemical reactions with the electrode chemicals. Eventually the electrolyte gets polluted with all the byproducts of these reactions degrading it.

How can any storage device keep information once unplugged from the computer/power?

Imagine a board with four switches. And each switch has either on or off position.

Imagine there's a bulb connected to each switch. So let's say you have the switches in on, on, off, on position. Logically the second to last bulb is off while the rest is on.

Now disconnect the board from your circuit. Did the switches go back to some default position? No, because there isn't any. They're still in their last set on/off position.

So now you can store the board in your drawer for years and it will still hold the information. On, on, off, on.

Connect it to the bulbs again and you will see what you saw years ago, Bulbs 1, 2 and 4 are on while the 3rd one is off.

So the board was able to hold four bits of information for years without any power source.

Does the human body really have a 24 hour body clock?

Kinda, yes. We have a circadian clock, a biological mechanism that works by releasing certain hormones over a 24 hour period, as well as taking external cues such as the Sun. Without external cues, the circadian clock can actually run a bit longer or shorter than 24 hours, and in babies it's still all messed up (which is why they have an irregular sleep schedule).

Not just humans have a circadian clock, almost every animal does.

This has nothing to do with leap years though, since leap years just add a whole day, not messing with our circadian clock.

What is a magnetic field flip?

The orientation of the natural magnetic field reverses once in a while. The field is currently getting weaker, this could indicate that it will flip in the next centuries.

A weaker field can be bad for some satellites and some astronauts. In rare cases it can affect the electricity grid as well.

None of this is a sudden process. The magnetic field will probably just continue to get slightly weaker within our lifetime.

Does a bullet shot into the air come down with a force strong enough to kill?

If you fire straight up in the air, no, it doesn't fall with a strong enough force to kill. But that's the caveat.  Straight up means the bullet tumbles down and it reaches a fairly slow terminal velocity, no different than if you'd dropped a penny from the same height.

But anything besides straight up (just at an upward angle) and it will still have a ballistic trajectory, will probably not tumble, and it will be moving at a velocity that will kill people.

A few years ago a 12-year-old died on the Fourth of July because a neighbor fired a gun in the air and the bullet came down into the boy's head.
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