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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.

Why are humans more energy-efficient in running than animals with four legs?

The really simple answer is that humans run more efficiently because we let gravity do a lot more of the work. When we go forward we’re basically putting one foot out and falling forward, then pulling ourselves forward and repeating the process with the other foot.

When quadrapedal animals run, they need to propel themselves forward with their front and back legs; the advantages of this are that they can put more of their total muscle mass into running and you get more sources of speed, and run faster/quicker; pretty much any quadraped can out-sprint a human. But humans are the undisputed champions of distance-running on Earth, partly because their run is more energy efficient.

The other thing that helps us run, just as a sidenote, is the fact that our bodies are really good at not overheating. A cheetah for instance can only keep up their vaunted 60 mph run-speed for a very short distance without overheating and exhausting themselves. But our ability to have the airflow of our forward motion wick heat away by evaporating sweat off of us is one of nature’s best heat regulation mechanisms, and allows for humans to run for hours on end without stopping, when properly trained.

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.

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 did sexual reproduction first develop in animals?

It is difficult to definitively say how it first came about, but there are some key factors that can be used to determine.

First, the main difference between sexual and asexual reproduction is that sexual reproduction “reorganizes” the parent DNA into a new pattern, while asexual is essentially the parent self-cloning. By being able to reorganize DNA, sexual reproduction had an advantage over asexual reproduction because it caused more mutations to occur in the DNA. This leads to a higher chance that a mutation will be beneficial to the organism, especially because the baby organism gets two sets of DNA to choose from, doubling its genetic resources. It also means that if one parent has a successful mutation that the other parent does not have, the baby organism will have a better chance at acquiring that mutation.

Second, we know that with two (or more) sexes, one sex must be more involved in the reproduction than the other. In most species, this is the female organism, which is able to do the reproductive work of bearing young. The male organism can merely contribute DNA, but does not actually bear young. With 50% of the population unable to make the babies, conditions must be good enough to allow the other 50% to reproduce often enough and quickly enough to maintain the whole species’ population. This means temperature, food sources, and safety from predators or environmental threats needed to be ideal.

We can break down the evolution of sexes a bit more; there is a term “anisogamy” which means reproduction with sperm and egg. This first evolved in tiny cells that contained only one set of chromosomes. Chromosomes are chains of DNA. When the cells would reproduce, the egg would provide one chromosome, and the sperm would provide a different chromosome. For a brief period, the baby cell would contain both chromosomes, and after a short period of development one of the chromosomes would “win” and that chromosome would become the DNA pattern that the new cell would eventually pass onto its own young.

This “anisogamy” developed when two compatible cells evolved, that were slightly different but able to mate with one another. In the first tiny cells that accomplished this, they were too similar to really be called “male” or “female,” but the difference was enough to spark the eventual evolution of male and female.

So, to recap:

Single cells would split in half to reproduce. Then, cells evolved a few changes, and this resulted in different types of cells that contained different sets of DNA. While some of these evolved cells eventually split off into entirely new species from the original cells, some others retained a special compatibility that allowed them to share their DNA, and they could mate with each other. Exactly how they started the ability to share the DNA (i.e. physically have sex, since they did not have vaginas or penises at that point) to make offspring is difficult to know for certain, but it may be similar to how some species of bacteria can “conjugate” or stick together to create new DNA combinations. A bit like the thing absorbing nearby cells and acquiring their DNA. So, the two new types of parent cells were able to provide not one, but two sets of DNA for their offspring to choose from. The offspring would typically end up with the most successful (dominant) DNA. This gave the offspring a better chance at surviving and reproducing, and this adaptation was so successful that it developed into fully fledged male and female versions of a single species.

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 the difference between Savings account and Checking account?

A checking account:

– usually accrues no interest
– can used to pay bills via checks, debit card transactions, and ATM withdrawals
– usually has no limit on the number of transactions that can be done

A savings account:

– accrues interest (though not much these days)
– typically limits the kind and number of transactions that can be done with it

So basically a checking account is where money for your day to day payments flows through, while a savings account is where you keep your savings.

In the US, when you put money into a checking account, the bank has to keep 10% (unless it is small bank, then the number is smaller) in reserve, and it can lend out the rest to people seeking loans (as long as it meets other conditions not relevant here).  If you put money into a savings account, the bank can lend out all of it without keeping any in reserve (as long as it meets other conditions not relevant here).

So, the bank can lend out more of the savings deposits than the checking deposits, which makes savings deposits worth more to them.

Because the regulators impose these differences in regulation between the two accounts, they don’t want banks to create something which is called a savings account but acts like a checking account.  So they have regulation D, which forces banks to limit savings account, such as “6 transactions per month” limit.

What is BitConnect and how people lost all their money on it?

BitConnect was a ponzi scheme using their own cryptocurrency, the BitConnect coin. Ponzi scheme means that a company offers a supposed investment opportunity to its customers, promising above-average returns (in this case 40% per month). They intend to make good on that promise by attracting more and more investors, so that the payouts can be paid by an ever increasing stream of money. In order to make this possible, they rely on multi-level marketing: They encourage the investors to do the marketing for them, by telling their friends, family and online communities.

The end-game for a ponzi scheme is that at some point, when no more people come in and investors start demanding money, they go bust. But not before the people who created it all siphon away all the money they can.

The way this worked here was that people bought the BitConnect coins with BitCoins, and then “lent” it to the BitConnect platform. At the end of it, investors wouldn’t get back their money in BitCoins, but the BitConnect coin – which is pretty much worthless everywhere else.

So what happened was that BitConnect grew so big that it attracted media attention, and people rightfully called it out for what it was. Due this and the recent Bitcoin crash then, they decided to close their platform, presumably keeping a lot of the Bitcoins that people gave them for their worthless cryptocurrency.

If photons (particles of light) have zero mass, how can they exist?

It’s very natural here on Earth to equate the word “mass” with the word “weight.” In fact, in our everyday lives, we can usually get away with using the two terms interchangeably. A massive thing is also going to be heavy.

It’s actually more accurate to define mass as “how much work it takes to push the thing down the road.” Again, very similar to “weight,” just a subtle distinction.

If I’m trying to push an elephant on roller skates down the road, and attain a speed of, say, 35 miles per hour, I have to do a lot of work.

I can either do this work all at once, maybe by firing the elephant out of a cannon, or I can spread the work out over time, pushing the elephant gradually faster and faster until the desired speed is attained.

Later, I can calculate how much work it took to get my elephant up to speed. (There are measurements for this stuff like joules and newtons.) In the end, I will find that, regardless of my method — either shooting the elephant out of a cannon, or slowly pushing it — the amount of work required to reach 35 miles per hour was exactly the same. It takes a certain, specific amount of work to get an object of a certain mass up to a certain speed.

With a massless object / particle like a photon, there’s no work required at all. The photon does not have to “explode” out of its flashlight as though it was shot from a cannon, it does not have to gradually accelerate over time, it’s already there. The “work,” in a sense, has already been done. That is also the reason photons are always moving at 300,000 km/s. They never speed up or slow down, they pop into being already traveling at the speed of light.