My Day In A Few Words

My Daughter Asked Me


My daughter asked me why a green filter doesn't absorb the green light and let the rest pass through. That is a light source minus its green element.

Most filters absorb some color(s) strongly, and what is left is both reflected and transmitted. So a green filter will absorb both red and blue light, and of the green light it doesn't absorb, some will be reflected and some will be transmitted out the other side.

There are some filters, called dichroic filters, which work by reflecting some wavelengths and transmitting different ones. So these filters will look different colors depending on whether you are looking at it, or looking through it. We tend to name these according to what light they allow through, so a "green" dichroic filter would allow green light through, and reflect purplish light.

To look at it a little bit differently you could say: Green filters are green because the light being reflected off of it and reaching your eye is green. If the original light was white, that means the green filter absorbed every other color except for the ones that make green.

So, its the exact opposite of what you were thinking. The Green filter is green not because it absorbs all green light, but because it reflects all green light. (which I believe means it absorbs Magenta light, leaving Cyan and Yellow light alone, and Cyan + Yellow = Green)

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These Are The Moments Of Our Lives


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There are 2 major factors that affect the passing of time.

  1. The amount of information your brain is processing
  2. Your Memory

Number one determines primarily how fast the seconds feel, while two is how long the minutes and longer time intervals feel.

Generally though, The more information you are processing, the slower time feels to be flowing. if normally, you get 1 unit of information a second, but during a period of adrenaline, you get 2 units of information in that one second, then naturally, it will feel as if that one second took longer to actually happen. This is related to the famous "bullet time" idea. Situations you would think time would slow down, are normally Adrenaline rich, dangerous, or the like, and our brains process as much as they can to deal with the situation.

Memory on the other hand determines how fast the longer times feel. The more you remember, the longer it feels. Sleep is the best example, because you remember nothing, except for maybe the last dream you have (which conveniently, you will always wake up in the middle of). So you fall asleep, and wake up, hours later, but have no memory of the time between it. As such, hours passed in what feels like an instant to you. When you are learning things, you are committing not only the natural experiences to memory, but the information. The extra memories will overall increase how much time it feels like passed.

There is really only one kind of exception to this, once you hit months and years, as you get older, they tend to feel faster. This is usually attributed to the fact that when you are 60 years old, one year is just 1/60th of your life, but when you are 5 or 10, its a whopping 1/5th or 1/10th of your life, far more. You also tend to be learning a lot of things as a child, which also will attribute to how it long it felt. Generally though, you remember less things as an adult as well, again with the learning things as a child.

So, how does this relate to being Drunk. Alcohol impairs your senses. Your brain is physically unable to process as much sensory information as it normally does. So individual seconds are going to feel faster, since there is only say, .5 to .75 units of information instead of the normal 1. It also inhibits memory. As such, you tend to forget far more things, so 10 minutes may pass, but because you cant remember what you did for those 10 minutes, they are kind of like those sleeping minutes, lost.

If you want a good video example about how memory affects perception of time, Vsause's new Youtube Red series Mind Field, has a free episode called Isolation. The host goes into a torture chamber of sensory deprivation called the White room for 3 days, and has No clock at all. Having no way to tell the time, he could not properly keep track of the time. He went to sleep shortly after starting, but after waking up about 5 hours later at 5AM, thought it was 8-9AM. Then at 11:30 AM, a mere 6.5 hours later, he thought it was 7-8PM. The massive lack of sensory information heavily distorted his ability to keep track of time.

Though you could attribute this to his mental confusion after 2.5 days of white torture, he did think over 72 hours had passed and they forgot about him 67 hours into the experiment.

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Did You Know Sharks Never Sleep?


For one thing, not all sharks have to keep swimming to continue "breathing". Nurse sharks, for example, can and do sit on the bottom all day with no trouble. As for the sharks that do swim all the time, a quick Google search suggests that there's no clear answer on whether or not they sleep at all or how to even define "sleep" for them.

However, dolphins have similar breathing troubles as sharks because breathing is always under conscious control for them (i.e. they only breathe when they think about it) so they'd drown if they fell asleep like humans do. Since dolphins are so much easier to study than sharks (sharks can't be trained to cooperate with researchers), we know that dolphins get around that problem by only sleeping with half of their brain at a time. At such times they have only one eye open, they tend to hang out at the surface, and they can and do move around sluggishly.

I know I didn't mention about dolphins in the title, but since there's no answer for the shark question, I figured I'd throw it in as lagniappe.

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Why Do We Use General Temperatures


You may have noticed most temperatures for food and other baking in the oven don't range below or above a scale of temperatures despite the oven being capable of them. Would you like to know why?

When you cook, you're trying to get heat from outside the food to inside the food.

There's lots of different ways to do that. Baking in an oven isn't actually very efficient! You can sear a steak on a very hot skillet in 2-3 minutes, but baking the same steak to the right doneness might take an hour in an oven. Because the oven's so bad at getting heat inside food, trying to turn the heat to the same levels as the skillet will leave you with a completely burned outside and a near-raw inside in a hurry.

There's also certain chemical things that happen in food when we cook it. At very high temperatures, beef "browns", which creates very pleasant and complex flavors. That's why fancy steaks are almost always seared. You can bake a smaller steak in an oven, but you'll never quite get the same kind of flavor that searing creates. Low temperatures also do things! Pot roasts are generally tough cuts of meat, but after being kept in a slow cooker at around 200 degrees for hours, the heat will have broken down much of the tissue that makes the meat tough and turned it into a tender, tasty meal. Brisket and many other cuts are almost inedible unless cooked this way.

That's beef, though. Why do most of the things we cook fall in the 350-425 degree range? Well, I'm thinking of a lot of the things I throw in the oven. Frozen pizzas, frozen snacks... I'm not trying to cook those so much as warm them. But "hot air" isn't super good at getting heat inside food. So if I crank the heat up too high, I'll burn the outside and have a frozen inside. (Microwaves are the opposite: they're better at getting heat inside food.

That's why pizza rolls take 20 minutes in the oven but only 2 minutes in the microwave. But that kind of 'heat' isn't so good at browning, so it never crisps them quite right, does it?)

That's what's going on with a lot of foods, too. Go much hotter than 425 and the heat can't penetrate the food fast enough to stop you from burning too much. Go much lower than 350 and it's going to take hours to heat the food enough, and in many foods like bread it might be important to generate some steam before certain reactions finish. That's why a lot of instructions for baking turkeys suggest cooking at two different temperatures. In one phase, the goal is to slowly get heat inside the turkey without drying out or burning the outside. In the other phase, the goal is to brown the outside to create more flavor.

In general, I wanted to cover "high heat burns the outside before the middle gets hot enough, low heat takes too long and can't brown". It's not an exhaustive guide to the science of cooking. There's lots of dishes that can't take 300 degrees, lots of processes like denaturing proteins I didn't get into, etc. I already feel like the post is too long for, I couldn't talk about every potential interaction.

Similarly, I appreciate corrections on how microwaves work, but again that was really a one-off example. I know about how microwaves excite water molecules, and that moisture content matters, etc. It's still true a microwave can cook, say, a chicken breast much faster than an oven but in so doing you miss out on things like browning. All of this makes the post even longer and distracts from answering, "Why do we bake things within a specific temperature range."

Sometimes, when explaining complicated topics to people who want a rough answer, it helps to make gross oversimplifications. I think is far more appropriate for the level of detail most of you are striving to find!

And yes, I do cook more things than pizza rolls. But it's a lot easier for people to relate to pizza rolls than "that time I made spanakopita", and if I'd started talking about baking bread I'd have been WAY too encouraged to get into the chemical details.

Cooking often involves a LOT of complex chemistry, and delicate balancing acts of temperature.

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Are Fats And Sugars The Same


Are fats and sugars the same in regards to calories?

No.

Not exactly.

Your body can't convert fat into sugar, but it can convert sugar into fat with insulin. Every cell in your body uses ATP as an energy source and it creates this either through glucosis or the Krebs cycle. The first simply converts sugar (glucose) and ADP into ATP. It's not nearly as effective as the Krebs cycle which converts oxygen, ADP, fat, and carbohydrates into ATP and CO2. You must have carbs in your system for the Krebs cycle to work. In absense of carbs, your body will use protein instead and produce ketones as a byproduct.

Some of the calories need to jump through some extra hoops to be used by the body, some sources have secondary effects that are beneficial or damaging to the body. Fructose for instance bypasses regulatory mechanisms and may lead to faster onset of diabetes as compared to say, glucose. Fat needs to be absorbed through the intestine, and this process isn't as efficient as most sugar's almost immediate entry to your bloodstream.

That being said, at it's heart, keeping track of the calories alone, and making sure that calories in is smaller then calories out is all you need in order to lose weight. The difference in metabolism is small in comparison to the effects of overall caloric restriction, but there are some foods that help make those limited calories feel more filling.

So as we have learned the calories themselves are exactly the same, as it is a measure unit for heat produced. The same mass of sugar and fat don't contain the same amount though. More importantly, both are processed differently in the body, so if you eat 500 kcal of fat you'll gain less weight than if you eat 500kcal of sugar, because of stuff like insulin and your liver processing sugar to produce fat. In short, the fat of your body is not so much the fat that you eat rather than the fat that your body produces from the sugar you eat.

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Made From Concentrate


Part of the reason juice companies use concentrate is so that they can keep their juice tasting similar throughout the season, despite different types of oranges being harvested from different countries even. By mixing the concentrates, it gives a uniform blend to their juice throughout the year. For example, when the winter oranges are harvested, part of their juice is added to summer concentrate, and part of it is frozen or canned. Then during summer, vice versa.

For soaps and such, it just means it's more concentrated, as the name would imply. Dish soaps and laundry detergents are typically mostly just water. The water added makes it mix easier and measure out easier. It also makes it look like you're buying more of something on the shelf, so you think you're getting a better deal (12oz soap for $1 vs 24oz for $1).

Most of the top juice replys are somewhat wrong. Juice (like orange juice) goes bad after not too long, even stored and refridgerated, and orange growing season is not steady all year. So science (florida university in the 1940's) figured out that heat and pressure can remove most of the water and many other compounds/nutrients from the juice to store for much longer, and then add it back when they need to use it. This leaves it tasting not the same as fresh squeezed, though.

Also, "not from concentrate" juice isn't really much different. Instead of freezing after removing water, they de-oxygenate it and store it as a liquid. This also strips much of the flavor and vitamins out of it, which are added back (usually added back from extractions of the orange peels. This is for concentrate and not from concentrate.) to it after being stored for up to a year.

Concentrates of liquids like dish soap and juices take up less space on shelves, and in the case of dish soap it cleans better with a smaller amount when it's concentrated. As for juice, it's easier to get a taste you like if you start with concentrate, since you just keep adding water until it tastes best.

For cleaning products, I suspect it is marketing. The thinking with that would be we assume and associate concentrate with with being stronger, so a concentrate cleaning product must be X times better than a non concentrate product.

For juices, again it can be marketing. But for juice from a supermarket has no concentrate. If it did, it would be a fruit drink, not fruit juice. A fruit juice has 100% fruit juice, a fruit drink has some fruit juice (usually not much) + all these additives, sugar etc. In this context concentrate means they have taken some water out of the juice to make it stronger. They've then put some of this concentrate juice into the drink along with other things to make a new fruity drink.

Another possibility (common in fast food joints), concentrate means they've taken some water out, transported it and added water back in, all to cut down on transport costs. In McDonald's (again, at least where I live), they link the concentrated drink, whether it be Coke or juice, directly into the dispensers. The dispenser also has a water hose and when pressed there is some ratio of water to concentrate that is supposed to come out.

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