Comments by "roidroid" (@roidroid) on "TED-Ed"
channel.
-
7800
-
211
-
198
-
85
-
41
-
39
-
35
-
25
-
23
-
22
-
20
-
20
-
19
-
19
-
18
-
16
-
14
-
13
-
9
-
9
-
9
-
9
-
7
-
6
-
6
-
5
-
5
-
This does a disservice to evolution education >:(
Bees don't decide anything, it's in their genes, it's instinctive. As bees (like all life) reproduce there is variation in each offspring, like a bit of experimentation. If the new bee's slightly different instincts make it build a hive which is slightly stronger and better, then the bee will survive better, and this means it will reproduce better - it's kids will carry the genes to build the better hives.
Whereas if the variation gave the bee the instincts to build a worse hive, then it will survive worse, it might die without having any kids at all, so the genes will not be passed on. Thus bad experiments get eliminated and good experiments become the next generation, so each generation is slightly better at building hives than the last was. Bees that can't build good hives DIE, and the only ones left are the ones who build good hives, that's the bees we're seeing - the ones who were lucky enough to be born with the right instincts, everyone else is dead.
The bees don't think about it or decide anything, they're just born with a slightly experimental variation in their instincts which either helps them live or die. DEATH is the one making the decisions, not the bee :(
5
-
1:45 >"i decided i try to print an entire fashion collection from my home. The problem was that i barely knew anything about 3D printing".
facepalm
Something that's confused me for a while is why we even refer to these artists as "professionals". If i decide to make something, that i have absolutely no idea howto do, then i'm described as a "layman". But this artist does the same thing, she has the exact same lack of necessary skillsets, and she's called a "designer".
I mean, an architect knows their material and howto make buildings from them. A mechanical engineer knows their material and howto make machines outof them.
If you have been trained in a profession where you know nothing about your chosen medium (lol how do i 3d print things?!), then of what use was your training? How would your results be of a higher quality than that of any other layman hired off the street?
Maybe that came out as more negative than i intended. I'm just confused why we elevate these people to a class label like "Artist", put them on stages, listen intently to what they have to say, when they clearly deserve no more respect nor attention than any other layman. Why is it a thing? Don't get me wrong - what she's doing is indeed quite cool & interesting, but it's no more interesting than what any other maker is doing *, why has she been elevated to a higher status class?
*infact less so, because other makers tend to know their mediums and thus more often are really pushing the boundaries of what's possible. All this artist is doing is buying off-the-shelf 3d printers & flexible filaments and repeating what others have already done, why does she bother? But more importantly - if this is so banal and derivative, why do we bother listening? Shouldn't our time be better spent listening to those who know their medium and are truly pushing the limits?
TL;DR: TED your entire stage is broken.
5
-
5
-
5
-
5
-
4
-
4
-
4
-
3
-
3
-
3
-
3
-
3
-
3
-
3
-
3
-
3
-
3
-
3
-
3
-
3
-
2
-
2
-
2
-
2
-
2
-
2
-
2
-
2
-
2
-
2
-
2
-
2
-
2
-
vanarcken113 Sadly what i said is indeed true. Algae farming (& biofuels in general) and solar power are competing interests of mine, a few years back i was closely following a fair few algae projects (as my old videos attest to), and i still occasionally tinker with algae-tech ideas to this day.
Algae is the fastest growing plant on the planet, it's the best, but photosynthesis isn't particularly efficient compared to man-made tech. It's great for producing liquid fuels though (ie: for vehicles), very simple. That's why there's so much buzz about algae, exciting stuff. But everything has it's limitations. It's more than just great for fuel, but also for food, and even carbon sequestration. This stuff has a lot of uses, but it doesn't do everything.
If you search for Algae Thermodynamics there's a fair few articles which will catch you up.
But as a quick explanation: Think of how much land is required to produce X amount of biofuel for combustion cars (wikipedia has some good biofuel yeild numbers, algae is the best). Then compare to the same land-area covered in solar panels charging electric cars. It's almost no comparison, the electric cars come out way in front, mostly because the thermodynamic limitations of photosynthesis just can't be routed around :(. You can easily charge your own electric car from the solar panels on your roof, but to grow enough biofuel to fuel your own car takes a relatively gigantic amount of land (i'd have to dig through my old notes to give you the exact land-size required), the yields are super low.
2
-
2
-
2
-
2
-
+Troy Milton errr, well the paraphrased answer is: because Science.
A slightly longer answer might be: Via various observations & iterative experiments in biology, chemistry, physics, etc. Gradually increasing our knowledge until we get to the level of understanding & confidence that we enjoy today.
Your question is very vague, it's sortof like a "To make an apple pie, one must first create the universe" thing. In Science, any new knowledge generally builds on existing knowledge, so to answer your question i'd need to know what you already believe - so i can build on that. I'd rather not explain the whole universe to you from first principles, it might take a while. So what do you already believe?
ie: Are you asking how we know that evolution exists?
or how we know that enzymes exist?
or how we know that cells exist?
or how we know that organs exist?
or how we know that the material world exists?
etc etc
To answer the question all the way back, would be to study the history of science & philosophy (ie: logic, rhetoric, etc).
2
-
+Troy Milton one way is that they can first have an number of ideas of how it might work, and then they devise relevant experiments to test the ideas individually. For instance, they can introduce a specially shaped molecule* which they imagine should block or interact with one of the processes. If it has absolutely no effect on the cell in an experiment, then it would heavily imply that their ideas on how that process works were wrong. They can keep doing this until they find things which do have effects, then they analyse all of these things to build up a picture of what could (or definitely couldn't) be happening inside the cell.
Over many experiments and testing of ideas, the picture becomes clearer. It's sortof like being in the dark, trying to figure out what an object is by repeatedly poking it with a stick from different angles, and keeping notes of when you hit something and when you don't. It can take a while, but over time this data paints an increasingly clear picture of the shape of what you're poking. It's like a game of connect the dots, each experiment gives you more dots, and marks some other places as "definitely no dots here".
Every time they do an experiment and get more dots, and more "no dots here" areas (i think i'll call these "anti-dots"), they then can have another round of brainstorming to try to figure out what the picture could be. They take the best ideas from this brainstorming, and then devise new experiments to test the ideas, ie: "if this idea is correct, then there MUST be dots right around here and here." Even if the experiment fails to reveal dots there, it will instead reveal a "no dots here" area, and this data will still add to their picture. So even if an experiment fails to prove a hypothesis, it's still a win win situation.
I guess the boardgame of "Battleship" is another which can be used as a metaphor. Each single shot you take gives you very little data, but over time it builds an increasingly clearer picture of things you couldn't previously see. It only takes a very little experiment, repeated slightly differently time & time again, to build up great amounts of knowledge.
*Thesedays we have such a huge amount of knowledge about chemistry, that we use computer simulations to model what we know. This makes it easy to find new things we can experiment with, because it's sortof like "the computer simulation shows that the shape of this molecule should effect this thing", and then we test it in the real world to see if it's true. Remember all the poking with a stick we've previously done, by now we have a really good idea of the shape of various things, we even have a whole bag of specially shaped poking sticks to speed up the process. Thesedays we're super confident about the shape of most things, we only really poke specific areas we're not sure about.
2
-
+Jesse Steck Since communication is a 2 person process, it's incorrect to assume that your inability to understand someone would be solely their fault (why not your fault? Why automatically assume you're in the correct position by default?).
You should look at people's differences in talking as the same as people who speak entirely different languages. You're going to have to be immersed in their culture for some time, to properly understand the nuances of what is being communicated. I very regularly have the sensation while listening to people from other cultures, where i can understand the words but i can also tell that there's something important that i'm missing out on. i don't assume i'm listening to idiots, what i assume is that i havn't been around this person or their culture enough to be able to pick up on the nuances, what they're really saying. It's not their fault per-se, since they're not a part of my culture either, they likely don't know all the nuances of my culture just as i don't know theirs.
Neither of us are speaking the universal default language/grammar, we both just have our own languages - i wouldn't want them to think i was an idiot because of how i talked, so why would i do that to them. Lets not let our first reactions be shallow, this is a real actual person infront of me, they have depth.
2
-
2
-
2
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
Instead of remembering all of the names for sugars, just go straight to the Nutritional facts table.
0:52 See the table to the left of the ingredients list. That's what you're interested in.
All sugars are carbohydrates, and if you're avoiding sugar then you're probably doing it for weight loss purposes, and thus you're really trying to avoiding all carbohydrates (not just sugar). Carbs are like slow release sugars, but you still get the same amount of calories - just slow release - you still get fat.
So you look at that table, you see how much carbohydrates it has per 100grams # and you basically treat that as percent sugar. If it's 90grams per 100 grams carb, then it's effectively 90% sugar.
Simple.
As a diabetic, when i compare foods i'm primarily concerned with the percent carb, percent fat, percent protein, and the glycemic index (ie: how fast the carbs are absorbed).
Even if you're not diabetic, it's handy to get a feel for this stuff beacuse it can remind you of why particular foods are so addictive (they generally have a lot of carbs and fat). It's good to be aware of where your feelings are comming from, coz if a food is actually really healthy for you AND yet you still really love eating it - you're onto a winner! Fill up your fridge with it!
# the table in this video doesn't actually show carbs per 100grams, but afaik most labels in the real world do.
1
-
1
-
1
-
+Osman Oglu USA's prison industrial complex makes a lot of money and free labour is a part of that. They make much more than just plates, they make all sorts of shit, which is then sold for profit by the prison.
Google it, check this shit out:
"All told, nearly a million prisoners are now making office furniture, working in call centers, fabricating body armor, taking hotel reservations, working in slaughterhouses, or manufacturing textiles, shoes, and clothing, while getting paid somewhere between 93 cents and $4.73 per day,"
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
Brandan09997 i scoff when i look at a shiny 3D rendering of a futuristic phone, with a caption reading "This amazing phone's charge could last for 100 years and be powered by unicorn farts, kitten giggles, & quantum woowoo", yes.
Any designer can render & write whatever fictional story they want to go with the artwork for their fictional devices, but actually constructing a device that will function under the known laws of physics is another story. Sadly, designers often aren't trained too well in this.
It's easy to design a (effective & competitive) hand-held laser pistol, low power prototypes already exist, hell you can watch real videos here on youtube of people's DIY pulsing laser blasters, it's known tech. What's hard though is powering it (to a sufficient level) with known battery tech, that's typically the limitation in the real world: the density of energy storage. Another one is the economics of actually constructing the device (It's common to see designs for all sorts of things that stipulate ridiculously expensive materials, or construction techniques which are still barely being understood in universities - let alone in use in industry right now).
Most of these things are "what if". But sadly the media reports on them as if they're just around the corner. This serves both the design firms and the media well, they're generally more interested in page views and SEO exposure ratings than any sort of accuracy in reporting.
To answer OP's question directly: TBH the reason we don't all have exoskeletal power armour is because we're civilians and have little need for armour. But the reason we don't have exoskeletal suits is because they're a relatively new tech. Exoskeletal suits already exist right now in a primitive (still mostly prototype, unaffordable) form, but it's good enough to predict that they'll be cheap and commonplace tech perhaps within 10 years, we'll get there with slow incremental improvements alone. No exotic materials needed, OP is in luck, we just need time.
I'm glad OP didn't ask for (useful) personal jetpacks tho, that's a much harder nut to crack. Sorry, no flying Ironman suits for a while yet.
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
AFAIK The amount of sugar in your blood would be more like 2-3 teaspoons, as this would be literally the amount of sucrose required to raise your blood sugar by 4-6 mmol/DL (which would be the normal range for your Blood Sugar Levels). If you only had 1 teaspoon of sugar in your blood, your BSLs (Blood Sugar Levels) would be around 2mmol/DL, you wouldn't feel very well as you'd be hypoglycemic.
2:55 It should be noted that your body actually does convert a significant amount of the protein you eat into glucose, something not mentioned in the video (but hey it's only 5 mins long). Eating cheese, meat and eggs does raise your BSL. From personal experience, i'd say the effect is about 1/3 or 1/2 that of eating the equivalent weight of complex carbohydrate.
Insulin sensitivity is something important even for type-1 diabetics, because if your sensitivity is high then you can take less insulin. I typically exercise at least once a week to keep my sensitivity up, and if i skip a few weeks i can tell because i have to raise the amount of insulin i give myself. If i then exercise again, my sensitivity goes up again immediately, literally WITHIN MINUTES, it's like flicking a light switch. Exercise: highly recommended, for everyone, diabetic or not (everyone has insulin).
Don't even think of it as burning calories, you're doing it to bump your insulin sensitivity up, and improve your mental state.
1
-
1
-
1
-
1
-
1
-
1
-
1
-
nitwndr The battery continues to (try to) supply power (somewhere between 2.5V and 4.2V) to the phone at the same time as the charger is supplying 4.2V to both the battery and the phone, the 2 sources are connected in parallel, so the phone only ever sees 4.2V like usual. It's all connected to the same single terminal: the positive of the phone, positive of the battery, and positive of the charger.
A fully charged battery will supply 4.2V to the phone, an almost discharged battery will supply maybe 2.5-3V. When the battery is being charged - the charger supplies 4.2V positive to the battery's positive terminal (ie: it's in parallel). So as far as the phone is concerned it just sees 4.2V positive on it's positive terminal, just like usual, all that's changed is that there's slightly more amperage at it's disposal (comming straight from the charger).
Inside the battery though is where things are different, it's suddenly seeing voltage at it's positive terminal (from the charger) which is comparitively MORE POSITIVE than it's own positive 2.5V. You have to remember that voltage is a relative thing. This means that to the battery - if it's charging it's own positive terminal to 2.5V positive, but there's an outside positive voltage of 4.2V, then what it's actually experiencing inside itself on it's positive terminal is 1.7V of NEGATIVE charge. The battery's own residual 2.5V positive is cancelling out 2.5V positive of the incomming 4.2V, (it experiences that 4.2V positive as relative to the 2.5V positive that the terminal already had) thus leaving a RELATIVE voltage difference of 1.7V in the other direction (ie: negative).
So yeah, while charging there is indeed a reversal of voltage going on, but it's only the inside of the battery itself that is experiencing it. :)
It's like having a bucket that is pouring it's water out onto the ground slowly, and you're occasionally topping up that bucket with a glass of water. The water pouring out from the bucket never stops, and the level in the bucket is normally going down. But when the glass is topping up the bucket - the water level in the bucket suddenly starts going up (this is like the internal reversal of voltage the battery is experiencing, the weird experience of it's water level going BACKWARDS is only experienced by the bucket itself and no-one else), even though the water pouring outof the bucket isn't effected and just keeping going during the whole process. My point is that when you are recharging that bucket, it doesn't effect the pouring out of the bucket's water onto the ground, it certainly doesn't make the pouring go in reverse. The only reversals that are happening are within the water-currents of the bucket itself. I hope that helps :)
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1
-
1