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Every eye has a tiny blind spot near the middle. But your brain makes it disappear and you don’t realize it’s there.
You can verify this. Draw a dot on a bit of paper. Close one eye, stare at a fixed point, now move the paper around the center until the dot disappears…magic
What we consider reality, is a synthesis our brain is presenting to us, it is an approximation… realizing that is a real mind blower
I’m going to qualify this—all vertebrate eyes have a blind spot. Cephalopods also have eyes that are like vertebrates (this type of eye is called ‘camera eyes’), but their eye anatomy is such that no blind spot exists for them.
Piggybacking on your fact about the brain effectively editing what we visually perceive, we don’t see our nose (unless you made a concerted effort to look at it) because the brain ignores it.
fun fact: the blind spot is because our optical sensors are installed backwards and that hole is so the optic nerve can pass back through the back of the eye to the brain. some other critters with independently evolved vision systems, such as cephalopods, avoided this particular evolutionary pitfall.
Another fun fact: through that hole there’s also vasculature and capillaries coming through and you can actually see them by looking at a well lit white surface and creating a tiny pinhole with your hand right in front of your eye and wiggling it. Better explained here at around 5:30
That’s awesome, I had no idea, thank you for sharing
What we consider reality, is a synthesis our brain is presenting to us, it is an approximation…
It’s also a coordinated synthesis from all of your input senses (sight, hearing, smell, etc). It also explains why those who have a certain sense stunted (aka blindness, deaf, etc) report having all their other senses heightened. And it’s up to the individual’s brain to assemble those sensory inputs into a complete picture of the world around them, what we dub “reality.” Which then brings into question the nature of common reality, and what defines it. Trippy shit.
Oh I thought my eyes were fucked. I look at a star in my periphery and it’s there, I look at it directly and it’s fucking gone.
This isn’t due to the blind spot, but it is still pretty weird to experience! Here’s some more info if you are curious: https://en.m.wikipedia.org/wiki/Averted_vision
Also we only see the past since our vision has a bit of “latency”.
So I guess we never see reality but just a delayed representation of our environment as interpreted by our brain.
The average person does not have 10 fingers. Maybe the median person, but not the average.
Most frequent occurence is the mode. Most ppl have 10. The median would be less than ten, while the mean average is skewed down, I would think, by some people losing fingers as the grow. Having extra fingers is pretty rare. So the mean might be 9.95 fingers, just to toss a number out.
I assume the median and mode are the same value, 10 fingers, but have no data to back that up. I guess saying mode would have been a safer statement to make, but think that even if 49% of people have 0-9 fingers, the median number of fingers would still be 10.
The median of a data set is the measure of center that is the middle value when the original data values are arranged in order of increasing (or decreasing) magnitude.
So ppl generally have, say, between 2 and 11 fingers. If those were your only 2 data points, the mean would equal the median, and there is no mode.
I was also assuming a sample size of more than two for it to be statically significant.
For 10 to not be the median it would also have to not be the case for the majority of people (just the plurality at best), and while I don’t have proof handy I’m pretty sure a vast majority have exactly 10, making that the precise median and the mode. Only the mean would be a different number of digits. (Both definitions)
The median of a data set is the measure of center that is the middle value when the original data values are arranged in order of increasing (or decreasing) magnitude.
So ppl generally have, say, between 2 and 11 fingers. If those were your only 2 data points, the mean would equal the median, and there is no mode.
Yes, but we don’t have only those two points.
It’s well known that most people have one specific value, so much so that our entire number system is based on it (literally the base, it’s ten)
Mode assumes categorical data and is unbounded by range, whereas median makes the most sense for decimal numbers, albeit with rounding in this case
“People have
round(median(data))fingers”edit: though, if we’re counting just fingers and not counting half-fingers, then maybe this really is categorical data (¯\(ツ)/¯?)
The median of a data set is the measure of center that is the middle value when the original data values are arranged in order of increasing (or decreasing) magnitude.
So ppl generally have, say, between 2 and 11 fingers. If those were your only 2 data points, the mean would equal the median, and there is no mode.
Um akchully…
Median is a type of average
NERDDDDD!
Ok, I had assumed average was the same as mean, but see that it’s ambiguous. Saying “the mean person does not have 10 fingers” just sounds wrong though.
Consider a dam that is 10m tall
Then consider the height of water behind that dam is 5m tall.
Does the dam need to be built stronger if the water behind it is 1 km long?
How about only 500m?
How about 1m?
The answer is, it doesn’t matter. Water exerts pressure equally regardless of how much water is behind it.
Therefore a graduated cylinder that is 10m tall needs to resist the same amount of force as a dam 10m tall regardless of how much water is behind the dam. Even a thin sliver of water 1mm thick and 5m tall has the same force as a 5m lake behind the dam.
Incompressible fluids are pretty insane
This is also why trees are so fucking crazy to think about. It is impossible to pump water up a hose more than ~32 feet. Like it’s literally physically impossible to stick a pump at the top of a tall building and suck water straight up a pipe. You need a complicated series of pumps and one-way valves to pump it up in stages. Because you’re not really “sucking” the water up the pipe. You’re just lowering the pressure in the pipe, and atmospheric pressure pushes the water upwards to fill the low pressure. After 32 feet tall, the top of the hose/pipe will be a perfect vacuum, atmospheric pressure won’t be able to push liquid water upwards any farther, and the water will just begin cold-boiling in the top of the pipe as the liquid water turns into gas (steam) to fill the vacuum.
But tall trees can move water all the way to their leaves by using only passive capillary action, and suction created by water evaporating out of their leaves. The capillary action is created by tiny straw-like fibers that run all the way up the tree and are bunched together really tightly. Due to surface tension, water is able to “climb” the capillaries as the surface tension fills as much surface area as possible. Then at the top of the tree, as the water evaporates out of the leaves, it draws up fresh water to fill the void.
But that means the bottom of the tree should need to support the pressure of all of the water above it. But it doesn’t, because the surface tension holds the water stable inside of the trunk.
Therefore a graduated cylinder that is 10m tall needs to resist the same amount of force as a dam 10m tall regardless of how much water is behind the dam. Even a thin sliver of water 1mm thick and 5m tall has the same force as a 5m lake behind the dam.
Technically only the pressures are equal, and the actual force will be linearly dependent on the area of the dam (or the surface area of the cylinder). That’s why you can make a tall water tank with relatively thin walls, but an actual dam will have to be quite thicc to handle the tensile/compressive stress (depending on the shape of the dam).
That is accounting for static bodies of water, wouldn’t there be force generated in a dynamic situation? Ie the flow of a fast river? Or if the lake is large enough tidal forces? I’m sure it’s negligible levels but still something that must be accounted for?
No, that’s absolutely true. Dynamic loads will need to be accounted for in real world examples.
Another point is that if the dam is 10m tall, it has to be built to withstand 10m of water. just because it sits at 5m most of the time doesn’t mean a heavy rain couldn’t raise the level, and if the dam collapses that’s going to be catastrophic vs just spilling over the top.
I’ve seen a few dynamic loads in my day and in my professional opinion I must agree
Thank you. Your hypothetical question has been a nagging, unresolved background radiation in my mind for decades, but I’d never gotten around to investigating.
There is a planet in our solar system populated entirely by robots.
Shouldn’t that be 2? Mars and Venus.
Pretty sure the one on Venus is dead.
well yeah, but that’s because the native robots killed it
by weight, theres more non-human DNA in you than human.
Wait. Please explain. How is DNA inside me, a verifiable human, not human?
It’s DNA from bacteria that live inside you.
Bacteria technically live in the tube of “outside” on your inside. Digestive system is just one hole all the way through the body that your body interacts with just like the air in the lungs.
Your poop is on the outside of your body
youre mostly bacterial dna
U got bugs in ur poop.
Your gut flora
I read that comes don’t actually eat grass. They have the extra stomachs, and the first stomach is basically a bacteria reactor that feeds on chewed up plant matter. As the bacteria reproduce they get sent to the next stomach which is what actually gives nutrients
we all know what you do when you visit the zoo.
were those giraffes looking thirsty, hmmm?
A few of my favorite fun facts are geography related.
The pacific side of the Panama canal is further east than the Atlantic side.
If you head south from Detroit the first foreign country you’ll hit is Canada.
Lake Tahoe is further west than Los Angeles
If you head south from Detroit the first foreign country you’ll hit is Canada.
There’s also Angle Inlet, Minnesota which is the only place in the contiguous United States north of the 49th parallel. To travel to Angle Inlet by road from other parts of Minnesota, or from anywhere in the United States, requires driving through Manitoba, Canada. It’s a really weird border.
Due to its high latitude and being in the middle of a continent, it is a contender for the most extreme winters in the contiguous United States.
Two square miles & 54 residents in North Bumblefuck, separated from the rest of the US by 60 miles. It’s an affront to reason.
All borders are weird
omg la is east of reno what is happening rn
Sharks are older than both trees and the north star
Both trees?
Laurelin and Telperion
Yeah Twin Pines Ma— I mean Lone Pine Mall.
Yes, both of them at the double tree inn obviously
Had to look this up- you are indeed correct. The North Star is at most 67 million years old: https://en.m.wikipedia.org/wiki/Polaris
The Allies avoided bombing specific factories in Nazi Germany in which US oligarchs owned equity.
the point was to post unbeliavable facts
This is an eminently believable fact.
I’m just going to leave this here
yes, but those same oligarchs were the one’s funding the entire war effort at the time time, and - ohwaitnvm…
Butterflies can remember things from their time as a caterpillar.
These memories are retained after going through metamorphosis, the breakdown of their caterpillar form into a cellular soup (or partial soup).
Details here
Humans have stripes that are invisible to us. However, cats can see our stripes.
Is it all humans or just those humans with two X chromosomes? Relevant video on the subject: https://www.youtube.com/watch?v=BD6h-wDj7bw
Also in this video, we can see female cat’s stripes in their fur color.
By this logic, does this mean my striped cat doesn’t realize she has stripes?
Wait, what?!?
If I asked for stripes and got this, I’d want my money back.
That Mark Zuckerberg holds several records for most fists shoved inside a human body at once
Just once it would be nice to see him on the receiving end
James Blunt possibly prevented the start of World War 3. (But became best known for the song You’re Beautiful. Reality is weird.)
Care to expand on that one? I know he’s ex military but haven’t heard anything like that before.
It’s explained on his Wikipedia page. He was an Army captain in the Kosovo War, when a NATO commander (Wesley Clark, who later ran for President) ordered his unit to secure Pristina Airport, which Russian troops had already occupied. Blunt refused to engage them, long enough for the British general get involved to countermand the order, on the grounds that he didn’t want his men to start WW3.
Well damn. That’s a pretty cool thing to do. Thanks for sharing.
There are more trees on earth by far than there are stars in the galaxy.
I had to looks this one up, but missed the “galaxy” vs “universe”. There are an estimated 3 trillion trees, 100-400 billion stars in the milky way galaxy, but potentially 1 septilliom stars in the universe.
However all three of these are estimates, so who actually knows.
I’m not sure where these numbers are from, but my guess is that you mean the Observable Universe, which is just the part of the universe that we can see.
We don’t know how big the full universe is, it could be infinite with an infinite number of stars.
Just some quick Google searches so not sure how reputable, but didn’t feel like copying random links.
But yeah, that’s why I called them out as estimates as I suspect there is a lot of room for error in those numbers.
- Catalan children get (some) of their Christmas presents by beating a cute piece of wood that then shits the presents out onto the floor. Seriously.
- There was a British guy who fought in WW2 with a scottish broadsword and bagpipes. However, the best thing is that he wasn’t even a Scotsman.
- On a small enough timescale, the electric field actually bounces around in your wires for a while after you flick a switch, even if it’s DC, just to “figure out” where it “needs to go”.
- More than twice as much time had passed from the invention of the motorcycle until the first motorcycle backflip, then had from the invention of the airplane until the first humans landing on the moon.
The electric field one is also interesting, because the cable length doesn’t actually determine how long it takes to turn on. All that matters is the distance between the power source and the device. Electricity travels at the speed of light, which means we can measure how long it should take to travel down the wire.
But let’s say you have a 1 light year long power cable, made out of a perfect conductor (so we don’t need to worry about power loss from things like wire resistance or heat). Then you set the power source right next to the device and turn it on. The logical person may say that the device would take a full year to turn on, because the cable is one light year long. Others may say that it will take two light years to turn on; Long enough for the electricity to make a full circuit down the cable and back to the power source again.
But instead, the device turns on (nearly) instantly. Because the wire isn’t actually what causes the device to turn on. The device turns on because of an EM field between itself and the power source. The wire is simply facilitating the creation of that field. The only thing that matters is the distance between the source of power and the device. That distance, divided by the speed of light, is how long the device will take to turn on. If the device was a full light year away from the power source, it would take a full year to turn on. But since the device is sitting right next to the power source, it turns on right away.
But instead, the device turns on (nearly) instantly. Because the wire isn’t actually what causes the device to turn on
That’s not exactly true. In this case, the energy transmission would go like this: (change of electric field in the little bit of wire next to the power source) -> (change of magnetic field in the air between the wires) -> (change of electric field in the wire next to the load). This limits the amount of energy transmitted significantly and incurs a lot of losses, meaning if you had something like a lamp plugged in it would start glowing extremely dimly at first (think about how some cheap LED lights keep glowing even with the switch off - it’s similar, albeit it happens due to inter-wire capacitance and not induction). It would then slowly ramp up to full power over a course of a year.
Here’s a video from the same person about it: https://www.youtube.com/watch?v=2Vrhk5OjBP8 (although I haven’t watched this yet)
Edit: after watching the video, I think I was actually wrong in a couple of my assumptions. First of all, it looks like the reason for the initial energy transmission is wire capacitance and not induction, so (electric field in wire) -> (electric field in air) -> (electric field in wire, in the “opposite direction”, but because the wire goes back and forth it’s the same current direction). This means that my LED example is even more potent. And the second one is that because it’s capacitance and not induction, this means that there’s no slow ramp-up, it just makes the light glow very dimly all the way until the electric field makes it through the wire, and then it ramps up very quickly.
Can you help me understand why the distance between the power source and the load impacts how long it would take to turn on? I remember a video a while back (veritasium maybe?) that explained it like metaphorically pushing/pulling a chain inside the wire, but why would distance to the source impact this?
wait so if you have another person travel to the other end of the wire, and do a time sync with consideration of time dilation to tell them to cut the wire 1hr after you turn on the power, will the device turn off after 1 year since it wouldn’t “know” the wire is cut until a year has passed?
The bluestones in Stonehenge come from West Wales. Instead of quarrying stone from near the monument, they dragged these huge blocks from ~278km away. Likewise, the altar stone comes from ~700km away in North-East Scotland. It must’ve been very important for the ancient Britons to’ve used these specific rocks for some reason, but their religious practices were conveyed via a now extinct oral tradition so no-one knows exactly why they did it.
(History Channel Hair Guy)
“MAGNETS”I thought this got debunked?
Edit: no, it was just the alter (from Scotland!) https://www.bbc.co.uk/news/articles/c207lqdn755o you are correct.
