Using the Leidenfrost effect to propel water drops uphill

Could you make a self-stirring frying pan by putting this texture in a spiral pattern on the bottom?

How does that work?


Cleaning up Space Trash.

Cleaning up Space Trash.

Sounds expensive.

high tech


about keeping stuff clean

Sounds expensive.

Yeah that definitely sounds like my country

EDIT: forgot a "n".

EDIT 2: Forgot another n: "an n"

I get that space debris is a problem, but isn't just returning a single cubesat rather inefficient?

Furthermore, I thought cubesats were deployed in such a way that they would deorbit on their own after a while.

Yeah... Wouldn't it be better to toss or jettison the cube towards Earth. Then, theoretically, attempt to grab another?

Vinyl disc needle

Vinyl disc needle

A better explanation (in gifs):



Vinyl records operate by a needle riding in a groove. In this case, a stereo record, which means the needle doesn't just vibrate up and down, but also side to side. Those vibrations are measured and turned into electrical signals which control an electromagnet attached to a cone (aka a speaker); the changes in magnetic force and polarity causing the cone to vibrate and make sound...

What exactly is this gif tryna teach me?

But if it wasnt for your comment i wouldnt know shit tho, thanks.

A breathing Earth

A breathing Earth

This is amazing! It always fascinated me, how much it snows in the northern hemisphere.

And that the areas with grassland/deciduous forest are so much whiter when it snows than areas with conifer forest.

Canadian prairie is like a white sheet.

How awesome is Britain?

All Hail The Gulf Stream!

I love how one patch in Africa is always green!

Here is why spacecraft orbits almost look like sine waves on maps.

Here is why spacecraft orbits almost look like sine waves on maps.

Maybe I'm being really really dim but I still have absolutely no idea why spacecraft orbit like sine waves. All I'm seeing is that they go up and down just because they do.

Edit: thanks for everyone's responses! Turns out I am just dim, haha.

ISS orbit

The point of my gif is to show that they are not going up and down. They go in circles around earth and it just looks like a wave when you track them on a flat map. If you'd strech a flat map around a sphere it would become a circle again. Now those maps you know from the internet are not perfectly transformed from a sphere into a rectangle as seen in the video. They warp the map so that the continents look closer to what they look in real life. This makes the orbits look even weirder with flat sections and what not! However, an orbit is always a circle. (There are a few exceptions when for example the moon disturbs an object orbit but generally speaking it's a circle or ellipse). What could be a little confusing in my animation, which I just realise is the earth spin. I just do that to show it from all angles. An orbit always faces the same direction. It does no hula hoop.

edit: I found an old video of mine where I animated the .


Ah okay, they have an inclination against the equator (the tilt) so that they also pass over northern and southern parts of earth. If they would only fly over the equator they wouldn't be able to make pictures from Europe or Canada for example. They get more bang for their buck so to speak. Another reason is the placement of the different launch sites. If you want to launch into an orbit which is above the earth equator you had to launch from the equator or do a really hard turn midflight which would be very difficult.

edit: Here an older of mine showing how the ISS passes over land.

Kerbal Space Program really helps one understand orbital mechanics and space travel in general.

Camera Lense Perspective Changes

Camera Lense Perspective Changes

Maybe I'm not as ugly as my selfies lead me to believe

My wife watches a YouTube make up girl who abuses this for before and after shots. I try and show her but apparently I don't understand conturing.

Front facing cameras on iPhones are about a 30mm, so yeah, they can be a little unflattering for some.


How a Sewing Machine Works

How a Sewing Machine Works

But what is the shuttle hook anchored to if the thread loop goes all the way around it on every side??


shows it well (skip to 3:20).

This animation also helps make it more clear how it hooks the thread.

I still don't understand this sorcery.

What, exactly, are you people unclear on? The nada code or how this model grab demolished?

Historical Events You Won't Believe Happened Simultaneously

Historical Events You Won't Believe Happened Simultaneously

Imagine going to Harvard and then realizing some dude created more math

Oxford University was created before the Aztec empire fell.

And not just 1 more year of math. There's enough math for every year you are in college.

And before it rose. (1096 vs 1428)

An Animated History of the States & Territories of the United States of America.

An Animated History of the States & Territories of the United States of America.

This is great. Thanks for sharing.

Welcome to all of human history.

Quick question: The colony of Louisiana was originally Spain's, but possession of the entire territory suddenly transfers to France. What caused this? War? A trade/purchase of sorts?

Treaty. Though Napoleon pressured Spain to a bad deal (and then France made a bad deal later).

the development of the human face in the womb

the development of the human face in the womb

Right before the end there I was thinking, 'It's a trap!'

Fun fact: you see how those two nostril holes are right in the middle for a bit, have a dangling flap below them? It soon merges with surrounding tissue and makes the nostrils proper and upper lip. Deeper in the head, the roof of the mouth forms. Often, those late stages don't happen fully. The cells just phone it in with a "eh, fuck it, it's pretty much done" and stop. The most minor evidence of this is Peg laterals, the teeth next to the big centrals. They are skinny and conical, not flat like a normal front tooth. Another sign is the uvula in the back of your mouth is forked as it's two halves don't come fully together before the work day ends. More severe evidence is a cleft lip. It's location is always right under a nostril. Cleft lip is superficial, just soft tissue. Cleft palate is deeper, the failure join extends to the bone of the roof of the mouth. That cleft palate can be bilateral, too.

When you consider a charity, please give to Operation Smile, doctors who surgically repair these defects for underprivileged children around the world.

This is going on in my uterus right now.



Try one of these subthreads