Educationalgifs educationalgifs

How they train drug-sniffer puppies

My grandfather had a drug sniffing dog that was a reject - not sure why. His name was Stash.

Stash may have been a failure, but he busted my brother with his weed when we came to visit.

Could have been many reasons. If they can’t obey orders perfectly, if they get distracted to easily, if they can’t behave near other dogs, if they’re two nice and playful, if they’re two mean and aggressive, if a mistake by their trainer was made midway or late during their training that might comprise them, if they were exposed to actual drugs and risked smell desensitization, etc. All these reasons can get a dog kicked to the curb from training. Besides how labor and expertise intensive their training is, the strict requirements to pass is what makes trained dogs, in any capacity, very expensive.

Edit: They’res’ you’re ‘to’ correction ya bastards.

I wish someone would feed me heroin treats all day like that...

This is an actual job!

These people are actually paid to play with puppies all day and they have a reference supply of recreational drugs? Fucking sign me up.

How changing the focal length affects how a person looks

Can someone help explain what's going on here? Why does focal length change his appearance so drastically?

Focal length isn't really the culprit here - it's the distance from the camera. It's kind of a weird idea to wrap your head around. As they changed focal lengths, they had to move the camera forwards or backwards to maintain framing. Due to perspective, objects further away seem compressed and objects closer seem extruded. This isn't as noticable in normal life but it is heightened when using longer and shorter camera lenses. Hope this helps! I'm a bit of a lens nerd haha.

What if our eyes all have different effective focal lengths and there is no one actual proportion and we all see a different one of these photos?

If you are using a standard 35mm sensor/film size (not a tiny phone sensor or APC size sensor) a 50mm lens is comparable to what our eyes see

Representation of how mass affects space-time. Note the clocks as nodes.

Representation of how mass affects space-time. Note the clocks as nodes.

This is a beautifully clear representation of a challenging concept.

I'm the author, glad you enjoyed it. (Here's more of my stuff on Wikipedia)

But please, understand that this is not really mathematically accurate, and many artistic liberties were taken. I made it as an attempt to get away from the usual rubber sheet model, while also addressing gravitational time dilation.

I have plans of visualizing orbits with something like this too, but I'm not sure when I'll get around to do it.

So since we are traveling very fast on a large mass object, are we in fact experiencing time slower than normal “space”?

Yes, but imperceptibly.

How to Self Rescue in the event you Fall Through Frozen Ice

He went into a freezing pond to teach us this lesson. What a guy

First video I have seen where the self rescuer did it in a full set of clothing and boots. Made it that much more informative/personally relatable for me, as I also frequently wear boots.

This is worth signing in and upvoting. I predict in 3 years someone will post a story about how they fell through thin ice, remembered this gif and saved their life.

I too was thinking somebody should give the guy actual gold for sacrificing his own comfort and risking his health simply to improve the odds of his annonymous viewers actually learning a life saving technique.

I say bravo and thank you.

The effect of neurotransmitter balance on the brain

/sub/badscience

This makes it look like depression is a kind of diluted ansiety

This is a gross oversimplification to the point of being wrong. Levels of different neurotransmitters can be associated with emotional states, but is highly variable based on anything from the area of effect to individual differences in emotional perception. Someone who takes an amphetamine, for example, will have large amounts of dopamine released and will cause euphoria, focus, and energy since dopamine is an exitatory neurotransmitter (and an inhibitory one in other parts of the body) and is stimulating areas that are used for those emotional states.

That doesn't mean a high level of dopamine during a period of anxiety causes those same effects, but rather the molecule is in use by the brain so as to activate the pathways for fear and panic. Same molecule, variable effect. Same goes for serotonin and oxytocin, they all do much much more than just specific emotional control. Relegating emotions into "how full is your serotonin meter?" type metrics is so ridiculously oversimplified it's like claiming an orange pixel is an image of a goldfish.

You’re worried about everything but just don’t care enough for it to matter at the moment.

Based on Arnold's discussion about Lissajous curves, I have made series of gifs (more in comments)

Based on Arnold's discussion about Lissajous curves, I have made series of gifs (more in comments)

The text is in Turkish, but it is not that important since the post is mostly animations.

Here they are:

http://bilimneguzellan.net/index.php/2017/12/17/temel-harmonikler-ve-lissajous-egrileri/

This discussion follows an article by Vladimir Arnold.

The snack that smiles back...

children

Translator did a pretty good job, have to read through the lines a bit though haha.

"You have a guitar tortoise in your hand and you want to make various notes. Gently pulled the guitar string and left it. Take a vibration like this:"

Artificial Gravity

Why does this GIF go past 9 seconds? Are you trying to hypnotize me by making me watch a box go around in circles?

Pretty neat. I think you might confuse people by just having the cube "fall" toward a wall. If it started with zero velocity, there isn't any reason it would fall like that, since you're not actually creating gravity by rotating the wheel. The centrifugal force will keep it against the interior wall once it's up to speed, but not cause any initial force.

If it started with zero velocity, there isn't any reason it would fall like that

True, but that would make a rather boring gif.

The centrifugal force will keep it against the interior wall once it's up to speed, but not cause any initial force.

In the spacecraft frame, there is a constant constantly acting centrifugal force as it is a rotating frame of reference. It moves in a curved path due to the Coriolis force. When the cube collides with the wall it's velocity in the spacecraft frame drops to zero so the Coriolis force also drops to zero and the centrifugal force is balanced by the contact force.

In the inertial frame there is no force acting on the cube until it contacts with the wall. After the collision, the contact force provides the centripetal force.

Edit: Sorry wrote constant centrifugal force while I mean that it is acting all the time. Its magnitude depends on the distance from the origin.

Now dance like a chicken and sing "hit me baby, one more time" by Brittany spears

The Formation of a New Island.

So like, will this erode and get smaller or will it get bigger? Is the only way to get bigger for the volcano to erupt again? Does it need to get a lot bigger in order for moss and stuff to grow there? So many questions.

Geologist here! Will this erode this island erode? Yes, it has been eroding ever since its formation, that is why you see sandy beaches. The reason why it has not eroded so much is that the rock the formed is most likely a very resistant rock or there is something that is protecting the island from larger waves which would erode it away faster. Is the only way for it to get bigger is a volcanic eruption? Yes, the tectonic plates that have created the Mariana trench are colliding into each other causing one of the oceanic plate to diverge under the continental plate creating the volcanoes. Does it need to get bigger to have stuff grow? No. Growth on island like this one is caused by bird shit. Seeds in the shit can grow as long as they are able to get there roots established.

Serious question: when this happens, is there a process for who can claim this? Or is it like the “dibs” comments here?

This is what train conductors are trained to do if somebody jumps in front of the train, this is done to prevent mental trauma

This is what train conductors are trained to do if somebody jumps in front of the train, this is ...
This is what train conductors are trained to do if somebody jumps in front of the train, this is ...
https://youtu.be/51zKl0Ta5KM

I've seen this video before and it's a collision avoidance measure. He also has to warn passengers to brace, that's why he's running. Not what the OP says in the headline. Why would you make this up? Edit: Here is the video where it happened in real life:

Why doesn't he just swerve?

Holy crap that is depressing.

How solid rocket fuel works

well that explains it perfectly

it explains the burn pattern/sequence. So that's something I guess =/

For reference

Being as how I didn't expect a gif to make me a rocket scientist, I think that's pretty neat.

Try one of these subthreads