[UPBEAT MUSIC] I know.

I am doing a life hacks video.

I know they're ridiculous, but I swear to you, I've been using these tricks in my life.

And I really actually want to share them with you.

And I swear I will not teach you things like you can cook a hot dog by hooking it up to either side of a 9 volt battery.

I just used this trick at a farmer's market.

There was a company selling sunglasses claiming that they were certified polarized.

To check whether sunglasses are actually polarized, put them in front of the phone screen and turn the glasses.

If they're polarized, you're going to see a change in the light, either the color or the brightness.

The light from most phone screens is polarized, meaning the light waves are aligned along a specific direction.

Polarized sunglasses let through light that is polarized in one direction.

It's the same thing that these polarizing filters do, but most people don't keep polarizing filters in their purse.

I do.

So caveat to this trick.

Screen protectors tend to make the light from your phone more randomly polarized.

So this trick may work differently if you have a screen protector.

But you can still look at a reflection from glass or water or a car window, because on some surfaces at the right angle, you'll see changes in the reflection as you turn the polarized glasses.

Oh yeah, so at the farmer's market, the glasses were not polarized.

And I told them so, because in real life, I am like you guys are in my comments.

They started explaining to me what polarization was and how it works.

And eventually were removing glasses from their shelves.

Whoops!

When you're putting away your headphones, instead of wrapping them in a loop, make a figure eight around your fingers.

After a day of carrying around your stuff, they're going to end up much less tangled.

This is the one I was so excited about, because I've been doing it for weeks and I can't believe how it works.

But it does.

Why?

Because your headphones are like a flat ribbon.

By wrapping them in a circle, you introduce a bunch of twists.

So when you straighten them, the twists stay there.

That doesn't happen with a figure eight.

Physicists have actually studied why headphones get so tangled and it has to do with the ends poking through the loops.

That makes knots and then you end up with twisted tangles in your knots.

So an added bonus of the figure eight is that though you get knots, your knots aren't all twisted.

And you're making smaller loops.

Harder for the ends to find.

Boom!

When you first get in a hot car, you might want to just blast the AC.

But you're still keeping the hot air inside.

So open those windows.

And you may not have checked this setting.

Recycling the hot air is just fighting against thermodynamics.

So take in the cooler air from outside first.

Then, once it cools down inside, recycle.

The air gets hot inside a parked car in the first place because of the greenhouse effect.

High energy light comes in the windows, gets absorbed by your seats and stuff, and then some low energy light is re-emitted but can't get back out the windows.

So the inside gets hot.

So let out the hot air first.

To avoid getting shocked by your car while getting out of it on a cold, dry day, touch the outside of the door frame as you get out.

That allows the static charge caused by sliding across the seat to flow into the metal frame through your hand.

So it never has a chance to build up and shock you.

It even works if you're riding shotgun.

Sorry.

That one was a stretch.

To remove the residue from an old sticker, put some oil on it and rub it off.

Or WD-40.

I had no idea why this works.

It's chemistry.

So here to help me explain is Elaine from the channel Reactions.

ELAINE: So why does oil remove sticker residue?

Well, it all comes down to the principle that like dissolves like.

Water and things that dissolve in water-- like sugar and salt-- are polar.

Oil and water don't mix, because oil is non-polar and water's polar.

Adhesives that don't resolve with water are non-polar.

So putting the non-polar oil with the non-polar adhesive mixes the two likes together and allows you to easily wipe it away.

Acetone, or nail polish remover, can also works, since it's non-polar, too.

However, nail polish remover tends to dry out your skin.

But that's a whole other story for a completely different day.

Thank you, Elaine.

That was awesome.

I didn't know that's why that trick worked.

Check out Reactions.

I'm going to put a link in the description.

We made it to the end of the life hacks video!

Do you have any life hacks?

I know you have some lame ones, because I tweeted out asking if you had any lame life hacks and I got these gems.

Tweet me @thephysicsgirl with your hashtag, #lamelifehacks or some legit life hacks related to science with hashtag #sciencelifehacks.

And put down that pen that you're using to carefully think of and curate the comments that you're going to leave below this video.

Because I have a PO box!

I know that I don't really talk directly to you guys that often because my content is about science.

But I'm a real person!

I'm real!

I really enjoy hearing from you guys.

So if you want to send me letters, puns, science experiments, questions, photos, hilarious drawings of your unique theories.

I really, really appreciated the letters you guys have sent so far.

You have a lot of lined notebook paper.

OK, so here's a joke from me.

What is Schrodinger's cat's favorite theory?

Tune back in next episode to get the answer to the joke.

Thank you so much for watching this video.

Also check out ACS Reactions.

They've got some other fun life hacks with chemistry in them.

Link in the description.

I'm going to go surfing, so happy physicsing.

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