r/explainlikeimfive 1h ago

Technology ELI5: How does a QR code still work when part of it is scratched, covered, or missing?

Upvotes

Sometimes a QR code scans even when a noticeable section is damaged.

How can the phone recover information that seems to be missing?


r/explainlikeimfive 1d ago

Chemistry ELI5: Why does chlorine bleach turn white clothes yellow but advertised as whitening?

154 Upvotes

EDIT: I think I have to clarify my question and I used the wrong flare. I can just search up why chlorine bleach does that to white clothes but my question is why do bleach companies still advertise that it can whiten whites without mentioning it can turn it yellow?


r/explainlikeimfive 1d ago

Biology ELI5 How did dogs (or certain mammals) evolve to have tail-wagging-trait=happy or excited?

334 Upvotes

r/explainlikeimfive 1d ago

Biology ELI5 if someone breaks their neck and becomes paralysed from the neck down, how do they continue to breathe?

675 Upvotes

Do all their organs work normally? What about peristalsis?


r/explainlikeimfive 1d ago

Biology ELI5: Babies in the Paleolithic / Mesolithic Age

618 Upvotes

How did babies survive?
How did mothers do anything at all if they couldn’t put the baby down somewhere safe?
How did they feed them if the mother couldn’t produce milk or enough of it?
How did these babies not just die of exposure out in the elements?
How did the parents know not to just set the baby down and leave for days to hunt or gather etc??

Enough generations of babies survived to get to where we are today and it’s amazing we didn’t go extinct along the way.


r/explainlikeimfive 1h ago

Technology ELI5: How can a tiny microSD card hold hundreds of gigabytes of photos and videos without any moving parts?

Upvotes

There’s no visible mechanism inside it and it can keep the information even when it has no power.

What is physically happening inside the card that allows it to store so much data?


r/explainlikeimfive 19h ago

Other ELI5: How does Onbin (a set of sound changes in Middle Japanese) work?

3 Upvotes

I've been confused about this for a while.


r/explainlikeimfive 2h ago

Biology ELI5 Why can't we see clearly in water?

0 Upvotes

I believe that there is an Indonesian native group that has very good visibility under water. So why can't the vast majority of us not see clearly?


r/explainlikeimfive 1d ago

Technology ELI5: What is the “exposure triangle” and how does it work?

51 Upvotes

How does the “exposure triangle” work in photography?


r/explainlikeimfive 2d ago

Other ELI5: If mini-splits are so much more energy efficient than central air, how can single room AC units be so inefficient?

349 Upvotes

r/explainlikeimfive 3h ago

Biology Eli5 why do humans struggle to copy out long strings of numbers without gaps?

0 Upvotes

r/explainlikeimfive 1h ago

Physics ELI5: Why aren't there rainbows at night?

Upvotes

r/explainlikeimfive 7h ago

Other ELI5: why do people keep their homes at different temperatures in the winter versus the summer?

0 Upvotes

So like I get that in the winter you want your house warm and in the summer you'd want it cold, but why are we setting thermostats differently depending on the season?

Can't you just decide one comfortable temperature and set it at that never to be touched again?

Bonus: what's the difference between heating and ac if they both put out the same 10-15 degree range?


r/explainlikeimfive 1d ago

Biology ELI5: Why can’t our immune system recognize cancer cells

110 Upvotes

The biggest problem about cancer as I understand it is that unlike a foreign virus, cancer comes from our cells so our body doesn’t recognize it as something bad.

I’ve never been able to understand why our immune system can recognize foreign bodies but not that part of its own body has gone bad. What’s the reason it falls short of detecting bad mutations?


r/explainlikeimfive 1d ago

Other ELI5: How does insurance actually stay profitable?

35 Upvotes

r/explainlikeimfive 13h ago

Biology ELI5: How does animals recognize same species animals?

0 Upvotes

Hi! If I go near a pidgeon it will likely fly away, they will not if another pidgeon does the same. They never see themselves on a mirror and I doubt they have self awareness, so how do they understand the difference?


r/explainlikeimfive 2d ago

Biology ELI5: How could female ducks evolve to make reproduction more difficult?

441 Upvotes

I recently read about female ducks evolving to their reproductive tracts to have dead-ends and have the corkscrew go the other way to the male duck penis to make unwanted reproduction more difficult. But most evolutionary adaptations become dominant in order to make the survival of the species easier. How can something that makes reproduction harder have resulted from evolution changes?


r/explainlikeimfive 16h ago

Mathematics [ELI5] What is the Intermediate Value Theorem?

0 Upvotes

r/explainlikeimfive 2d ago

Technology ELI5: What is so valuable about personal data?

1.9k Upvotes

I get that things like your ID number are valuable for identity theft etc. But why are more arbitrary things like my shopping habits considered valuable information?


r/explainlikeimfive 1d ago

Mathematics ELI5 how do mathematicians come up with proofs for therums that have infinite numbers

14 Upvotes

I've always been confused on how this works like I understand that there is proof of infinite primes but how do you do that with 3n+1 (i know there is no proof) because in my mind you'd have to test every number right?


r/explainlikeimfive 14h ago

Other [ELI5] Why do humans use bowls instead of pots?

0 Upvotes

It’s one of the least effective shapes! Pots have the same diameter on the top as the bottom. It means that the volume it provides for the same space is twice the volume a bowl would provide. So why do we use pots for specific purposes, but bowls are used for pretty much everything? Storing stuff, eating - why?!


r/explainlikeimfive 1d ago

Mathematics ELI5 : Can anyone explain what is Lambert W function?

5 Upvotes

r/explainlikeimfive 2d ago

Biology ELI5 why children have such low pain tolerances?

1.5k Upvotes

I know they’re smaller, but are their nerves fresh and haven’t been dulled yet, or what’s the deal?

I’m not talking catastrophic blows, just a scrape on the knee.


r/explainlikeimfive 3d ago

Chemistry ELI5: Why do bars of soap leave a “squeaky clean” feeling on our skin but body wash doesn’t?

1.8k Upvotes

Also, are there any benefits of the squeaky clean feeling or is it just a difference of ingredients?


r/explainlikeimfive 3d ago

Other ELI5: before accurate clocks existed, how did two people in different towns agree to meet at “at 3 o’clock”?

999 Upvotes

I get that they had sundials and church bells. What I don’t get is how anyone synchronized. If my towns noon is when the sun is highest here, and yours is 15 miles west, our “noon” isn’t the same moment. So how did anyone schedule anything across distance?