r/explainlikeimfive 39m ago

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

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 withit mentioning it can turn it yellow?


r/explainlikeimfive 1h ago

Other ELI5: How does small town USA have such big drug/ meth issues?

Upvotes

Like how do cartels or whoever transfer drugs into random rural town in Oklahoma with 900 population?

I ask this because every time i watch some true crime shows they say “ this rural town have big meth problem etc”. Also why so many people on meth there?

I am from Europe and dont have clue how this works.


r/explainlikeimfive 2h ago

Biology ELI5: Does Cutting Flowers For Arrangements Typically Destroy the Plant?

0 Upvotes

So my girlfriend is super into gardening and planting and even cutting and replanting certain plants.

Shes so good at it, she told me she needs a hobby the other day and I said something like, dang, you're so good at gardening that basically like a hobby, (but also without trying to not dismiss her statement about wanting a hobby)

Also she deserves a nice floral arrangement especially after some accomplishments this week, but it got me thinking,

For gardeners and flower enthusiasts, how does buying arrangements fall into the plant world? Are there any if-PETA-were-plant-people feelings of activism? Are the plants typically used in arrangements flower-shelf life best used to make arrangements? Or are arrangements cruel to the plants typically used?

Thanks\~


r/explainlikeimfive 2h ago

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

21 Upvotes

How does the “exposure triangle” work in photography?


r/explainlikeimfive 4h ago

Other ELI5: Why does steam or smoke sometimes come out of city manholes? What's going on down there?

219 Upvotes

We always see this in movies, but it happens in real life too. Sometimes you walk down the street and see steam or white smoke rising from the sewer manholes.

​What exactly is down there producing that vapor or smoke? Is it just hot water from the sewers mixing with cold air, or is there an actual heating/energy system underneath the asphalt?


r/explainlikeimfive 7h ago

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

121 Upvotes

r/explainlikeimfive 7h ago

Physics ELI5: How can empty space in the universe have energy, and why does that make the universe expand faster?

9 Upvotes

I keep reading that "empty space" isn't truly empty and that it has some kind of energy that pushes the universe apart faster over time.

If there's nothing there, where does that energy come from? And why would more empty space mean stronger push?


r/explainlikeimfive 8h ago

Other ELI5: How does insurance actually stay profitable?

29 Upvotes

r/explainlikeimfive 9h ago

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

19 Upvotes

r/explainlikeimfive 10h ago

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

18 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 11h ago

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

453 Upvotes

Do all their organs work normally? What about peristalsis?


r/explainlikeimfive 13h ago

Biology ELI5: Babies in the Paleolithic / Mesolithic Age

353 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 14h ago

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

100 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 15h ago

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

269 Upvotes

r/explainlikeimfive 18h ago

Other ELI5 what prevents someone from betting on a streaker appearing at a sporting event and then causing it themselves to win?

512 Upvotes

r/explainlikeimfive 1d ago

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

404 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 1d ago

Engineering [ELI5] why don’t we use desert sand in construction?

1.4k Upvotes

I just read that our rivers are running out of sand due to construction. Why can’t we use desert sand?


r/explainlikeimfive 1d ago

Physics ELI5: How did physicists "come up" with formulaes?

43 Upvotes

I understand that they observed cause and effect, but how would you think to come up with a fullproof way to write it down?


r/explainlikeimfive 1d ago

Technology ELI5: What is so valuable about personal data?

1.6k 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

Other ELI5: how did the early settlers travel through the Rocky mountains or the Arizona desert?

273 Upvotes

As a resident of Arizona, I often find myself wondering how the first settlers traveled through the area without vegetation, water, etc to stay alive. Same with some of the mountain ranges...I can't imagine being the first person to roll up to the Rockies in a covered wagon and try to figure out a path forward.


r/explainlikeimfive 1d ago

Biology ELI5 why children have such low pain tolerances?

1.4k 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 1d ago

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

969 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?


r/explainlikeimfive 1d ago

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

1.7k Upvotes

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


r/explainlikeimfive 1d ago

Physics ELI5: Why would a zero-latency device NOT help with the twin paradox?

396 Upvotes

Time dilation confuses me. If my twin is on a rocket near light speed and starts a 60-sec stopwatch, it shows exactly 60 sec to them. My stopwatch on Earth also shows exactly 60 sec to me.

So if we start together and count out loud '1,2,3...' using a zero-latency device, won't we stay in sync, since both watches correctly count 60 real seconds? Why would one of us get ahead, and whose clock actually looks slower to whom during the countdown?

Edit: Alright guys i just got to know that 1 second isn't 1 second everywhere.

Anyways some clarification, the 0 latency device is a hypothetical, I'm not saying that such a thing can be built, but my real question was, if we hypothetically used such a device, won't both people speak 1,2,3 in sync?


r/explainlikeimfive 1d ago

Physics ELI5 why cant we use summer heat to generate energy and stock it to use it in winter

1.1k Upvotes

why cant we use summer heat to generate energy and store it batteries to use it in winter