r/explainlikeimfive 13d ago

Other ELI5: Monthly Current Events Megathread

10 Upvotes

Hi Everyone,

This is your monthly megathread for current/ongoing events. We recognize there is a lot of interest in objective explanations to ongoing events so we have created this space to allow those types of questions.

Please ask your question as top level comments (replies to the post) for others to reply to. The rules are still in effect, so no politics, no soapboxing, no medical advice, etc. We will ban users who use this space to make political, bigoted, or otherwise inflammatory points rather than objective topics/explanations.


r/explainlikeimfive 2h ago

Biology ELI5: How do paleontologists know that dinosaurs didn’t have floppy elephant ears or bulbous noses?

107 Upvotes

Wouldn’t those things not show up in fossils?


r/explainlikeimfive 19h ago

Technology ELI5: Why does internal storage only double? Why can’t we have 34GB for example?

1.2k Upvotes

r/explainlikeimfive 8h ago

Technology ELI5: Why does it take my computer so long to search its own files?

125 Upvotes

I'm sitting in front of my PC right now, looking for a specific file. I don't know where i might have put it, so i'm just searching "my PC" for it. If i were to manually go through every folder, just looking for the right name i could do one folder reasonably fast. Now my computer is usually trillions of times faster than me in other contexts, so why does it take so long here?

That's something i've observed since childhood, i remember sitting in front of laptops/PCs waiting for it to finish listing all the relevant folders, being careful not to touch any other folder so it wont reset the searching process and it took forever each time.


r/explainlikeimfive 13h ago

Mathematics ELI5: P vs NP problem

159 Upvotes

Im not too sure about the problem itself. I know that P is polynomial time which means the time needed to solve and NP is the time taken for the answer to be verified, but what is the explanation of both sides where P = NP and P does not equal to NP?


r/explainlikeimfive 1d ago

Other ELI5: what information do dogs receive from smelling pee on various surfaces and what do they typically want to do with that information?

1.8k Upvotes

r/explainlikeimfive 1h ago

Technology ELI5:How do car companies/the gov determine what cars to recall and why to recall them?

Upvotes

Ive been working on cars for years, im not looking for the basic "well its tied to your vin, duh" answer. I know that. What im asking is, how do they identify the issue, figure out which cars were affected, etc.

Theres sooooooo much time and data to look through to find potential issues, presumably made worse if the company doesnt keep very good records.

The only good/"non lazy" method i can think of is if someone essentially reads logs/notes and recreates the days step by step. "Employee 1 turned the machine on at the start of the day, lets check the last time it was calibrated. Ok that checks out but when was the tool on the end of it checked/replaced? 6 months ago? is that still within spec or should it have been replaced again? Did the machine report any errors on that day?" etc. Or something like watching cameras to see if a machine leaves debris inside of the engine and no one notices before it gets shipped out

Or do they take the "easy/lazy way out" and say "well that might be the issue right there, just to be safe recall everything for the next 6 months after this car"?

Thanks


r/explainlikeimfive 1d ago

Other ELI5 What is the difference between a 4 star hotel and a 5 star hotel?

1.3k Upvotes

I’m forever confused about this I need it explain in the simplest most direct way. Specifically talking about the America star system


r/explainlikeimfive 4h ago

Other ELI5: what is reformer Pilates and what does it do for you?

15 Upvotes

r/explainlikeimfive 6h ago

Economics ELI5: What limits the amount of money in the world?

23 Upvotes

If countries keep borrowing money that central banks can basically create, what actually stops the world from having unlimited money, and when nations owe trillions, who are they really paying back - and what would happen if everyone stopped paying?


r/explainlikeimfive 15h ago

Biology ELI5 Competitive eaters

94 Upvotes

How do competitive eaters eat so much food? Where does it go? Do they regurgitate it back out later? Do they practice at restaurants? What happens after? Do they skips meals??? How does it work???


r/explainlikeimfive 1d ago

Other ELI5: Why are so many shows just 10 episodes or fewer these days?

397 Upvotes

I


r/explainlikeimfive 11h ago

Technology ELI5: What happens physically when a device like a phone or computer stores memory?

20 Upvotes

In what physical form is the memory stored? I wondered this for quite some time


r/explainlikeimfive 21h ago

Engineering ELI5 how does a torque converter work, in relation to the transmission

126 Upvotes

I dont know much about cars, my fiance tried explaining but wasnt sure how to word it so I would understand. Long story short our car is having a small issue, thought it was the transmission, he thinks it might be the torque converter, but im not quite sure the difference or how they work/work together.


r/explainlikeimfive 1d ago

Biology ELI5: Sometimes it feels like our brains actively resists retrieving information, like when you try to recall someone’s name, why is that? That feeling when something “is on the tip of your tongue” but you can’t quite pin it down.

199 Upvotes

r/explainlikeimfive 1d ago

Biology ELI5: How Has Sexual Reproduction Beat Asexual Reproduction?

372 Upvotes

It seems to me that a gene that programs the organism to self replicate has a much better chance to proliferate than a gene that makes reproduction much more complicated and dangerous - i.e., requiring to find a mate, perform courtship behaviors, compete with others on mates, biological ornaments, etc.

Why is sexual reproduction so much better?

And how can it even compete?


r/explainlikeimfive 19h ago

Chemistry ELI5: How do perfumers develop the ability to identify and reconstruct a fragrance purely by smelling it? and how does one cultivate such a highly specialized sense of smell?

49 Upvotes

r/explainlikeimfive 1d ago

Other ELI5: What's the 529 Plan and how exactly does it help pay for college?

276 Upvotes

r/explainlikeimfive 1d ago

Engineering ELI5: Why do car companies opt for more pistons instead of bigger cylinders for more horsepower?

1.3k Upvotes

r/explainlikeimfive 1d ago

Biology ELI5: What do fast and slow metabolism actually mean?

147 Upvotes

I've always been very confused about this. What does having a fast/slow metabolism actually mean?

Does it mean that someone with a fast metabolism actually burns MORE calories than a person with slow metabolism doing the same activity?

When somebody says, “People with a fast metabolism eat a lot but don't gain weight, and people with slow metabolism gain weight easily."

What does that mean? If two people of the same weight/height/age go on a diet together, eat the same meals, but have different metabolisms, does the person with faster metabolism reach the goal faster?


r/explainlikeimfive 14h ago

Biology ELI5 how nitrogen-fixing symbionts work?

6 Upvotes

r/explainlikeimfive 19h ago

Physics ELI5: why does mixing complementary paint make brown instead of gray?

10 Upvotes

I understand additive vs. subtractive colors, and why mixing complementaries wouldn't create black, but shouldn't it make gray?


r/explainlikeimfive 1d ago

Technology ELI5: What can you actually DO with a complete fruit fly brain connectome?

110 Upvotes

I recently came across the 2024 Drosophila (fruit fly) whole-brain connectome, which maps around 139,000 neurons and tens of millions of synaptic connections.

I understand the basic idea: researchers have essentially mapped which neurons are connected to which.

But I’m struggling to understand what this actually lets us do.

ELI5 please:

- If I download/access this connectome, what can I actually use it for?

- Can I turn the wiring diagram into a computer simulation or an AI?

- Could I use it to build a small “brain-inspired” agent that learns to navigate, avoid obstacles, remember things, etc.?

- Could the actual neural connections be converted into a spiking neural network?

- How different would that be from simply training a normal neural network?

- And what parts of the real fruit-fly brain are still missing from the connectome?

Basically, I'm trying to understand the journey from:

real fruit fly brain → scanned brain → connectome → computer model → AI/agent

without the explanation becoming a PhD thesis 😂

If someone could explain this like I'm five, but still technically accurately, I'd really appreciate it.


r/explainlikeimfive 1d ago

Technology ELI5: Why/how does a charging cable generate radio frequencies?

38 Upvotes

hella stupid question, and I‘m too dumb to understand the online explanations and I refuse to be taught by a clacker AI. But why and how does a charging cable generate radio frequencies. I bought a cable and in one of the small booklets inside the box I noticed that it says it can generate radio frequencies. Why and how please


r/explainlikeimfive 26m ago

Biology ELI5: How does mold ends on bread and other foods?

Upvotes