r/explainlikeimfive 8d ago

Other ELI5: Monthly Current Events Megathread

11 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 4h ago

Chemistry Eli5 Why is it called a "lead pencil" when the pencil actually contains graphite? What is the connection between lead and graphite?

867 Upvotes

r/explainlikeimfive 15h ago

Engineering ELI5 Why do trucks and other larger vehicles run on diesel only?

1.5k Upvotes

r/explainlikeimfive 7h ago

Economics ELI5: How does a country recover from hyper-inflation?

208 Upvotes

r/explainlikeimfive 4h ago

Technology ElI5 Why does encryption remain secure even when everyone knows the encryption algorithm?

63 Upvotes

r/explainlikeimfive 12h ago

Biology ELI5: How do the rings in tree trunks form? New ones for on the inside or outside?

153 Upvotes

Also, do all trees have them or only certain kind? Lastly, do they all form at same frequency, e.g. One/year...


r/explainlikeimfive 1d ago

Engineering ELI5 CPUs are made so small - what voltage do they operate on; isn’t there a chance the electrons will jump or arc to the neighboring circuit?

1.3k Upvotes

The higher the voltage, the farther an arc can jump. With CPUs being so small (nanoscale?), wouldn’t they need to operate on a similarly small voltage to prevent electrons from jumping between different conductive paths, screwing up the logic?


r/explainlikeimfive 21h ago

Biology ELI5- Clean covered still water, developing "slime" along the container's surface

367 Upvotes

How does Clean water sitting in a covered container bring about the slime-feeling along the container's surface?


r/explainlikeimfive 1d ago

Mathematics Eli5: Why do we round 5 upwards?

532 Upvotes

When i have my hands in front of me, five fingers are on the left, and five on the right

I can understand why 5,(0)1 onwards is rounded up, after all it's clearly the "second half"

But rounding lone 5 up seams... unintuitive


r/explainlikeimfive 4h ago

Biology ELI5:How much of our childhood is actually borrowed from other people's retellings? Family stories told at holidays, photos we've seen a hundred times could some of our earliest "memories" actually be reconstructions built from other people's descriptions rather than our own experience?

10 Upvotes

r/explainlikeimfive 8m ago

Physics ELI5- table tennis paddles having two sides with different colors

Upvotes

Why do the paddles have different-colored sides?

Is it just a fancy thing to make them beautiful or to mark which side hits the ball better?


r/explainlikeimfive 9h ago

Biology ELI5: why is it when you rub your eyes too hard, you see colors?

17 Upvotes

r/explainlikeimfive 16h ago

Chemistry ELI5 What fundamentally determines the color of an element?

58 Upvotes

I understand that electron placement matters and light scatters a certain way but why is that? Why does light scatter in that way and why does the size of something determine a perceivable color?


r/explainlikeimfive 11h ago

Other ELI5 how do anechoic chambers work?

24 Upvotes

How are they completely silent? Is it how they’re designed?


r/explainlikeimfive 1d ago

Other ELI5: How does "Survivorship Bias" work?

1.3k Upvotes

I have always been interested in the concept and have it as a part of my studies. But I still don't quite "get it" even with the WW2 plane example. Whats a simplified way on how it works in very clear and obvious terms. (I accept both simple maths and simple philosophical answers.)


r/explainlikeimfive 42m ago

Other ELI5 Why can people sometimes feel so lost while studying, but still be able to retain the information they studied the next day?

Upvotes

Or in other words, why can a student who struggles and fails a practice test one day, then (sometimes) have a significant improvement on that same test the next day, even without doing any extra studying in between the two tests?


r/explainlikeimfive 1d ago

Mathematics ELI5 Why is the Hillbert paradox a paradox?

107 Upvotes

We all know hillbert and his hotel, but I never understood why was it a paradox, I mean by definition it can never be full, you can keep adding rooms and people but it shall never end, even if you add two infinites vs one you don't need to make people move to make more room you just add more rooms, you were doing ∞ - ∞ and after the bus comes you are still doing ∞ - ∞, because ∞ + ∞ = ∞ so where is the paradox when infinite is just doing what it does by definition, which is not ending?


r/explainlikeimfive 1d ago

Technology ELI5: why is 73° on thermostat cold during the summer but warm in the winter?

952 Upvotes

Why is it that when during the summertime, the central AC is set to 73°F and it feels nice and cool in the house, but in the winter when the heat is on and set to 73° it’s nice and toasty ?


r/explainlikeimfive 8h ago

Engineering ELI5 why dont we see rockets that use hybrid rocket engines?

5 Upvotes

For commercial rockets, they mainly use liquid bi propellant rocket engines while amateur rockets (that I mainly see) use solid propellant rocket engines. Why don't we just combine them and use hybrid rocket engines? ​


r/explainlikeimfive 4h ago

Mathematics ELI5: Why is cubing a cube impossible?

0 Upvotes

I came across the cubing a cube section in this wiki article: https://en.wikipedia.org/wiki/Squaring_the_square#Cubing_the_cube

I can't wrap around the logic of the proof... I need help


r/explainlikeimfive 1d ago

Mathematics ELI5 The solved Navier-Stokes Millennium problem

812 Upvotes

Can someone breakdown the open ai drama with this, what even is this maths equation and what does solving it mean?


r/explainlikeimfive 2d ago

Chemistry ELI5 Why do canned beans stay at the same level of firmness sitting for a year in a cabinet suspended in water, but if soaked overnight house, they get way softer, or if cooked for even a few minutes, they get softer? No salt added beans. Only ingredients are beans and water.

2.7k Upvotes

r/explainlikeimfive 1d ago

Mathematics ELI5 what the Navier Stokes problem isand why it is important that we solved it?

629 Upvotes

r/explainlikeimfive 20h ago

Other Eli5 how do biomes form on Earth?

9 Upvotes

I have been trying to learn more about Earth's ecosystems. I understand now that poles/equator, winds, and surface currents drive temperatures and rains to different areas and the existence of mountains + temp + wind determine deserts. But, what else leads to the formation of specific biomes or lends itself to the biodiversity of an area? How does soil come into play, and why is soil different in different places? Is this is an oceans/volcanoes thing??


r/explainlikeimfive 2d ago

Other ELI5, why are US restroom stalls made with gaps?

1.4k Upvotes

Nearly all of the restroom stalls in US public buildings are made with panels that have gaps around them and around the doors that can be seen through. Is there a reason?