I was pretty amazed by the Casimir Effect when I first learned of it. https://en.wikipedia.org/wiki/Casimir_effect
I think I need to get an advanced degree just to be able to read that wikipedia entry.
Ask HN: What is a science fact that blew your mind when you learned it?
111–120 of 189 posts
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#112A gallon of gasoline creates 20 pounds of carbon dioxide. So my trip to the grocery store could be adding as much carbon dioxide to the air as the groceries I pick up!
That is fascinating. A gallon of gasoline weighs 6 pounds, so it probably must be using 14 pounds of oxygen.
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#113Growing up, I was taught that the main reason why it's bad to drink is because it kills brain cells and brain cells don't grow back. Apparently that is not the case anymore: https://www.scientificamerican.com/article/the-adult-brain-d...
It's exercise that causes the brain growth.
(the famous rat experiment with the "stimulating environment" and brain grown was later attributed to the exercise wheel)
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#114That when we look up at distant stars, nebulas, & galaxies and the like...we are looking back in time. What we see could have been gone for decades, centuries, or longer.
Sort of similar to tree rings and even... dirt. We could probably dig in our backyards and find artifacts of 10,000 year old life. We are transient.
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#115How prion diseases work and spread. They're basically infectious lego. You may not thank me if you read about them...
I read somewhere they survive even 1000°C cleaning of stuff.
Maybe dental implements.
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#116Electrons in a copper wire do not travel at the speed of electricity. Not even close. Electricity travels at nearly the speed of light. Electrons themselves travel like molasses: "In the case of a 12 gauge copper wire carrying 10 amperes of current (typical of home wiring), the individual electrons only move about 0.02 cm per sec or 1.2 inches per minute (in science this is called the drift velocity of the electrons.…
Movement of charge is more like wave in water than flow of water. Also, the current tends to travel on the outside (skin) of the conductor.
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#117That something trivial like seeing speckle patterns in my eyes when I'm tired is proof of the quantum nature of light.
Interesting. How does that work?
I'm sure I'll do a poor job articulating it. It's similar to bokeh that photographers are familiar with. You look at a light source and the light seems to bounce through the pupil and back out again. If there's a drop of liquid on your eyelashes you'll see a bokeh ring with interference ripples around the edge.
I just remember as a child I thought it was strange, then in high school physics I saw how laser light was always grainy, and even things like the solidity of matter can be thought of as optical illusion (caused by the wavelengths of visible light casting a well-defined shadow).
Then later I got into photography and realized what you can do with even a little knowledge about light and optics. I still have a sense of wonder about it even though I'm an average shooter at best.
Hope that all made sense.
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#118I absolutely cannot psychologically deal with the Monty Haul paradox. https://en.wikipedia.org/wiki/Monty_Hall_problem I've coded it multiple times in multiple programming languages as a cathartic exercise. Despite seeing the results obviously printed out in a console in front of me, I just can't handle it. I lose SAN just thinking about it.
The explanation that makes the most sense to me, from wiki: Yet another insight is that your chance of winning by switching doors is directly related to your chance of choosing the winning door in the first place: if you choose the correct door on your first try, then switching loses; if you choose a wrong door on your first try, then switching wins; your chance of choosing the correct door on your first try is 1/3,…
The bit that gets me... If he opens one door, which is a goat, so there is 1 goat and 1 prize remaining... then the chance should be 50% staying put or switching, right? That's the part that gets me. The whole bit about 3 doors and opening one of them and "do you want to switch" is all a ruse, it seems to me. At the end of the day there are two doors, one with a goat and one with a prize, and however you choose between 2 doors, you will win or lose 50% of the time. Right? Aargh the SAN loss...
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#119That there is such a thing as deterministic chaos (aka the butterfly effect), ie. infinitesimal perturbations can quickly produce macroscopic changes, and all the philosophical implications that result from it. That despite the apparent complexity of the weather many atmospheric phenomena can be explained from first principles with pen and paper calculations. That the existence of elementary particles can be derived…
Isn't that just probability distributions?
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#120Earlier quoted context omitted.
Interesting. How does that work?
I'm sure I'll do a poor job articulating it. It's similar to bokeh that photographers are familiar with. You look at a light source and the light seems to bounce through the pupil and back out again. If there's a drop of liquid on your eyelashes you'll see a bokeh ring with interference ripples around the edge. I just remember as a child I thought it was strange, then in high school physics I saw how laser light was…
This is what I'm taking about, when I was a kid before I got fitted with glasses, I remember the world looking like this...
https://photo.stackexchange.com/questions/99407/what-is-the-...