That 'normal' matter only makes up 5% of the universe. That some omnipresent dark energy field makes up the majority (63%) of the universe.
Ask HN: What is a science fact that blew your mind when you learned it?
41–50 of 189 posts
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#42The selective attention test, aka the "invisible gorilla" experiment, and the finding that 50% of people didn't see the gorilla.
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#43From Introduction to Elementary Particles by David Griffiths: a neutrino of moderate energy could easily penetrate a thousand lightyears of lead.
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#44A compressed spring weighs more than the same spring uncompressed. The moon and earth weigh less together than if you weighed them separately and added the values together. Most of the weight of solid objects is due to the high speeds and binding energies of the elementary particles within them rather than the rest mass of the constituent particles. The number of particles that exist is relative to how fast you are a…
>A compressed spring weighs more than the same spring uncompressed.
This is false. The dilemma is that you can't "just weigh" a compressed spring without assistance. However, you can get around it by weighing a compression device with the spring, both when it's compressing and not compressing the spring. The weight will be the same.
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#45A compressed spring weighs more than the same spring uncompressed. The moon and earth weigh less together than if you weighed them separately and added the values together. Most of the weight of solid objects is due to the high speeds and binding energies of the elementary particles within them rather than the rest mass of the constituent particles. The number of particles that exist is relative to how fast you are a…
> The number of particles that exist is relative to how fast you are moving.
I thought the existence of particles was relative to how fast you're accelerating? If it's relative to how fast you're moving, wouldn't that imply that absolute velocity exists, i.e. that given two objects with known relative velocity to each other, we could potentially establish which one was "really" moving and which one was "really" still?
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#46The dual slit experiment. Run the experiment with no one watching it, it produces result A. Run it again and watch it, it produces result B. Watching the experiment changes the result. WTF????
It's false information. It's debunked multiple times. "Watching" means "placing or turning on an additional detector", which ruins interference pattern. To develop intuition, look at double slit experiment made at macro scale using walking droplet.
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#47I think "mind blown" is an accurate description when I first saw the Hubble Deep Field image: https://hubblesite.org/contents/articles/hubble-deep-fields I already knew that "the universe is incomprehensibly large", but seeing how many entire galaxies there were in a random dark patch of sky was eye opening to me.
I've been getting into astronomy a bit and found this image to be awe inspiring: https://upload.wikimedia.org/wikipedia/commons/4/4a/Location...
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#48A compressed spring weighs more than the same spring uncompressed. The moon and earth weigh less together than if you weighed them separately and added the values together. Most of the weight of solid objects is due to the high speeds and binding energies of the elementary particles within them rather than the rest mass of the constituent particles. The number of particles that exist is relative to how fast you are a…
>Most of the weight of solid objects is due to the high speeds of the elementary particles within them rather than the rest mass of the constituent particles. Wait i agree energy is mass but is this specifically correct? The rest mass is always much higher when i've seen it in equations.
Whoops, I forgot binding energy. But yes, rest mass of quarks is only about 1% of a proton or neutron’s mass.
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#49A compressed spring weighs more than the same spring uncompressed. The moon and earth weigh less together than if you weighed them separately and added the values together. Most of the weight of solid objects is due to the high speeds and binding energies of the elementary particles within them rather than the rest mass of the constituent particles. The number of particles that exist is relative to how fast you are a…
> The number of particles that exist is relative to how fast you are moving. I thought the existence of particles was relative to how fast you're accelerating? If it's relative to how fast you're moving, wouldn't that imply that absolute velocity exists, i.e. that given two objects with known relative velocity to each other, we could potentially establish which one was "really" moving and which one was "really" still…
Should have said how fast you are accelerating. Edited now. See http://www.scholarpedia.org/article/Unruh_effect
Re: Ask HN: What is a science fact that blew your mind when you learned it?
#50Not a fact per se, but: the sheer amount of living things that came before me, in the sense of my direct ancestors and their direct ancestors etc. etc – not only my human ancestors, but the whole of my ancestors all the way back to the origins of life itself – and I would not be here today if even one of them would have died before reproducing... that manages to blow my mind every single time I think about it.
And it can be reeeeally depressing to think about for those that aren't having children.