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Ask HN: What is a science fact that blew your mind when you learned it?

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Re: Ask HN: What is a science fact that blew your mind when you learned it?

#21

The 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????

The dual slit experiment produces different results? I must be thinking of something else - I thought that electrons passing through a dual slit always produce an interference pattern.

Anyone got a link?

Re: Ask HN: What is a science fact that blew your mind when you learned it?

#23
I 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.

Re: Ask HN: What is a science fact that blew your mind when you learned it?

#24

The 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????

The dual slit experiment produces different results? I must be thinking of something else - I thought that electrons passing through a dual slit always produce an interference pattern. Anyone got a link?

There is a long Wikipedia article at

https://en.wikipedia.org/wiki/Double-slit_experiment

The most mind boggling aspect of this for me is the single photon version, which is under the "Interference of individual particles" section of the above article. The point is that you get an interference pattern even when only a single photon at a time is sent through the slits!

Re: Ask HN: What is a science fact that blew your mind when you learned it?

#30

When i could "see" my visual blindspot. https://lasikofnv.com/try-these-3-fun-tests-to-find-your-vis... .

somewhat related, I was so glad when I found out the reason behind a dim bulb that's just turned off appearing brighter when _you look away_.

The answer is in the density of rod cells (which are photon receptors of the eye that specialize in low-light) are concentrated on the outer edges of the retina. So if you look straight at a dim bulb - the photons hit the cone cells, which aren't sensitive enough, but if you look away, the photons hit the rod cells and you can see the bulb!

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