This Blew My Mind!
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Did you know that the Milky Way galaxy, one of 2 trillion galaxies that we know of (and my intuition is that it is one of an infinite number of galaxies), is so vast that if it were the size of the continental US, our solar system would be the size of a quarter, and Earth the size of a grain of sand?
Mind-boggling—check out this incredible video on the topic.
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My mind is definitely blown!
I always love to inform my students of the factoid that there are as many stars in our galaxy as there are grains of sand on every beach across the entire planet!! And each one of those stars is a sun that has its own planets orbiting around it.
WTB
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@mclaincausey I need a lie down after watching that. Absolutely mind blowing. Thanks for sharing.
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@Mizmazzle I know this fact, and it's one that I've repeated, yet our brains cannot comprehend that scale of anything, and it will never cease to absolutely amaze me. And the fact that the universe is also constantly expanding in every direction hurts my brain. And if it weren't expanding, and it just IS, is it just... infinite?!
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@seawolf thank god I had a couple sips of coffee before I read your post, otherwise my brain would have gone into full scale, level 5, meltdown.
And by definition of infinite, the universe MUST be expanding…otherwise we’d reach an end point and someone would finally win the “I called shotgun, no place backs, time infinity!” Rule.
WTB
IHSH 301 large -
What blows my mind beyond the fact that it's expanding, is that the rate of expansion is accelerating, not decelerating or staying constant. Then you get into dark matter and dark energy...
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A couple more for you.
The scale I talked about for the size of the galaxy, which requires 120,000 years for a beam of light moving at the maximum physically possible speed through space, is inconsequentially small next to the size of the observable universe, which is 93 billion light years. Because the expansion of space isn’t limited by light speed, the relative speed of recession for far flung galaxies exceeds the speed of light.
Here’s the kicker: as vast as the universe is known to at least be, there are more orders of magnitude to the smallest possible scale (the Planck length) than there are to the largest observable scale (the observable universe). The observable universe : us is not as large of a difference as us : the smallest possible scale understood by physics.
There are four kinds of multiverses in the way that Max Tegmark breaks it down and I’ll summarize those when I have more time later.
Think it, be it.
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Yep. I find this very interesting while comprehending very little at the same time.
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@mclaincausey I love this stuff…preach brother!
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Here is Tegmark’s pop science article about multiverses: https://space.mit.edu/home/tegmark/PDF/multiverse_sciam.pdf
Level 1: this is saying that the universe is likely to be large enough for a given configuration of particles in space to be infinitely replicated. So there would be an infinite number of copies of us, for example, across an unimaginably large swath of space and time. Anything that the laws of physics allows happens somewhere. Any possible configuration of particles within a given space happens somewhere. These would not be observable since they would be so far away and receding from us at over the speed of light—no signal could reach us. It is beyond our “cosmic horizon.“ while I think this is probable, it’s not testable and thus more philosophy than science, which is true of a lot of this. But there is reason to suspect it’s true.
Level 2: the predominant theory for the formation of our universe is called cosmic inflation. This theory predicts that we are in one of a possibly infinite number of “bubbles” that form after a period of inconceivably rapid expansion of the universe. Each bubble would have its own physical constants and laws of physics. If there is an infinite number of them, eventually one identical to ours would be out there.
Level 3: the most parsimonious explanation for the “weirdness” of quantum theory where a particle doesn’t have a position until it is observed is something called the universal wave function or the many worlds interpretation of quantum mechanics, versus the Copenhagen interpretation which says the act of observation somehow collapses a waveform of probably locations into a single discrete location. This interpretation basically says that all locations are valid, and that the universe splits in along every valid location.
Level 4 gets into simulation theory and that we’re living effectively in a vast computer.
I think 1, 2, and 3 are probably true.
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Me, pretending to understand this thread, whilst wishing I hadn’t rewatched The Matrix yesterday…
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I only popped on here to look at the jeans.
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@Mizmazzle This honestly made me nauseated for a second as my brain tried to comprehend.
