Tangible pervasiveness
Matter can indeed sprout out of nothingness, causing the universe to expand.

“Nothing" is one of those words that inspire all sorts of musings. Not, of course, in the sense used to answer questions like “What've you been up to?"
But the nothing nothing—the void, total emptiness. Is there such a thing? Or is Nothing—let's use a capital “N" to characterize it—just an idea, a concept we invented to help us organize the way we see the world?
In the real sense of the word, this is a metaphysical question—the branch of philosophy concerned with the first principles of things, including being, space, time, cause, etc. But then, it is also a very physical question, concerning the stuff that exists in the universe.
There is a sense where Nothing can only be conceived in a materialistic worldview: “Nothing" would mean the absence of matter, the no-stuff parts of reality. The Greeks were into it—at least the Atomists Leucippus and Democritus, and, later, Epicurus. To them, all that existed was Atoms and the Void, bits of matter moving about in perfectly empty space, i.e., Nothing. So it had to be a materialistic worldview with an added property, that matter was made of tiny bits of stuff, perfectly separated and independent from one another. There were no forces between them, they just collided and stuck to one another upon touching.
Aristotle would have none of it. He conceived reality as never having any emptiness. Space was filled up with “ether," the fifth essence. So, Aristotle added a strange kind of matter to the mix, a matter that had different properties from the usual kinds of matter we see. This idea, with variations, would come in and out of fashion throughout the centuries, as physicists grappled with the bizarre twists reality threw at them.
Religions complicate the conversation, especially the ones that presuppose omnipresence, that the divine essence is everywhere at once. So even if matter may be discrete and there is void in between, there is no emptiness in a strict sense, as everything is pervaded by some intangible divinity. But I'll leave this sort of intangible pervasiveness out of our conversation today. Our focus is tangible pervasiveness.
In the 17th century, Newton went back full force to the Atomistic worldview, rejecting the notion that space was filled with some kind of material. In particular, he attacked Descartes' idea of a plenum, somewhat similar to that of Aristotle, that some material filled all of space. The key difference between Descartes and Aristotle was that for Descartes this stuff acted on normal matter, creating, for example, vortices that were responsible for the planetary orbits about the sun. Newton, using his brand new theory of gravity, showed that any kind of stuff out there capable of moving moons and planets about would cause enough friction to have them all spiral down to the center of their orbits. No game.
Newton was missing something
But Newton knew something was missing in his theory. When he proposed that any two masses attracted one another, the assumption was that they did so instantaneously. The sun tugged on the Earth (and the Earth on the sun) with a mysterious force that acted at a distance. What caused it, Newton wouldn't try to answer: “I feign no hypotheses," he wrote. A clever choice. Physics is about the how and not the why of things. It describes what we can see of reality and, so long as the description explains the data, we are good. Why masses attract one another the way they do is not, it was decided, a scientific question.
Light, to Newton, was made of tiny corpuscles, little atoms. Using this idea, he explained many of the properties of light. But then, there were others that he couldn't explain, or did so convolutedly. The alternative that gained impetus during the nineteenth century was that light was a wave. Light diffracts when passing through a small aperture or across an edge, and refracts when moving from one medium (say, air) to another (water). But if light was a wave, it needed a medium to support it, just like water waves move in water and sound waves in air.
The solution was the “luminiferous ether," an imponderable plenum whose sole purpose was to allow for light to move from point A to B. A weird medium it had to be, echoing Aristotle a bit: weightless, transparent (so we could see stars), offering no friction to matter (to avoid Descartes' issues), and very rigid (to allow for fast wave propagation). In short, a pretty magical plenum.
The alternative, light propagating on empty space, was unthinkable, unacceptable, deeply counter-intuitive. For about fifty years, the ether ruled. But experiments searching for it came back empty-handed. Finally, in 1905, Einstein proposed his special theory of relativity where he demonstrated that the ether wasn't needed: light, mysteriously, does travel in empty space. So, no ether.
Einstein and the vacuum
But then, Einstein himself confused the issue when he proposed, in 1917, that the whole of space is filled with something called a “cosmological constant." This he did out of desperation, after he found out that his equations predicted an unstable universe that would collapse upon itself. This extra term is understood as an energy of the “vacuum," of empty space itself. So, in a sense, the ether was back, in new clothes.
How can empty space have energy? Well, this goes back to Newton and his mysterious action-at-a-distance. In the nineteenth century, physicists came up with the concept of a field, the idea that the space around the source of a force—say, a mass that attracts other masses gravitationally, or an electric charge that attracts or repels other electric charges—is actually filled with a field that has energy and affects other masses and electric bodies. The field is how other masses and charges “know" there is a mass or charge somewhere out there. Within this classical view of the world, all of space has some field in it, even if the sources are very, very far away. It may be weak and negligible, but it isn't zero.
Things get even more interesting when you add ideas from quantum physics. In this case, even if you could imagine a completely empty space, devoid of any sources of gravitational or electric force, there would still be a leftover energy, the “zero point energy," the energy of nothingness. How come? Well, according to quantum theory, there is a fundamental uncertainty in nature, an uncertainty that affects the values of physical quantities such as distance, momentum, energy, and time. Every measurement of these quantities fluctuates about the mean, even if a system has zero energy.
Something from nothing
Now, combine these fluctuations in energy with Einstein's idea that energy and mass are interconvertible (with some caveats we don't need to worry about), the famous E=mc2 formula. Then, these small fluctuations of energy could produce pairs of particles that would bubble out of the vacuum, or empty space: yup, matter sprouting out of quantum nothingness. The best part is that we know this is right: empty space can actually produce attractive forces between electric plates, an effect known as the Casimir Effect.
The big question is whether something like this is responsible for the mysterious accelerated expansion of the whole universe. We know it's happening, and we have called the culprit “dark energy." The best candidates right now are Einstein's cosmological constant, the energy of the vacuum somehow dialed to have just the right value to match observations, or a strange quantum field that pervades all of space, called, not surprisingly, quintessence, echoing Aristotle's plenum.
In its turbulent existence over the past 25 centuries (or more), it seems that Nothingness is now relegated to a mere metaphysical concept, incompatible with physical reality. Space does appear to be filled with stuff, stuff that determines the fate of the universe itself.
The post Tangible Pervasiveness appeared first on ORBITER.
Big ideas.
Once a week.
Subscribe to our weekly newsletter.

Adam Frank

Marcelo Gleiser

Your body’s full of stuff you no longer need. Here's a list.
Evolution doesn't clean up after itself very well.
- An evolutionary biologist got people swapping ideas about our lingering vestigia.
- Basically, this is the stuff that served some evolutionary purpose at some point, but now is kind of, well, extra.
- Here are the six traits that inaugurated the fun.
The plica semilunaris
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NjgwMS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY3NDg5NTg1NX0.kdBYMvaEzvCiJjcLEPgnjII_KVtT9RMEwJFuXB68D8Q/img.png?width=980" id="59914" width="429" height="350" data-rm-shortcode-id="b11e4be64c5e1f58bf4417d8548bedc7" data-rm-shortcode-name="rebelmouse-image" />The human eye in alarming detail. Image source: Henry Gray / Wikimedia commons
<p>At the inner corner of our eyes, closest to the nasal ridge, is that little pink thing, which is probably what most of us call it, called the caruncula. Next to it is the plica semilunairs, and it's what's left of a third eyelid that used to — ready for this? — blink horizontally. It's supposed to have offered protection for our eyes, and some birds, reptiles, and fish have such a thing.</p>Palmaris longus
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NjgwNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzMzQ1NjUwMn0.dVor41tO_NeLkGY9Tx46SwqhSVaA8HZQmQAp532xLxA/img.jpg?width=980" id="879be" width="1920" height="2560" data-rm-shortcode-id="4089a32ea9fbb1a0281db14332583ccd" data-rm-shortcode-name="rebelmouse-image" />Palmaris longus muscle. Image source: Wikimedia commons
<p> We don't have much need these days, at least most of us, to navigate from tree branch to tree branch. Still, about 86 percent of us still have the wrist muscle that used to help us do it. To see if you have it, place the back of you hand on a flat surface and touch your thumb to your pinkie. If you have a muscle that becomes visible in your wrist, that's the palmaris longus. If you don't, consider yourself more evolved (just joking).</p>Darwin's tubercle
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NjgxMi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0ODUyNjA1MX0.8RuU-OSRf92wQpaPPJtvFreOVvicEwn39_jnbegiUOk/img.jpg?width=980" id="687a0" width="819" height="1072" data-rm-shortcode-id="ff5edf0a698e0681d11efde1d7872958" data-rm-shortcode-name="rebelmouse-image" />Darwin's tubercle. Image source: Wikimedia commons
<p> Yes, maybe the shell of you ear does feel like a dried apricot. Maybe not. But there's a ridge in that swirly structure that's a muscle which allowed us, at one point, to move our ears in the direction of interesting sounds. These days, we just turn our heads, but there it is.</p>Goosebumps
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NzMxNC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNzEyNTc2Nn0.aVMa5fsKgiabW5vkr7BOvm2pmNKbLJF_50bwvd4aRo4/img.jpg?width=980" id="d8420" width="1440" height="960" data-rm-shortcode-id="8827e55511c8c3aed8c36d21b6541dbd" data-rm-shortcode-name="rebelmouse-image" />Goosebumps. Photo credit: Tyler Olson via Shutterstock
<p>It's not entirely clear what purpose made goosebumps worth retaining evolutionarily, but there are two circumstances in which they appear: fear and cold. For fear, they may have been a way of making body hair stand up so we'd appear larger to predators, much the way a cat's tail puffs up — numerous creatures exaggerate their size when threatened. In the cold, they may have trapped additional heat for warmth.</p>Tailbone
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NzMxNi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3MzQwMjc3N30.nBGAfc_O9sgyK_lOUo_MHzP1vK-9kJpohLlj9ax1P8s/img.jpg?width=980" id="9a2f6" width="1440" height="1440" data-rm-shortcode-id="4fe28368d2ed6a91a4c928d4254cc02a" data-rm-shortcode-name="rebelmouse-image" />Coccyx.
Image source: Decade3d-anatomy online via Shutterstock
<p>Way back, we had tails that probably helped us balance upright, and was useful moving through trees. We still have the stump of one when we're embryos, from 4–6 weeks, and then the body mostly dissolves it during Weeks 6–8. What's left is the coccyx.</p>The palmar grasp reflex
<img class="rm-lazyloadable-image rm-shortcode" type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8xOTA5NzMyMC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNjY0MDY5NX0.OSwReKLmNZkbAS12-AvRaxgCM7zyukjQUaG4vmhxTtM/img.jpg?width=980" id="8804c" width="1440" height="960" data-rm-shortcode-id="67542ee1c5a85807b0a7e63399e44575" data-rm-shortcode-name="rebelmouse-image" />Palmar reflex activated! Photo credit: Raul Luna on Flickr
<p> You've probably seen how non-human primate babies grab onto their parents' hands to be carried around. We used to do this, too. So still, if you touch your finger to a baby's palm, or if you touch the sole of their foot, the palmar grasp reflex will cause the hand or foot to try and close around your finger.</p>Other people's suggestions
<p>Amir's followers dove right in, offering both cool and questionable additions to her list. </p>Fangs?
<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Lower mouth plate behind your teeth. Some have protruding bone under the skin which is a throw back to large fangs. Almost like an upsidedown Sabre Tooth.</p>— neil crud (@neilcrud66) <a href="https://twitter.com/neilcrud66/status/1085606005000601600?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>Hiccups
<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Sure: <a href="https://t.co/DjMZB1XidG">https://t.co/DjMZB1XidG</a></p>— Stephen Roughley (@SteBobRoughley) <a href="https://twitter.com/SteBobRoughley/status/1085529239556968448?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>Hypnic jerk as you fall asleep
<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">What about when you “jump” just as you’re drifting off to sleep, I heard that was a reflex to prevent falling from heights.</p>— Bann face (@thebanns) <a href="https://twitter.com/thebanns/status/1085554171879788545?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script> <p> This thing, often called the "alpha jerk" as you drop into alpha sleep, is properly called the hypnic jerk,. It may actually be a carryover from our arboreal days. The <a href="https://www.livescience.com/39225-why-people-twitch-falling-asleep.html" target="_blank" data-vivaldi-spatnav-clickable="1">hypothesis</a> is that you suddenly jerk awake to avoid falling out of your tree.</p>Nails screeching on a blackboard response?
<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Everyone hate the sound of fingernails on a blackboard. It's _speculated_ that this is a vestigial wiring in our head, because the sound is similar to the shrill warning call of a chimp. <a href="https://t.co/ReyZBy6XNN">https://t.co/ReyZBy6XNN</a></p>— Pet Rock (@eclogiter) <a href="https://twitter.com/eclogiter/status/1085587006258888706?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>Ear hair
<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Ok what is Hair in the ears for? I think cuz as we get older it filters out the BS.</p>— Sarah21 (@mimix3) <a href="https://twitter.com/mimix3/status/1085684393593561088?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>Nervous laughter
<blockquote class="twitter-tweet" data-lang="en"><p lang="en" dir="ltr">You may be onto something. Tooth-bearing with the jaw clenched is generally recognized as a signal of submission or non-threatening in primates. Involuntary smiling or laughing in tense situations might have signaled that you weren’t a threat.</p>— Jager Tusk (@JagerTusk) <a href="https://twitter.com/JagerTusk/status/1085316201104912384?ref_src=twsrc%5Etfw">January 15, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>Um, yipes.
<blockquote class="twitter-tweet" data-conversation="none" data-lang="en"><p lang="en" dir="ltr">Sometimes it feels like my big toe should be on the side of my foot, was that ever a thing?</p>— B033? K@($ (@whimbrel17) <a href="https://twitter.com/whimbrel17/status/1085559016011563009?ref_src=twsrc%5Etfw">January 16, 2019</a></blockquote> <script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>Godzilla vs. Kong: A morphologist chooses the real winner
Ultimately, this is a fight between a giant reptile and a giant primate.
The 2021 film “Godzilla vs. Kong" pits the two most iconic movie monsters of all time against each other. And fans are now picking sides.
How do you tell reality from a deepfake?
The more you see them, the better you get at spotting the signs.
Ancient cave artists were getting high on hypoxia
A new study says the reason cave paintings are in such remote caverns was the artists' search for transcendence.
