"Everything is connected" is one of those sentences that sounds true in almost any context, which is exactly why it deserves suspicion. It gets applied to quantum entanglement and to the Buddhist teaching of dependent origination with equal enthusiasm, as though the two were pointing at the same fact from different angles — physics catching up, once again, to what contemplative traditions supposedly always knew. Both ideas really do undercut the comfortable picture of the world as a collection of separate, self-contained things sitting next to each other. That much they share. What they don't share is almost everything else: what kind of claim each one is, how general it is, what would count as evidence against it, and what follows from it. Worth taking each seriously enough to see exactly where the resemblance runs out.
What entanglement actually is
When two quantum systems are prepared together in an entangled state, measurements performed on them show correlations that no classical, common-cause explanation can reproduce — a result proven rigorously through Bell's theorem and its many experimental confirmations. Erwin Schrödinger, who coined the term in 1935, put the strangeness precisely: "the best possible knowledge of a whole does not necessarily include the best possible knowledge of all its parts." An entangled pair has a well-defined joint state even when neither particle, considered alone, has a well-defined state of its own. That's the real, rigorously demonstrated physics: non-separability, a mathematical fact about how the joint system's description doesn't factor into two independent descriptions.
What entanglement does not claim is just as important. There is no faster-than-light signal: whichever measurement you make on your particle, the outcome you personally see is random, and no arrangement of measurements lets you send a message to the distant partner faster than light — a result sometimes called the no-signaling theorem. There is no persistent mystical "energetic bond" that survives regardless of context: entanglement is fragile, decays rapidly through interaction with the environment (the same decoherence that erases quantum superpositions generally), and applies to specifically prepared pairs of systems under controlled conditions, not to arbitrary objects, and certainly not to two people who happen to care about each other.
What dependent origination actually claims
Pratityasamutpada — usually translated as dependent origination or dependent arising — is a foundational teaching shared across Buddhist schools, formalized in the compact phrase: "if this exists, that exists; if this ceases, that also ceases." It states that every phenomenon arises in dependence on conditions, and that nothing — no object, no self, no mental state — exists as a fixed, independent thing prior to or apart from the web of conditions that give rise to it. The philosopher Nagarjuna, working several centuries after the historical Buddha, drew out what many regard as the doctrine's sharpest implication: because everything arises dependently, everything is empty (śūnyatā) of the kind of fixed, self-sufficient existence ordinary language and perception assume things have. This is a claim of total generality — it applies to a chariot's wheel, a passing emotion, and a philosophical concept exactly alike — and it's a metaphysical and soteriological claim, not an empirical one awaiting confirmation by an experiment.
A qubit pair decoheres in microseconds under the wrong conditions. Dependent origination doesn't come with conditions under which it stops applying.
Where the metaphor helps, and the much larger place where it doesn't
Both ideas dislodge the same intuitive picture: a world made of separately existing things that merely happen, afterward, to relate to one another. Entanglement shows that at least some physical systems can't be fully described except jointly. Dependent origination claims that nothing whatsoever can be fully described except jointly, with its conditions, always. That difference in scope is the whole story. Entanglement is an empirical, falsifiable, narrowly scoped physical phenomenon — it applies to specific systems prepared under specific conditions, it can be measured, quantified, and destroyed by an ordinary interaction with the environment. Dependent origination is a general metaphysical framework offered as insight into the nature of all conditioned existence, defended through argument and direct contemplative investigation rather than laboratory measurement, and it doesn't decohere — there's no experimental setup under which it would stop holding, because it isn't the kind of claim an experiment could confirm or refute in the first place.
There's also a further step the Buddhist teaching takes that entanglement was never asked to take: dependent origination is offered as grounds for compassion, on the reasoning that if nothing exists independently, the sharp boundary between self and other that underwrites indifference to another's suffering is itself something to examine rather than assume. Entanglement carries no ethical payload of any kind; two electrons prepared in a singlet state have no stake in each other's welfare. Treating the physics as quiet confirmation of the ethics — "we're all entangled, so we're all one, so be kind" — borrows the authority of a hard science for a conclusion the science neither reaches nor needs to reach. The ethical claim can and should be argued on its own terms. It doesn't get stronger by wearing a lab coat it was never issued.
For how this same caution about borrowed vocabulary applies to the loss of quantum coherence and the Buddhist teaching of impermanence, see Decoherence and Impermanence. For the narrower case of what an "observer" does in each tradition, see The Observer Effect and Mindful Attention.