In 2020, the world ran an unplanned experiment. Millions of knowledge workers went remote overnight, armed with video calls, shared documents, and chat platforms. If digital connectivity could truly replace physical proximity, this was the moment to prove it.

And yet, something curious happened. Real estate prices in established innovation hubs didn't collapse—they barely flinched. Venture capital continued to flow disproportionately to startups within a short drive of Sand Hill Road. Biotech firms still clustered around Cambridge, Massachusetts. The financial world still orbited a few square miles of Manhattan and the City of London.

Network science offers an explanation that goes deeper than habit or inertia. The connections that drive innovation and economic dynamism aren't just about exchanging information—they depend on the type of information, the quality of trust, and the speed of recombination that physical proximity uniquely enables. Understanding why clusters persist reveals something fundamental about how networks actually work.

Information comes in two fundamentally different forms. Explicit knowledge—data, instructions, documented processes—travels effortlessly across digital networks. You can email a spreadsheet to someone on another continent and lose nothing in transit. But tacit knowledge—the kind embedded in intuition, judgment, and skilled practice—resists codification. It's the difference between reading a recipe and watching a chef's hands.

In innovation clusters, tacit knowledge is the currency that matters most. An engineer doesn't just need to know that a particular approach failed—she needs to understand how it failed, what the team's body language suggested about confidence levels, and what unspoken assumptions shaped the decision. These signals travel poorly through screens. They require shared physical context: the whiteboard sketch that sparks a tangent, the hallway aside that reframes a problem, the lunch conversation where someone mentions a half-formed idea they'd never put in a Slack message.

Mark Granovetter's research on information flow helps explain this. Weak ties—casual acquaintances—are powerful conduits for novel explicit information. But the transfer of complex, ambiguous, tacit knowledge depends on stronger ties with higher bandwidth. Physical co-location doesn't just make these interactions possible; it makes them frequent, low-cost, and serendipitous. You don't schedule a Zoom call to share a half-baked hunch. But you might mention it while waiting for coffee.

This is why industries that depend heavily on tacit knowledge—venture-backed startups, cutting-edge biotech, high-frequency finance—remain stubbornly clustered. The information they need most is precisely the information that digital networks transmit worst. Remote work handles execution well. But the messy, ambiguous front end of innovation still runs on proximity.

Takeaway

The most valuable knowledge in innovation is the kind you can't write down. If the information that matters most in your field is tacit—intuitive, contextual, half-formed—then proximity to the people who hold it isn't a convenience, it's a competitive necessity.

Networks aren't just pipes for information. They're structures of trust—and trust determines what information people are willing to share in the first place. The most consequential exchanges in business and innovation involve vulnerability: admitting what you don't know, sharing proprietary insights, making introductions that put your reputation on the line. None of this happens without deep relational trust.

Research on trust formation consistently shows that in-person interaction builds relational depth faster and more durably than remote communication. There are neurological reasons for this. Shared physical presence activates mirror neurons, enables micro-expressions to be read in real time, and allows for the kind of synchronized body language that signals genuine engagement. A handshake, sustained eye contact, even sharing a meal—these aren't social niceties. They're trust infrastructure.

In geographic clusters, this trust infrastructure compounds over time. The venture capitalist who coaches at her portfolio founder's kid's soccer game. The engineers who rotate between three competing firms over a decade and maintain friendships across all of them. The angel investor who takes a bet on someone because a trusted friend vouched for them at a dinner party. These overlapping, multi-context relationships create what sociologists call multiplex ties—connections that span professional and personal domains simultaneously. Multiplex ties carry more trust, more nuance, and more willingness to take risks on each other.

Digital tools can maintain trust that was built in person. They're far less effective at creating it from scratch. This is why remote-first companies often invest heavily in periodic in-person retreats—they intuitively understand that the relational foundation must be laid face to face. Clusters provide this foundation continuously, at scale, without anyone needing to organize an offsite.

Takeaway

Digital communication maintains trust efficiently but builds it poorly. If your most important professional relationships started online and stayed there, consider what depth of exchange you might be missing—and what a single in-person meeting could unlock.

If clusters are so powerful, how do they form—and how can outsiders access their benefits? Network science points to a few key dynamics. Clusters typically begin with an anchor: a major university, a pioneering firm, or a government research lab that attracts talent to a specific place. Once a critical mass of skilled people gathers, a self-reinforcing cycle kicks in. Specialized labor markets form. Support services—legal, financial, logistical—tailor themselves to the cluster's industry. Knowledge spillovers accelerate because ideas recombine faster when the people carrying them bump into each other regularly.

This creates a structural advantage that's difficult to replicate remotely. It's not that any single connection within a cluster is irreplaceable—it's that the density of relevant connections generates a combinatorial explosion of potential interactions. In network terms, the cluster's value lies in its local clustering coefficient: the probability that any two of your contacts also know each other. High clustering means faster diffusion of norms, reputations, and opportunities.

For outsiders, the implication isn't that you must relocate permanently. Research on network brokerage suggests a more strategic approach. Periodic immersion—attending key conferences, spending a few weeks co-working in a cluster, participating in industry-specific gatherings—can create bridging ties that connect your home network to the cluster's resources. The goal is to become what network theorists call a broker: someone who spans structural holes between otherwise disconnected groups.

The most effective strategy combines digital maintenance with physical initiation. Identify the two or three clusters most relevant to your work. Invest in face-to-face time there, even briefly. Then use digital tools to sustain the connections you've made. You don't need to live in the cluster—but you need to visit it with intention and frequency, converting weak digital ties into the kind of multiplex relationships that unlock tacit knowledge and deep trust.

Takeaway

You don't have to live inside a cluster to benefit from one. But you do need a deliberate strategy of periodic physical presence to build the bridging ties that connect your network to its resources. Think of cluster access as an investment, not a relocation decision.

The digital revolution didn't eliminate the advantages of place—it clarified them. What clusters provide isn't merely information, which flows freely online, but the conditions under which the most valuable forms of knowledge and trust are produced.

This isn't an argument against remote work or digital networks. It's an argument for understanding what each channel does best. Use digital tools for reach and maintenance. Use physical proximity for depth and formation.

The next time you wonder whether geography still matters, ask yourself: what kind of knowledge do I need, and what kind of trust does my work require? Your answer will tell you whether a screen is enough—or whether you need to show up in person.