One persistent criticism of Silicon Valley is that it no longer works on big, world-changing ideas. Every few months, a dumb startup will make the news – most recently the one selling a US$700 ($943) juicer – and folks outside the tech industry will begin singing I-told-you-so's.

But don't be fooled by expensive juice. The idea that Silicon Valley no longer funds big things isn't just wrong, but also obtuse and fairly dangerous. Look at the cars, the rockets, the internet-beaming balloons and gliders, the voice assistants, drones, augmented and virtual reality devices, and every permutation of artificial intelligence you've ever encountered in sci-fi. Technology companies aren't just funding big things – they are funding the biggest, most world-changing things. They are spending on ideas that, years from now, we may come to see as having altered life for much of the planet.

At the same time, the US government's appetite for funding big things – for scientific research and out-of-this-world technology and infrastructure programs – keeps falling, and it may decline further under President Donald Trump.

This sets up a looming complication: Technology giants, not the government, are building the artificially intelligent future. And unless the government vastly increases how much it spends on research into such technologies, it is the corporations that will decide how to deploy them.

Consider Google. On Wednesday, the internet search company kicked off its annual developer conference near its headquarters in Mountain View, California. The company showed off several advances to its voice-enabled assistant and its mobile operating system. Among other things, you can now point your phone at an object in the real world – a flower, a sign in another language, a marquee for a rock concert – and the phone will give you more information about what you're looking at (for instance, a button to buy tickets for the concert). Some of this was cool, but little was truly groundbreaking, which isn't surprising: We're in an awkward phase of the tech industry, one marked by incremental improvements to technologies that we think of as boring – and lots of exciting promises about far-off tech that isn't quite ready for prime time.

The real advances at Google are in that second category. At last year's show, Sundar Pichai, Google's chief executive, inaugurated what he called a new era for Google. The search company would henceforth be an "AI-first" company – that is, most of its advances would be driven by artificial intelligence techniques.

The technology would play a role in consumer products, like Google's instant translator or its photo app, which can recognise uniquely human search terms (it can find pictures of "hugs," for instance). But AI also informs Google's more ambitious plans. The company is using artificial intelligence to teach computers to understand language, to see and hear, to diagnose diseases, and even to create art.

A lot of these plans will fail, but Google isn't making big, long-term bets out of altruism. The company understands that the AI-based projects that succeed could be transformational: They will alter existing industries and create huge new ones, including a stream of new businesses from which Google can profit.

Google is not alone in this quest to build a future out of AI. Its parent company, Alphabet, is spending billions to inject machine intelligence into much of the global economy, from self-driving cars to health care.

Then there are the other members of the Frightful Five – Amazon, Apple, Facebook and Microsoft – which are also spending heavily on the intelligent future. Collectively, the five are among the biggest investors in research and development on the planet. According to their earnings reports, they are on track to spend more than US$60 billion this year on research and development. By comparison, in 2015, the US federal government spent about $67 billion on all nondefense-related scientific research.

There are two ways to respond to the tech industry's huge investments in the intelligent future. On the one hand, you could greet the news with optimism and even gratitude. The technologies that Google and other tech giants are working on will have a huge impact on society. Self-driving cars could save tens of thousands of lives a year, for instance, while computerised methods for diagnosing and treating disease could improve our health and cut the cost of care.

What's more, experts in the field say that many tech giants are currently approaching AI with a kind of academic ethos. For instance, they regularly publish papers on their findings, and – through their cloud server businesses – they are allowing third-party companies to access some of their latest AI tech.

But the tech industry's huge investments in AI might also be cause for alarm, because they are not balanced by anywhere near that level of investment by the government.

In the waning days of the Obama administration, the White House published a report examining the ways artificial intelligence would alter the world. The report found that the federal government spent only US$1.1 billion on unclassified AI research in 2015. It argued for increasing spending on artificial intelligence by several times. With greater federal funding, the report said, researchers could focus more on basic research – more tenuous, potentially less immediately applicable areas of AI – and through the grant-making process, the government would have a greater say in how the technology develops.

What's interesting is that many in the tech industry agree with the need for greater federal funding. OpenAI was created by Elon Musk, Peter Thiel and other tech luminaries, and it has received funding from Microsoft, Amazon and Y Combinator, the startup incubator.

Google also favours federal funding for tech research. In May, Eric Schmidt, Alphabet's executive chairman, was one of the authors of an op-ed in The Washington Post arguing that federal funding of science and technology had created a "miracle machine": a public-private partnership that has churned out dozens of new industries over decades.

"If we don't change course and invest in scientific research, we risk losing one of America's greatest advantages," he wrote.

In other words, the tech giants that are building the future would like some help changing the world. We would be wise to chip in – or let them take over the future for themselves.

The New York Times