"Expensive" is terrible when talking about programs like this. This is not military spending - it isn't money just sucked out of the economy to effectively be dumped off a cliff with no economic return on investment (yes, military spending has a tiny rate of ROI, that doesn't change how absurdly inefficient an R&D program it is compared to, say, NASA). In a zero-overhead UBI system where you used existing databases to model who to send money to, every dollar in goes immediately back out to another taxpayer to spend.

There is absolutely no associated "cost" of the program, and there is demonstrable evidence that the poorer you are, the more efficient your dollar is at stimulating growth, because you are much more likely to have real goods demand rather than capital growth demand like the rich, where inevitably the money for a UBI comes from.

Everything a government does has some rate of ROI on it, determining how much it impacts the economy and how well the dollars are spent. Infrastructure and education are known force multipliers where every dollar spent produces many times more economic growth in return, making almost any infrastructure or education worth it until you get particularly exploitative. Likewise, having a good healthcare system compared to the American one would produce significant returns in quality of life, and economic factors like time working and it would cost less to use more preventative medicine to mitigate problems before they are life threatening catastrophes that cost the state millions.

In the same vein of thinking, healthcare is certainly a net positive investment. You spend a ton on it, but the alternative is people getting sick and dying and lost potential productivity from that outweighs the money you spend preventing it. In the same way, if UBI prevents social unrest, crime, violence, despondence, and death, then it also likely offsets the money going in and then some as well, despite possible overhead, since unlike healthcare / infrastructure / etc money going in does not take years to get a return on - the people who get it predominantly will turn around and spend it immediately on goods and services to keep your consumerism strong.

I'm not an economist but I'm wondering what do you think would happen to technology research and science and such if the rich were taxed this way? Would the economy shift more towards what the poor buy, rather than shift to what the rich spend their money on? Or does it all grow together or equalize in some way?

Of course it would shift - the financial incentives to start business come from uncountable factors, but one of the most significant has to be simply "where the money is".

UBI, by its design, creates incredible demand for a standard of living equal to it. Even if your margins are razor thin, the market is still very desirable because the revenue is some of the most reliable money there is (government money) and it is insanely consistent (people will need housing at the minimum level).

Which should terrify you. Any shift in real market demand for necessities post-UBI just represents how many people were impoverished without it, who did not have their base needs fulfilled and how much human rather than fiscal demand for needs was going unmet. The kind of progressive taxes necessary to redistribute so much money on so regular a basis would of course be significant for the higher earners, which would of course significantly curtail their economic influence, because while innovation is not zero sum, the annual allocation of finite resources is distributed in accordance with capital allocation to it - and that of course includes the spending habits of the poor.

It is a simple reality of markets that the more money you have the louder your demands are heard. So if you take from the rich and give to the poor, their relative voices change, but everyone grows together insofar as progress is always being made somewhere.