You'd need to redefine the derived SI Units, or take new measurements for newly derived units. Newtons, joules, pascals, hertz, coulombs, watts, volts, ohms, farads, siemens, webers, teslas, henrys, becquerels, grays, sieverts, and katals.
Also not to mention motion and heat.
You could say there's a large amount of pressure to not change, or that it's a high "bar"...
I hope you smiled, because that is one joke I will not be making again.
There are (roughly) 86400 seconds in a day. This metric time describes a day with 100000 seconds. If you don't redefine the second, then I guess we'll just redefine the day, right?
Though I like the idea a lot, 60 has the great advantage that you can devide it by 2,3,4,5 and 6 which is a very useful property... The real power move would be to use the 60-system for everything... Like the Babylonians did, or so I heared
It's useful. But when was the last time you used it? You usually don't say a twelves or a third or a sixth of an hour, you say 5, 20 or 10 minutes. Half and quarter are available the same in decimal time.
It's more a matter of habbit. You know what a second, a minute and an hour are because you had all your life to precisely learn it.
If you take rhe same 24 hour day, and convert it to 10 metric hours, or mours, and split that to 100 metric minutes, or cenutes, and then 100 meconds, one cenute is 1.44 minutes, and one mecond is 0.86 seconds. The practical difference would be almost imperceptible. A mour would be significantly longer than an hour, 2.4 times, but you'd have the metric system attour disposal to break it into decimals.
That's not to say we should switch, but it wouldn't be that different.
I always thought that the argument is that metric time sounds nice but it's actually worse than traditional time because 24 and 60 have much more factors that are more convenient in every day use. You can split them in half, in quarters, in thirds, in sixths.
You can make that same argument for Imperial units like inches and feet and cups and ounces. That's why imperial units are still popular, because decimals are great for science and conversions, but 100 doesn't have many divisors.