Roomba (specifically the brand of the American company iRobot) only added lidar in 2025 [1]. Earliest Roombas navigated by touch (bumping into walls), and then by cameras.
But if you use "roomba" as a generic term for robot vacuum then yes, Chinese Ecovacs and Xiaomi introduced lidar-based robot vacuums in 2015 [2].
> Earliest Roombas navigated by touch (bumping into walls)
My ex got a Roomba in the early 2010s and it gave me an irrational but everlasting disdain for the company.
They kept mentioning their "proprietary algorithm" like it was some amazing futuristic thing but watching that thing just bump into something and turn, bump into something else and turn, bump into something again and turn again, etc ... it made me hate that thing.
Now when my dog can't find her ball and starts senselessly roaming in all the wrong directions in a panic, I call it Roomba mode.
> Suppose you pass a parameter, N, and you also would like to pass a tensor, and you would like to specify the tensor's shape (N, N).
You can do that, and it might be cleaner and less lines of code that way.
But you don't necessarily need to pass the array dimensions as a parameter, as you can call `size` or `shape` to query it inside your function.
program main
implicit none
real :: a(2, 2) = reshape([1., 2., 3., 4.], [2, 2])
call print_array(a)
contains
subroutine print_array(a)
real, intent(in) :: a(:, :)
integer :: n, m, i, j
n = size(a, 1) ; m = size(a, 2)
write(*, '("array dimensions:", 2i3)') [n, m]
do i = 1, n
do j = 1, m
write(*, '(f6.1, 1x)', advance='no') a(i, j)
end do
print *
end do
end subroutine
end program
This is not valid C, though. The characters allowed for identifiers are defined in Unicode Standard Annex #31, and those easily understood as operators, like arrows, are not included.
> More than 20 years ago, I corresponded with famous UFO researcher Stanton T. Friedman. His central claim was that “the evidence is overwhelming that some UFOs are extraterrestrial spacecraft”.
I don't believe in UFOs. But if I had to believe in UFOs, this would be my position:
We have had modern humans for 500 000 years [1]. If it takes 10 000 years to make it from stone age to space age, we have theoretically had time to make that 50 times over. Maybe there was a previous version of a human civilization [2], then wiped out by ice ages or something, but a small number of highly advanced humans have survived and keep hiding from us. I think this could be somewhat more plausible than interstellar travel.
The largest obstacle to this theory being taken seriously is the lack of evidence in long term records, such as ice cores.
Our current age will show up in future ice cores as a massive spike; we affect CO2, Methane, Sulfates, and probably a lot more. Additionally we produce and have produced various synthetic compounds that will remain detectable in the environment for hundreds of thousands of years, if not millions.
In order to circumvent this lack of evidence such a society would have had to had a very small footprint, taken very specific industrial steps, and had a focus on research that wasn't exploited. This is highly unlikely - most of our lessons have actually been learned from exploitation, and most of our research facilities require astounding amounts of labour to construct. This isn't even touching on the social improbability of maintaining such a society.
Sorry, I was overly polite. It should have read "this is a bloody stupid position to take".
Visitors from other star systems are significantly more likely (on the order of dice roll vs impossible) than a secret highly advanced human society developing and remaining present and hidden.
> If India can have voters vote and tally all the votes in one day, then so can everyone else.
In most countries, in the elections you vote or the member of parliament you want. Presidential elections, and city council elections are held separately, but are also equally simple. But in one election you cast your vote for one person, and that's it.
With this kind of elections, many countries manage to hold the elections on paper ballots, count them all by hand, and publish results by midnight.
But on an American ballot, you vote for, for example:
- US president
- US senator
- US member of congress
- state governor
- state senator
- state member of congress
- several votes for several different state judge positions
- several other state officer positions
- several votes for several local county officers
- local sheriff
- local school board member
- several yes/no votes for several proposed laws, whether they should be passed or not
I don't think it would be possible to calculate all these 20 or 40 votes, if calculated by hand. That's why they use voting machines in America.
How is it not possible? It's just additional votes, there isn't anything actually stopping counting by hand, is there? How was it counted historically without voting machines?
Say, how many voting stations are there in a typical city/county in the US?
Here in Indonesia, in a city of 2 million people there are over 7000 voting stations. While we vote for 5 ballots (President, Legislative (National, Province, and City/Regency), we still use paper ballots and count them by hand.
Wikipedia page doesn't have any estimates on when the contamination event might have started (so products processed before that would be safe). It only tells that the food recall in the US started 2 months ago.
> Radiation scans revealed at least 22 plants in the industrial zone were contaminated. The Indonesian taskforce did not name the 21 other production facilities, but said they would immediately undergo decontamination procedures conducted by Indonesia’s nuclear agency.
But if you use "roomba" as a generic term for robot vacuum then yes, Chinese Ecovacs and Xiaomi introduced lidar-based robot vacuums in 2015 [2].
[1] https://www.theverge.com/news/627751/irobot-launches-eight-n...
[2] https://english.cw.com.tw/article/article.action?id=4542
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