i just picked up an ultimaker s5 for $400 on ebay with tons of extra filament and it worked off the bat. Been printing for almost 2 weeks straight and my daughter loves it :D
Christmas 1999 my father's business had just gone under when the banks stopped lending after the dot com bubble. We didn't have any presents until Christmas morning when our church dropped off a bunch of presents for us. We got a Razor scooter and I spent all day riding it downstairs.
I just got my daughter a scooter and she's doing the same this year :)
Was going to say about the same - this is ~2500 years after construction of the pyramids. How do you coordinate something that massive without any form of writing?
> Was going to say about the same - this is ~2500 years after construction of the pyramids.
The first Egyptian pyramid known was built ~2780 BCE, the alphabetic writing in this article was from ~2500 BCE. That’s a gap of ~250 years, not ~2,500.
> How do you coordinate something that massive without any form of writing?
The Egyptians at the time of the Pyramids had writing, but it was logographic (symbols directly represent a word/concept), not alphabetic (a small inventory of symbols are combined in different ways to represent words/concepts.)
An alphabetic – and also phonetic – script is a big advance not because of what you communicate with it, but because if you know a fairly small set of symbols and their phonetic interpretation, you can encode a spoken language in it in a reasonably intelligible way to anyone who knows the same script (and you can even encode different spoken languages in the same script intelligibly, if they have a similar-enough phonetic inventory.)
I'm no expert, but my understanding is that Coptic made use of hieroglyphs as an alphabet, and co-existed with their use for Egyptian: https://en.wikipedia.org/wiki/Coptic_language
The article is about alphabets. There was writing prior to alphabets, but it was done in hieroglyphics, cuneiform, and characters. Alphabets are easier to learn and therefore more widely used.
From there:
Dr. van Belle continues, “Observations of binary star systems let us determine the masses because of their orbital motion around each other, and BFT adds extra value by then directly measuring the radii of those stars. Resolved exoplanet transits is going to be the wicked cool one. We will be able to see the resolved disk of another world as it passes in front of its host star. This sort of thing will be good for further characterization of exoplanets, as well as searches for exomoons. There’s a bunch of other BFT science that isn’t part of the core ‘marquee’ cases – many hundreds of different types of stars that we’ll be able to make pictures of and see how those pictures change over time.”
I think of geothermal the same way I think of tidal power - seemingly renewable but not really. Harnessing tides dampens the lunar oscillations surprisingly fast (as discussed here: https://news.ycombinator.com/item?id=37383283).
With geothermal, yes there is a huge reservoir of potential energy but speeding up the extraction of this energy is absolutely a terrible idea long term. I'm not gonna rant here, but look at what happened to Mars (only slightly smaller than earth) when the core cooled and the dynamo shut down.
It's sustainable in the short term (for a very long definitoon of short term) though, which is what really matters wrt migrating off of fossil fuels. We could pull many times humanity's energy consumption from the earth for a century and it would still be a drop in the bucket.
Now, some of these hot spots might not be renewable (in the sense that we drain too much ehat from them and they don't have sufficient heat flux to sustain as much extraction as might seem), but I don't think there's any risk of cooling the core.
Yeah the scale of thermal energy contained in the earth makes this fear (prematurely cooling the earth) irrelevant. The entire global consumption of energy is less than 2% of earth's thermal heat flow from the core.
Whoops, thanks for the correction. I was looking at end-user electricity consumption so it didn't include all the losses involved.
That's staggering at first glance. So much energy!
But then, I wonder how much it would really matter if we were harvesting that energy to move objects around on earth and turn on LEDs vs letting it dissipate into space. So I'm still skeptical of the concern.
If this is something we actually need to be worried about, why not rant here? I think most people are pretty far from convinced that literally cooling off the earth through geothermal is a possibility we need to be taking seriously.
If this works and becomes a common dental procedure I will be soooo happy. Every time I go to the dentist I ask them if anything like this is coming down the pipeline and they laugh...
True currently, but laser form factors are shrinking quickly. Reminds me of this article from a couple months ago where a team built (among a host of other sizes/use cases) a 20W(!) laser using a 500um PCSEL which they describe, mounted, as "roughly the size of a webcam". Their lasers are also at comparable wavelengths
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