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Comment by naikrovek | Hacker News Reader

Enameled wire completely submerged in water makes for a fantastic electrical load.

I’ve sunk 40 amps at 30VDC into a plastic tub filled with water for hours.

When the water gets hot, put fresh water in. For long term testing, trickle cold water in and let the hot water rise to the top and spill out.

DO NOT let the enamel on the wire burn off, or you will put some very nasty stuff into the air. Keep it completely submerged.

It is amazing how much energy it takes to heat up a volume of water. (This is also why it scares the shit out of me when I read about ocean temperatures rising and I think about how much water is in the oceans.)

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Sunlight puts in a serious amount of energy. Roughly 1000 W/m2 at sea level as a global average according to https://en.m.wikipedia.org/wiki/Solar_irradiance

Yes and CO2 keeps that energy here, and the ocean absorbs a lot of that heat.

If you’re trying to say that the sun is responsible for rising ocean temperatures, I’d like you to consider how long the sun and the oceans have been around, and I ask you why they haven’t boiled away, yet.

The sun is not responsible for the recent dramatic increase in ocean temperatures. That’s on us (humanity).

Less at high latitudes, due to the angle. But if you build a solar power plant there (I have), you might be surprised to learn the electrical output is nearly as large as at the equator.

Of course that assumes angled panels, so the space taken is larger.

when they say the ocean temperature rises 1 degree, they should really put it in terms of joules it would take to do that, which is a really big number, rather than 1 degree, because people read more into bigger numbers.

And if you really want to scare people, convert it into Mt of TNT.

Did some quick napkin maths, and the energy required to raise sea temperatures one degree requires the energy of 1 368 000 gigatons of TNT equivalent. In comparison, Tsar Bomba is estimated 50–58 megatons of TNT, so you'd need quite a lot of these to produce the same effect.

According to NOAA, there's 1.335×10^9 km^3 of water in the oceans. This amounts to 1.335×10^21 liters, and with the density of sea water of 1.025kg/L, 1.368×10^21 kg.

The heat capacity of water is 4182 J/(kg×K) around room temperature. This means that when the temperature of oceans raise one degree (Celsius/Kelvin), the energy needed is (1.368×10^21 × 4182) J = 5.722544×10^24 J.

One gigaton of TNT equivalent releases 4.184×10^18 J of energy, and dividing the above result with this, you get the amount of gigatons required.

> 1 368 000 gigatons of TNT

that sounds a helluva lot worse than 1 degree

You could go with enough energy to drive an f150 around the equator 69720537774 times at 24 miles per gallon

No one knows what a Joule is though. “1 Watt Second” is not a familiar term for most people.

convert it into Hiroshima's then.

As lambdanana calculated above, it's enough Hiroshimas that it wraps back around to being a number the human brain cannot comprehend.

Surplus power resistors are great for this. Less likely to open immediately in a cooling glitch. (And yes, submerged too). It's really unfortunate electronics surplus stores are extinct around here.

PTC heating elements might be the safest, they'll just draw less current if they get too hot

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