dkf295 t1_je21y5x wrote

It's not impossible, however it would be like dropping 8 beach balls and a few dozen tennis balls in random parts of the pacific ocean, and then plotting a random course across the pacific ocean without hitting any of those balls. Sure it's POSSIBLE you could hit one of those balls, but given the vast size of the ocean and the comparatively tiny size of the balls, the chances are pretty darn close to zero.

Only instead of like that, about a million times less likely.


dkf295 t1_jaerbnr wrote

When delivering more current a given piece of metal heats up more. This is why you see warnings about not using flimsy extension cords for high current appliances like space heaters. A USB-C connector only needs to deliver up to 240 watts. A standard 120/15a outlet will go up to 1800 watts - so to keep the same reliable and safe temperature on your connector, those power-delivering terminals would need to be 7.5 times larger.

But yes, you could make a new connector that would be harder to make contact with accidentally. But then you’d need to convince people to swap out potentially billions of power outlets


dkf295 t1_jaeotpp wrote

A few things.

  1. The default voltage for USB-C is a measly 5V. Think half (okay 5/9) that of a 9V battery if you've ever licked one. It can go as high as 20V but the receiving device specifically needs to request that - even then, not necessarily fun to be shocked with but not particularly dangerous.

  2. The USB-C connector delivers power through pins on the INSIDE of the connector, making it extremely difficult to make contact

  3. A USB connector serves DC power, your wall outlet is AC.

So in order to implement it on wall plugs you'd need all wall outlets and devices (from power strips to computers to stoves to vibrators) to be swapped out with new versions that negotiate the proper voltage, convert to DC. And new connectors - which is harder to make in a non-exposed package if you need to support up to 120V.

Edit: mixed up AC/DC


dkf295 t1_ja8kk9f wrote

Unless you plan to live 100% on public assistance (which has its own notable downsides and tradeoffs), life costs money. You have no guarantee of getting another job/in any particular timeframe - what happens if you quit your job without another one lined up, then something happens like your car breaking down or getting evicted? Even if you did have the money saved up, good luck getting a loan or apartment without any income. And yeah, at this moment it's a hot job market but what happens if there's another financial crash or pandemic and everyone and their uncle gets laid off again? You're screwed.

Being unemployed is also quite expensive (especially if you don't get unemployment, as would be the case if you voluntarily quit) - If you're making $2000 a month now, that's $2000 a month you're not earning while you're looking for a new job.


dkf295 t1_ja8k3qw wrote

Because everyone else would skip out on it too - it's a hassle, and you might be tied up for only a day or two or maybe weeks if it's a more complicated trial.

If you only get jurors that have the means and desire to take days or weeks off from their lives, you're likely going to have a demographic that isn't very representative of the overall population, defeating the point of the whole "jury of your peers" thing.


dkf295 t1_j8248dt wrote

A 5 second test is already longer than the rocket will remain on the stand, and damage (thermal and otherwise) decreases exponentially as distance to the pad increases. Which is to say, by a couple seconds into the burn the rocket will be taking off, and by 5 seconds the rocket will be far enough from the mount for the thermal stresses and shockwaves will be less than the 50% intensity, 5 second burn.

Between this and the 10 second, 14 engine test back in November (which was done with inferior concrete that held up dramatically less well than the current 'crete they're using) it's safe to say they're fairly confident there will be no showstopping problems. It is also extremely likely they will have the water deluge system in place for the full launch which will further reduce any damage.

Finally even if they did completely wreck the pad, it's no biggie. Sure, it's not sustainable but this is a test campaign, and they've already re-done the pad several times.


dkf295 t1_j6jbd75 wrote

Most power plants do use water in their power generation, but it's largely a closed loop and freshwater is used. Fossil fuels/trash/radioactive decay is used to heat water which evaporates into steam and turns turbines, then cools and gets used in the cycle again.

If you decided to use saltwater in this process, the salt would be super super hard on the powerplant, piping, etc and dramatically reduce the lifespan and increase the maintenance costs of the power plant. You also wouldn't be able to generate water safe for use, as the water would likely be contaminated. You're better off with a dedicated power plant and a dedicated desalination plant.

Finally, you still need to figure out what to do with all that salt. If you dump it back in the ocean, you're going to kill off wildlife en masse and just generate more and more salt over time, as the salt concentration in the water you're pumping in increases. You can't dump it on land, it will completely destroy the ecosystem and you will need a TON of space. Unlike landfills, it won't decompose over time - just wash away (which means you're killing things elsewhere). You could potentially use old mines and such, but those aren't reliably structurally sound and you're still risking runoff or even worse, getting massive amounts of salt into the water table.


dkf295 t1_j6ja1cf wrote

Desalination itself is super easy. Take salt water, evaporate and recondense it to separate the salt and other minerals/etc from the water. You can do it yourself on a stovetop or a campfire.

The problem is that there's no way to scale it easy for the massive demands of human use (personal, industrial, and agriculture). It takes a decent amount of energy to heat up water, and you need to do something with all of the salt you've got left over - no matter where you dump it, you're going to cause environmental problems. Salt is also corrosive so there's longevity problems with equipment/piping/etc but those are relatively minor problems with partial solutions. You can't ignore physics, or just make giant piles of salt disappear.


dkf295 t1_j2dxbaw wrote

According to Garmin -

“The Temperature widget will display the ambient air temperature near the barometric altimeter port. This reading can be affected by body heat. To get the most accurate temperature reading, remove the watch from your wrist, place it on a temperature neutral surface, and wait 10 minutes or more.”

As another user stated, a smartwatch also runs a lot cooler even than an otherwise idle smartphone. It also spends time on your arm as opposed to in your pocket which helps it cool.


dkf295 t1_j2c5xx4 wrote

Having a thermometer that can measure ambient air temperature (that being, the air around you, not the air in/on the phone) would require having some sort of probe jutting out of the phone, which is not something people want on their phones. Putting one just on the surface of the case without jutting out a lot means that what it tells you the temperature is will be heavily impacted by the internal temperature of the phone, how you're holding it, etc.

Phones DO have thermometers internally to monitor how hot for example, the CPU is getting.


dkf295 t1_j29pvn5 wrote

To add on to it, same reason why being hit in the hand with a baseball line drive will probably break your hand, but you're fine swinging the bat.

The force is distributed over a larger area - less force is applied on any given area, so it does less damage

The force is spread over a longer period of time so the amount of force at any given time is going to be lower.

Similarly with a gun, the recoil is going to be in the neighborhood of 0.45m/s. The bullet is going to be traveling at 370m/s. The bullet is going to apply all of its force hundreds of times faster than the gun, on a dramatically smaller surface area.


dkf295 t1_j1vc0kl wrote

While it's not 100% clear, I read the above as connecting "state-of-the art stealth drones" as being connected to "bolster our surveillance capability.”, especially considering the previous statement regarding monitoring facilities (presumably used to launch drones). That being, that the drone development is for surveillance, not for interception of drones. Later in the article it also states:

"Kang said South Korea will establish drone units with various capacities and aggressively deploy military assets to shoot down enemy drones."

While military assets can definitely INCLUDE drones, I'm not really seeing anything in the article stating that the focus is on developing drones to shoot down drones.

>My concern with fixed defense assets is they are sitting targets and once they are knocked out its not an easy fix.

I was speaking more towards man-portable systems such as the Stinger. Quick, dirty, easy to deploy, generally not super obvious to spot like various larger batteries with dedicated launchers, radar, and control vehicles.

Overall as you touched on a bit, there's definitely use cases for air to air drones but at a certain point, you have to start asking yourself what is a drone and what is a missile, and whether you're better off developing large drones with long range and high speed that can keep up with your 6th gen fighter, that have their own munitions to counter drones. Or just creating smaller drone-specific munitions for the existing fighter.

Then again I'm just some rando on Reddit and hardly an expert.


dkf295 t1_j1v8kgl wrote

The big challenge with fielding drones to defend against drone attacks, is the limited warning you get considering the tiny radar cross section of a drone. You need a much faster "interceptor" drone to be able to catch up with the drone you're trying to target which will also necessarily cost substantially more than for example a Shahed-136 on account of needing to be faster, reusable, and having targeting systems and munitions besides quick and dirty onboard explosives.

What I think will be more likely is smaller, cheaper, and likely slower SAMs built to counter drones specifically. A Stinger may be 10 times the cost of a drone, but if you're taking down a drone you don't need nearly as much speed or ordinance (which also brings down the total unit size). Defense will always be behind Offense and will be more expensive, but think more like 3 times as expensive.


dkf295 t1_iyaay5z wrote

But imagine you're a bear and can just bust out a window and go in and grab the pie. And now not only is your pie eaten, but you have a bear in your house.

Not only do you need to lock the pie up, you need to hang it from a rope from a tree such that a bear cannot access it, sufficiently far from the campsite that the bear is not presenting a danger to you/others. Keep in mind that bears can climb trees.


dkf295 t1_iu4hs19 wrote

Reply to comment by Ghostdr1 in eli5: Calorie Deficit by OnlyBoss_01

If this sounds like a ton of work and intimidating, it can be to begin with but after a week or three you'll start memorizing how many calories are in what, and begin to start being able to make decent estimates of unknown foods. Which for the most part is fine if you're not consistently guessing either low or high. I don't calorie count anymore, but it was rare that I actually needed to check a label unless it was a prepackaged food I hadn't eaten before.