WEBVTT - A Sweating Robot, the Best Way to Merge, and What Your Phone Battery Wants 0:00:00.840 --> 0:00:03.160 Welcome to How Stuff Works Now. I'm your host, Lauren 0:00:03.240 --> 0:00:09.240 vocal Bam, a researcher and writer. Here at How Stuff Works. 0:00:07.640 --> 0:00:12.680 Every week, I'm bringing you three stories from our team 0:00:12.720 --> 0:00:16.160 about the weird and wondrous advances we've seen in science, technology, 0:00:16.200 --> 0:00:19.920 and culture. This week, there's some science that says drivers 0:00:19.920 --> 0:00:22.200 who wait until the last second to merge out of 0:00:22.200 --> 0:00:26.439 an ending lane are actually in the right and unrelated 0:00:26.640 --> 0:00:29.400 researchers have built a humanoid robot that can do push 0:00:29.480 --> 0:00:33.440 ups and cool itself off by sweating. But first, Tex 0:00:33.479 --> 0:00:36.800 Stuff host Jonathan Strickland, via our freelance writer David Ruse, 0:00:37.159 --> 0:00:39.680 debunks a few myths about the care and feeding of 0:00:39.720 --> 0:00:43.160 smartphone batteries. There's a lot of conflicting information out there, 0:00:43.320 --> 0:00:49.120 but we're here to straighten things out. You've probably taken 0:00:49.200 --> 0:00:53.000 note of all the talk about smartphones and lithium ion batteries, 0:00:53.240 --> 0:00:56.280 so we thought we'd take this opportunity to address three 0:00:56.560 --> 0:01:00.680 burning questions. Question one, isn't a bad idea to leave 0:01:00.720 --> 0:01:03.560 your phone plugged in overnight? You might have heard that 0:01:03.600 --> 0:01:05.840 if you leave your phone plugged in for too long, 0:01:05.920 --> 0:01:08.840 it will damage the battery in some way. But assuming 0:01:08.880 --> 0:01:11.959 your charger is in proper working order, there's nothing to 0:01:12.000 --> 0:01:15.880 worry about. Smartphone battery stopped charging once they hit a limit. 0:01:16.240 --> 0:01:19.919 It's as if your phone is already unplugged, so good news. 0:01:20.319 --> 0:01:23.440 As long as your charger is working correctly, you don't 0:01:23.560 --> 0:01:25.280 have to set an alarm for the middle of the 0:01:25.400 --> 0:01:28.960 night so that you don't accidentally overcharge your smartphone into 0:01:28.959 --> 0:01:33.720 the incredible hulk. Question two, should you run your smartphone's 0:01:33.760 --> 0:01:37.680 battery out completely before recharging it. You've probably heard that 0:01:37.760 --> 0:01:41.280 batteries have a limited number of power cycles. This represents 0:01:41.319 --> 0:01:44.360 the number of times a battery can discharge and recharge 0:01:44.400 --> 0:01:48.000 before it loses so much capacity then it's pretty much useless. 0:01:48.600 --> 0:01:52.600 This is true. Batteries experienced stress through usage, similar to 0:01:52.640 --> 0:01:55.960 what you'd see in a mechanical system. Eventually the battery 0:01:56.000 --> 0:02:00.000 wears out, But recharging your phone when it's at say 0:02:00.080 --> 0:02:03.600 capacity doesn't represent a full charge. It's not like you 0:02:03.680 --> 0:02:06.440 lose one cycle every time you plug in your phone. 0:02:06.880 --> 0:02:10.000 That means you don't need to discharge a battery completely 0:02:10.200 --> 0:02:13.760 before recharging it. In fact, that would cause more stress 0:02:13.800 --> 0:02:18.120 to your battery, wearing it out faster. Experts suggest recharging 0:02:18.120 --> 0:02:22.040 your battery when it's between forty and eight capacity. This 0:02:22.080 --> 0:02:25.239 will decrease the amount of stress the battery experiences as 0:02:25.240 --> 0:02:28.800 it discharges and recharges. For some of us, this means 0:02:28.800 --> 0:02:31.800 recharging our phones several times throughout the day. If you 0:02:31.880 --> 0:02:34.720 can't do that, don't sweat it. Most of us replace 0:02:34.760 --> 0:02:39.040 our phones before we've significantly whittled down battery capacity. And 0:02:39.080 --> 0:02:44.320 now question three, how does heat affect battery performance? Not great, bob. 0:02:44.840 --> 0:02:48.080 Heat will reduce a battery's capacity faster than going through 0:02:48.160 --> 0:02:51.520 lots of charging cycles in a short time. That means 0:02:51.600 --> 0:02:55.160 when you fully recharge your smartphone, you'll have fewer hours 0:02:55.160 --> 0:02:57.960 of operation because the battery won't be able to store 0:02:57.960 --> 0:03:01.160 as much energy as it did previous sleep. So don't 0:03:01.240 --> 0:03:04.200 leave your smartphones sitting out in the sun or in 0:03:04.240 --> 0:03:07.800 a hot car, or I don't know, on the stove 0:03:07.919 --> 0:03:15.600 or something. It's better. Next up step, editor Christopher Hasiotus 0:03:15.680 --> 0:03:20.040 and freelancer Jescelin Shields explain how one annoying traffic behavior 0:03:20.200 --> 0:03:22.200 turns out to be for the good of all of us. 0:03:22.800 --> 0:03:26.560 Merging lanes at the last possible second isn't just more efficient, 0:03:27.040 --> 0:03:32.040 it's safer To imagine you're driving down the road, and 0:03:32.120 --> 0:03:34.239 all of a sudden you see a brightly colored sign 0:03:34.440 --> 0:03:38.080 announcing lane closed in one thousand feet. You've got a 0:03:38.080 --> 0:03:41.360 couple of options. One, immediately turn on your blinker and 0:03:41.400 --> 0:03:44.360 wait until someone in the next lane lets you in. Two, 0:03:44.960 --> 0:03:46.560 just stay in your lane and wait for all the 0:03:46.560 --> 0:03:48.800 plaite people to get out of your way. Then zoom 0:03:48.840 --> 0:03:50.600 to the front of the line and merge at the 0:03:50.680 --> 0:03:54.040 last moment, right where the lane closes. Watches people who 0:03:54.080 --> 0:03:57.400 merge hurley rage in your general direction, silent behind their 0:03:57.440 --> 0:04:01.240 glass windows, but faces twisted in fury. To most people, 0:04:01.400 --> 0:04:05.040 the first option seems more courteous and patient, less selfish, 0:04:05.360 --> 0:04:09.680 but study upon study proves the upstanding early mergers among 0:04:09.760 --> 0:04:13.080 us are just creating a single slow line of traffic 0:04:13.120 --> 0:04:17.760 that's not only frustrating for drivers, it's inefficient. That's because 0:04:17.800 --> 0:04:21.000 by merging early, we minimize the amount of usable road, 0:04:21.320 --> 0:04:24.880 leaving a long swath of perfectly good street capacity open 0:04:25.040 --> 0:04:28.120 and unused. What we all should be doing is called 0:04:28.160 --> 0:04:31.200 the late merge zipper system, and by the way, the 0:04:31.279 --> 0:04:34.600 Germans naturally have their own word for it, rice verst 0:04:34.640 --> 0:04:38.320 loose system. In this system, every car in the lane 0:04:38.360 --> 0:04:40.839 that's ending drives all the way up to the front 0:04:40.839 --> 0:04:43.240 of the line and takes turns merging with the other 0:04:43.320 --> 0:04:46.479 lane of traffic. From above, it looks a bit like 0:04:46.560 --> 0:04:49.599 the teeth on a zipper coming together. Because the system 0:04:49.680 --> 0:04:53.120 uses all the available road space for as long as possible, 0:04:53.440 --> 0:04:58.000 it cuts congestion by according to recent studies from various 0:04:58.080 --> 0:05:01.080 US state departments of Transportation and as well as the 0:05:01.120 --> 0:05:05.640 Federal Highway Administration. The late merge zipper system also reduces 0:05:05.680 --> 0:05:08.400 crashes because it keeps all traffic moving at the same 0:05:08.520 --> 0:05:11.720 rate of speed, rather than having some cars going slow 0:05:12.000 --> 0:05:15.960 to merge early while others zoom passed them. So why 0:05:16.000 --> 0:05:18.839 don't we all just zipper merge at the last minute? Already? 0:05:19.040 --> 0:05:21.320 The problem is, of course, that our driving habits are 0:05:21.360 --> 0:05:24.440 baked in pretty deep. But to help steer us to 0:05:24.480 --> 0:05:27.360 a more rational place, some states are shelling out big 0:05:27.400 --> 0:05:30.719 bucks to actually retrain their drivers to use the zipper merge. 0:05:31.560 --> 0:05:34.200 Colorado and Minnesota have been working on encouraging the late 0:05:34.240 --> 0:05:37.839 merge zipper for a decade, already, followed by Washington, Missouri 0:05:37.839 --> 0:05:41.120 in Kansas, and even earlier this year, Missouri launched its 0:05:41.120 --> 0:05:45.200 own public education campaign. Will this efficient and safe merging 0:05:45.200 --> 0:05:48.600 technique find a place in our traffic habits. Minnesota Radio's 0:05:48.640 --> 0:05:52.480 Bob Collins reflected after his state implemented its campaign, saying 0:05:53.160 --> 0:05:55.719 the zipper merge is going to be this centuries conversion 0:05:55.760 --> 0:05:59.000 to the metric system in the seventies great idea made 0:05:59.000 --> 0:06:04.200 perfect sense and was dead on arrival. However, change could 0:06:04.200 --> 0:06:06.840 be on its way thanks to a generational shift. A 0:06:06.880 --> 0:06:10.120 two thousand thirteen Minnesota survey found that only eight percent 0:06:10.200 --> 0:06:14.279 of senior drivers felt comfortable with the late March zipper system. 0:06:14.360 --> 0:06:17.640 On the other hand, among drivers aged to thirty four, 0:06:18.160 --> 0:06:22.240 a full fort of the young population are okay zipping 0:06:22.320 --> 0:06:27.920 up for common sense and the common good. Finally, this week, 0:06:28.120 --> 0:06:30.599 I'm bringing you a story from our freelance writer Patrick 0:06:30.720 --> 0:06:33.720 Jake Tiger about a robot built to manage the heat 0:06:33.760 --> 0:06:37.760 from its machinery by sweating. It's only gross and or 0:06:37.839 --> 0:06:41.640 hilarious until you start thinking about how efficient biomimicry can be. 0:06:44.480 --> 0:06:47.800 When you physically exert yourself, you break a sweat. You've 0:06:47.839 --> 0:06:51.680 probably noticed this that dripping is a biological mechanism that 0:06:51.880 --> 0:06:55.440 keeps your body from overheating when the water secreted out 0:06:55.440 --> 0:06:58.160 of your sweat glands evaporates, it draws off heat and 0:06:58.200 --> 0:07:01.800 cools you down. Now, if a machine does something strenuous, 0:07:02.040 --> 0:07:04.320 it has to get rid of the resulting heat energy too. 0:07:04.880 --> 0:07:07.880 In the past, engineers have relied upon fans, motors, and 0:07:08.000 --> 0:07:12.480 radiators to cool robotic gadgetry. But those solutions are pretty bulky, 0:07:12.520 --> 0:07:15.240 and when you're talking about robotic gadgetry that mimics living 0:07:15.280 --> 0:07:20.760 creatures movements, bulky equals cumbersome. That's why University of Tokyo 0:07:20.960 --> 0:07:23.720 j s K Lab researchers, who are designing robots with 0:07:23.800 --> 0:07:26.840 muscular and skeletal systems based on the human body, have 0:07:27.000 --> 0:07:29.480 come up with a solution to the heat problem that's 0:07:29.480 --> 0:07:33.600 either ingenious or obvious. They've created a robot that uses 0:07:33.680 --> 0:07:38.000 sweat to cool itself. The robot, named Kenoto, was presented 0:07:38.040 --> 0:07:41.720 at the International Conference on Intelligent Robots and Systems in October. 0:07:42.120 --> 0:07:44.320 It's a five and a half foot tall, hundred and 0:07:44.320 --> 0:07:47.400 twenty three pound automaton, which is one point seven ms 0:07:47.440 --> 0:07:50.760 and about fifty six ks for our metric friends. It's 0:07:50.800 --> 0:07:53.680 stuffed with circuitry and a hundred and eight motors that 0:07:53.760 --> 0:07:57.560 need to remain relatively cool to function. Optimally. To do that, 0:07:57.600 --> 0:08:00.320 the designers created a system of channels that allow water 0:08:00.400 --> 0:08:03.000 to run through the robot's body and then evaborate out 0:08:03.040 --> 0:08:06.800 from its metal skin. To accomplish that, the engineers three 0:08:06.880 --> 0:08:10.840 D printed a highly permeable aluminum frame with a spongelike 0:08:10.960 --> 0:08:14.520 array of tiny gaps and tunnels through which water can trickle. 0:08:15.560 --> 0:08:18.440 Ken Godo has to be kept constantly hydrated for the 0:08:18.480 --> 0:08:20.680 cooling to be effective, just like you or me, but 0:08:20.880 --> 0:08:22.840 ken Godo only needs about half a cup of water 0:08:22.920 --> 0:08:26.080 per day, far less than a human. To demonstrate how 0:08:26.120 --> 0:08:29.040 well the system works, researchers had the robot do push 0:08:29.120 --> 0:08:33.239 ups for eleven minutes straight, which it managed without overheating. 0:08:33.840 --> 0:08:36.600 The whole thing looks well a lot like you'd expect 0:08:36.640 --> 0:08:39.480 to push up maniac robot to look, which is to say, 0:08:39.600 --> 0:08:42.400 something like a Terminator T eight hundred skeleton, except it's 0:08:42.440 --> 0:08:45.719 ropey muscles are more puffy than sleek, and they gave 0:08:45.760 --> 0:08:49.040 it a face based in classic manga think Samu Tezuka, 0:08:49.120 --> 0:08:51.880 but more Buddha than Astro Boy. For anyone who doesn't 0:08:51.880 --> 0:08:54.000 speak fluent nerd, there's a video on now dot how 0:08:54.040 --> 0:08:56.880 stuff works dot com with a visual and of course, 0:08:57.000 --> 0:08:59.320 the j s K Lab isn't just interested in making 0:08:59.400 --> 0:09:02.160 robots that do push ups. Lots of their research is 0:09:02.200 --> 0:09:05.080 bent toward designing bots that are humanoid enough to move 0:09:05.120 --> 0:09:08.200 with ease around space. Is built for humans like the 0:09:08.280 --> 0:09:10.880 homes of the elderly and other people who need help 0:09:10.880 --> 0:09:14.400 with housework or around offices. Do you think how stuff 0:09:14.400 --> 0:09:16.960 Works would buyas a robot that delivers our inter office mail, 0:09:17.120 --> 0:09:25.720 sets up teleconferencing, and microwaves our luncheons. That's our show 0:09:25.760 --> 0:09:28.000 for this week. Thank you so much for tuning in. 0:09:28.320 --> 0:09:31.400 Subscribe now for more of the latest and strangest science news, 0:09:31.480 --> 0:09:33.120 and send us links to anything you'd like to hear 0:09:33.200 --> 0:09:36.240 us cover, plus the name of your favorite local charity. 0:09:36.520 --> 0:09:38.680 We're feeling the weight of our civic duty this week. 0:09:39.080 --> 0:09:41.280 You can send us an email at now podcast at 0:09:41.280 --> 0:09:44.400 how stuff works dot com, and of course, for lots 0:09:44.440 --> 0:09:46.600 more stories like these, head on over to our home 0:09:46.640 --> 0:10:03.160 planet now dot how stuff works dot com.