Score
Title
260
AskScience Panel of Scientists XVIII
624
AskScience AMA Series: IAmA restoration ecologist focused on restoring oysters to the NY Harbor in New York City. AMA!
969
How does sunscreen stop you from getting burnt?
2844
How are drugs like antidepressants (who’s effects aren’t immediately apparent) developed?
5494
In the last 5-10 years, there’s been tremendous efforts made by many of the first world countries to curb carbon emissions. Have we made a dent?
8
Why does the space shuttle's transonic transition end so abruptly (see linked video)?
30
How do spacewalking astronauts get rid of body heat and CO2 they generate?
3
How does a catalyst affect activation energy?
3122
Why doesn't microwave energy escape through the holes in the screen of a microwave oven?
5
Why does the United States generally have a colder climate than most of Western Europe despite being at the same lattitude, and some parts even being further south?
15
How does the mind make up a physical feeling you've never experienced before while dreaming? For example, a virgin having a wet dream or having a foot amputated?
2
How often do collisions in LEO happen?
4
Why do people start to shrink once they get past a certain age?
3
Do bees have spatial memory when foraging for food?
7
How do we know the composition of Earth's core?
3
Suppose in an X speaking country, a child is raised by 2 parents; one speaks Y language around them, the other speaks Z language. What's the science behind this kid learning to differentiate all three languages and eventually being able to speak all 3, as opposed to if they were only exposed to 1?
25
Why does alcohol kill bacteria?
22
Why is the output power greater than the input power for a microwave?
5
Why do 3 polarising filters, at certain angles, allow some light through when two are at right-angles?
0
What happens do humans blood brain barrier as we age?
5
How do plants react to opiates? If I were to, say, use fentanyl as fertilizer, would the plant die? And what about other popular types of drugs, such as coke?
9
When can you consoder a organism dead?
2
Is chemical rocket exhaust usually a plasma?
12
Does hydraulic fracturing contribute to increased seismic activity(earthquakes) and how likely is it for the mix of chemicals+water ,that are used to displace the shale, to contaminate wells and body’s of water?
7
Why do car wheels look like they're rolling backward when moving fast?
4
Does everything rotate in space? If so, why?
2
Why don't lakes with streams flowing into other lakes eventually completely drain into the other lake?
9
Do animals have a really good sense of time or is it confirmation bias by humans?
10
What is the difference between an imaginary friend and a hallucination? What about Tulpas?
4
Where do scientists come up with temporal timelines for dinosaurs?
4987
This may be a stupid question, but what defines GMO. Is it simply changing a plant through cross pollinating (at its simplest level) such as Mendel, or does GMO mean laboratory tested and genetically altered through a laboratory?
14
What defines an “oil”?
136
Why is an Alpha particle denoted as a Helium atom?
0
When you pull at a slinky from the top, why does the bottom take a second to go with it?
3
a spider learns to build a net from other spiders or is it instinct ?
6
Why do molecules interact with others when they both have 8 valence electrons?
5
Is it more energy efficient to put cold water in a kettle, or hot water?
8
Do the planets in our solar system all orbit the sun on the same plane?
1
Which regions of the brain show diminished cell count with aging?
8
If Radiation is cumulative in our body, is Bluetooth (even with BLE) harmful to humans if we are constantly exposed to it with cellphones, smartwatch, etc. and also from other's electronic devices around us?
0
Can you feel the cold in space?
188
Are there any "weird" uses for heavy/transuranic elements?
207 [deleted] [removed]
160 Valid_Argument Probably not true for every phone but in general: Charger gives you 5V 1-2A over usb Charging circuit in phone reads battery decides how much current to pull Charging circuit feeds the battery at around 4V because Li-Ion is fully charged around 4ish volts. This brings us to relevant bit number one. The phone doesn't run on 5V 1-2A directly, it runs on the battery, which is less than 5V. To run directly on the 5V input the manufacturer would have needed to plan ahead, which costs money, so most don't. The second point is if you yank out the battery in most phones the charging circuit isn't even connected to the main power, it just runs through the battery typically, so you can't even feed charge to the device without running it through the battery. Third point is retarded charging circuit might say "hey no battery no phone" regardless of if it can run or not. So the answer is it depends. It possible to run right off the charger, but it's cheaper and easier to pass through the battery. A few phones will run with the battery pulled out. Some will run if you take a 4-pin adapter and stick where the battery is supposed to be to connect charge circuit and main power. Some phones probably do this already by having a bypass inside the battery itself, but to be honest manufacturers seem to prefer that your battery die earlier. Maybe the most salient point is that Li-Ion don't like being plugged in all day. Li-Ion batteries are happiest when hovering around 40% charge, in general they suffer the least degradation if they are used from around 30-80%. If longevity is your concern the primary ways to keep your battery are 1) never go below 20%, 2) limit the amount of time spent near full charge, 3) always use the slowest wired charger you have. Basically trickle charging throughout the day. [Here's](https://imgur.com/a/wHg8Q) my Axon 7 after about 1.5 years. 50 hours on battery with light use, still another 25 hours left. I get up to 5 days sometimes.
12 thephantom1492 Should be the power adapter, but may, in some case, use a bit of the battery. A common power circuit is a T. power on the left, battery on the right, load at the bottom. It should in theory take the power from the side with the highest voltage. 5V supply, 3-4.4V battery. The real path is more: adapter -> current sense resistor -> diode -> output <- diode <- current sense resistor <- battery. Bridging the two ends of the current sense resistors, sitting across the output, sit the charging circuit. The diode prevent a direct battery to input and input to battery current path, but allow both to power the load. Take note that it is usually also in parallel with a mosfet, and some circuit to turn on and off the mosfet (the diode first conduct, but lose some voltage. The circuit detect it and turn on the mosfet, which short the diode and basically no voltage is lost, making a 'perfect diode'). The charger then can see the battery voltage and current, and the amount of power used at the input, and control the charge as to not overcharge and not overload the adapter...
1 [deleted] [removed]
211 0 [deleted] [removed]
161 0 Valid_Argument Probably not true for every phone but in general: Charger gives you 5V 1-2A over usb Charging circuit in phone reads battery decides how much current to pull Charging circuit feeds the battery at around 4V because Li-Ion is fully charged around 4ish volts. This brings us to relevant bit number one. The phone doesn't run on 5V 1-2A directly, it runs on the battery, which is less than 5V. To run directly on the 5V input the manufacturer would have needed to plan ahead, which costs money, so most don't. The second point is if you yank out the battery in most phones the charging circuit isn't even connected to the main power, it just runs through the battery typically, so you can't even feed charge to the device without running it through the battery. Third point is retarded charging circuit might say "hey no battery no phone" regardless of if it can run or not. So the answer is it depends. It possible to run right off the charger, but it's cheaper and easier to pass through the battery. A few phones will run with the battery pulled out. Some will run if you take a 4-pin adapter and stick where the battery is supposed to be to connect charge circuit and main power. Some phones probably do this already by having a bypass inside the battery itself, but to be honest manufacturers seem to prefer that your battery die earlier. Maybe the most salient point is that Li-Ion don't like being plugged in all day. Li-Ion batteries are happiest when hovering around 40% charge, in general they suffer the least degradation if they are used from around 30-80%. If longevity is your concern the primary ways to keep your battery are 1) never go below 20%, 2) limit the amount of time spent near full charge, 3) always use the slowest wired charger you have. Basically trickle charging throughout the day. [Here's](https://imgur.com/a/wHg8Q) my Axon 7 after about 1.5 years. 50 hours on battery with light use, still another 25 hours left. I get up to 5 days sometimes.
12 0 thephantom1492 Should be the power adapter, but may, in some case, use a bit of the battery. A common power circuit is a T. power on the left, battery on the right, load at the bottom. It should in theory take the power from the side with the highest voltage. 5V supply, 3-4.4V battery. The real path is more: adapter -> current sense resistor -> diode -> output <- diode <- current sense resistor <- battery. Bridging the two ends of the current sense resistors, sitting across the output, sit the charging circuit. The diode prevent a direct battery to input and input to battery current path, but allow both to power the load. Take note that it is usually also in parallel with a mosfet, and some circuit to turn on and off the mosfet (the diode first conduct, but lose some voltage. The circuit detect it and turn on the mosfet, which short the diode and basically no voltage is lost, making a 'perfect diode'). The charger then can see the battery voltage and current, and the amount of power used at the input, and control the charge as to not overcharge and not overload the adapter...
1 0 [deleted] [removed]