Score
Title
282
AskScience Panel of Scientists XVII
958
AskScience AMA Series: European Southern Observatory announcement concerning groundbreaking observations.
696
Do hydrogen isotopes affect chemical structure of complex hydrocarbons?
663
How far can a big passenger aircraft (for instance an Airbus A340) glide after catastrophic engin failure?
33
What is happening when a chip goes stale?
95
Is there a difference in suicide rates between people who have already had children and those who haven't?
7
What is happening when a computer generates a random number? Are all RNG programs created equally? What makes an RNG better or worse?
19
Why do electrons have a constant mass?
269
Why don’t we use salt water for toilet water? Wouldn’t it save millions of gallons of freshwater?
2
How do we calculate the exhaust speed of ions in a Hall-effect thruster ?
48
If you drop something on a solid, does it ripple like a liquid would except much less noticeably?
4803
How do audio books, printed books, and videos differ in terms of how our brains retain and process the information?
9
Why do some trees leaves turn red some yellow and some orange and if a tree is red this year then is it always red or can it be yellow next year?
1
Are the social behaviors we label under 'group dynamics' universal? In other words, do the subconscious behaviors of a group change between cultures/ethnic lines, or are we all the same in this fundamental respect?
59
Can there be anything higher than a pH of 14 or lower than a pH of 0?
0
How can we prove that earth is rotating?
16
Why are sloths so slow?
17
Will sterilisation with gamma rays not make the product radioactive or destroy the product?
7
Human fetal development: When does the uterus start to form?
1
Why is Ruthenium's electron configuration [Kr] 5s1 4d7?
2
Is the low dosage of cosmic background radiation we are constatly exposed to a driver of evolution?
11
The impact of canals in a city?
15
How do tree rings form?
10
Does a flashing LED light use less electricity than a steady light? Would a light on a 1/2 second on/off flash use half the electricity?
11
Can deaf people get tinnitus?
8
Do you burn more calories when cold compared to when you are warm when doing the same activity?
1
What factors lead to the Wisconsin glaciation?
10
How do the switching mechanisms in transistors work, and how are they triggered?
0
Why does absence of blood flow cause cell death?
7
Concerning the photoelectric effect, if an electron's energy is nearly proportional to the frequency of the incident photons, why don't solar panels work on cloudy days? Doesn't UV light, which is higher energy than visible and infrared, pass through clouds?
0
Why is it that, when traveling in space, the heavier the food is, the more expensive it is to transport? Who pays money to who?
2
Was bacon used as a treatment for dermatobia hominis?
6285
Do you use muscles to open or close your eyes?
6
I know a catalyst works by lowering the activation energy but how does it do that?
2
Risk Factors vs Indicators for Disease - What's the difference?
8
How do we know how much a planet weights/the mass of the planet, without knowing exactly what it is made of?
13
My physics tutor said that we are now able to change the wavelength of an already emitted laser beam. How is this possible?
0
Why is drinking Fluoridated water safe if Fluorine is highly reactive?
1
Given low enough temperature and high enough pressure, is everything able to freeze?
3
Why does NaCl always has a Crystal structure when solid ?
3
How does a mirror reflect light?
1
Do light waves affect how sound waves travel or vice versa?
16 EricHunting The ISS is hit by very small debris occasionally and has had near-misses by larger debris. Things in orbital space don't move around at random but on consistent paths. Most of these paths are not perfectly stable, being affected by the varying gravity of the Earth, the light drag of gasses in the stratosphere, and the forces of solar wind and even the pressure of light, and so their orbits can 'decay' over time, causing them to fall into the Earth after some period of time. Active satellites maintain or change these paths with periodic boosts by small on-board rockets or thrusters. The paths of most large objects in space are recorded and continuously tracked so that their possible locations at any time in the future can be predicted, allowing collisions to be avoided. But very small objects cannot be easily detected by radar or telescopes and so are much harder to predict. So manned spacecraft are usually armored for protection against being hit by these small objects. With the number of things in orbit today very large, there is a potential hazard called the Kessler Syndrome. This is when a collision between two things in orbit produce a lot of small debris that fly off in many directions and can't be tracked, colliding into other things producing even more debris, and so on. If this was severe enough, it could destroy most satellites and create a vast swarm of debris preventing manned spacecraft from safely travelling to space for decades or centuries, until all these small objects were finally swept out of orbit naturally or deliberately cleared by other means we haven't yet developed. This is what makes the militarization of space very dangerous for our future in space. You can't use or even test weapons in space without the risk of causing one of these Kessler events.
2 katinla Whenever there is a risk that the ISS may come closer than 5 km to another satellite or a catalogued debris, they perform a collision avoidance manoeuvre. This can only work for objects that are larger than a few cm across so they can be tracked. Smaller objects are handled by MMOD shields. Post-flight inspection of the MPLM modules has revealed that the ISS has been hit several times, but the shields were strong enough to resist. These modules weren't shielded very heavily anyway because they weren't expected to stay in orbit for long time - other modules and especially those at the front of the station (Columbus, Kibo) are shielded much more paranoidly. This NASA document is quite detailed: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20060026214.pdf
2 Lazrath First off real satellites are at much higher altitudes, nowhere near the ISS The ISS is at such a low altitude that there is still some atmosphere, so most things "junk"(and other micro-satellites) would eventually decay and fall back to earth. The ISS re-boosts itself every month or so, to stay in orbit source graph; http://www.heavens-above.com/IssHeight.aspx
17 0 EricHunting The ISS is hit by very small debris occasionally and has had near-misses by larger debris. Things in orbital space don't move around at random but on consistent paths. Most of these paths are not perfectly stable, being affected by the varying gravity of the Earth, the light drag of gasses in the stratosphere, and the forces of solar wind and even the pressure of light, and so their orbits can 'decay' over time, causing them to fall into the Earth after some period of time. Active satellites maintain or change these paths with periodic boosts by small on-board rockets or thrusters. The paths of most large objects in space are recorded and continuously tracked so that their possible locations at any time in the future can be predicted, allowing collisions to be avoided. But very small objects cannot be easily detected by radar or telescopes and so are much harder to predict. So manned spacecraft are usually armored for protection against being hit by these small objects. With the number of things in orbit today very large, there is a potential hazard called the Kessler Syndrome. This is when a collision between two things in orbit produce a lot of small debris that fly off in many directions and can't be tracked, colliding into other things producing even more debris, and so on. If this was severe enough, it could destroy most satellites and create a vast swarm of debris preventing manned spacecraft from safely travelling to space for decades or centuries, until all these small objects were finally swept out of orbit naturally or deliberately cleared by other means we haven't yet developed. This is what makes the militarization of space very dangerous for our future in space. You can't use or even test weapons in space without the risk of causing one of these Kessler events.
2 0 tminus7700 They can actually move the station, depending on the prediction of a orbit of an object that might collide with the station. https://sma.nasa.gov/news/articles/newsitem/2015/11/23/two-more-collision-avoidance-maneuvers-for-the-international-space-station https://orbitaldebris.jsc.nasa.gov/quarterly-news/pdfs/odqnv16i2.pdf
2 0 katinla Whenever there is a risk that the ISS may come closer than 5 km to another satellite or a catalogued debris, they perform a collision avoidance manoeuvre. This can only work for objects that are larger than a few cm across so they can be tracked. Smaller objects are handled by MMOD shields. Post-flight inspection of the MPLM modules has revealed that the ISS has been hit several times, but the shields were strong enough to resist. These modules weren't shielded very heavily anyway because they weren't expected to stay in orbit for long time - other modules and especially those at the front of the station (Columbus, Kibo) are shielded much more paranoidly. This NASA document is quite detailed: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20060026214.pdf
2 0 Lazrath First off real satellites are at much higher altitudes, nowhere near the ISS The ISS is at such a low altitude that there is still some atmosphere, so most things "junk"(and other micro-satellites) would eventually decay and fall back to earth. The ISS re-boosts itself every month or so, to stay in orbit source graph; http://www.heavens-above.com/IssHeight.aspx