Score
Title
285
AskScience Panel of Scientists XVII
961
AskScience AMA Series: European Southern Observatory announcement concerning groundbreaking observations.
1190
Do hydrogen isotopes affect chemical structure of complex hydrocarbons?
977
How far can a big passenger aircraft (for instance an Airbus A340) glide after catastrophic engin failure?
116
What is happening when a chip goes stale?
82
What is happening when a computer generates a random number? Are all RNG programs created equally? What makes an RNG better or worse?
105
Is there a difference in suicide rates between people who have already had children and those who haven't?
3
How is Mills's constant calculated? How does it relate to the Riemann hypothesis? Why don't we know if it's rational?
20
Why do electrons have a constant mass?
274
Why don’t we use salt water for toilet water? Wouldn’t it save millions of gallons of freshwater?
3
How do we calculate the exhaust speed of ions in a Hall-effect thruster ?
54
If you drop something on a solid, does it ripple like a liquid would except much less noticeably?
2
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?
4793
How do audio books, printed books, and videos differ in terms of how our brains retain and process the information?
3
How can we prove that earth is rotating?
11
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?
63
Can there be anything higher than a pH of 14 or lower than a pH of 0?
15
Why are sloths so slow?
4
Why is Ruthenium's electron configuration [Kr] 5s1 4d7?
16
Will sterilisation with gamma rays not make the product radioactive or destroy the product?
6
Human fetal development: When does the uterus start to form?
13
The impact of canals in a city?
1
Why does absence of blood flow cause cell death?
2
Is the low dosage of cosmic background radiation we are constatly exposed to a driver of evolution?
16
How do tree rings form?
11
Can deaf people get tinnitus?
12
Do you burn more calories when cold compared to when you are warm when doing the same activity?
9
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?
1
What factors lead to the Wisconsin glaciation?
7
How do the switching mechanisms in transistors work, and how are they triggered?
9
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?
3
Was bacon used as a treatment for dermatobia hominis?
6278
Do you use muscles to open or close your eyes?
8
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?
14
My physics tutor said that we are now able to change the wavelength of an already emitted laser beam. How is this possible?
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?
17 lythronax-argestes Yes, there are theoretical upper limits on the maximum size which can be attained by any given animal group. (The below is from sauropod biomechanics researcher Heinrich Mallison at [[1]](http://www.askabiologist.org.uk/answers/viewtopic.php?pid=15164#p15164).) At a superficial level, a big animal requires a lot of sustenance for both metabolism and locomotion. In particular, metabolism gets a lot less efficient for large animals as the surface area becomes very small relative to the volume (per the square-cube law). Overheating or starvation would be problems for large animals, which would be exacerbated if the climate of the time is unfavourable (i.e. heat waves, or droughts leading to a lack of food). Then, once you get down to an animal's skeletal structure (talking about vertebrates here), the square-cube law strikes again. Of course, as an animal's volume grows, its weight grows accordingly. However, the tensile strength of muscles and bones do not scale cubically; they scale quadratically. So it becomes harder for an animal's skeletal structure to support it as it grows. Sauropod dinosaurs were really pushing it in terms of the size limit, and they "cheated" in many ways, so to speak. They have columnar limbs, which improves support, and they have bones lightened by air sacs, which reduces weight. Air sacs also alleviated the thermoregulatory problem. And of course their long necks are specializations for efficiently acquiring food.
2 the-real-apelord The base reasons from a structural POV are that: -Mass and therefore weight scales cubically so if something is made 2x bigger in size it becomes 8x heavier -But the cross-sectional area of the load bearing elements (legs for example) only increases with the square of scale so 2x bigger gives you just 4x the area to support 8x the weight so, in this example, the stress (force/area) has doubled. -All materials and structures have a limit to the amount of force/area they can sustain and at some point with increasing size will eventually fail (pancake in pure compression). In short weight grows faster than the area over which the weight has to be spread as a creature increases in size. Another limit is of course the presence of gravity, since weight only exists in a gravitational field. However it's worth noting that even in zero gravity there's limits on the size of a living thing, if that thing hopes to move, since as before mass increases cubically meaning forces required (for same acceleration) increase cubically but again those forces are spread over areas that is only growing with square of scale. There's a cool book called: "Why things don't fall down" that covers this question and lots else.
1 annomandaris Its mostly the square-cubed law, as anything gets bigger, its volume gets bigger a lot faster than its cross-sectional area. so if you take an animals leg, and double length/height/thickness of it, its cross-section will square, but its volume will be cubed. So basically theres a point where that animal thats getting bigger, the bone cant take the weight, and would just split apart. Also the bigger an animal gets, the bigger the problem of overheating gets, getting oxygen to areas of the body, and just how much it has to eat. Brontosaurus's were about as big as an animal can be, and if you notice they have short stubby legs that are really thick and short. and most of their size was a skinny neck and tail.
-2 lbruss95 some animals were able to attain massive size due to oxygen availability at the time, with that many resources it was a viable evolutionary strategy to be huge as to avoid predation. If an environment were created with "unlimited" resources, large predators would increase in size to out compete each other. mountain sized animals didn't exist because that would have no evolutionary benefit within an individual's lifetime.
18 0 lythronax-argestes Yes, there are theoretical upper limits on the maximum size which can be attained by any given animal group. (The below is from sauropod biomechanics researcher Heinrich Mallison at [[1]](http://www.askabiologist.org.uk/answers/viewtopic.php?pid=15164#p15164).) At a superficial level, a big animal requires a lot of sustenance for both metabolism and locomotion. In particular, metabolism gets a lot less efficient for large animals as the surface area becomes very small relative to the volume (per the square-cube law). Overheating or starvation would be problems for large animals, which would be exacerbated if the climate of the time is unfavourable (i.e. heat waves, or droughts leading to a lack of food). Then, once you get down to an animal's skeletal structure (talking about vertebrates here), the square-cube law strikes again. Of course, as an animal's volume grows, its weight grows accordingly. However, the tensile strength of muscles and bones do not scale cubically; they scale quadratically. So it becomes harder for an animal's skeletal structure to support it as it grows. Sauropod dinosaurs were really pushing it in terms of the size limit, and they "cheated" in many ways, so to speak. They have columnar limbs, which improves support, and they have bones lightened by air sacs, which reduces weight. Air sacs also alleviated the thermoregulatory problem. And of course their long necks are specializations for efficiently acquiring food.
2 0 the-real-apelord The base reasons from a structural POV are that: -Mass and therefore weight scales cubically so if something is made 2x bigger in size it becomes 8x heavier -But the cross-sectional area of the load bearing elements (legs for example) only increases with the square of scale so 2x bigger gives you just 4x the area to support 8x the weight so, in this example, the stress (force/area) has doubled. -All materials and structures have a limit to the amount of force/area they can sustain and at some point with increasing size will eventually fail (pancake in pure compression). In short weight grows faster than the area over which the weight has to be spread as a creature increases in size. Another limit is of course the presence of gravity, since weight only exists in a gravitational field. However it's worth noting that even in zero gravity there's limits on the size of a living thing, if that thing hopes to move, since as before mass increases cubically meaning forces required (for same acceleration) increase cubically but again those forces are spread over areas that is only growing with square of scale. There's a cool book called: "Why things don't fall down" that covers this question and lots else.
1 0 annomandaris Its mostly the square-cubed law, as anything gets bigger, its volume gets bigger a lot faster than its cross-sectional area. so if you take an animals leg, and double length/height/thickness of it, its cross-section will square, but its volume will be cubed. So basically theres a point where that animal thats getting bigger, the bone cant take the weight, and would just split apart. Also the bigger an animal gets, the bigger the problem of overheating gets, getting oxygen to areas of the body, and just how much it has to eat. Brontosaurus's were about as big as an animal can be, and if you notice they have short stubby legs that are really thick and short. and most of their size was a skinny neck and tail.
0 0 lbruss95 some animals were able to attain massive size due to oxygen availability at the time, with that many resources it was a viable evolutionary strategy to be huge as to avoid predation. If an environment were created with "unlimited" resources, large predators would increase in size to out compete each other. mountain sized animals didn't exist because that would have no evolutionary benefit within an individual's lifetime.