Score
Title
98
AskScience Panel of Scientists XVIII
550
AskScience AMA Series: I am Melinda Krahenbuhl and I am the director of the Reed Research Reactor, the only nuclear reactor operated primarily by undergraduate students. AMA!
8468
What elements are at genuine risk of running out and what are the implications of them running out?
269
Can you break sound barrier under water or any other material?
4021
What’s the largest star system in number of planets?
19
Why does plastic turn white at the creases when folded/bent?
3
How does thermal imaging work?
21
Do microwaves leave residual changes to molecules after heating?
4
Can a setup of hall engines provide enough thrust to keep a satellite stationary above earth?
2
Does the temperature have any (noticable) effect on air resistance?
6
How does a memristor work?
1
How does radiation poisoning work?
1
How is the height of the mountain measured?
3827
What is the effect, positive or negative, of receiving multiple immunizations at the same time; such as when the military goes through "shot lines" to receive all deployment related vaccines?
4
If a planet had a radius that was equal to the altitude of Earth’s geosynchronous orbit, but had the same mass and rotational period as the Earth now, would there be reduced or zero gravity on the surface?
1
What is lost and what is preserved in a particle collider?
8
Why does snow melt in the sunlight, even when the temperature outside is below freezing?
11
Mar's summer temperature can be 20 celsius. Could a human survive with just an oxygen mask?
2
Is there an altitude at which there is no longer a speed of sound?
0
How would a moving target affect the rate of nuclear fission vs a stationary target?
14
What would a spaceship moving at 0.9c firing lasers both in front of it and behind it look like to an external reference frame?
6
Does adiabatic warming occur when air descends in the Earth's polar cells?
24
How does the cosmic microwave background persist? Why hasn't it been distorted and destroyed by new sources of energy pumping into space?
6
How does cancer metastasis work?
7
Can a comet maintain an atmosphere?
1
How does RFID blocking material work?
0
Does the Meissner effect relate to Lenzs law?
9
Why hasn't The Asteroid Belt formed a planet?
10
Can you use a normal (CMOS) camera for detecting scintillation?
3
How do people know that the Island of Stability exists? And could there possibly be another "island" after it?
59
How can brain cells cause tumours even though they can not multiply?
7
How far back can you go before carbon dating becomes unreliable?
2
How does a computer process “simple” events?
1578
Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology
3
What is the nonrenewable fuel cost to produce x quantity of electricity?
1132
What triggers beta particles to form, and for what reason can they not penetrate substantially thick aluminium?
0
What is the strongest a magnet could be?
1242
If capacitance increases as distance between plates decreases, why aren't there very small 1F capacitors?
0
What makes astronomers think life in general isn't possible on gas giants?
1
How applicable are Newtonian Physics in real life? Is it completely false or are there some concepts which can be used to accurately predict real-life situations?
1050
is it possible to move an object in circular motion using magnets?
4
What would hydrogen in metal form look like?
11 wonkey_monkey Imagine a bunch of cars on a road. They all travel at the same speed, but all the red cars have a special lane to themselves. The cars come to a tunnel. Inside the tunnel, red cars have to travel at half the usual speed, but the other cars can carry on as normal. Once they get to the exit, the red cars can speed up again. What happens is that you get a delay on a *particular* red car, but overall the *rate* of red cars after the tunnel is the same as all the other cars.
3 Astrokiwi This effect applies more for transparent or near-transparent material. Most of the Sun is pretty opaque, so it's not really best to think of it as the "same" photon bouncing around until it escapes. It's better to think of it as photons being absorbed and new photons being emitted. This is important, because the photons we see give us a picture of the surface of the Sun. The combination of wavelengths of photons that we get is right for photons emitted at ~6000 K, the surface temperature of the Sun. The core of the Sun is more like ~1,000,000 K, but these photons do not reach us directly. What we get is photons emitted very close to the surface, which then only pass through very thin plasma before reaching our eyes.
5 I_hate_usernamez Faster speed does not increase the number of collisions in a random walk; it only decreases the time needed to escape the sun because the collisions happen faster. The main thing that matters is the chance of scattering (which affects the number of collisions). According to [this lecture](http://farside.ph.utexas.edu/teaching/em/lectures/node96.html), the scattering is not dependent on wavelength.
10 0 wonkey_monkey Imagine a bunch of cars on a road. They all travel at the same speed, but all the red cars have a special lane to themselves. The cars come to a tunnel. Inside the tunnel, red cars have to travel at half the usual speed, but the other cars can carry on as normal. Once they get to the exit, the red cars can speed up again. What happens is that you get a delay on a *particular* red car, but overall the *rate* of red cars after the tunnel is the same as all the other cars.
3 0 Astrokiwi This effect applies more for transparent or near-transparent material. Most of the Sun is pretty opaque, so it's not really best to think of it as the "same" photon bouncing around until it escapes. It's better to think of it as photons being absorbed and new photons being emitted. This is important, because the photons we see give us a picture of the surface of the Sun. The combination of wavelengths of photons that we get is right for photons emitted at ~6000 K, the surface temperature of the Sun. The core of the Sun is more like ~1,000,000 K, but these photons do not reach us directly. What we get is photons emitted very close to the surface, which then only pass through very thin plasma before reaching our eyes.
3 0 I_hate_usernamez Faster speed does not increase the number of collisions in a random walk; it only decreases the time needed to escape the sun because the collisions happen faster. The main thing that matters is the chance of scattering (which affects the number of collisions). According to [this lecture](http://farside.ph.utexas.edu/teaching/em/lectures/node96.html), the scattering is not dependent on wavelength.