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?
304 contact_fusion Last month they did publish an [erratum](http://science.sciencemag.org/content/357/6352/eaao5843) to the original [Science](http://science.sciencemag.org/content/355/6326/715) article detailing the findings. They claim their conclusions stand. I'm sure that several groups are working to replicate the work and that it is under some intense scrutiny. Especially in a field like this, where there are a handful of groups with the necessary expertise to replicate the work, it can take a while. As I understand it, just replicating it is a feat on the order of the original discovery.
250 Astromike23 Even without experimental proof, we know about as well as we possibly can that metallic hydrogen does exist without the need for lab results. By mass, Jupiter is *mostly* liquid metallic hydrogen. We still haven't seen it directly, but literally no other substance could fit the bill for such low density to fit the planet's mass, yet high conductivity to fit the planet's enormous magnetic field. Don't get me wrong - lab results are still important, because while tons of computer simulations predict the properties of metallic hydrogen, there are probably still a few surprises about the material waiting for us. Nonetheless, even if this study is debunked, gas giants provide ample evidence that metallic hydrogen does exist. **EDIT** to add some background: To be clear, researchers have been claiming metallic hydrogen in the lab for over 20 years now, usually creating it for a split-second with some kind of implosion. Citations start with [Weir, et al (1996)](http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.76.1860), conductivities were measured by [Ternovoi, et al (1999)](http://www.sciencedirect.com/science/article/pii/S0921452698013039), deuterium was made metallic by [Celliers, et al (2000)](http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.84.5564), claims of *atomic* metallic hydrogen were made by [Badiei, Holmlid (2004)](http://iopscience.iop.org/article/10.1088/0953-8984/16/39/034/meta), and so on. What's so different about this detection is that it's the first claim of *solid* metallic hydrogen, which is difficult since it must be at high enough pressure to be metallic, but also cold enough to be solid.
42 sweedeh So the scientists who discovered that hydrogen may have a metallic phase using incredibly high pressure. They conducted to test to determine if the hydrogen had become metallic and more importantly superconducting. The first was a laser shinning through the sample which was block when the hydrogen went from clear solid to the metallic phase and they attempted to pass a current through it. This gave an inconclusive result as to whether the material had become metallic or superconducting. I don't believe they have published anything more on the discovery so other than what's in the original paper nothing more is known
5 [deleted] [removed]
305 0 contact_fusion Last month they did publish an [erratum](http://science.sciencemag.org/content/357/6352/eaao5843) to the original [Science](http://science.sciencemag.org/content/355/6326/715) article detailing the findings. They claim their conclusions stand. I'm sure that several groups are working to replicate the work and that it is under some intense scrutiny. Especially in a field like this, where there are a handful of groups with the necessary expertise to replicate the work, it can take a while. As I understand it, just replicating it is a feat on the order of the original discovery.
248 0 Astromike23 Even without experimental proof, we know about as well as we possibly can that metallic hydrogen does exist without the need for lab results. By mass, Jupiter is *mostly* liquid metallic hydrogen. We still haven't seen it directly, but literally no other substance could fit the bill for such low density to fit the planet's mass, yet high conductivity to fit the planet's enormous magnetic field. Don't get me wrong - lab results are still important, because while tons of computer simulations predict the properties of metallic hydrogen, there are probably still a few surprises about the material waiting for us. Nonetheless, even if this study is debunked, gas giants provide ample evidence that metallic hydrogen does exist. **EDIT** to add some background: To be clear, researchers have been claiming metallic hydrogen in the lab for over 20 years now, usually creating it for a split-second with some kind of implosion. Citations start with [Weir, et al (1996)](http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.76.1860), conductivities were measured by [Ternovoi, et al (1999)](http://www.sciencedirect.com/science/article/pii/S0921452698013039), deuterium was made metallic by [Celliers, et al (2000)](http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.84.5564), claims of *atomic* metallic hydrogen were made by [Badiei, Holmlid (2004)](http://iopscience.iop.org/article/10.1088/0953-8984/16/39/034/meta), and so on. What's so different about this detection is that it's the first claim of *solid* metallic hydrogen, which is difficult since it must be at high enough pressure to be metallic, but also cold enough to be solid.
39 0 sweedeh So the scientists who discovered that hydrogen may have a metallic phase using incredibly high pressure. They conducted to test to determine if the hydrogen had become metallic and more importantly superconducting. The first was a laser shinning through the sample which was block when the hydrogen went from clear solid to the metallic phase and they attempted to pass a current through it. This gave an inconclusive result as to whether the material had become metallic or superconducting. I don't believe they have published anything more on the discovery so other than what's in the original paper nothing more is known
6 0 [deleted] [removed]