Score
Title
9439
Megathread: 2017 Hurricane Season
47
Earthquake Megathread
5027
Nutrition Facts: Why is sodium listed instead of salt?
5
If NASA's mission to Mars is successful, will Mars become American Territory?
6
How heavy is fire? If something catches on fire is it heavier or lighter?
9952
Duck fat melts at 57 degrees Fahrenheit. So on a 90 degree day, is a living duck's fat just... sloshing around?
15
How does deodorant work?
15
What gas is inside of unopened peppers? Or is it just air?
6
How much Asteroid mining/extra mass until it has an impact on earth's orbit?
1
What is a kilowatt hour, and why do electric companies charge based on this instead of kilowatts?
4
Why is drinking milk after spicy foods better than drinking water?
192
If natural fruit juices contain large amounts of sugar, why do we only seem to refine sugars from a select few plants (sugarcane, sugar beets) instead of from fruits in general?
152
What have we learned from Cassini's dive into Saturn so far?
78
Why do hospitals have heart clinics specifically for Women? Aren't all hearts the same?
279
How does computer memory work when the computer is turned off?
45
Do ape's toenails grow slower than their fingernails, like humans?
8399
What have been the implications/significance of finding the Higgs Boson particle?
1
If we want to colonise mars, why don't we colonise it first with Cyanobacteria and then plants in order to create a habitable atmosphere?
97
Can microwaves work without using water molecules to heat up food?
7
Why does the fourth power show up in the Stefan–Boltzmann law?
7
When I scratch a piece of metal, do small amounts of atoms break off from it?
5
Do lactose intolerant people absorb the same amount of calories from milk as regular people?
3
What has kept land animals from evolving to enormous sizes, i.e. the size of a mountain?
14
How do they prevent the ISS from crashing into satellites and space junk?
29
Do small songbirds - a finch, say - ever get stung by bees/ wasps? If so, is it typically fatal?
45
It's been about 5 years since the Mochizuki's ABC Conjecture proof was originally published. What's its current status?
1
How do vaccines fail?
8
Does Quinine glow even after you remove it from a black light?
7
Can we forecast the northern and/or southern lights?
240
On a planet with more than 1 sun, what would a rainbow look like?
6
What can layers and swrils in rock indicate?
5
How do insects protect their eyes from direct sunlight?
4
Why can't you count the number of things touching you in a certain spot?
216
We are carbon based life forms, however, is it possible for life to be based off another element?
124
Is there a maximum size for a raindrop?
6
In a coronary bypass surgery, why do doctors use veins instead of arteries? Is there an advantage to this?
2110
Are there any challenges for parasites living in animal blood?
14
How real is the threat of human extinction by gamma ray bursts?
3
What happens when wind / a fluid is put through a T-shaped tube, where the bottom of the T is closed off, but the two sides are open? What happens to the fluid in the closed, vertical tube?
46
Is learning another language simply additive to your mother tongue, or is the second language "separate" in your brain?
8
What is actually happening when an electric current flows through an a salt solution or a molten salt?
3
How can Burning wood (carbon) generate UV radiation?
1160 cantgetno197 The wavelength of light that comes out of an X-ray laser is in the tens of nanometers, versus in the hundreds of nanometers that comes out of a "regular" (i.e. visible wavelength) laser and versus the hundreds of millions of nanometers that came out of their fore bearer the maser (Microwave-aser). But, at the end of the day, it's all light and all the same basic mechanism.
89 antimony121 To perhaps add a few more details to the main difference mentioned already (energy of the light being produced) *and explain differences in the process of creating x-ray beams: It might first be useful to point out that laser light, unlike that from a light bulb, is coherent, so all the light waves are in phase with one another which is a direct result of how the energy is produced. In standard lasers, this energy is coming from the relaxation of excited electrons (excited by some mechanism, pretty much always deliberate to ensure the highest probability for the relaxation of the energy you're wanting, using something like a flash lamp, electric current, or even another laser, depending on the specific type of laser). The relaxation gives off the light you're looking for. Once this happens in one electron, that light prompts a neighboring, similarly excited electron to do the same with the nice bonus of doing so perfectly in phase with the original stimulating light/photon (this is the "stimulation" and "amplification," since you're getting two for the price of one, in the acronym that makes the word laser -- Light Amplification by the Stimulated Emission of Radiation). Since this means you need to have the electrons excited to an energy at least as high as the energy you want to get out of the laser, and for a relatively long amount of time as far as atomic/molecular excitations are concerned, the higher the lasing energy, the harder the process is to control and produce. When you reach the energy of x-rays, this is so much that it will usually just ionize whatever is being excited, stripping off the electron completely, which kills your shot at the whole coherent light production process. The first x-ray lasers got around this by using just the high energy electrons themselves, produced in [linear accelerators](https://portal.slac.stanford.edu/sites/lcls_public/aboutlcls/Pages/About-LCLS.aspx), using magnetic field to giggle them back an forth fast enough to give of coherent x-rays. More recently (and using technology I'm still trying to get my head around fully that totally blows my mind), [table-top x-ray](https://jila.colorado.edu/kmlabs/research/articles/attosecond-nonlinear-optics) lasers are coming out that are made by -- in the absolute simplest of analogies that doesn't completely capture the process -- almost but not quite ionizing atoms by kind of slingshotting electrons around their nuclei in such a way that the angular acceleration it gains has the x-ray energy you want, which it then gives off as it relaxed back to its regular orbit around the nucleus. Again, the details of this one I'm still catching up on so I hopefully I'm not too off on these points and it still makes some kind of sense. Not sure how much you already knew about laser physics, so sorry if this is overly in-depth and telling you stuff you already knew. I didn't mention some of the other aspects that will affect the type of light you get out (such as pulsed lasers vs. CW that are a single wavelength emitted constantly), but I'd be happy to further elaborate if you're interested.
11 LeWorgen The frequency is higher i.e. the energy in an X-ray laser is higher (E=hv, where E is the energy of the photon, h is the plank constant and v is the frequency), therefore more dangerous than a regular (visible-light) laser.
10 BeardySam Lots of good answers here so I'm just throwing in a fact not a lot of people know: the US 'Star Wars' program under Reagan was a space-bourne x-ray laser, using a nuclear bomb to pump the states of the lasing medium.
3 XJindosh Awesome, thanks! Is the difference down to the geometry of the magnets? Or is there other differences between the two? (I.e. input beam properties) I'd imagine for the broadband source you'd need an electron pulse with a larger range of kinetic energies, whilst the converse would be true for the narrow band output? Which leads me to think it's more than the geometry of the magnets....
1156 0 cantgetno197 The wavelength of light that comes out of an X-ray laser is in the tens of nanometers, versus in the hundreds of nanometers that comes out of a "regular" (i.e. visible wavelength) laser and versus the hundreds of millions of nanometers that came out of their fore bearer the maser (Microwave-aser). But, at the end of the day, it's all light and all the same basic mechanism.
89 0 antimony121 To perhaps add a few more details to the main difference mentioned already (energy of the light being produced) *and explain differences in the process of creating x-ray beams: It might first be useful to point out that laser light, unlike that from a light bulb, is coherent, so all the light waves are in phase with one another which is a direct result of how the energy is produced. In standard lasers, this energy is coming from the relaxation of excited electrons (excited by some mechanism, pretty much always deliberate to ensure the highest probability for the relaxation of the energy you're wanting, using something like a flash lamp, electric current, or even another laser, depending on the specific type of laser). The relaxation gives off the light you're looking for. Once this happens in one electron, that light prompts a neighboring, similarly excited electron to do the same with the nice bonus of doing so perfectly in phase with the original stimulating light/photon (this is the "stimulation" and "amplification," since you're getting two for the price of one, in the acronym that makes the word laser -- Light Amplification by the Stimulated Emission of Radiation). Since this means you need to have the electrons excited to an energy at least as high as the energy you want to get out of the laser, and for a relatively long amount of time as far as atomic/molecular excitations are concerned, the higher the lasing energy, the harder the process is to control and produce. When you reach the energy of x-rays, this is so much that it will usually just ionize whatever is being excited, stripping off the electron completely, which kills your shot at the whole coherent light production process. The first x-ray lasers got around this by using just the high energy electrons themselves, produced in [linear accelerators](https://portal.slac.stanford.edu/sites/lcls_public/aboutlcls/Pages/About-LCLS.aspx), using magnetic field to giggle them back an forth fast enough to give of coherent x-rays. More recently (and using technology I'm still trying to get my head around fully that totally blows my mind), [table-top x-ray](https://jila.colorado.edu/kmlabs/research/articles/attosecond-nonlinear-optics) lasers are coming out that are made by -- in the absolute simplest of analogies that doesn't completely capture the process -- almost but not quite ionizing atoms by kind of slingshotting electrons around their nuclei in such a way that the angular acceleration it gains has the x-ray energy you want, which it then gives off as it relaxed back to its regular orbit around the nucleus. Again, the details of this one I'm still catching up on so I hopefully I'm not too off on these points and it still makes some kind of sense. Not sure how much you already knew about laser physics, so sorry if this is overly in-depth and telling you stuff you already knew. I didn't mention some of the other aspects that will affect the type of light you get out (such as pulsed lasers vs. CW that are a single wavelength emitted constantly), but I'd be happy to further elaborate if you're interested.
11 0 LeWorgen The frequency is higher i.e. the energy in an X-ray laser is higher (E=hv, where E is the energy of the photon, h is the plank constant and v is the frequency), therefore more dangerous than a regular (visible-light) laser.
8 0 BeardySam Lots of good answers here so I'm just throwing in a fact not a lot of people know: the US 'Star Wars' program under Reagan was a space-bourne x-ray laser, using a nuclear bomb to pump the states of the lasing medium.
3 0 XJindosh Awesome, thanks! Is the difference down to the geometry of the magnets? Or is there other differences between the two? (I.e. input beam properties) I'd imagine for the broadband source you'd need an electron pulse with a larger range of kinetic energies, whilst the converse would be true for the narrow band output? Which leads me to think it's more than the geometry of the magnets....