Heeey... Fermi Bubbles are new science discovered by Fermi né GLAST telescope, not something predicted by its physicist-awesomekin namesake.
Badass-sauce
The telescope was named after the physicist, so in a way the bubbles are named after the physicist.
But yeah, it's not the same as the naming of the Fermi Paradox or it's like.
Right, mostly excited about finding something unexpected so close to home, and I was big into astronomy when NASA did the public naming thing. And Fermi was a god damned badass.
They moistly come out at night, moistly.
0
Options
Just_Bri_ThanksSeething with ragefrom a handbasket.Registered User, ClubPAregular
Launch aborted this morning, the live stream sounded like they couldn't verify the range was clear. Next launch attempt is on the 9th.
...and when you are done with that; take a folding
chair to Creation and then suplex the Void.
If you sweep a laser pointer across the Moon fast enough, you can create spots that actually move faster than light. Anyone can do it...
Flashes, dubbed "photonic booms" because they are directly analogous to sonic booms, may be detectable on the Moon, on passing asteroids, on fast moving shadows cast on reflecting dust clouds near variable stars, and on objects illuminated by the rapidly rotating beam of a pulsar, said Nemiroff, author of a study accepted for publication by the Publications of the Astronomical Society of Australia, with a preliminary version available online at http://arxiv.org/abs/1412.7581 . "And if detected, we could learn more about all of these objects," said Nemiroff...
To reveal the size and surface features of asteroids passing near the Earth, a laser beam might be swept across the rock's surface thousands of times a second, with each sweep forcing a harmless but telling photonic boom. The flashes could be recorded with high-speed cameras attached to large telescopes, potentially mapping out major features on the asteroid.
If you sweep a laser pointer across the Moon fast enough, you can create spots that actually move faster than light. Anyone can do it...
Flashes, dubbed "photonic booms" because they are directly analogous to sonic booms, may be detectable on the Moon, on passing asteroids, on fast moving shadows cast on reflecting dust clouds near variable stars, and on objects illuminated by the rapidly rotating beam of a pulsar, said Nemiroff, author of a study accepted for publication by the Publications of the Astronomical Society of Australia, with a preliminary version available online at http://arxiv.org/abs/1412.7581 . "And if detected, we could learn more about all of these objects," said Nemiroff...
To reveal the size and surface features of asteroids passing near the Earth, a laser beam might be swept across the rock's surface thousands of times a second, with each sweep forcing a harmless but telling photonic boom. The flashes could be recorded with high-speed cameras attached to large telescopes, potentially mapping out major features on the asteroid.
That is kind of a bizarre one, it's tricky to wrap your head around the concept of something without mass producing a shockwave. I'll have to think on this one a while I feel, but if it can be used like they say that is pretty awesome.
0
Options
ShivahnUnaware of her barrel shifter privilegeWestern coastal temptressRegistered User, Moderatormod
That's in no way analogous to a sonic boom, at least from the blurb. A sonic boom is due to something passing through a medium faster than... well, sound/vibrations/general movement.
It's as analogous to a sonic boom as the sound of my typing, which hits the walls in front of and behind me at the same time despite the speed of sound being much slower than that.
That's in no way analogous to a sonic boom, at least from the blurb. A sonic boom is due to something passing through a medium faster than... well, sound/vibrations/general movement.
It's as analogous to a sonic boom as the sound of my typing, which hits the walls in front of and behind me at the same time despite the speed of sound being much slower than that.
Makes sense to me.
The sweeping laser's splash moves faster than the speed of light across the surface of the moon or asteroid. So it's faster than the speed of light (similar to sound) when it moves through space (similar to air) and creates a visible byproduct (similar to an audible sonic boom).
Relevant, from the article:
The physics that creates the photonic boom is tied to the faster-than-light sweep speeds of the illuminating spots and cast shadows. Specifically, a flash is seen by an observer when the speed of the scattered spot toward the observer drops from above the speed of light to below the speed of light. The phenomenon is possible only because the spots contain no mass and so cannot only move faster than light, but decelerate past the speed of light without violating Einstein's theory of special relativity.
If you sweep a laser pointer across the Moon fast enough, you can create spots that actually move faster than light. Anyone can do it...
Flashes, dubbed "photonic booms" because they are directly analogous to sonic booms, may be detectable on the Moon, on passing asteroids, on fast moving shadows cast on reflecting dust clouds near variable stars, and on objects illuminated by the rapidly rotating beam of a pulsar, said Nemiroff, author of a study accepted for publication by the Publications of the Astronomical Society of Australia, with a preliminary version available online at http://arxiv.org/abs/1412.7581 . "And if detected, we could learn more about all of these objects," said Nemiroff...
To reveal the size and surface features of asteroids passing near the Earth, a laser beam might be swept across the rock's surface thousands of times a second, with each sweep forcing a harmless but telling photonic boom. The flashes could be recorded with high-speed cameras attached to large telescopes, potentially mapping out major features on the asteroid.
It's simple. You sweep a laser beam across some object and watch the reflected light. If the spot of light traverses the object in such a way that it is moving toward you, it gets a little brighter (not in frequency, but in intensity--the spot is closer to you than it was a second ago, so the returned light from now is overlapping with the returned light from 1 second ago, which was delayed by traveling farther). If the topography of the object, and the speed at which you sweep the laser, is sufficient, the spot might move radially toward you at the speed of light. If this happens, all the returns from however long this lasts stack up and arrive instantly--the spot appears to suddenly become much brighter. If you sweep the beam across the object in the reverse direction, it will suddenly become much dimmer at that spot, so you can guess that it's probably not a surface albedo feature that increased the return.
That's in no way analogous to a sonic boom, at least from the blurb. A sonic boom is due to something passing through a medium faster than... well, sound/vibrations/general movement.
It's as analogous to a sonic boom as the sound of my typing, which hits the walls in front of and behind me at the same time despite the speed of sound being much slower than that.
That is kind of a bizarre one, it's tricky to wrap your head around the concept of something without mass producing a shockwave. I'll have to think on this one a while I feel, but if it can be used like they say that is pretty awesome.
There's no shockwave; the analogy to a sonic boom is in the sudden increase in intensity due to the source of the waves (the laser spot) moving towards you at the same speed as the waves move (in this case, the speed of light).
The laser spot isn't a "thing" anywhere except in our minds, and nothing's going faster than light. You are just shining a light on two different locations at two different times, and if the radial distance between those locations matches the distance light travels in your time interval the reflected light will return to you at the same time.
If you sweep a laser pointer across the Moon fast enough, you can create spots that actually move faster than light. Anyone can do it...
Flashes, dubbed "photonic booms" because they are directly analogous to sonic booms, may be detectable on the Moon, on passing asteroids, on fast moving shadows cast on reflecting dust clouds near variable stars, and on objects illuminated by the rapidly rotating beam of a pulsar, said Nemiroff, author of a study accepted for publication by the Publications of the Astronomical Society of Australia, with a preliminary version available online at http://arxiv.org/abs/1412.7581 . "And if detected, we could learn more about all of these objects," said Nemiroff...
To reveal the size and surface features of asteroids passing near the Earth, a laser beam might be swept across the rock's surface thousands of times a second, with each sweep forcing a harmless but telling photonic boom. The flashes could be recorded with high-speed cameras attached to large telescopes, potentially mapping out major features on the asteroid.
It's simple. You sweep a laser beam across some object and watch the reflected light. If the spot of light traverses the object in such a way that it is moving toward you, it gets a little brighter (not in frequency, but in intensity--the spot is closer to you than it was a second ago, so the returned light from now is overlapping with the returned light from 1 second ago, which was delayed by traveling farther). If the topography of the object, and the speed at which you sweep the laser, is sufficient, the spot might move radially toward you at the speed of light. If this happens, all the returns from however long this lasts stack up and arrive instantly--the spot appears to suddenly become much brighter. If you sweep the beam across the object in the reverse direction, it will suddenly become much dimmer at that spot, so you can guess that it's probably not a surface albedo feature that increased the return.
No, that's not quite what's going on. At least, I don't think it is, but I'm pretty positive your closer and/or further comments has nothing to do with it.
This goes over it a bit, specifically from 1:00 to 1:30 (rest of video is awesome, too):
The speed of light says that a beam of light takes .0116 seconds to travel the moons diameter. Now imagine the shadow in that video is actually you pointing a laser pointer at the moon and swipe it side to side and I can guarantee you can do it in under .01 seconds. The moon's less than 2 inches wide from earth, and I can easily do that to a 20 foot wall just a few feet away. This means the point of the laser travels faster than light across the surface of the Moon, and I believe (layman here, so I very probably am wrong) the flashes are a build up of photon's that are released all at once instead of as the point travels across the surface, similar to how a sonic boom is a build up of the sound's pressure wave. If you were to watch the dot travel across it would appear to skip and each time it does skip it produces the tiny flash.
Veevee on
0
Options
Just_Bri_ThanksSeething with ragefrom a handbasket.Registered User, ClubPAregular
It's the picard maneuver.
...and when you are done with that; take a folding
chair to Creation and then suplex the Void.
Unnggghhh.... I do not like some of these usages of words like 'moves' and 'is' and 'sonic' and 'no mass'
But, they are getting coherent light to refelect off different bits if a body in such a way that diffrent bits of light (temporally and specially adjacent)interfere with each other and then can use this interference to determine details of depth?
Like, if you sweep across a parabolic surface with a radius the same as it's distance, and it is angled such that the period of the sweep is the same as the time it would take light to travel the the difference in radius between the nearest and most distant point from the projector, you'd get, like, total positive inference. All the returned light would get back at the same time.
And there are a bunch of other outcomes that could happen as well, and you can get the change in distant with respect to the change in angle out of them.
Unnggghhh.... I do not like some of these usages of words like 'moves' and 'is' and 'sonic' and 'no mass'
But, they are getting coherent light to refelect off different bits if a body in such a way that diffrent bits of light (temporally and specially adjacent)interfere with each other and then can use this interference to determine details of depth?
Like, if you sweep across a parabolic surface with a radius the same as it's distance, and it is angled such that the period of the sweep is the same as the time it would take light to travel the the difference in radius between the nearest and most distant point from the projector, you'd get, like, total positive inference. All the returned light would get back at the same time.
And there are a bunch of other outcomes that could happen as well, and you can get the change in distant with respect to the change in angle out of them.
Neat.
This.
That article (and/or the people who gave that presentation) kind of ticks me off for how it pretends to be something it isn't.
EDIT: I wish they had talked about stuff correctly! And there is neat stuff there. Like, if you had observers standing at both ends of your beam sweep, they couldn't agree on which way the beam was going!
Aioua on
life's a game that you're bound to lose / like using a hammer to pound in screws
fuck up once and you break your thumb / if you're happy at all then you're god damn dumb
that's right we're on a fucked up cruise / God is dead but at least we have booze
bad things happen, no one knows why / the sun burns out and everyone dies
In a way, that's what it seems to be. They even figured out how to have the thyroid regenerate after the fact. Based on that, this could be big for part of a functional HIV treatment by treating the harvested stem cells to have the double CCR5 deletion that removes the surface receptor that HIV needs to replicate; you would still be carrying the disease in reservoirs, but you might be able to go without any drugs.
It's that time again: SpaceX's third try for the launch of CRS-5 to the International Space Station
The launch - if it's not delayed again - will occur at 4:47 AM EST, and will of course involve the first attempted recovery of the first stage of a rocket. In fact, there has just recently been an announcement that if the landing succeeds its footage will be replayed on the webcast shortly after Dragon makes orbit. The start of the landing procedure begins immediately after stage separation, and thus there will be no lengthy delay for said replay footage.
Just_Bri_ThanksSeething with ragefrom a handbasket.Registered User, ClubPAregular
Follow up post: The first stage made it to the barge, but came down too hard and broke. The ship is fine, but some equipment on the deck needs replacing. No video is available.
Overall, a teaching moment, I would say. I look forward to seeing the next try.
...and when you are done with that; take a folding
chair to Creation and then suplex the Void.
Follow up post: The first stage made it to the barge, but came down too hard and broke. The ship is fine, but some equipment on the deck needs replacing. No video is available.
Overall, a teaching moment, I would say. I look forward to seeing the next try.
For the first launch I've watched live (well, a few minutes behind), it was pretty awesome. The images towards the end from the outside of the ship showing the Sun coming over the horizon were amazing.
Shame the landing didn't work out.
This stuff makes me want to work on a PHD so I can go work with them...
Steam ID: natinator Xbox Live: Natman PRIME LoL: A1 Sauce
Follow up post: The first stage made it to the barge, but came down too hard and broke. The ship is fine, but some equipment on the deck needs replacing. No video is available.
Overall, a teaching moment, I would say. I look forward to seeing the next try.
So... they were able to make the first stage land on the exact spot they wanted it to though? If all they need to do is soften the impact, that doesn't seem as hard as getting the accuracy.
According to Elon Musk's twitter, the grid fins ran out of hydraulic fluid just before landing, so it may simply be that they lost the ability to precisely control the angle of approach for a level touchdown on the barge.
I would guess the same reasons aircraft run lose hydraulic fluid, pressure change and g-force.
As the pressure changes from one atmosphere to less the differential from inside to outside ends up putting more stress on all of the connections in the hydraulic system. Any nuts used to connect tubes start to develop slow leaks, the swaged tubes start to leak, pinhole leaks cans develops, and you lose more and more each time. That's not counting the amount lost due to leaks that develop due to stresses caused by g-force.
At several thousand PSI on the ground even titanium hydraulic tubing can take a beating.
As the pressure changes from one atmosphere to less the differential from inside to outside ends up putting more stress on all of the connections in the hydraulic system.
Stress, vibration, thermal cycling I'd give you, but if changing the total pressure differential by an insignificant 14 psi causes hydraulic leaks you've got bigger problems.
Just remember that half the people you meet are below average intelligence.
They're losing hydraulic fluid because they're running an open-loop system: they have pressurized tanks spewing the fluid through the mechanisms and out apertures on the exterior of the vehicle. Why have an open loop system vs closed loop? Because having a closed-loop system requires a very large power supply which is very, very heavy and adds a lot of complexity to a vehicle that's only going to be flying for 10-minute stretches at a time anyways.
Edit: also, it makes the plumbing very similar to the fuel tanks (which are pressurized exactly the same way, by ramming them full of pressurized inert gasses like Nitrogen or Helium) which could add yet more cost savings in terms of development time and shared components with the rest of the craft's subsystems.
Posts
Some things are too vast and too amazing to really process properly.
The telescope was named after the physicist, so in a way the bubbles are named after the physicist.
But yeah, it's not the same as the naming of the Fermi Paradox or it's like.
Right, mostly excited about finding something unexpected so close to home, and I was big into astronomy when NASA did the public naming thing. And Fermi was a god damned badass.
chair to Creation and then suplex the Void.
My bad, this was just a preview to the image being released in full today
http://i.imgur.com/wlBnbON.jpg
4000 x 1279 view of Andromeda Galaxy.
3DS: 0473-8507-2652
Switch: SW-5185-4991-5118
PSN: AbEntropy
http://phys.org/news/2015-01-faster-than-light-illuminate-astronomical-secrets.html
I... what...
I think I get it? That's... huh.
3DS: 0473-8507-2652
Switch: SW-5185-4991-5118
PSN: AbEntropy
It's as analogous to a sonic boom as the sound of my typing, which hits the walls in front of and behind me at the same time despite the speed of sound being much slower than that.
Makes sense to me.
The sweeping laser's splash moves faster than the speed of light across the surface of the moon or asteroid. So it's faster than the speed of light (similar to sound) when it moves through space (similar to air) and creates a visible byproduct (similar to an audible sonic boom).
Relevant, from the article:
The laser spot isn't a "thing" anywhere except in our minds, and nothing's going faster than light. You are just shining a light on two different locations at two different times, and if the radial distance between those locations matches the distance light travels in your time interval the reflected light will return to you at the same time.
No, that's not quite what's going on. At least, I don't think it is, but I'm pretty positive your closer and/or further comments has nothing to do with it.
This goes over it a bit, specifically from 1:00 to 1:30 (rest of video is awesome, too):
The speed of light says that a beam of light takes .0116 seconds to travel the moons diameter. Now imagine the shadow in that video is actually you pointing a laser pointer at the moon and swipe it side to side and I can guarantee you can do it in under .01 seconds. The moon's less than 2 inches wide from earth, and I can easily do that to a 20 foot wall just a few feet away. This means the point of the laser travels faster than light across the surface of the Moon, and I believe (layman here, so I very probably am wrong) the flashes are a build up of photon's that are released all at once instead of as the point travels across the surface, similar to how a sonic boom is a build up of the sound's pressure wave. If you were to watch the dot travel across it would appear to skip and each time it does skip it produces the tiny flash.
chair to Creation and then suplex the Void.
But, they are getting coherent light to refelect off different bits if a body in such a way that diffrent bits of light (temporally and specially adjacent)interfere with each other and then can use this interference to determine details of depth?
Like, if you sweep across a parabolic surface with a radius the same as it's distance, and it is angled such that the period of the sweep is the same as the time it would take light to travel the the difference in radius between the nearest and most distant point from the projector, you'd get, like, total positive inference. All the returned light would get back at the same time.
And there are a bunch of other outcomes that could happen as well, and you can get the change in distant with respect to the change in angle out of them.
Neat.
This.
That article (and/or the people who gave that presentation) kind of ticks me off for how it pretends to be something it isn't.
EDIT: I wish they had talked about stuff correctly! And there is neat stuff there. Like, if you had observers standing at both ends of your beam sweep, they couldn't agree on which way the beam was going!
fuck up once and you break your thumb / if you're happy at all then you're god damn dumb
that's right we're on a fucked up cruise / God is dead but at least we have booze
bad things happen, no one knows why / the sun burns out and everyone dies
So it's a complete reboot of the immune system?
In a way, that's what it seems to be. They even figured out how to have the thyroid regenerate after the fact. Based on that, this could be big for part of a functional HIV treatment by treating the harvested stem cells to have the double CCR5 deletion that removes the surface receptor that HIV needs to replicate; you would still be carrying the disease in reservoirs, but you might be able to go without any drugs.
This seems to be a nuke it all and re-populate approach, I wonder if in the future they'll just be able to target the Memory T cells alone.
EDIT: And of course, the event itself: http://new.livestream.com/spacex/events/3665355
Overall, a teaching moment, I would say. I look forward to seeing the next try.
chair to Creation and then suplex the Void.
For the first launch I've watched live (well, a few minutes behind), it was pretty awesome. The images towards the end from the outside of the ship showing the Sun coming over the horizon were amazing.
Shame the landing didn't work out.
This stuff makes me want to work on a PHD so I can go work with them...
So... they were able to make the first stage land on the exact spot they wanted it to though? If all they need to do is soften the impact, that doesn't seem as hard as getting the accuracy.
3DS: 0473-8507-2652
Switch: SW-5185-4991-5118
PSN: AbEntropy
It is always a possibility that the barge smacked it from below.
chair to Creation and then suplex the Void.
As the pressure changes from one atmosphere to less the differential from inside to outside ends up putting more stress on all of the connections in the hydraulic system. Any nuts used to connect tubes start to develop slow leaks, the swaged tubes start to leak, pinhole leaks cans develops, and you lose more and more each time. That's not counting the amount lost due to leaks that develop due to stresses caused by g-force.
At several thousand PSI on the ground even titanium hydraulic tubing can take a beating.
That was more a heat expansion thinger
B-1B bombers are just as bad
(The black rectangles and shadows on there are where the concrete is stained with hydraulic fluid)
Stress, vibration, thermal cycling I'd give you, but if changing the total pressure differential by an insignificant 14 psi causes hydraulic leaks you've got bigger problems.
They're losing hydraulic fluid because they're running an open-loop system: they have pressurized tanks spewing the fluid through the mechanisms and out apertures on the exterior of the vehicle. Why have an open loop system vs closed loop? Because having a closed-loop system requires a very large power supply which is very, very heavy and adds a lot of complexity to a vehicle that's only going to be flying for 10-minute stretches at a time anyways.
Edit: also, it makes the plumbing very similar to the fuel tanks (which are pressurized exactly the same way, by ramming them full of pressurized inert gasses like Nitrogen or Helium) which could add yet more cost savings in terms of development time and shared components with the rest of the craft's subsystems.
Fast forward to 7:20 and prepare to facepalm harder than you have ever facepalmed in the history of existence.
fuck.... I thought I was ready to see anything... I was not