The key word "discovery" has been removed from the headline from TFA: "The James Webb Space Telescope Reveals Its First Direct Image Discovery of an Exoplanet". I.e, this is the first time that direct imagery was used to _discover_ a planet we didn't know existed previously.
Submitted title was "James Webb Space Telescope reveals its first direct image of an exoplanet", which I'm sure was just a good-faith attempt to fit HN's 80 char title limit. I've achieved that by compressing to JWST now :)
Because exoplanets by definition are going to be found adjacent to stars, which limits the area you need to search. Planets are fairly common, so you don't need to look at that many stars before you find evidence of an exoplanet, provided you have a good-enough telescope.
A hypothetical planet beyond Pluto be in a huge part of the sky: Presumably the orbit of such a planet could be inclined about as much as Pluto's. The 17-degree inclination of Pluto's orbit means it could be in a 34-degree wide strip of the sky, which, if I'm doing my math right, is about 29% of the full sky. If we allow for up to a 30 degree inclination, then that's half the sky.
There's also the matter of object size and brightness. The proposed Planet Nine[1] was supposed to be a few hundred AU away, and around the mass of 4 or 5 Earths. The object discovered in this paper is around 100 M🜨, at around 52 AU from its star. Closer and larger. (Of course, there's a sweet spot for exoplanet discovery, where you want the planet to be close enough to be bright, but far enough away to be outside the glare of the star.)
Most replies are talking about the low density of the matter in that area, which is one part of the equation. The other part of the equation is radiative heat transfer. Without radiation pulling heat away, the spacecraft would asymptotically heat up to the temperature of the surrounding matter.
Radiative heat transfer, roughly speaking, tries to bring the temperature of the probe to the average temperature of all the matter that it has line of sight to -- somewhere between the temperature of the sun and the temperature of the cosmic background radiation. Since the probes are far away from the sun, this average temperature is very low.
Both effects are present everywhere. On Earth, with our dense atmosphere, conductive transfer is usually the stronger effect. In space, with extremely low density, radiative heat transfer is stronger.
.RAW is an image format, but it's rarely used. Raw photos are usually stored in a manufacturer-defined format like .NEF (Nikon) or .CR3 (Canon), or occasionally in .DNG files. Nevertheless, it's fairly common to see the word capitalized as RAW.
Unless the egg rotates significantly during the fall, the distance from the floor to the bottom surface of the egg determines the potential energy that could go into falling speed before the egg hits the floor. In order to fall further, the egg either needs to have already cracked or to roll once hitting the floor (unlikely to cause cracking if the initial impact didn't).
The irony is that in many cases, it'd take less carbon for them to deliver to your front door than it would for you to get to the post office -- if they're already delivering to someone else near you, their extra distance traveled might be a block or so (or 0 if they were going to drive past your house anyway).
For delivery-to-post-office to be more carbon-efficient than them delivering to your house, the inequality (additional distance you need to travel to get to post office / your mpg) < (additional distance they need to travel to get to your house / their mpg) must be true. If you were gonna drive past the post office anyway, or your vehicle is significantly more efficient than their delivery van, then it might pencil out. If you're making an extra trip, it probably doesn't make sense.
That doesn't sound right. The tube the mac was displaying on was much closer to a TV-style 4:3 ratio anyway, there were significant blank spaces at the top and bottom.
If I was placing bets, it was another hardware limitation. Maybe 342 put them right at some particular DRAM timing limit for the chips they were signing contracts for. Or maybe more likely, the ~21.5 kHz scan rate was a hard limit from the tube supplier (that was much faster than TVs could do) and they had a firm 60 Hz requirement from Jobs or whoever.
You guys are ignoring the horizontal and vertical blanking periods, which were usually 25~35% of the active horizontal period and 8~10% of the active vertical period. I could find these two links that explain that the actual signal sent to the CRT was around 704x370 pixels:
Wikipedia for NTSC alludes to a couple reasons why you'd want your refresh rate to be based on your power line frequency:
> Matching the field refresh rate to the power source avoided intermodulation (also called beating), which produces rolling bars on the screen. Synchronization of the refresh rate to the power incidentally helped kinescope cameras record early live television broadcasts, as it was very simple to synchronize a film camera to capture one frame of video on each film frame by using the alternating current frequency to set the speed of the synchronous AC motor-drive camera.
(I suspect shows that were pre-recorded and telecined for broadcast would've also been filmed at 30fps using a synchronous AC motor.)
> In early TV systems, a master voltage-controlled oscillator was run at twice the horizontal line frequency, and this frequency was divided down by the number of lines used (in this case 525) to give the field frequency (60 Hz in this case). This frequency was then compared with the 60 Hz power-line frequency and any discrepancy corrected by adjusting the frequency of the master oscillator.
I think later TVs would've just synchronized to the received signal.
The key word "discovery" has been removed from the headline from TFA: "The James Webb Space Telescope Reveals Its First Direct Image Discovery of an Exoplanet". I.e, this is the first time that direct imagery was used to _discover_ a planet we didn't know existed previously.
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