News for hackers. Stuff that matters.

A comment on A one-second video taken by the Rosetta probe on the surface of a comet.

Re:A one-second video taken by the Rosetta probe on the surf... by bwang29 on Wednesday April 25, 2018 @02:58AM (#16919118)
To put things in perspective, the comet, 67P/Churyumov-Gerasimenko, is about 4km in diameter, moving at 135,000kms per hour. Rosetta's rendezvousing with the comet required travelling a cumulative distance of over 6.4 billion kms. Gravity assists were needed from four planetary flybys – one of Mars (2007) and three of Earth (2005, 2007 and 2009) – a long circuitous trip that took ten years to complete.

Now back to my Javascript callback bugs

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by mark_edward on Wednesday April 25, 2018 @03:12AM (#16919195)
To be fair, people have been studying and predicting celestial movements for millennia, and boiled it down to unbelievably precise mechanical formulae. JS is poorly understood in comparison.

I say this to hope you feel better at work. I've been pressed into frontend web work and it's fractal complexity.

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by tenaciousDaniel on Wednesday April 25, 2018 @07:56AM (#16920668)
JS is poorly understood in comparison

This might be the most hilariously ridiculous true statement I've ever heard.

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by Tepix on Wednesday April 25, 2018 @08:14AM (#16920774)
In javascript:

x == x _ is true. Good.

x == !x _ is also true. Oops?

And guess what:

Array(3)==",," _ is also true.

But

NaN == NaN _ is false.

Math.max()>Math.min() _ is also false!

but then again

Math.max()<Math.min() _ is true.

Madness, I tell you!

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by scott_s on Wednesday April 25, 2018 @10:14AM (#16921670)
NaN not being equal to itself is true in all languages with IEEE compliance: https://en.wikipedia.org/wiki/NaN
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by conistonwater on Wednesday April 25, 2018 @10:58AM (#16922072)
Nitpick: NaN is supposed to work like that: the rule is that every comparison of any value against NaN returns false.
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by bjoli on Wednesday April 25, 2018 @08:47AM (#16920995)
I just looked at the famous left-pad for the fastest way o implementing a pad function in JS.

I asked a friend that does web dev and it is apparently pretty idiomatic JS. Pretty appalling. I finally understood why people claimed it was "hard to get right".

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by SkyMarshal on Wednesday April 25, 2018 @10:44PM (#16928397)
:D Many more Javascript WTF's here: https://www.youtube.com/results?search_query=javascript+wtf
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by sixothree on Wednesday April 25, 2018 @11:32AM (#16922456)
At least x === x, right?
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by dak1 on Wednesday April 25, 2018 @01:00PM (#16923562)
const x = NaN;

x === x; // false

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by joezydeco on Wednesday April 25, 2018 @01:13PM (#16923715)
But they're close to getting two numbers to add together!

https://twitter.com/thomasfuchs/status/933447631514169344

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by sandebert on Thursday April 26, 2018 @01:30AM (#16929067)
They should use jQuery for that. I hear it's good for all the things.
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by bitwize on Wednesday April 25, 2018 @09:54AM (#16921499)
Yes, but you're wading into the JavaScript weeds for what? More CRUD forms? Meanwhile...

"With a combination of large ground-based FORTRAN programs and small spacecraft-based assembly language programs, [Real Programmers] are able to do incredible feats of navigation and improvisation -- hitting ten-kilometer wide windows at Saturn after six years in space, repairing or bypassing damaged sensor platforms, radios, and batteries. Allegedly, one Real Programmer managed to tuck a pattern-matching program into a few hundred bytes of unused memory in a Voyager spacecraft that searched for, located, and photographed a new moon of Jupiter.

The current plan for the Galileo spacecraft is to use a gravity assist trajectory past Mars on the way to Jupiter. This trajectory passes within 80+/-3 kilometers of the surface of Mars. Nobody is going to trust a PASCAL program (or a PASCAL programmer) for navigation to these tolerances."

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by Jesus_Jones on Wednesday April 25, 2018 @03:09PM (#16924963)
Those are impressive sounding achievements. I haven't heard of all of those, can you provide references or details about the stories?
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by bitwize on Wednesday April 25, 2018 @03:19PM (#16925064)
I'd like to, but the original was from "Real Programmers Don't Use Pascal" by Ed Post: http://web.mit.edu/humor/Computers/real.programmers

You would be better off asking him about the veracity of the stories.

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by adonovan on Wednesday April 25, 2018 @10:01AM (#16921553)
It's true. Some of the greatest minds have spent 20 fruitless years trying to discover a unified theory of object fields and elementary values in JavaScript.
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by soru on Wednesday April 25, 2018 @10:36AM (#16921853)
Has everyone given up on string theory, or is there still hope another few hundred genius-years will bring progress?
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by yetihehe on Wednesday April 25, 2018 @11:52AM (#16922712)
At least it's not erlang's string-list of integers duality.
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by dehef on Wednesday April 25, 2018 @05:47AM (#16919987) 

    Observable.of(rosetta)
         .map(rocket => gravityAssist(rocket,'Earth'))
         .map(rocket => gravityAssist(rocket,'Mars'))
         .map(rocket => gravityAssist(rocket,'Earth'))
         .map(rocket => gravityAssist(rocket,'Earth'))
         .do(rocket => land(rocket))
         .do(rocket => tweetVideo())
         .catch(error => kaput(error))
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by iliketosleep on Wednesday April 25, 2018 @07:29AM (#16920513)
Or just simply:

npm install rosetta-67P-rendezvous

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by aalleavitch on Wednesday April 25, 2018 @08:01AM (#16920695)
Then somehow get a completely incomprehensible error about Visual Studio executables.
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by matte_black on Wednesday April 25, 2018 @08:37AM (#16920935)
Use yarn
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by VikingCoder on Wednesday April 25, 2018 @10:54AM (#16922031)
Oops. The new probe smashed into Mars at 146 km per second.

It was a leftpad error.

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by mkirklions on Wednesday April 25, 2018 @08:41AM (#16920954)
>Now back to my Javascript callback bugs

Check to make sure you are running the right files... Spelling/Capital letter errors... Returning after selecting a case...

Just some horror stories that cost me 8 days...

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by robotresearcher on Wednesday April 25, 2018 @10:43AM (#16921914)
Moving at 135,000 km/h relative to what? (honest question)
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by logfromblammo on Wednesday April 25, 2018 @02:52PM (#16924799)
I presume relative to the solar barycenter, and Wikipedia says that speed is its maximum speed (at perihelion of about 1.3 AU).

For reference, Earth does a mean speed of about 107,000 km/h relative to the solar system's center of mass.

[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by z3t4 on Wednesday April 25, 2018 @02:59PM (#16924872)
I guess relative to the stars in the image, using parallax.
[ Parent | on HN ]
Re:A one-second video taken by the Rosetta probe on the surf... by ars on Wednesday April 25, 2018 @04:38PM (#16925861)
No, relative to the stars it's going a LOT faster than that!

Most likely it's relative to the sun.

[ Parent | on HN ]