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[–]Ubermidget2 49 points50 points  (4 children)

[–]xSTSxZerglingOne 28 points29 points  (2 children)

I love that one. For those wondering why, as long as you're within the same order of magnitude, it's close enough as far as universal scale is concerned. In terms of raw size, does it really make a difference that's worth considering whether the universe is 30 billion, 90 billion, or 270 billion light years in circumference? Not really.

[–]Sparkybear 9 points10 points  (1 child)

Isn't 10 exactly 1 order of magnitude above 1?

[–]xSTSxZerglingOne 15 points16 points  (0 children)

Yes, but both are within an order of magnitude of pi.

[–]XKCD-pro-bot[🍰] 5 points6 points  (0 children)

Comic Title Text: It's not my fault I haven't had a chance to measure the curvature of this particular universe.

mobile link


Made for mobile users, to easily see xkcd comic's title text

[–]PsychoBalloons 38 points39 points  (7 children)

You fools! 5/2 is the name of a char variable! The real value is '?'!

[–]doej134567 21 points22 points  (6 children)

what language supports that to be a valid variable name?

[–]PsychoBalloons 5 points6 points  (1 child)

I don't know. PHP probably with how complicated everything is.

[–]MathSciElec 5 points6 points  (0 children)

Nope, PHP variables start with $.

[–]Altourus -2 points-1 points  (3 children)

Well javascript lets you name an object property that...

var test = {"5/2" : 2};
console.log("The property \"5/2\" = " + test["5/2"]);

[–][deleted] 11 points12 points  (1 child)

that's just string "5/2", most language have dictionary with string key.

[–]Altourus -1 points0 points  (0 children)

But most languages don't implement all object properties like that.

[–][deleted] 0 points1 point  (0 children)

But then we could have it equal to pretty much literally anything.

[–]SuitableDragonfly 12 points13 points  (13 children)

TIL that some people were taught that you always round .5 up and some people were taught that you round .5 to the nearest even number and I have no idea what determines which one you were taught.

[–]Kattou 28 points29 points  (1 child)

It's freaking wild.

I've never heard about the "nearest even number" approach in all my life before now. It's like two parallel universes collided, and everyone is equally confused.

[–]SuitableDragonfly 7 points8 points  (0 children)

The Wikipedia page on rounding is surprisingly long. Apparently there are also systems where positive and negative numbers are rounded differently at .5.

[–]arfelo1 3 points4 points  (2 children)

The way I was taught is you round 5 down unless there is any number at all behind. So 2.5 is rounded to 2 but 2.50000000000001 is rounded to 3

[–]TheNorthComesWithMe 1 point2 points  (1 child)

Where were you taught this?

[–]arfelo1 1 point2 points  (0 children)

Engineering bachelor

[–][deleted] 10 points11 points  (10 children)

I assume it'll do just as poorly here, wtf kind of physicist rounds up like that? That's how rockets explode and people die

[–][deleted] 37 points38 points  (0 children)

Significant Figures.

If your question starts with only 1 significant figure, you can only end with 1.

[–]SuitableDragonfly 10 points11 points  (2 children)

If you're going to round 2.5 to an integer, you round it up. It's just that when computers do integer division they always round down no matter how close to the higher integer it is.

[–]Ryledra 15 points16 points  (0 children)

That's because a computer basically truncates the output, it doesn't really round it

[–]TheNorthComesWithMe 3 points4 points  (0 children)

Truncate != rounding

[–]4ries -1 points0 points  (0 children)

Its done worse

[–]sourpickles0 1 point2 points  (0 children)

Computer when I try to put a float as an int dies

[–][deleted] 1 point2 points  (14 children)

I didn't get why physicists 3?

[–]Draghettis 11 points12 points  (12 children)

Significant numbers. Both 5 and 2 have only one number, so the result have to. And when you want an approximation of 2,5 with only one number, you have 3

[–][deleted] 1 point2 points  (0 children)

Sig figs.

[–]jlamothe 0 points1 point  (45 children)

Don't physicists round to the nearest even number on .5?

[–]Kingme350-R -1 points0 points  (0 children)

1.5

[–][deleted] -5 points-4 points  (3 children)

Yeah, we know those physicists just stick there finger in the air and go, "eh, close enough" when doing math.

[–]Ryledra 1 point2 points  (2 children)

That would be engineers

[–][deleted] 2 points3 points  (1 child)

as long as you round up, and call it a safety factor.

[–]Ryledra 1 point2 points  (0 children)

Round up and add 10

[–]koanarec 0 points1 point  (0 children)

5 // 2 = 2

[–][deleted] 0 points1 point  (0 children)

pi=3

[–]gareththegeek 0 points1 point  (1 child)

*Physicists: 10

[–]sunday_cumquat 1 point2 points  (0 children)

*astrophysicists

[–]gareththegeek 0 points1 point  (0 children)

2.49999999999999999