Is CT number a dimensionless quantity?

The only thing I’m confused about tbh

πŸ‘︎ 11
πŸ’¬︎
πŸ‘€︎ u/Top_Hearing_9932
πŸ“…︎ Jan 23 2022
🚨︎ report
Why is radians a dimensionless quantity and not an unit

So while i was studying about arc length
why does arc length when theta is used in radians has unit metre and not metre raidians.

πŸ‘︎ 5
πŸ’¬︎
πŸ‘€︎ u/ad1t
πŸ“…︎ Sep 27 2021
🚨︎ report
TIL that the fine-structure constant, a dimensionless quantity roughly equal to 1/137, is one of nature's most important numbers. While this constant has now been determined to many decimal places, it is used to characterize the strength of the electromagnetic force affecting charged particles. quantamagazine.org/physic…
πŸ‘︎ 120
πŸ’¬︎
πŸ‘€︎ u/KimCureAll
πŸ“…︎ May 15 2021
🚨︎ report
ELI5: Dimensionless Physical Quantities

I've done my fair share of reading and seem to still lack some basic understanding that is inhibiting me from grasping why pi or e are dimensionless. Does this have to do with SI or is something dimensionless because it lacks previous or subsequent quantities?

Thanks!

πŸ‘︎ 2
πŸ’¬︎
πŸ‘€︎ u/jal1992
πŸ“…︎ Feb 15 2021
🚨︎ report
Expanding on the awesome yin-yang finding by /u/traviscrisp - showing that a nested seed of life constructed yin-yang contains a 1/64th dimensionless quantity of scale - hinting at octaves of fractal 64THM. More in comments imgur.com/4eQnL7G
πŸ‘︎ 22
πŸ’¬︎
πŸ‘€︎ u/d8_thc
πŸ“…︎ Dec 31 2015
🚨︎ report
"Radians etc, are a dimensionless quantities so it doesn't make sense to talk about '10 radians'." np.reddit.com/r/math/comm…
πŸ‘︎ 16
πŸ’¬︎
πŸ‘€︎ u/Waytfm
πŸ“…︎ Oct 30 2014
🚨︎ report
Dimensionless quantity en.wikipedia.org/wiki/Dim…
πŸ‘︎ 6
πŸ’¬︎
πŸ“…︎ Jan 03 2019
🚨︎ report
A list of dimensionless quantities en.wikipedia.org/wiki/Dim…
πŸ‘︎ 3
πŸ’¬︎
πŸ‘€︎ u/xcoders
πŸ“…︎ Dec 08 2009
🚨︎ report
Why does it make sense to multiply/divide units?
πŸ‘︎ 9
πŸ’¬︎
πŸ‘€︎ u/supposenot
πŸ“…︎ Nov 30 2021
🚨︎ report
What is the history of the "elasticity" concept in economics?

I'm aware that elasticities were introduced to economics by Alfred Marshall. Formally, elasticity of a function is the derivative times the input variable divided by the original function:

[;\text{E}\left[g(x)\right]=\frac{x\cdot g'(x)}{g(x)};]

I've never seen this concept used in any other field, be it pure mathematics, statistics, or physical science. It seems to differ quite substantially from the concept of elasticity used in physics.

The justification used by Varian in Intermediate Microeconomics is that it allows us to see dimensionless (percentage) changes. This seems to work fine for monomial functions, but behaves quite oddly when dealing with most other functions.

πŸ‘︎ 5
πŸ’¬︎
πŸ‘€︎ u/pepin-lebref
πŸ“…︎ Nov 10 2021
🚨︎ report
Is the notion of a radian "natural" or arbitrary? Would we end up with different formulations of cosines or e.g. Euler's formula if we used a different way to measure angles?

I don't think I understand how this works, and I would welcome any good intuition pumps.

In terms of "data types", the sine function is supposed to take in an angle and return a number. This shouldn't depend on whether we use radians or degrees or something else -- sin(pi radians) should be the same as sin(180 degrees). But in a lot of places I see it interpreted as taking a number and returning a number. The input number is assumed to be radians in this case, so that sin(1) == sin(1 radian). But is this fundamental, or is this arbitrary? Can I say that I'm representing my angles in some other dimensionless quantities? Like multiples of a circle, so that sin(1) == sin(360 degrees) == 0.

This becomes important when we consider data types. I often see people writing something like sin(x) / x. For us to be able to take a sine of x, x needs to be an angle. So sin(x) / x is dividing a number by an angle -- why does this work, is it not a mismatch in data types? One way we can fix this is to assume that the sine function converts a number to an angle "under the hood", so to speak, so that the resulting function takes a number and returns a number. But for this to work, we need to define how exactly a number is converted into an angle. We can say it interprets the number as the amount of radians, or we can say that it interprets the number as the amount of multiples of a circle. Sin(1) takes up different values depending on how exactly we convert a plain number into an angle. So -- I'm not sure if I'm making sense here, correct me if I'm wrong -- there isn't a single sin function, there is a family of sin-like functions that differ in how exactly they convert a number into an angle. Sin_radians(1) is 0.84, sin_degrees(1) is 0.02, and sin_multiples_of_circle(1) is 0.

So the question is -- is sin_radians special in any way, for us to consider it the "default" sine function in our applications?

There's Euler's formula: e^(ix) = cos(x) + isin(x). X is clearly a number, because it's used as an exponent. Is it important how exactly it gets converted into an angle on the right side of the equation? What kind of sine and cosine function does the formula use? Would the formula look different if we conventionally measured angles in multiples of a circle rather than in radians? Euler's formula is used to define complex exponentiation -- does that mean that the way complex exponentiation works depends on an arbitrary choice of measuring stick? Or is the radia

... keep reading on reddit ➑

πŸ‘︎ 60
πŸ’¬︎
πŸ‘€︎ u/thetimujin
πŸ“…︎ Oct 03 2021
🚨︎ report
SERIOUS: This subreddit needs to understand what a "dad joke" really means.

I don't want to step on anybody's toes here, but the amount of non-dad jokes here in this subreddit really annoys me. First of all, dad jokes CAN be NSFW, it clearly says so in the sub rules. Secondly, it doesn't automatically make it a dad joke if it's from a conversation between you and your child. Most importantly, the jokes that your CHILDREN tell YOU are not dad jokes. The point of a dad joke is that it's so cheesy only a dad who's trying to be funny would make such a joke. That's it. They are stupid plays on words, lame puns and so on. There has to be a clever pun or wordplay for it to be considered a dad joke.

Again, to all the fellow dads, I apologise if I'm sounding too harsh. But I just needed to get it off my chest.

πŸ‘︎ 17k
πŸ’¬︎
πŸ‘€︎ u/anywhereiroa
πŸ“…︎ Jan 15 2022
🚨︎ report
Explanation of deciBels, signal loss, antenna gain, and POC11

I hope this is helpful:

tl/dr; you can subtract the cable loss from your dBi value in the app, but only because the math happens to work out that way, not because it actually changes the dBi value of your antenna

 


#deciBels and logarithms

 

The base unit here is the Bel (named after Alexander Graham Bell) and deci means 1/10^th (like how centi means 1/100^th in centimeter), so 1 dB = 0.1 Bel.

When we express a number in Bels or dB, we are just choosing a logarithmic representation, i.e., to express numbers as 10 to some power. For example, 2 = 10^0.3 = 0.3 Bels = 3 dB so we are just choosing to represent the number "2" as 3 dB because 10^0.3 = 2 instead of just saying "2". We can express any number this way. This implies that every 3 dB represents a factor of 2, and every 10 dB represents a factor of 10 (because 10^1.0 = 10). The reason we do this is because it allows us to cover a much larger range of values using small numbers (e.g., 100 dB is much more compact than 10000000000). It also allows us to add quantities instead of multiplying because 10^x * 10^y = 10^x+y.

 


#What's the difference between dB, dBm, and dBi?

Because logarithms and, therefore, dB, are dimensionless quantities, they must be expressed relative to something to have any physical meaning. For example, dBm stands for deciBel-milliWatts and is in reference to 1 mW. If the Bobcat miner has a power rating of 25 dBm, for example, we can express it in a more familiar quantity using the above relations: 25 dBm = 2.5 Bel * 1 mW = 10^2.5 * 1 mW = 316 mW.

dBi stands for deciBel-isotropic and is relative to an ideal, isotropic source (i.e., it emits radiation uniformly in all directions). Antennas are passive devices, so this gain actually describes the shape of the radiation pattern (i.e., it's deviation from an isotropic sphere). It's not actually a single value but rather a function that depends on direction; when a single value is given, it is taken to be the maximum, which occurs perpendicular to the axis of the antenna (the radiation is identically zero along the axis of the antenna for a real source).

Side note, dBd stands for deciBel-dipole and is relative to an electric dipole, which is much more physcially meaningful because these are dipole antennas and perfect isotropic radiators do not really exist. You simply add 2.15 dB to convert from dBd to dBi, so it is actually sometimes frowned upon when manufacturers

... keep reading on reddit ➑

πŸ‘︎ 22
πŸ’¬︎
πŸ‘€︎ u/stonerphysics
πŸ“…︎ Nov 11 2021
🚨︎ report
Just because it's a joke, doesn't mean it's a dad joke

Alot of great jokes get posted here! However just because you have a joke, doesn't mean it's a dad joke.

THIS IS NOT ABOUT NSFW, THIS IS ABOUT LONG JOKES, BLONDE JOKES, SEXUAL JOKES, KNOCK KNOCK JOKES, POLITICAL JOKES, ETC BEING POSTED IN A DAD JOKE SUB

Try telling these sexual jokes that get posted here, to your kid and see how your spouse likes it.. if that goes well, Try telling one of your friends kid about your sex life being like Coca cola, first it was normal, than light and now zero , and see if the parents are OK with you telling their kid the "dad joke"

I'm not even referencing the NSFW, I'm saying Dad jokes are corny, and sometimes painful, not sexual

So check out r/jokes for all types of jokes

r/unclejokes for dirty jokes

r/3amjokes for real weird and alot of OC

r/cleandadjokes If your really sick of seeing not dad jokes in r/dadjokes

Punchline !

Edit: this is not a post about NSFW , This is about jokes, knock knock jokes, blonde jokes, political jokes etc being posted in a dad joke sub

Edit 2: don't touch the thermostat

πŸ‘︎ 6k
πŸ’¬︎
πŸ‘€︎ u/CzarcasmRules
πŸ“…︎ Jan 23 2022
🚨︎ report
Blind Girl Here. Give Me Your Best Blind Jokes!

Do your worst!

πŸ‘︎ 5k
πŸ’¬︎
πŸ‘€︎ u/Leckzsluthor
πŸ“…︎ Jan 02 2022
🚨︎ report
Petition to ban rants from this sub

Ants don’t even have the concept fathers, let alone a good dad joke. Keep r/ants out of my r/dadjokes.

But no, seriously. I understand rule 7 is great to have intelligent discussion, but sometimes it feels like 1 in 10 posts here is someone getting upset about the jokes on this sub. Let the mods deal with it, they regulate the sub.

πŸ‘︎ 8k
πŸ’¬︎
πŸ‘€︎ u/drak0ni
πŸ“…︎ Jan 24 2022
🚨︎ report
I heard that by law you have to turn on your headlights when it’s raining in Sweden.

How the hell am I suppose to know when it’s raining in Sweden?

πŸ‘︎ 10k
πŸ’¬︎
πŸ‘€︎ u/justshtmypnts
πŸ“…︎ Jan 25 2022
🚨︎ report
French fries weren’t cooked in France.

They were cooked in Greece.

πŸ‘︎ 9k
πŸ’¬︎
πŸ“…︎ Jan 20 2022
🚨︎ report
This subreddit is 10 years old now.

I'm surprised it hasn't decade.

πŸ‘︎ 14k
πŸ’¬︎
πŸ‘€︎ u/frexyincdude
πŸ“…︎ Jan 14 2022
🚨︎ report
You've been hit by
πŸ‘︎ 6k
πŸ’¬︎
πŸ‘€︎ u/mordrathe
πŸ“…︎ Jan 20 2022
🚨︎ report
I'm sick of you guys posting dumb wordplay in here for awards and upvotes.

Don't you know a good pun is its own reword?

πŸ‘︎ 11k
πŸ’¬︎
πŸ‘€︎ u/diggitygiggitycee
πŸ“…︎ Jan 21 2022
🚨︎ report
My 4 year oldest favourit joke, which he very proudly memorized and told all his teachers.

Two muffins are in an oven, one muffin looks at the other and says "is it just me, or is it hot in here?"

Then the other muffin says "AHH, TALKING MUFFIN!!!"

πŸ‘︎ 9k
πŸ’¬︎
πŸ‘€︎ u/smoffatt34920
πŸ“…︎ Jan 22 2022
🚨︎ report
Dropped my best ever dad joke & no one was around to hear it

For context I'm a Refuse Driver (Garbage man) & today I was on food waste. After I'd tipped I was checking the wagon for any defects when I spotted a lone pea balanced on the lifts.

I said "hey look, an escaPEA"

No one near me but it didn't half make me laugh for a good hour or so!

Edit: I can't believe how much this has blown up. Thank you everyone I've had a blast reading through the replies πŸ˜‚

πŸ‘︎ 20k
πŸ’¬︎
πŸ‘€︎ u/Vegetable-Acadia
πŸ“…︎ Jan 11 2022
🚨︎ report
What starts with a W and ends with a T

It really does, I swear!

πŸ‘︎ 6k
πŸ’¬︎
πŸ‘€︎ u/PsychedeIic_Sheep
πŸ“…︎ Jan 13 2022
🚨︎ report
My wife left me because I couldn’t stop doing impressions of pasta

And now I’m cannelloni

πŸ‘︎ 6k
πŸ’¬︎
πŸ‘€︎ u/bluestratmatt
πŸ“…︎ Jan 23 2022
🚨︎ report
Why did Karen press Ctrl+Shift+Delete?

Because she wanted to see the task manager.

πŸ‘︎ 11k
πŸ’¬︎
πŸ‘€︎ u/Eoussama
πŸ“…︎ Jan 17 2022
🚨︎ report
Steve JOBS would have made a better President than Donald Trump

But that’s comparing apples to oranges

πŸ‘︎ 8k
πŸ’¬︎
πŸ‘€︎ u/Ok-Ingenuity4838
πŸ“…︎ Jan 22 2022
🚨︎ report
I just flew in from Chernobyl

And boy are my arms legs.

πŸ‘︎ 7k
πŸ’¬︎
πŸ‘€︎ u/JhopkinsWA
πŸ“…︎ Jan 23 2022
🚨︎ report
So 2 trees got arrested in the town I live...

Heard they've been doing some shady business.

πŸ‘︎ 7k
πŸ’¬︎
πŸ‘€︎ u/K1ll47h3K1n9
πŸ“…︎ Jan 18 2022
🚨︎ report
I was almost upset that my coffee tasted like dirt today

but then I remembered it was ground this morning.

Edit: Thank you guys for the awards, they're much nicer than the cardboard sleeve I've been using and reassures me that my jokes aren't stale

Edit 2: I have already been made aware that Men In Black 3 has told a version of this joke before. If the joke is not new to you, please enjoy any of the single origin puns in the comments

πŸ‘︎ 8k
πŸ’¬︎
πŸ‘€︎ u/scarf_spheal
πŸ“…︎ Jan 19 2022
🚨︎ report
No gains
πŸ‘︎ 8k
πŸ’¬︎
πŸ‘€︎ u/ridi86
πŸ“…︎ Jan 22 2022
🚨︎ report
How eggs-traordinary
πŸ‘︎ 5k
πŸ’¬︎
πŸ‘€︎ u/Rix27_
πŸ“…︎ Jan 21 2022
🚨︎ report
What is the scariest tree?

BamBOO!

πŸ‘︎ 6k
πŸ’¬︎
πŸ‘€︎ u/K1ll47h3K1n9
πŸ“…︎ Jan 18 2022
🚨︎ report
What is a a bisexual person doing when they’re not dating anybody?

They’re on standbi

πŸ‘︎ 11k
πŸ’¬︎
πŸ‘€︎ u/Toby-the-Cactus
πŸ“…︎ Jan 12 2022
🚨︎ report
A queen size statement.
πŸ‘︎ 4k
πŸ’¬︎
πŸ‘€︎ u/Flight-less
πŸ“…︎ Jan 22 2022
🚨︎ report
My ten-year-old daughter came up with this at dinner tonight: What do you get if put a copy of Macbeth on top of a dictionary?

A play on words.

πŸ‘︎ 6k
πŸ’¬︎
πŸ‘€︎ u/ah1887
πŸ“…︎ Jan 20 2022
🚨︎ report
My son, Luke, loves how I named our kids after Star Wars characters...

My daughter, Chewbecca, not so much.

πŸ‘︎ 9k
πŸ’¬︎
πŸ‘€︎ u/andersonfmly
πŸ“…︎ Jan 21 2022
🚨︎ report
When I was a single man, I had loads of free time.

Now that I listen to albums, I hardly ever leave the house.

πŸ‘︎ 4k
πŸ’¬︎
πŸ‘€︎ u/porichoygupto
πŸ“…︎ Jan 25 2022
🚨︎ report
Geddit? No? Only me?
πŸ‘︎ 6k
πŸ’¬︎
πŸ‘€︎ u/shampy311
πŸ“…︎ Dec 28 2021
🚨︎ report
I wanna hear your best airplane puns.

Pilot on me!!

πŸ‘︎ 3k
πŸ’¬︎
πŸ‘€︎ u/Paulie_Felice
πŸ“…︎ Jan 07 2022
🚨︎ report
E or ß?
πŸ‘︎ 9k
πŸ’¬︎
πŸ‘€︎ u/Amazekam
πŸ“…︎ Jan 03 2022
🚨︎ report
Which actor drives the least?

Christopher Walken

πŸ‘︎ 3k
πŸ’¬︎
πŸ‘€︎ u/TR1771N
πŸ“…︎ Jan 18 2022
🚨︎ report
What did Spartacus say when the lion ate his wife?

Nothing, he was gladiator.

πŸ‘︎ 9k
πŸ’¬︎
πŸ‘€︎ u/rj104
πŸ“…︎ Jan 15 2022
🚨︎ report
Pun intended.
πŸ‘︎ 5k
πŸ’¬︎
πŸ‘€︎ u/Sharmaji1301
πŸ“…︎ Jan 15 2022
🚨︎ report

Please note that this site uses cookies to personalise content and adverts, to provide social media features, and to analyse web traffic. Click here for more information.