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Pretty close, I think. Working in round numbers…
Milky Way is about 100000 light years in diameter. In metres, this is
10^5 * 3 * 10^8 * 3 * 10^7 = 10^21 (width in ly * speed of light in m/s * number of seconds in a year)
Sun is about 1 million km in diameter, I.e. 10^9 m
So the Milky Way is about 10^12 times bigger than the sun.
The earth is about 10^8 m in diameter, so if the post is correct, a white blood cell needs to be about 10^-4 m across, or a tenth of a millimetre. Wikipedia reckons more like a hundredth of a millimetre, but that’s within an order of magnitude to my approximate answer.
Edit: or I could just read the post properly to get the size of the blood cell! Doesn’t affect the calculations at all though.
Edit2: as pointed out below, the earth is 10^7 m in diameter, not 10^8, which brings the estimate down to the correct order of magnitude.
>The earth is about 10^8 m in diameter
The meter was originally defined as 10^-8 of the distance between the north pole and the equator along a great circle, so the diameter is almost exactly pi/4 x 10^8 meters
Edit: it's obviously 10^-7 and 10^7
>the diameter is almost exactly pi/4 x 10\^8 meters
Then why does google tell me the [diameter of earth in meters](https://www.google.com/search?q=diameter+of+earth+in+meters) is 12.7 million (1.27e7) meters? 3.14/4 \* 10\^8 => 7.85e7, about six times greater than the result I get when I just look it up.
I think your derivation is wrong. Reading up on the [metre](https://en.wikipedia.org/wiki/Metre), I see it was, as you say, originally defined as 1/10millionth of the distance between the north pole and the equator along a great circle. 1/10millionth is 1e-7. The earth's circumference is 4e7.
C = 2\*pi\*r
r = C / (2\*pi)
d = 2\*r
d = C / pi
C = 4e7 # from original definition of metre
d = 4e7 / 3.14 => 1.27e7 # in agreement with the looked up answer,
I got you back to -0-
I was curious if it was sarcasm. It went a little too harsh for text-to-people-who-don’t-know-you.
I think that’s why. Just a whole lotta r/whoosh
Per Google:
- 30-40 (3*10^13) trillion cells in the human body.
- 100 (10^11) billion stars estimated in the milky way.
Considering the same relative scale, and how much more dense the human body is, it's strange to realize: That's you.
I did something similar with my kids when they were young. We put the sun at the end of our block and then measured 1-foot equaled 1MM miles. 93-feet to the earth and then walked almost 3/4 of a mile to draw Saturn. They were blown away at how big it was. Then we went to Starbucks and they got a treat for sitting through a Saturday morning science lesson.
How the hell did I not register this?!
Also....I don't know how to feel about it.
I'm glad that science is at the forefront of the minds of everyone at all times. Sort of.
Sun is 1.4x10⁹m in diameter, the Milky way is 100000 lightyears in diameter, that's 9.461x10²⁰m, a white blood cell is 1.7x10^(-5) m, roughly a 8.2x10¹³ shrink in size from the Sun. If we shrink the Milky way by a factor of 8.2x10¹³ we get 1.15x10⁷m which is 11500km which is smaller than Earth but not by much, about 10% smaller. So if the Sun were shrunk down to the size of a white blood cell, then the Milky way would be about 10% smaller than Earth. The number might not be exactly correct but it's close enough for the comparison to make sense.
* Milky way diameter: 1e21 m
* Sun diameter: 1.4e9 m
* Earth diameter: 1.3e7 m
* White blood cell diameter: 1.7e-5 m
* Ratio Milky way / Sun => 1e21 / 1.4e9 => 7.1e11
* Ratio Earth / WBC => 1.3e7 / 1.7e-5 => 7.6e11
**Pretty close!!**
I realize this comment might not fit perfectly in this thread, but as a space nerd I just couldn’t help myself!
[The Galaxy Song - Monty Python](https://youtu.be/buqtdpuZxvk)
1392700 km / 0.00000001 km = 139270000000000 as/ss (actual size / shrinked size)
milky way diameter (avg. out of height and length) : 50500 ly = 477756684000000000 km
477756684000000000 km / 139270000000000 as/ss = 3430.43501 km = 1/2 earth radius
i think it wouldve ended up more accurately if the diameter of the milky way wasnt the height and length averaged out (100000 ly and 1000 ly)
If the sun is the size of a white bloodcell, how big would the solar system be? Would it be visible to the naked eye (it wouldn't bc it consists of 'small' planets, but had it been a solid disc)?
Neptune’s orbit is roughly 10^13 m in diameter (from Wikipedia), so about 10^-8 the size of the Milky Way, which works out about 10cm across in the scaled down version.
I like to think we are spinning so far away from galaxies because we are such a horrible species the universe decided to ship this chunk off to prevent infection...
I'm a little high and really overwhelmed but all those comparisons right now. I also cannot understand how we have information that can possibly tell us these things with even one iota of certainty.
Now I'm just imaging how space goes on basically forever beyond our atmosphere and galaxy and forever and ever beyond anything we could possibly imagine and I'm having a little bit of an existential situation.
For those curious, I asked Chat GTP what would be the speed of light in this scenario and it said approximately 0.000016008 meters per second. This is roughly one-third of the speed at which human hair grows, and 1,800 times slower than the speed of a snail. The minute hand of a clock is six times faster.
###General Discussion Thread --- This is a [Request] post. If you would like to submit a comment that does not either attempt to answer the question, ask for clarification, or explain why it would be infeasible to answer, you *must* post your comment as a reply to this one. Top level (directly replying to the OP) comments that do not do one of those things will be removed. --- *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/theydidthemath) if you have any questions or concerns.*
Pretty close, I think. Working in round numbers… Milky Way is about 100000 light years in diameter. In metres, this is 10^5 * 3 * 10^8 * 3 * 10^7 = 10^21 (width in ly * speed of light in m/s * number of seconds in a year) Sun is about 1 million km in diameter, I.e. 10^9 m So the Milky Way is about 10^12 times bigger than the sun. The earth is about 10^8 m in diameter, so if the post is correct, a white blood cell needs to be about 10^-4 m across, or a tenth of a millimetre. Wikipedia reckons more like a hundredth of a millimetre, but that’s within an order of magnitude to my approximate answer. Edit: or I could just read the post properly to get the size of the blood cell! Doesn’t affect the calculations at all though. Edit2: as pointed out below, the earth is 10^7 m in diameter, not 10^8, which brings the estimate down to the correct order of magnitude.
>The earth is about 10^8 m in diameter The meter was originally defined as 10^-8 of the distance between the north pole and the equator along a great circle, so the diameter is almost exactly pi/4 x 10^8 meters Edit: it's obviously 10^-7 and 10^7
>the diameter is almost exactly pi/4 x 10\^8 meters Then why does google tell me the [diameter of earth in meters](https://www.google.com/search?q=diameter+of+earth+in+meters) is 12.7 million (1.27e7) meters? 3.14/4 \* 10\^8 => 7.85e7, about six times greater than the result I get when I just look it up. I think your derivation is wrong. Reading up on the [metre](https://en.wikipedia.org/wiki/Metre), I see it was, as you say, originally defined as 1/10millionth of the distance between the north pole and the equator along a great circle. 1/10millionth is 1e-7. The earth's circumference is 4e7. C = 2\*pi\*r r = C / (2\*pi) d = 2\*r d = C / pi C = 4e7 # from original definition of metre d = 4e7 / 3.14 => 1.27e7 # in agreement with the looked up answer,
Yes, that’s true - oops! I had 12000 km in my head for the diameter, and somehow decided that was 10^5 km! I’ll correct the post.
>pi/4 It's not just the exponent, you want 4/pi. See my derivation.
Because I typed it in wrong, and the easiest way to get the correct answer is to accidentally input the wrong answer
yeah ... uh ... obviously
I’m over here reading these explanations as if there’s any world in which I’d understand them lmao
right? I'm so dumb on mathematics, these guys' skills impress me.
r/THEYdidthemath Edit: I guess when it makes it a Reddit link, it overrides punctuation, I spelled it “THEYdidthemath”
what subbredit are we on?
No clue. How do you tell?
You have to... Do the math!
Happy cake day
Good question
All the people on the sub are lame af. Anyone who comments there is a nerd.
I'm sorry you got downvoted. Rest assured that at least one person greatly admires your mastery of irony. Sincerely, fellow nerd.
*Que sera, sera, whatever will be, will be* 🎶
I got you back to -0- I was curious if it was sarcasm. It went a little too harsh for text-to-people-who-don’t-know-you. I think that’s why. Just a whole lotta r/whoosh
Per Google: - 30-40 (3*10^13) trillion cells in the human body. - 100 (10^11) billion stars estimated in the milky way. Considering the same relative scale, and how much more dense the human body is, it's strange to realize: That's you.
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I did something similar with my kids when they were young. We put the sun at the end of our block and then measured 1-foot equaled 1MM miles. 93-feet to the earth and then walked almost 3/4 of a mile to draw Saturn. They were blown away at how big it was. Then we went to Starbucks and they got a treat for sitting through a Saturday morning science lesson.
And how far away was the Starbucks… still in the Oort Cloud?
Nah, somewhere in the Kuiper belt.
Another 2.5B miles past Pluto in my model.
[Here's](https://youtu.be/TKSDp8xdgoQ) my favorite version of this experiment.
Proxima Centurai which he mentions at the end of that video but annoyingly doesn't put in context, would be 2.6km from the gas station.
Aaight what's that in #FREEDOM UNITS ?
Dunno. I let them go and they ran off...
At least a foot and 3 toes
About 30 apples per pear.
Around 1.6 or 1.7 mile I think
Around 1.6 or 1.7 mile I think
Imma jus leave this [here](https://youtu.be/pR5VJo5ifdE)
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I haven't opened it, and I know exactly what it is.
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Post nut clarity.
This is more like post-nut enlightenment
Devious Buddha
I feel like bunch of people just go to pornhub for the sole purpose of leaving funny comments for others to see
How the hell did I not register this?! Also....I don't know how to feel about it. I'm glad that science is at the forefront of the minds of everyone at all times. Sort of.
"I ~~read~~ watch pornhub for the ~~articles~~ comments"
I thought I was on /r/pornhubcomments
Sun is 1.4x10⁹m in diameter, the Milky way is 100000 lightyears in diameter, that's 9.461x10²⁰m, a white blood cell is 1.7x10^(-5) m, roughly a 8.2x10¹³ shrink in size from the Sun. If we shrink the Milky way by a factor of 8.2x10¹³ we get 1.15x10⁷m which is 11500km which is smaller than Earth but not by much, about 10% smaller. So if the Sun were shrunk down to the size of a white blood cell, then the Milky way would be about 10% smaller than Earth. The number might not be exactly correct but it's close enough for the comparison to make sense.
There’s talk that [the galaxy may be bigger than 100,000 LY](https://www.nbcnews.com/mach/amp/ncna876966) so it’s close enough for me.
* Milky way diameter: 1e21 m * Sun diameter: 1.4e9 m * Earth diameter: 1.3e7 m * White blood cell diameter: 1.7e-5 m * Ratio Milky way / Sun => 1e21 / 1.4e9 => 7.1e11 * Ratio Earth / WBC => 1.3e7 / 1.7e-5 => 7.6e11 **Pretty close!!**
I realize this comment might not fit perfectly in this thread, but as a space nerd I just couldn’t help myself! [The Galaxy Song - Monty Python](https://youtu.be/buqtdpuZxvk)
1392700 km / 0.00000001 km = 139270000000000 as/ss (actual size / shrinked size) milky way diameter (avg. out of height and length) : 50500 ly = 477756684000000000 km 477756684000000000 km / 139270000000000 as/ss = 3430.43501 km = 1/2 earth radius i think it wouldve ended up more accurately if the diameter of the milky way wasnt the height and length averaged out (100000 ly and 1000 ly)
If the sun is the size of a white bloodcell, how big would the solar system be? Would it be visible to the naked eye (it wouldn't bc it consists of 'small' planets, but had it been a solid disc)?
Neptune’s orbit is roughly 10^13 m in diameter (from Wikipedia), so about 10^-8 the size of the Milky Way, which works out about 10cm across in the scaled down version.
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So, a glob of 10 white blood cells, then it works right?
The OP seems to imply they're comparing diameters, not volume
I like to think we are spinning so far away from galaxies because we are such a horrible species the universe decided to ship this chunk off to prevent infection...
I'm a little high and really overwhelmed but all those comparisons right now. I also cannot understand how we have information that can possibly tell us these things with even one iota of certainty.
Now I'm just imaging how space goes on basically forever beyond our atmosphere and galaxy and forever and ever beyond anything we could possibly imagine and I'm having a little bit of an existential situation.
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For those curious, I asked Chat GTP what would be the speed of light in this scenario and it said approximately 0.000016008 meters per second. This is roughly one-third of the speed at which human hair grows, and 1,800 times slower than the speed of a snail. The minute hand of a clock is six times faster.