What-If 0115: "Into the Sun"

What if there was a forum for discussing these?

Moderators: Moderators General, Prelates, Magistrates

User avatar
cellocgw
Posts: 1869
Joined: Sat Jun 21, 2008 7:40 pm UTC

Re: What-If 0115: "Into the Sun"

Postby cellocgw » Thu Oct 09, 2014 6:53 pm UTC

stoppedcaring wrote:He added mouse-over text!


Yay -- and he even put in a shout-out to Johnathan Livingston. Wasn't that before he was born?

ETA: Page Pope! :oops:
https://app.box.com/witthoftresume
Former OTTer
Vote cellocgw for President 2020. #ScienceintheWhiteHouse http://cellocgw.wordpress.com
"The Planck length is 3.81779e-33 picas." -- keithl
" Earth weighs almost exactly π milliJupiters" -- what-if #146, note 7

rmsgrey
Posts: 3343
Joined: Wed Nov 16, 2011 6:35 pm UTC

Re: What-If 0115: "Into the Sun"

Postby rmsgrey » Thu Oct 09, 2014 9:14 pm UTC

stoppedcaring wrote:
rmsgrey wrote:
stoppedcaring wrote:For an example of what 1.74 milliseconds feels like...Earth's orbital speed around the sun is roughly 29.8 km/s. So if you teleported to the sun for 1.74 milliseconds and back to the exact same spot you left from, the Earth would have moved underneath you by roughly 100 feet. Let's hope you're shoveling snow close to noon, or you'll end up either underground or floating in midair.

But at least you'd be warm.

That does assume the Sun is fixed...

The assumption is that if you're teleporting to something, you're teleporting relative to its inertial reference frame.

Why not relative to your departure inertial reference frame? Why should teleporting change your inertia?

Nicias
Posts: 161
Joined: Tue Aug 13, 2013 4:22 pm UTC

Re: What-If 0115: "Into the Sun"

Postby Nicias » Thu Oct 09, 2014 9:49 pm UTC

You are missing the point of using the same units for all dimensions. It like saying, "yeah I know that north-south and east-west are really just two orthogonal directions, and can both be measured in meters, but the question asked about a distance north, so it should be measured in north-miles"

armandoalvarez
Posts: 126
Joined: Thu May 03, 2012 1:39 am UTC

Re: What-If 0115: "Into the Sun"

Postby armandoalvarez » Thu Oct 09, 2014 11:58 pm UTC

stoppedcaring wrote:He added mouse-over text!

armandoalvarez wrote:Is there a time when you can be nicely warmed, or would you go straight from cold to burned? I know very little about thermodynamics, but if you put something in the oven at a higher temperature for a shorter time, the result is often that the outside is burned and the inside is still cold, so I would think as you increase the time on the sun, there would never be a time when you got warm, you would either feel nothing or be burned.

1.74 milliseconds.

Sorry. Poor scanning skills.

KittenKaboodle
Posts: 136
Joined: Thu Dec 16, 2010 6:36 am UTC

Re: What-If 0115: "Into the Sun"

Postby KittenKaboodle » Fri Oct 10, 2014 12:01 am UTC

rmsgrey wrote:Actually, there are benefits to working base-p where p is a prime - I used to know specific examples, but it's been a while since I looked at it...


I believe 2 is prime :wink: There seems to be some confusion as to whether it is the largest even prime, but then, others are advocating for base 8 already.

peregrine_crow
Posts: 180
Joined: Mon Apr 07, 2014 7:20 am UTC

Re: What-If 0115: "Into the Sun"

Postby peregrine_crow » Fri Oct 10, 2014 7:35 am UTC

rmsgrey wrote:
Barstro wrote:I'm sure we both agree that either base is better than base 7.
Actually, there are benefits to working base-p where p is a prime - I used to know specific examples, but it's been a while since I looked at it...


If you remember any, I'd definitely be interested to hear them. Because my first instinct is to agree wholeheartedly with Barstro on this.
Ignorance killed the cat, curiosity was framed.

iosonologio
Posts: 2
Joined: Thu Mar 08, 2012 11:14 am UTC

Re: What-If 0115: "Into the Sun"

Postby iosonologio » Fri Oct 10, 2014 9:19 am UTC

I believe there is a small error:
At this point, the retinal cells wouldn't even have begun responding. Over the next few million nanoseconds (milliseconds) the retinal cells—having absorbed a bunch of light energy—would get into gear and start signaling your brain that something had happened.


As you can read here (doi:10.1038/35107042) the retina reacts in less than 1ps by photoisomerization of retinal (1ns is plenty of time to absorb light).

By the way, is crazy the neat use of femtosecond laser pulses to measure events on that scale.

Regards

Giovanni

User avatar
cellocgw
Posts: 1869
Joined: Sat Jun 21, 2008 7:40 pm UTC

Re: What-If 0115: "Into the Sun"

Postby cellocgw » Fri Oct 10, 2014 12:08 pm UTC

iosonologio wrote:I believe there is a small error:
At this point, the retinal cells wouldn't even have begun responding. Over the next few million nanoseconds (milliseconds) the retinal cells—having absorbed a bunch of light energy—would get into gear and start signaling your brain that something had happened.


As you can read here (doi:10.1038/35107042) the retina reacts in less than 1ps by photoisomerization of retinal (1ns is plenty of time to absorb light).

By the way, is crazy the neat use of femtosecond laser pulses to measure events on that scale.

Regards

Giovanni


The retina reacts in the sense that molecules change. The signal takes rather longer to get to the optic nerve, and much longer to reach even the automatic-response portions of the brain, let alone the conscious response portions.
https://app.box.com/witthoftresume
Former OTTer
Vote cellocgw for President 2020. #ScienceintheWhiteHouse http://cellocgw.wordpress.com
"The Planck length is 3.81779e-33 picas." -- keithl
" Earth weighs almost exactly π milliJupiters" -- what-if #146, note 7

User avatar
david.windsor
Posts: 121
Joined: Mon Sep 09, 2013 3:08 pm UTC

Re: What-If 0115: "Into the Sun"

Postby david.windsor » Fri Oct 10, 2014 3:11 pm UTC

davearonson wrote:The "footnote" for "reverse blink" says, "Is there a word for that? There should be a word for that."

There is indeed, and it's just what you'd probably think it should be. Google "knilb" for details. (Sorry, I haven't posted enough to be able to post a link. :( )


Yes there is a word for it, it is called "Peek".
"All those ... moments, will be lost ... in time, like tears ... in rain."

User avatar
david.windsor
Posts: 121
Joined: Mon Sep 09, 2013 3:08 pm UTC

Re: What-If 0115: "Into the Sun"

Postby david.windsor » Fri Oct 10, 2014 3:33 pm UTC

rmsgrey wrote:
Heimhenge wrote:I know what Randall meant, but shouldn't the sign in the first drawing read "Must be 4 light-nanoseconds tall to ride"?


Because space and time are not distinct under Einstein's theories of Relativity, units of time are units of distance...


This makes total sence; where I grewup, on the prairies in Alberta, any directions given to somewhere new sounded something like this "...turn left and drive 10 mins, you can't miss it."
"All those ... moments, will be lost ... in time, like tears ... in rain."

User avatar
david.windsor
Posts: 121
Joined: Mon Sep 09, 2013 3:08 pm UTC

Re: What-If 0115: "Into the Sun"

Postby david.windsor » Fri Oct 10, 2014 3:57 pm UTC

stoppedcaring wrote: 85F is a nice toasty temperature, I think. So going from 10F to 85F is a 75F difference, which translates to a 41.7C difference,


You're outside, dressed for snow shoveling, a 41.7ºC temperature jump would have you drenched in sweat. Sounds as cozy as heat stroke. :oops:
"All those ... moments, will be lost ... in time, like tears ... in rain."

User avatar
clarkbhm
Posts: 11
Joined: Sat Oct 04, 2014 12:14 am UTC
Location: Pittsburgh, PA

Re: What-If 0115: "Into the Sun"

Postby clarkbhm » Fri Oct 10, 2014 4:08 pm UTC

I kept wondering when he would include the effects of gravity and how whether you would be squished to a puddle in that nanosecond.

User avatar
Klear
Posts: 1965
Joined: Sun Jun 13, 2010 8:43 am UTC
Location: Prague

Re: What-If 0115: "Into the Sun"

Postby Klear » Fri Oct 10, 2014 4:28 pm UTC

I've been using "light-nanosecond" instead of "30 centimetres" for a while now. Kinda handy, though rather nerdy.

speising
Posts: 2213
Joined: Mon Sep 03, 2012 4:54 pm UTC
Location: wien

Re: What-If 0115: "Into the Sun"

Postby speising » Fri Oct 10, 2014 5:26 pm UTC

clarkbhm wrote:I kept wondering when he would include the effects of gravity and how whether you would be squished to a puddle in that nanosecond.

squished against what?

stoppedcaring
Posts: 364
Joined: Thu Dec 19, 2013 7:21 pm UTC

Re: What-If 0115: "Into the Sun"

Postby stoppedcaring » Fri Oct 10, 2014 5:49 pm UTC

rmsgrey wrote:
stoppedcaring wrote:
rmsgrey wrote:
stoppedcaring wrote:For an example of what 1.74 milliseconds feels like...Earth's orbital speed around the sun is roughly 29.8 km/s. So if you teleported to the sun for 1.74 milliseconds and back to the exact same spot you left from, the Earth would have moved underneath you by roughly 100 feet. Let's hope you're shoveling snow close to noon, or you'll end up either underground or floating in midair.

But at least you'd be warm.

That does assume the Sun is fixed...

The assumption is that if you're teleporting to something, you're teleporting relative to its inertial reference frame.

Why not relative to your departure inertial reference frame? Why should teleporting change your inertia?

Depends on your definition of teleportation, I suppose, but matching your target reference frame seems much more reasonable. Otherwise, you'd end up with the entire tangential velocity of the orbiting Earth at a completely different point. At its simplest, teleportation is a movement from one spacetime coordinate to another spacetime coordinate, which naturally involves a different gravitational potential and inertial frame. If we were to attempt to maintain the departure reference frame, you'd have to deal with a discontinuity in being at a different gravitational potential. A different gravitational potential and reference frame means that simultaneity is different, the flow of time itself is different, and so forth. So the only way that a teleportation can be meaningful is if it is a seamless transition from one reference-frame-defined spacetime coordinate to a difference reference-frame-defined spacetime coordinate.

This does raise the light-travel-time problem. You can't very well teleport there and back faster than lightspeed, which means the trip would take a minimum of 16 minutes. But perhaps you wouldn't notice it because you'd be moving at lightspeed?

clarkbhm wrote:I kept wondering when he would include the effects of gravity and how whether you would be squished to a puddle in that nanosecond.

Well, you won't be squished. Being at or near the surface of the sun, you'd be in free fall, so gravity isn't going to hurt you unless there's something for you to hit. Of course, if the surface of the sun was solid and you landed on it, you'd weigh 28 times more than you do now, which would certainly squish you...but not in a nanosecond, and not in free fall.

Tidal effects, however, could stretch you rather than squish you. The sun's gravity would be pulling harder on your near side than on your far side. However, the difference would be negligible; your body isn't nearly thick enough to make a difference given the tremendous size of the sun. Tidal effects really only mess you up when you're close to a neutron star or a black hole, or if you're a large astronomical body.

david.windsor wrote:
stoppedcaring wrote: 85F is a nice toasty temperature, I think. So going from 10F to 85F is a 75F difference, which translates to a 41.7C difference,


You're outside, dressed for snow shoveling, a 41.7ºC temperature jump would have you drenched in sweat. Sounds as cozy as heat stroke. :oops:

It would only be your exposed skin, remember?

User avatar
clarkbhm
Posts: 11
Joined: Sat Oct 04, 2014 12:14 am UTC
Location: Pittsburgh, PA

Re: What-If 0115: "Into the Sun"

Postby clarkbhm » Fri Oct 10, 2014 7:42 pm UTC

speising wrote:
clarkbhm wrote:I kept wondering when he would include the effects of gravity and how whether you would be squished to a puddle in that nanosecond.

squished against what?


Squished to a puddle was my non technical term for describing the gravitational forces that would tear your body apart.

rmsgrey
Posts: 3343
Joined: Wed Nov 16, 2011 6:35 pm UTC

Re: What-If 0115: "Into the Sun"

Postby rmsgrey » Fri Oct 10, 2014 7:58 pm UTC

clarkbhm wrote:
speising wrote:
clarkbhm wrote:I kept wondering when he would include the effects of gravity and how whether you would be squished to a puddle in that nanosecond.

squished against what?


Squished to a puddle was my non technical term for describing the gravitational forces that would tear your body apart.


If you're getting torn apart by tidal forces, the usual term used is "spaghettification" - pretty much the exact opposite of being squished to a puddle since, instead of being compressed along one axis and stretched in the complementary plane, you'd be stretched in one axis and compressed in the complementary plane...

User avatar
clarkbhm
Posts: 11
Joined: Sat Oct 04, 2014 12:14 am UTC
Location: Pittsburgh, PA

Re: What-If 0115: "Into the Sun"

Postby clarkbhm » Fri Oct 10, 2014 8:05 pm UTC

rmsgrey wrote:
clarkbhm wrote:
speising wrote:
clarkbhm wrote:I kept wondering when he would include the effects of gravity and how whether you would be squished to a puddle in that nanosecond.

squished against what?


Squished to a puddle was my non technical term for describing the gravitational forces that would tear your body apart.


If you're getting torn apart by tidal forces, the usual term used is "spaghettification" - pretty much the exact opposite of being squished to a puddle since, instead of being compressed along one axis and stretched in the complementary plane, you'd be stretched in one axis and compressed in the complementary plane...


Right. I was hoping that the "What if" would address whether the nanosecond would have time to do that.

stoppedcaring
Posts: 364
Joined: Thu Dec 19, 2013 7:21 pm UTC

Re: What-If 0115: "Into the Sun"

Postby stoppedcaring » Fri Oct 10, 2014 8:26 pm UTC

clarkbhm wrote:
rmsgrey wrote:If you're getting torn apart by tidal forces, the usual term used is "spaghettification" - pretty much the exact opposite of being squished to a puddle since, instead of being compressed along one axis and stretched in the complementary plane, you'd be stretched in one axis and compressed in the complementary plane...


Right. I was hoping that the "What if" would address whether the nanosecond would have time to do that.

Assuming you are fairly close to the surface of the sun and your body is roughly 30 cm thick from front to back, then the gravitational acceleration differential from your chest to your back will be 2 millionths of a percent of one g. So, no. Not gonna feel it, let alone be spaghettified by it. In one nanosecond, the 29 gs of the sun's surface gravity will pull you forward by 0.014 femtometres, about one twentieth the diameter of an electron. The "spaghettification" would be approximately 0.12 yoctometres, which is really not enough to say anything meaningful about.

Now, in the 1.74 milliseconds it would take to actually get warm, that's different. The sun's gravity is going to pull you (in free fall) a whole half-millimeter forward. But the spaghettification still will be negligible -- not the least of which because those forces are many orders of magnitude lower than the internal forces holding your body together.

Now, if you teleport to the event horizon of a small black hole, THEN you could be in trouble.
Last edited by stoppedcaring on Fri Oct 10, 2014 8:38 pm UTC, edited 2 times in total.

ps.02
Posts: 378
Joined: Fri Apr 05, 2013 8:02 pm UTC

Re: What-If 0115: "Into the Sun"

Postby ps.02 » Fri Oct 10, 2014 8:35 pm UTC

Barstro wrote:I think the usefulness of having an easy way to convert to binary is better than the ability to divide by 3.

Eh ... why optimize all of life for ease of computation? They have Moore's Law for that. We don't. Optimize for the rest of us.

Anyway, so long as we plan to keep 8-bit bytes or 128-bit IPv6 addresses, octal (base 8) is kinda ridiculous compared to hexadecimal (base 16). If you wanted to retrain your brain to make life easier for your computers (rather than the converse, as I would suggest), hex is the way to go. Conveniently, you can count a hex digit on the fingers of one hand, leaving your thumb free for texting.

ps.02
Posts: 378
Joined: Fri Apr 05, 2013 8:02 pm UTC

Re: What-If 0115: "Into the Sun"

Postby ps.02 » Fri Oct 10, 2014 8:51 pm UTC

rmsgrey wrote:Actually, there are benefits to working base-p where p is a prime - I used to know specific examples, but it's been a while since I looked at it...

I think the main benefit is in picking pseudo-random numbers. Think "eeny-meeny-miney-moe," if you will. Where the number of choices and the number of syllables are relative primes, you get more even coverage of your choices. Related is hashing: pseudo-randomly putting N items into M piles. If there are numeric patterns to the N-item sequence, having M be either prime, or at least prime relative to any recurring pattern lengths in N, makes it easier to distribute the patterns more evenly.

User avatar
gmalivuk
GNU Terry Pratchett
Posts: 26164
Joined: Wed Feb 28, 2007 6:02 pm UTC
Location: Here and There
Contact:

Re: What-If 0115: "Into the Sun"

Postby gmalivuk » Sat Oct 11, 2014 6:30 am UTC

schapel wrote:Given that even light can travel only one foot, how far are atoms going to travel, even at millions of degrees? I would suspect that few atoms or other particles would bombard you. On the other hand, they would each have so much energy that mere heating would be the least of your concerns... wouldn't they rip through your tissue causing cell damage deep into your body? I would think hydrogen and helium atoms would constitute ionizing radiation at those temperatures.

How many atoms hit you doesn't depend only on how far they move in that time. It also depends on their density in space. (After all, the million-degree example for a femtosecond involves light traveling a really tiny distance and yet it still delivers enough energy to be somewhat of an inconvenience.)

Barstro wrote:
schapel wrote:. It's chosen so that 24*60*60 of them occur each day. It would be very awkward telling time if there weren't some even number of seconds in a day.


1) 60 and 24 are horrible numbers to work with. I believe it comes from society starting with base 12 (joints on four fingers of a hand; if only we did my base 8 for fingers on each hand (instead of 10 for digits on each hand)).
2) About 24*60*60. It's not exact. We get leap years and leap seconds.
3) It's arbitrary to base time on our speck of a planet.
4) When we take our place in the stars, a second becomes meaningless everywhere except earth. Rather than having everyone convert to arbitrary Earth Time (hopefully we will have done away with time zones by then), everyone can be on universal time.


Since a second on this planet is imprecise anyway, just convert it to something precise. Base it on something to do with hydrogen in binary. (Not a scientist, so I don't know what hydrogen does on a regular basis that can be multiplied by 2^x to get to a reasonable time unit.)

1) Those are super easy numbers to work with, but base-60 doesn't come from base-12 as evidenced by the fact that cuneiform numbers are base-10 up to 60.
2) Leap years have nothing whatsoever to do with the number of seconds in a day, and there've only been 13 leap seconds added in the past 30 years, which means it's still remarkably close to 86400 of them on average every day.
3) Arbitrary for the rest of the universe, perhaps, but not terribly arbitrary for those of us whose entire species was born on this speck of a planet.
4) The universal time, unless it's whatever the Galactic Federation decided on in our absence, will almost certainly still be based on seconds. It might be metricized or something, and days might no longer matter, but given that the second is currently the only universally agreed-upon standard unit, I don't see it going anywhere soon. (As in, every other base unit is different in different systems.)

Seconds are based on cesium in whatever base you choose to write your integers in.
Unless stated otherwise, I do not care whether a statement, by itself, constitutes a persuasive political argument. I care whether it's true.
---
If this post has math that doesn't work for you, use TeX the World for Firefox or Chrome

(he/him/his)

User avatar
Eternal Density
Posts: 5544
Joined: Thu Oct 02, 2008 12:37 am UTC
Contact:

Re: What-If 0115: "Into the Sun"

Postby Eternal Density » Sat Oct 11, 2014 11:31 pm UTC

Here's a video of Grace Hopper explaining nanoseconds: https://www.youtube.com/watch?v=JEpsKnWZrJ8
Play the game of Time! castle.chirpingmustard.com Hotdog Vending Supplier But what is this?
In the Marvel vs. DC film-making war, we're all winners.

Gil-Galad
Posts: 8
Joined: Fri Mar 29, 2013 8:19 am UTC

Re: What-If 0115: "Into the Sun"

Postby Gil-Galad » Tue Oct 14, 2014 8:23 am UTC

While we are discussing about units: Could it be that Americans are afraid of SI-prefixes or exponents? Those „X is 10,000,000 Y“ are just cumbersome and won’t help a layman anymore than „X is 10⁷ Y“. ns, ps, fs etc. should be pretty clear too (and if you want to explain them write „femto is 10⁻¹⁵“).

But it don’t really want to overexert you with exponents or SI-prefixes, it would be great if you used SI-units at all :P

User avatar
mathmannix
Posts: 1410
Joined: Fri Jul 06, 2012 2:12 pm UTC
Location: Washington, DC

Re: What-If 0115: "Into the Sun"

Postby mathmannix » Tue Oct 14, 2014 12:49 pm UTC

xkcd wrote:The Sun's surface is relatively cool. It's hotter than, like, Phoenix...


What about the Phoenix Suns? They're supposed to be pretty hot this year... [citation needed]
I hear velociraptor tastes like chicken.

Barstro
Posts: 103
Joined: Mon Aug 13, 2012 2:34 pm UTC

Re: What-If 0115: "Into the Sun"

Postby Barstro » Tue Oct 14, 2014 2:58 pm UTC

ps.02 wrote:Anyway, so long as we plan to keep 8-bit bytes or 128-bit IPv6 addresses, octal (base 8) is kinda ridiculous compared to hexadecimal (base 16). If you wanted to retrain your brain to make life easier for your computers (rather than the converse, as I would suggest), hex is the way to go. Conveniently, you can count a hex digit on the fingers of one hand, leaving your thumb free for texting.

I have no problem with hex. But given how much humanity refuses to try anything new, I figured going down to 8 was easier than going up to 16 and trying to come up with new integers. It also made it easier to make the alphabet have 24 letters (number of numerals x3), but that isn't an easy number given the amount of sounds we can produce and I never got it to work anyway. :?

gmalivuk wrote:1) Those are super easy numbers to work with, but base-60 doesn't come from base-12 as evidenced by the fact that cuneiform numbers are base-10 up to 60.
2) Leap years have nothing whatsoever to do with the number of seconds in a day, and there've only been 13 leap seconds added in the past 30 years, which means it's still remarkably close to 86400 of them on average every day.
3) Arbitrary for the rest of the universe, perhaps, but not terribly arbitrary for those of us whose entire species was born on this speck of a planet.
4) The universal time, unless it's whatever the Galactic Federation decided on in our absence, will almost certainly still be based on seconds. It might be metricized or something, and days might no longer matter, but given that the second is currently the only universally agreed-upon standard unit, I don't see it going anywhere soon. (As in, every other base unit is different in different systems.)

Seconds are based on cesium in whatever base you choose to write your integers in.

1) They are "easy" because they are traditional. Celsius is easy to work with, but many vocal Americans refuse because Fahrenheit is traditional. Then they make up BS reasons that Fahrenheit is better and Celsius makes no sense.
2) Having even one leap second ever means that there is not a perfect number of seconds in a day.
3) We will not always be on this planet. When we do rise off this rock ("rise" being dependent on point of view) all other places will have differing times.*
4a) You assume that Earth will be the cause of an agreed-upon time unit in the Universe. Possible, but not definite.
4b) "Second" is currently the only Earthly agreed-upon standard. Man has been around much much longer than the second was "the" unit of time. Other things from other tribes existed before but died out from conquering, trade, etc..

5) Seconds are not based on cesium. They are based on the movement of our planet and sun. We use cesium as a way to give a standard measurement, but that makes cesium-reference the effect, not the cause. Or, at least, that's how it started. Perhaps now the roles are reversed, but the origin remains the same.

*Your arguments, while not exactly wrong (much as mine are not exactly correct), are the same sort of arguments that existed before the railroad "forced" the US into having timezones. Prior to that, every town had noon when the sun was the highest and scheduling was horrible. Now, noon is very rarely at "high noon", but the social-economic workings of the country rather depend on an agreed-upon time that works better for the system than it does for the individual. In the end; because it works better for the system, it eventually works better for the individual.

stoppedcaring
Posts: 364
Joined: Thu Dec 19, 2013 7:21 pm UTC

Re: What-If 0115: "Into the Sun"

Postby stoppedcaring » Tue Oct 14, 2014 5:31 pm UTC

Barstro wrote:They are "easy" because they are traditional. Celsius is easy to work with, but many vocal Americans refuse because Fahrenheit is traditional. Then they make up BS reasons that Fahrenheit is better and Celsius makes no sense.

Celsius seems neater, and is easier to convert to and from Kelvin when necessary, but is not otherwise any easier to work with than Fahrenheit. Since most people have little need to convert to Kelvin, it's really no different.

Fahrenheit has the advantage that its 0 and 100 correspond to the lower and upper range of temperatures most commonly experienced by human beings. "The coldest it gets in the winter" and "the warmest it gets in the summer" are very close to 0 and 100 for the majority of people; this is also the range of temperature in which people can survive for extended periods of time. Which makes it rather more natural. People don't usually stick their hands into boiling water to feel what 100C is like.

"Second" is currently the only Earthly agreed-upon standard. Man has been around much much longer than the second was "the" unit of time. Other things from other tribes existed before but died out from conquering, trade, etc..

I doubt any timekeeping period anywhere close to the second existed prior. Before the invention of the pendulum clock, the hour was the closest unit of time anyone used.

Tyndmyr
Posts: 10531
Joined: Wed Jul 25, 2012 8:38 pm UTC

Re: What-If 0115: "Into the Sun"

Postby Tyndmyr » Tue Oct 14, 2014 9:02 pm UTC

Barstro wrote:2) Having even one leap second ever means that there is not a perfect number of seconds in a day.


Orbital times do vary slightly. In the case of earth, it does so extremely little, but there is no solution that has absolutely perfect accuracy without leap seconds ever. Our solution is pretty good in that they are quite rare.

3) We will not always be on this planet. When we do rise off this rock ("rise" being dependent on point of view) all other places will have differing times.*


This sounds like the perfect example of a problem that we need not worry about now. This one is convenient for current needs. Adopting a different one would be inconvenient now, and is unlikely to be significantly more convenient in the future.

5) Seconds are not based on cesium. They are based on the movement of our planet and sun. We use cesium as a way to give a standard measurement, but that makes cesium-reference the effect, not the cause. Or, at least, that's how it started. Perhaps now the roles are reversed, but the origin remains the same.


Yes, the historical reason is not the same as the modern definition. This is fine.

rmsgrey
Posts: 3343
Joined: Wed Nov 16, 2011 6:35 pm UTC

Re: What-If 0115: "Into the Sun"

Postby rmsgrey » Tue Oct 14, 2014 9:03 pm UTC

stoppedcaring wrote:I doubt any timekeeping period anywhere close to the second existed prior. Before the invention of the pendulum clock, the hour was the closest unit of time anyone used.

Heartbeats.

Not ideal (they vary rather) but better than most alternatives.

Legend has it that Galileo discovered/invented the use of pendulums for timekeeping by timing the slow swing of a chandelier with his pulse...

Mikeski
Posts: 984
Joined: Sun Jan 13, 2008 7:24 am UTC
Location: Minnesota, USA

Re: What-If 0115: "Into the Sun"

Postby Mikeski » Tue Oct 14, 2014 9:16 pm UTC

stoppedcaring wrote:
Barstro wrote:They are "easy" because they are traditional. Celsius is easy to work with, but many vocal Americans refuse because Fahrenheit is traditional. Then they make up BS reasons that Fahrenheit is better and Celsius makes no sense.

Celsius seems neater, and is easier to convert to and from Kelvin when necessary, but is not otherwise any easier to work with than Fahrenheit. Since most people have little need to convert to Kelvin, it's really no different.

Fahrenheit has the advantage that its 0 and 100 correspond to the lower and upper range of temperatures most commonly experienced by human beings. "The coldest it gets in the winter" and "the warmest it gets in the summer" are very close to 0 and 100 for the majority of people; this is also the range of temperature in which people can survive for extended periods of time. Which makes it rather more natural. People don't usually stick their hands into boiling water to feel what 100C is like.

Fahrenheit also has useful natural-language temperature ranges. "It's in the teens"; I should wear my parka. "It's in the twenties"; I should wear my leather coat and gloves. "It's in the thirties"; leather coat, but maybe no gloves. "It's in the low forties"; a windbreaker is probably enough. That whole range in Celsius is covered by... -12 to +7. "It's in the twenties" in Celsius covers everything from comfortable room temperature to swimsuit weather.

So the usual argument for SI units (they match up nicely with the 10s that people think in) works better for Fahrenheit than for Celsius for everyday life. Celsius is just better when you're doing science and need it to match up your temperatures with your other units.

And I don't know that I've heard anyone say "Celsius makes no sense". That's silly. Almost as silly as Fahrenheit only surviving because of "traditional vocal American BS". :wink:

User avatar
gmalivuk
GNU Terry Pratchett
Posts: 26164
Joined: Wed Feb 28, 2007 6:02 pm UTC
Location: Here and There
Contact:

Re: What-If 0115: "Into the Sun"

Postby gmalivuk » Tue Oct 14, 2014 9:24 pm UTC

Barstro wrote:1) They are "easy" because they are traditional. Celsius is easy to work with, but many vocal Americans refuse because Fahrenheit is traditional. Then they make up BS reasons that Fahrenheit is better and Celsius makes no sense.
No, they are easy because they have lots of factors. 60 is divisible by 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30. 24 is divisible by 2, 3, 4, 6, 8, and 12. Ten is only divisible by 2 and 5.

Ease of use is what made them traditional in the first place, not the other way around. (Same with the nice powers of 2 in the Fahrenheit scale.)

2) Having even one leap second ever means that there is not a perfect number of seconds in a day.
No number of any length of time will consistently fit in a day or a year or any other astronomical phenomenon on Earth or any other planet, because celestial mechanics are messy and periodic things on that scale don't actually maintain quite a constant period.

3) We will not always be on this planet. When we do rise off this rock ("rise" being dependent on point of view) all other places will have differing times.
Which will be the case regardless of what time unit we use.

4a) You assume that Earth will be the cause of an agreed-upon time unit in the Universe. Possible, but not definite.
No, in fact I explicitly admit this may not be the case. But if we meet an existing network of civilizations, we'll probably adopt their base unit of time regardless of what we were using before, meaning we'll have to change our ways regardless.
Unless stated otherwise, I do not care whether a statement, by itself, constitutes a persuasive political argument. I care whether it's true.
---
If this post has math that doesn't work for you, use TeX the World for Firefox or Chrome

(he/him/his)

ps.02
Posts: 378
Joined: Fri Apr 05, 2013 8:02 pm UTC

Re: What-If 0115: "Into the Sun"

Postby ps.02 » Tue Oct 14, 2014 9:57 pm UTC

Barstro wrote:I have no problem with hex. But given how much humanity refuses to try anything new, I figured going down to 8 was easier than going up to 16 and trying to come up with new integers.

But for the vast majority of humanity, neither is of any tangible benefit. The days of toggling a boot loader into the front panel switches in order to boot your computer are gone, and never coming back. People do not need to know how to convert between their favored number base and binary. It just doesn't come up anymore. And as I said, computers themselves have no trouble converting back and forth, because Moore's Law. Even your calculator watch from the 80s could do that.

Now, for those of us who flip bits for a living and, for that matter, probably not even close to all of us, it's still quite useful to look at a data dump and parse it in your head, into ASCII or bitfields or other structured data, a far easier feat when you're looking at hex, so that's what we use. I have to say, I don't feel disadvantaged at having to learn how to think in hex on account of having learned decimal first. I don't ever seem to need to do complicated math in hex in my head anyway, mostly bitmasking and shifting, which aren't things I would expect to have learned in primary school anyway.

(One annoyance of decimal / binary conversion used to be IP subnet masks, but we rarely use those anymore, we've almost entirely switched to number-of-bits, from 0 to 128. Knowing that 255.255.248.0 is a /21 and represents 2048 contiguous IPs is handy, but becoming less so over time. And again, only specialists ever needed this. Casual users can use subnet calculator apps, in the quite unlikely event that the question ever comes up. And really it's not like the hex representation, ff.ff.f8.00, would really help the non-specialist to understand it.)

You want to reform something that would actually improve people's lives in a tangible way? Try the calendar. Unlike conversions between base 10 and base 2, figuring out weeks and months is something everyone has to do all the time, and you can't just apply a simple formula. I had to like the version Dr. Asimov proposed in an essay I read maybe 25 years ago. 12 months are replaced by 4 seasons of 91 numbered days each, and one day per year (two on leap years) is special, a member of neither season nor week. That way you keep your 7-day weeks (as Asimov explained, even he, progressive sciencey type that he was, couldn't really give up the "weekend") - and the correspondence between day of the week and day of the month is constant. This correspondence is something people have to look up manually now - even if you have a calendar app on your phone, you still have to consult it if you happen to need to know "what day of the week it will be on November 12" or "what day is the first Saturday in March". Instead, over time, you'd learn those answers for each number from 1 to 91 and that would be that.

Mambrino
Posts: 388
Joined: Tue Aug 02, 2011 9:45 pm UTC
Location: No we don't have polar bears. Except in zoos.

Re: What-If 0115: "Into the Sun"

Postby Mambrino » Tue Oct 14, 2014 10:10 pm UTC

stoppedcaring wrote:
Barstro wrote:They are "easy" because they are traditional. Celsius is easy to work with, but many vocal Americans refuse because Fahrenheit is traditional. Then they make up BS reasons that Fahrenheit is better and Celsius makes no sense.

Celsius seems neater, and is easier to convert to and from Kelvin when necessary, but is not otherwise any easier to work with than Fahrenheit. Since most people have little need to convert to Kelvin, it's really no different.

Fahrenheit has the advantage that its 0 and 100 correspond to the lower and upper range of temperatures most commonly experienced by human beings. "The coldest it gets in the winter" and "the warmest it gets in the summer" are very close to 0 and 100 for the majority of people; this is also the range of temperature in which people can survive for extended periods of time. Which makes it rather more natural. People don't usually stick their hands into boiling water to feel what 100C is like.


That doesn't sound especially rigorous. Why 0 °F is whatever it is, and not -1 °F? I don't feel like reiterating the point about the importance of water for human (and other) life everyone has surely already heard before, but I'd like to point that about any standard way to measure things (or about any thing even, for example such a fundamental stuff like what is the preferred civilized way one is supposed dispose excrement produced by their body) begins to feel natural if it sticks around for long enough time. The usual outdoors temperature and respective suitable clothing in a given geographical location during certain time of year is the kind of background 'noise' that is easily picked up, though.

I don't know if it were worth the hassle for people to change into using Celsius where they still have Fahrenheit, but surely it feels more connected to everyday scientific phenomena nor any less 'natural', whatever that means.

(Also, 100°C feels like ... quite pleasant actually, for air temperature. Depends on how you define "extended periods of time". A couple of hours?)

rmsgrey
Posts: 3343
Joined: Wed Nov 16, 2011 6:35 pm UTC

Re: What-If 0115: "Into the Sun"

Postby rmsgrey » Tue Oct 14, 2014 11:00 pm UTC

ps.02 wrote:You want to reform something that would actually improve people's lives in a tangible way? Try the calendar. Unlike conversions between base 10 and base 2, figuring out weeks and months is something everyone has to do all the time, and you can't just apply a simple formula. I had to like the version Dr. Asimov proposed in an essay I read maybe 25 years ago. 12 months are replaced by 4 seasons of 91 numbered days each, and one day per year (two on leap years) is special, a member of neither season nor week. That way you keep your 7-day weeks (as Asimov explained, even he, progressive sciencey type that he was, couldn't really give up the "weekend") - and the correspondence between day of the week and day of the month is constant. This correspondence is something people have to look up manually now - even if you have a calendar app on your phone, you still have to consult it if you happen to need to know "what day of the week it will be on November 12" or "what day is the first Saturday in March". Instead, over time, you'd learn those answers for each number from 1 to 91 and that would be that.


I quite like Shire Reckoning, which again adopts the sensible convention of having one day per year not be a weekday; two in a leap year, allowing the calendar to be static, rather than needing 28 calendars to cover all possibilities.

The downside of having the same date always be the same day of the week is that it means people's birthdays and other anniversaries will always fall on the same day of the week each year...

User avatar
gmalivuk
GNU Terry Pratchett
Posts: 26164
Joined: Wed Feb 28, 2007 6:02 pm UTC
Location: Here and There
Contact:

Re: What-If 0115: "Into the Sun"

Postby gmalivuk » Wed Oct 15, 2014 12:04 am UTC

Mambrino wrote:That doesn't sound especially rigorous. Why 0 °F is whatever it is, and not -1 °F?
Of course it's arbitrary, but so is every other base unit. Except time, actually, which at least corresponds to the natural length of a day even if that isn't quite as constant as we'd like it to be. Whatever solution freezes at 0° in a particular system, that particular solution at that particular pressure is unlikely to be quite what you actually have on hand in most real-life situations. Nothing important happens outdoors at exactly 0°C, because wind and current and salinity and pressure and the temperature of the ground and at different places in the atmosphere all play their parts, so we can have snow above 0°C and rain below 0°C, we can have ice on the roads above 0°C and water below 0°C.

surely it feels more connected to everyday scientific phenomena
Only because we use K in science and K is designed to be the same size as °C.

(Also, 100°C feels like ... quite pleasant actually, for air temperature. Depends on how you define "extended periods of time". A couple of hours?)
I dare you to try it sometime. You would last minutes, tops.
Unless stated otherwise, I do not care whether a statement, by itself, constitutes a persuasive political argument. I care whether it's true.
---
If this post has math that doesn't work for you, use TeX the World for Firefox or Chrome

(he/him/his)

Mikeski
Posts: 984
Joined: Sun Jan 13, 2008 7:24 am UTC
Location: Minnesota, USA

Re: What-If 0115: "Into the Sun"

Postby Mikeski » Wed Oct 15, 2014 12:48 am UTC

gmalivuk wrote:
Mambrino wrote:(Also, 100°C feels like ... quite pleasant actually, for air temperature. Depends on how you define "extended periods of time". A couple of hours?)
I dare you to try it sometime. You would last minutes, tops.

Stand around in 100 degree heat? I'll pass. Pork and beef are smoked at a temperature of only 105-110. The craziest Finnish sauna you can buy in the USA only goes to 90. "Quite pleasant" isn't the usual idea for a sauna; "sweating your ass off" is.

schapel
Posts: 244
Joined: Fri Jun 13, 2014 1:33 am UTC

Re: What-If 0115: "Into the Sun"

Postby schapel » Wed Oct 15, 2014 11:42 am UTC

Barstro wrote:2) Having even one leap second ever means that there is not a perfect number of seconds in a day.

That's because the period of the Earth's rotation varies. There is no value for a second that will allow for no leap seconds. Seconds are determined by the Earth's rotation period (not arbitrary) and the number of hours in a day, minutes in an hour, and seconds in a minute. These last three are arbitrary, but given that they are integers, there are only a small number of possible values for one second. The value for one foot, on the other hand, is entirely arbitrary and could be any value at all without causing a problem. So, what a second is really is less arbitrary than what a foot is.

User avatar
Neil_Boekend
Posts: 3220
Joined: Fri Mar 01, 2013 6:35 am UTC
Location: Yes.

Re: What-If 0115: "Into the Sun"

Postby Neil_Boekend » Wed Oct 15, 2014 11:48 am UTC

Mikeski wrote:
gmalivuk wrote:
Mambrino wrote:(Also, 100°C feels like ... quite pleasant actually, for air temperature. Depends on how you define "extended periods of time". A couple of hours?)
I dare you to try it sometime. You would last minutes, tops.

Stand around in 100 degree heat? I'll pass. Pork and beef are smoked at a temperature of only 105-110. The craziest Finnish sauna you can buy in the USA only goes to 90. "Quite pleasant" isn't the usual idea for a sauna; "sweating your ass off" is.

I have often been in a sauna at 105-110­°C. It is comfortable if you are used to being in a sauna. If you aren't then it is uncomfortably hot and nauseating. Since I haven't been in a decent sauna in years I expect it would once again be uncomfortable.
Sweating your ass off and quite comfortable can be the same event. For me a sauna is meant to be relaxing, while sweating my ass off.
Mikeski wrote:A "What If" update is never late. Nor is it early. It is posted precisely when it should be.

patzer's signature wrote:
flicky1991 wrote:I'm being quoted too much!

he/him/his

Barstro
Posts: 103
Joined: Mon Aug 13, 2012 2:34 pm UTC

Re: What-If 0115: "Into the Sun"

Postby Barstro » Wed Oct 15, 2014 2:35 pm UTC

Mikeski wrote:Fahrenheit also has useful natural-language temperature ranges. "It's in the teens"; I should wear my parka. "It's in the twenties"; I should wear my leather coat and gloves. "It's in the thirties"; leather coat, but maybe no gloves. "It's in the low forties"; a windbreaker is probably enough. That whole range in Celsius is covered by... -12 to +7. "It's in the twenties" in Celsius covers everything from comfortable room temperature to swimsuit weather.

Mikeski wrote:And I don't know that I've heard anyone say "Celsius makes no sense". That's silly. Almost as silly as Fahrenheit only surviving because of "traditional vocal American BS". :wink:


You made the exact argument people use to say Celsius makes no sense, and then claimed there is no such argument. :shock:

"It's in the twenties" is a response to Fahrenheit. Canadians have some other way to describe that temperature (something like "it's aboot time for a Tim Horton's and a two-four").

stoppedcaring
Posts: 364
Joined: Thu Dec 19, 2013 7:21 pm UTC

Re: What-If 0115: "Into the Sun"

Postby stoppedcaring » Wed Oct 15, 2014 2:56 pm UTC

rmsgrey wrote:
stoppedcaring wrote:I doubt any timekeeping period anywhere close to the second existed prior. Before the invention of the pendulum clock, the hour was the closest unit of time anyone used.

Heartbeats.

Not ideal (they vary rather) but better than most alternatives.

Legend has it that Galileo discovered/invented the use of pendulums for timekeeping by timing the slow swing of a chandelier with his pulse...

Good point. Hadn't thought of that.

Mambrino wrote:
stoppedcaring wrote:Fahrenheit has the advantage that its 0 and 100 correspond to the lower and upper range of temperatures most commonly experienced by human beings. "The coldest it gets in the winter" and "the warmest it gets in the summer" are very close to 0 and 100 for the majority of people; this is also the range of temperature in which people can survive for extended periods of time. Which makes it rather more natural. People don't usually stick their hands into boiling water to feel what 100C is like.


That doesn't sound especially rigorous. Why 0 °F is whatever it is, and not -1 °F? I don't feel like reiterating the point about the importance of water for human (and other) life everyone has surely already heard before, but I'd like to point that about any standard way to measure things (or about any thing even, for example such a fundamental stuff like what is the preferred civilized way one is supposed dispose excrement produced by their body) begins to feel natural if it sticks around for long enough time. The usual outdoors temperature and respective suitable clothing in a given geographical location during certain time of year is the kind of background 'noise' that is easily picked up, though.

I don't know if it were worth the hassle for people to change into using Celsius where they still have Fahrenheit, but surely it feels more connected to everyday scientific phenomena nor any less 'natural', whatever that means.

(Also, 100°C feels like ... quite pleasant actually, for air temperature. Depends on how you define "extended periods of time". A couple of hours?)

The 0 in Fahrenheit came from the lowest temperature to which Daniel Fahrenheit could reproducibly cool ammonia brine without modern equipment, though there is some speculation that it was also based on the lowest temperature reached in his hometown every year. 100F was defined as a temperature fairly close to human body temperature. So that's why it matches heat and cool extremes pretty well.


Return to “What If?”

Who is online

Users browsing this forum: No registered users and 3 guests