1440: Geese

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1440: Geese

Postby Dr What » Wed Oct 29, 2014 4:32 am UTC

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title="Anyway, that's a common misconception. Geese live for a long time; all the ones we can see will probably keep flying around for billions of years before they explode."

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Re: 1440: Geese

Postby Himself » Wed Oct 29, 2014 4:49 am UTC

Yes. That misconception is a bit of a pet peeve. Kinda funny that, given how big the universe is, that people would actually overestimate the distance between things.
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Re: 1440: Geese

Postby rhomboidal » Wed Oct 29, 2014 5:06 am UTC

The Doppler shift heard in passing honking geese is one of the marvels of nature. And optical latency is a beautiful, terrifying thing.

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Re: 1440: Geese

Postby Envelope Generator » Wed Oct 29, 2014 5:54 am UTC

Did you know? The expanding splats left by exploding geese are the origin of the term "Messier object".
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Re: 1440: Geese

Postby quolnok » Wed Oct 29, 2014 6:24 am UTC

A few hundred yards? that doesn't seem very precise. For a start, are we talking about front yards, back yards or grave yards?

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Re: 1440: Geese

Postby keithl » Wed Oct 29, 2014 6:26 am UTC

Yeah, and the problem with stars is all the particles they leave on the sidewalk near the lake.

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Re: 1440: Geese

Postby Pfhorrest » Wed Oct 29, 2014 7:19 am UTC

keithl wrote:Yeah, and the problem with stars is all the particles they leave on the sidewalk near the lake.

Technically, all the particles on every sidewalk were left by stars. The particles that make up the sidewalk too. Pretty much all the particles of everything.
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Re: 1440: Geese

Postby DaveMcW » Wed Oct 29, 2014 7:19 am UTC

Is this supposed to be a pun on G's?

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Re: 1440: Geese

Postby eviloatmeal » Wed Oct 29, 2014 7:34 am UTC

DaveMcW wrote:Is this supposed to be a pun on G's?

I don't think it's quite that complicated - it's simply taking the typical observation that stars "are so far away that the light they emit takes lifetimes to reach us", and absurdly applying it to something which is much, much closer (for instance, birds).
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Re: 1440: Geese

Postby CharlieP » Wed Oct 29, 2014 9:39 am UTC

quolnok wrote:A few hundred yards? that doesn't seem very precise. For a start, are we talking about front yards, back yards or grave yards?


My first thought was "why yards, and not feet?". As somebody who prefers SI measurements, I'm yet to figure out what the rule is.

Length of a tapered drinking vessel with a bulb at one end: 1 yard
Height of a tall person: 6 feet
Length of a football field: 100 yards
Length of a Nimitz-class aircraft carrier: 1,092 feet
Length of a two-lap running race: 880 yards
Altitude of Alan Eustace's recent jump: 135,906 feet
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Re: 1440: Geese

Postby da Doctah » Wed Oct 29, 2014 9:58 am UTC

CharlieP wrote:My first thought was "why yards, and not feet?". As somebody who prefers SI measurements, I'm yet to figure out what the rule is.

Length of a tapered drinking vessel with a bulb at one end: 1 yard
Height of a tall person: 6 feet
Length of a football field: 100 yards
Length of a Nimitz-class aircraft carrier: 1,092 feet
Length of a two-lap running race: 880 yards


ITYM "half a mile".

Altitude of Alan Eustace's recent jump: 135,906 feet


I had this with my first GPS receiver. Longer distances were in miles, but shorter ones could be in either feet or yards, configurable from a menu. Distances to the next turn made more sense in yards, but I couldn't tie elevations to anything useful, having learned of "life zones" and the fact that dominant plant species change dramatically at almost perfect two-thousand-foot intervals ("instead of agave yuccas I'm seeing century plants; that means we're above the 8000' line").

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Re: 1440: Geese

Postby orthogon » Wed Oct 29, 2014 10:41 am UTC

CharlieP wrote:
quolnok wrote:A few hundred yards? that doesn't seem very precise. For a start, are we talking about front yards, back yards or grave yards?


My first thought was "why yards, and not feet?". As somebody who prefers SI measurements, I'm yet to figure out what the rule is.

Length of a tapered drinking vessel with a bulb at one end: 1 yard
Height of a tall person: 6 feet
Length of a football field: 100 yards
Length of a Nimitz-class aircraft carrier: 1,092 feet
Length of a two-lap running race: 880 yards
Altitude of Alan Eustace's recent jump: 135,906 feet

I speculated about this in another thread, but there's definitely a tendency to use different units for quantities that have the same dimensions when those physical quantities are felt to be qualitatively different; even the most rigid adherent of SI would hesitate to use the Joule as a unit of torque, for example.

Orientation is one distinguishing factor. For human beings living in a strong gravitational field, vertical distances are completely different to horizontal distances. I would generally (when in an imperial frame of mind) only use yards and miles for horizontal distances in the context of travel; vertical distances are measured in feet. Yards of Ale and the Mile High Club are interesting examples: the former is probably partly because it's held horizontally and partly to emphasize the extraordinary size of the vessel by deliberately using the "wrong" unit; the Mile High Club is probably another example of the "wrong unit".

Objects, natural or man-made, are generally measured in feet rather than yards, hence the aircraft carrier. I guess a football pitch is conceived more in terms of distances that the players have to travel marked out on the ground, rather than as an artefact or object.

I don't expect to come up with a definitive set of rules - many of these things are probably arbitrary convention - but it isn't completely random either.

One final point is that yards aren't very useful when you want to provide a fractional part: you can say 6ft 4ins, but 2yds 4ins? 2 yds 0 ft 4 ins?
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Re: 1440: Geese

Postby Neil_Boekend » Wed Oct 29, 2014 11:06 am UTC

That is not the reason I would not use Joule for torque. The reason is that torque force and not energy. Torque * rpm is. But then again I am not a rigid adherent of SI. I am more of a "rigid adherent of noting what units were used" so I can convert them to SI if I need to.

And I am a rigid opponent to stupid stuff like having multiple non compatible tube standards with the same name. 1" tube can be had in 3 sizes for cryng out loud. Even DN15 can be had in 2 sizes.
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Re: 1440: Geese

Postby orthogon » Wed Oct 29, 2014 11:22 am UTC

Neil_Boekend wrote:That is not the reason I would not use Joule for torque. The reason is that torque force and not energy. Torque * rpm is. But then again I am not a rigid adherent of SI. I am more of a "rigid adherent of noting what units were used" so I can convert them to SI if I need to.

And I am a rigid opponent to stupid stuff like having multiple non compatible tube standards with the same name. 1" tube can be had in 3 sizes for cryng out loud. Even DN15 can be had in 2 sizes.

Torque (or moment) is force times distance, and so is work (or energy). Torque times angular speed (rpm) has the dimensions of power, not energy. This discussion of the distinction between the Joule and the Newton-Metre is quite interesting. I was about to say that maybe I chose a bad example, but in a way it's exactly analogous to the difference between vertical and horizontal distances; vertical distances are parallel to the force of gravity whereas horizontal distances are at right-angles; similarly in work the force is parallel to the distance whereas for torque it's at right-angles.
xtifr wrote:... and orthogon merely sounds undecided.

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Re: 1440: Geese

Postby Gil-Galad » Wed Oct 29, 2014 12:41 pm UTC

Himself wrote:Yes. That misconception is a bit of a pet peeve. Kinda funny that, given how big the universe is, that people would actually overestimate the distance between things.

They just underestimate the speed of light. Everything in Space is huge, so a couple (hundred) lightyears doesn’t sound much.

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Re: 1440: Geese

Postby Garnasha » Wed Oct 29, 2014 1:05 pm UTC

Himself wrote:Yes. That misconception is a bit of a pet peeve. Kinda funny that, given how big the universe is, that people would actually overestimate the distance between things.
Actually, I have another theory about that. What if their sense of distance isn't off, having quite accurately grasped that the distances involved are huge, but they then ignore the word 'light year"* and go on to underestimate the speed of light since they've been told that it's "very fast, but not as instant as it seems". Light is FAST. Speed of causality is finite but not easily imagined.

And I think photons would disagree with the bit about their travel not being instant: as I understand special relativity (barely, did a unit about it in high school) it would seem to me photons observe the universe as standing still in time and being perfectly flat (with the plane perpendicular to the direction of travel). And infinitely heavy, I think? Or at least those are limit cases, as v approaches c from below, for a function that is ill-defined for v=c.

Ps. And regarding sense of distance being off or not: I must admit my own sense of distance just gives up for stellar distances, unless I start thinking in "light times" as the base unit of distance, at which point all my reference distances effectively become 0, so I still have no sense of how big space really is. Rules of thumb: however vast you think interstellar space is, it's bigger than that, and however fast you think light is, it's faster than that. And those cancel out. And I wonder how they compare to supernovae.

*hey, a front yard a yard long is really tiny, feet a foot long are huge, and taking a thousand (mille) paces will take you half a mile forward. Imperial system users are USED to units, especially of distance, not making the foggiest bit of sense etymologically. The metric system has it better as far as I know: none of their units seem to refer to any object-derived distance/volume/time/force/energy in their etymology at all.

*edit*: dammit, ninja.

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Re: 1440: Geese

Postby rmsgrey » Wed Oct 29, 2014 1:20 pm UTC

Gil-Galad wrote:
Himself wrote:Yes. That misconception is a bit of a pet peeve. Kinda funny that, given how big the universe is, that people would actually overestimate the distance between things.

They just underestimate the speed of light. Everything in Space is huge, so a couple (hundred) lightyears doesn’t sound much.


Yeah, humans have never been more than a few light-seconds from the Earth's center. Voyager 1, the farthest (known) man-made object is still within a light fortnight (assuming my mental arithmetic holds up). That's still less than 1% of the distance to Alpha Centauri.

Light travels so fast that you can treat its speed as infinite when measuring the speed of sound without appreciable error - 1 part in a million. Space is so really, really, really big that even light hasn't had time to get here from the farthest portions of the Big Bang fireball. Even just the distance to the Moon and back is enough to make conversation difficult due to the time lag...

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Re: 1440: Geese

Postby Introbulus » Wed Oct 29, 2014 1:25 pm UTC

Of course, the real reason those geese explode is because they're on a gluten-free diet.

Somebody should've told them that birds aren't supposed to eat rice.*

*That's actually a myth
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Re: 1440: Geese

Postby orthogon » Wed Oct 29, 2014 1:37 pm UTC

See also xkcd1342.
xtifr wrote:... and orthogon merely sounds undecided.

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Re: 1440: Geese

Postby PinkShinyRose » Wed Oct 29, 2014 1:48 pm UTC

Yet 3*10^8 m/s doesn't sound fast at all. When I think big number I tend to think at least in the order of 10^15. Then again 3*10^18 Å/s doesn't sound fast either. What should I be thinking of when thinking of the size of the universe? Does it relate to the size of a planet roughly as a planets size relates to the size of an atomic nucleus (for this I'm assuming the type of atom and planet don't really matter at these scales, if I'm wrong about this take ¹²C and Neptune)?

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Re: 1440: Geese

Postby cellocgw » Wed Oct 29, 2014 2:35 pm UTC

PinkShinyRose wrote:Yet 3*10^8 m/s doesn't sound fast at all. When I think big number I tend to think at least in the order of 10^15. Then again 3*10^18 Å/s doesn't sound fast either. What should I be thinking of when thinking of the size of the universe? Does it relate to the size of a planet roughly as a planets size relates to the size of an atomic nucleus (for this I'm assuming the type of atom and planet don't really matter at these scales, if I'm wrong about this take ¹²C and Neptune)?


It gets worse. I did some calculations for a "top secret, fastest yet military ship" from an Iain Banks novel which could hit 2200*c . At that speed it still takes years to cross a galaxy.

If you examine alleged :oops: Warp Speed values, most of them are pitifully slow in comparison with the distances between galaxies.

At the very least, we're going to need the Binford Warp Drive to get anywhere by dinnertime.
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Re: 1440: Geese

Postby Klear » Wed Oct 29, 2014 2:48 pm UTC

orthogon wrote:See also xkcd1342.


I'm going to pretend this comic happened the day after and that they were watching the sky whole night.

cellocgw wrote:
PinkShinyRose wrote:Yet 3*10^8 m/s doesn't sound fast at all. When I think big number I tend to think at least in the order of 10^15. Then again 3*10^18 Å/s doesn't sound fast either. What should I be thinking of when thinking of the size of the universe? Does it relate to the size of a planet roughly as a planets size relates to the size of an atomic nucleus (for this I'm assuming the type of atom and planet don't really matter at these scales, if I'm wrong about this take ¹²C and Neptune)?


It gets worse. I did some calculations for a "top secret, fastest yet military ship" from an Iain Banks novel which could hit 2200*c . At that speed it still takes years to cross a galaxy.

If you examine alleged :oops: Warp Speed values, most of them are pitifully slow in comparison with the distances between galaxies.

At the very least, we're going to need the Binford Warp Drive to get anywhere by dinnertime.


What I find strange is that if you flew with a constant acceleration 1 g, you'd reach the edge of the observable universe in about 45 years, which is within a human lifetime.

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Re: 1440: Geese

Postby rmsgrey » Wed Oct 29, 2014 2:55 pm UTC

Klear wrote:What I find strange is that if you flew with a constant acceleration 1 g, you'd reach the edge of the observable universe in about 45 years, which is within a human lifetime.


Well, in a non-relativistic universe. In the real world, I've been accelerating (relative to local free-fall) at an average of 1g for more than three decades, and I'm still only ~3m above ground level...

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Re: 1440: Geese

Postby five dollars » Wed Oct 29, 2014 2:56 pm UTC

They're seeing geese that flew overhead centuries ago, and hearing the honking of other geese that, by pure coincidence, flew overhead millions of centuries ago at exactly the right time to make us perceive the first flock of geese's light and the second flock of geese's sound to be synchronized.

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Re: 1440: Geese

Postby Essah » Wed Oct 29, 2014 3:29 pm UTC

red birds are not really red, they just appear red because of the redshift happening when the bird and the earth is moving away from each other relatively.

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Re: 1440: Geese

Postby ctdonath » Wed Oct 29, 2014 3:37 pm UTC

Related observation:

Light is slow enough that in just the time it takes for light from your monitor to reach your eyes, your computer has executed about a dozen instructions.

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Re: 1440: Geese

Postby cellocgw » Wed Oct 29, 2014 3:42 pm UTC

ctdonath wrote:Related observation:

Light is slow enough that in just the time it takes for light from your monitor to reach your eyes, your computer has executed about a dozen instructions.


So move closer to the monitor: problem solved!
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Re: 1440: Geese

Postby Neil_Boekend » Wed Oct 29, 2014 3:47 pm UTC

orthogon wrote:
Neil_Boekend wrote:That is not the reason I would not use Joule for torque. The reason is that torque force and not energy. Torque * rpm is. But then again I am not a rigid adherent of SI. I am more of a "rigid adherent of noting what units were used" so I can convert them to SI if I need to.

And I am a rigid opponent to stupid stuff like having multiple non compatible tube standards with the same name. 1" tube can be had in 3 sizes for cryng out loud. Even DN15 can be had in 2 sizes.

Torque (or moment) is force times distance, and so is work (or energy). Torque times angular speed (rpm) has the dimensions of power, not energy. This discussion of the distinction between the Joule and the Newton-Metre is quite interesting. I was about to say that maybe I chose a bad example, but in a way it's exactly analogous to the difference between vertical and horizontal distances; vertical distances are parallel to the force of gravity whereas horizontal distances are at right-angles; similarly in work the force is parallel to the distance whereas for torque it's at right-angles.

Ok, I stand corrected. Brainfart on my side. It does feel wrong to call torque energy though.
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Re: 1440: Geese

Postby 7lions » Wed Oct 29, 2014 3:48 pm UTC

All that is well and good, but why are the geese flying backwards!?

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Re: 1440: Geese

Postby Garnasha » Wed Oct 29, 2014 4:38 pm UTC

ctdonath wrote:Related observation:

Light is slow enough that in just the time it takes for light from your monitor to reach your eyes, your computer has executed about a dozen instructions.
Similarly, CPU cache needs to be on-chip because even at light speed (or at least light speed through copper), signals wouldn't be able to go back and forth between RAM and CPU at 3GHz (at least, RAM-CPU distances estimated once when I did the original calculation. Not sure what I put it at any more, 10-20cm?).

Of course, in the case of light going monitor -> eyeball (method arguments here), you don't really care about that dozen instructions because the monitor itself only runs at ~60Hz, takes a while to swap pixels from light to dark and vice versa, and neurons are slooooow (both as sensors and as transmitters). Still cool that the likely shortest step in that journey still isn't anywhere near instant.


Other subtopic: anyone here in favour of replacing km/h with nc (nanolights)? So a 120km/h highway becomes 110nc, or our nutjob minister of Infrastructure, who wants to raise the speed limit to 130km/h (like we don't have enough pollution and accidents yet, not to mention driver fatigue), could just get her way by changing 120 km/h to 120nc. And sound would move at roughly 1µc(microlight).

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Re: 1440: Geese

Postby orthogon » Wed Oct 29, 2014 5:28 pm UTC

Neil_Boekend wrote:
orthogon wrote:
Neil_Boekend wrote:That is not the reason I would not use Joule for torque. The reason is that torque force and not energy. Torque * rpm is. But then again I am not a rigid adherent of SI. I am more of a "rigid adherent of noting what units were used" so I can convert them to SI if I need to.

And I am a rigid opponent to stupid stuff like having multiple non compatible tube standards with the same name. 1" tube can be had in 3 sizes for cryng out loud. Even DN15 can be had in 2 sizes.

Torque (or moment) is force times distance, and so is work (or energy). Torque times angular speed (rpm) has the dimensions of power, not energy. This discussion of the distinction between the Joule and the Newton-Metre is quite interesting. I was about to say that maybe I chose a bad example, but in a way it's exactly analogous to the difference between vertical and horizontal distances; vertical distances are parallel to the force of gravity whereas horizontal distances are at right-angles; similarly in work the force is parallel to the distance whereas for torque it's at right-angles.

Ok, I stand corrected. Brainfart on my side. It does feel wrong to call torque energy though.

I agree absolutely. I didn't mean to claim that torque is the same as energy, just that they have the same dimensions. Furthermore they use different units. I'm claiming that distance and height are also different quantities, with the same dimensions, as a reason to use different units for them. The local laws of physics don't have V-H symmetry, after all.
ctdonath wrote:Related observation:

Light is slow enough that in just the time it takes for light from your monitor to reach your eyes, your computer has executed about a dozen instructions.

Yours might. Mine often does absolutely bugger all in the time it takes me to go for a piss and make a coffee.
xtifr wrote:... and orthogon merely sounds undecided.

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Re: 1440: Geese

Postby Klear » Wed Oct 29, 2014 6:26 pm UTC

rmsgrey wrote:
Klear wrote:What I find strange is that if you flew with a constant acceleration 1 g, you'd reach the edge of the observable universe in about 45 years, which is within a human lifetime.


Well, in a non-relativistic universe. In the real world, I've been accelerating (relative to local free-fall) at an average of 1g for more than three decades, and I'm still only ~3m above ground level...


That argument is for the birds. I did write "fly".

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Re: 1440: Geese

Postby Boson Collider » Wed Oct 29, 2014 6:40 pm UTC

rmsgrey wrote:
Klear wrote:What I find strange is that if you flew with a constant acceleration 1 g, you'd reach the edge of the observable universe in about 45 years, which is within a human lifetime.


Well, in a non-relativistic universe. In the real world, I've been accelerating (relative to local free-fall) at an average of 1g for more than three decades, and I'm still only ~3m above ground level...


Ignoring gravity, traveling large distances by accelerating at a constant rate in your reference frame is always faster with special relativity than without(from your perspective). This is because in your reference frame and at high speeds, time dilation increases as an exponential function of the rapidity, so the distance you travel increases as an exponential function(hyperbolic cosine) of the time you've spent accelerating. In the newtonian case, you have s = at^2/2 so the distance only increases quadratically with time spent accelerating.

So relativity makes it strictly easier to travel large distances without a lifetime. It just makes the trip take a long time for everyone else.

The 1g gravity example you mentioned is kind of interesting, and actually illustrates how the geometry of a black hole works. The horizon would be an infinitely long radial distance below you, so if you lived on a 1g shellworld around a black hole and dropped your watch into the black hole, it would fall down a roughly corresponding distance radially. But time is equally compressed, so the clock would get forzen in time and never show an hour beyond a certain point. From it's point of view, it would reach the horizon in a finite amount of time. From the point of view of someone standing on the shell, it would on the other hand never reach the horizon in a finite of time since the horizon is infinitely far down.

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Re: 1440: Geese

Postby Tofe » Wed Oct 29, 2014 8:03 pm UTC

I wonder: how much should a geese be stuffed so that it becomes a black hole when it reaches its end-of-life ?

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Re: 1440: Geese

Postby NMcCoy » Wed Oct 29, 2014 8:18 pm UTC

7lions wrote:All that is well and good, but why are the geese flying backwards!?

They're not, it's just that the earth is rotating beneath them, like how the moon rises in the east even though it actually orbits in an eastward direction.
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Re: 1440: Geese

Postby Himself » Wed Oct 29, 2014 8:32 pm UTC

Garnasha wrote:
Himself wrote:Yes. That misconception is a bit of a pet peeve. Kinda funny that, given how big the universe is, that people would actually overestimate the distance between things.
Actually, I have another theory about that. What if their sense of distance isn't off, having quite accurately grasped that the distances involved are huge, but they then ignore the word 'light year"* and go on to underestimate the speed of light since they've been told that it's "very fast, but not as instant as it seems". Light is FAST. Speed of causality is finite but not easily imagined.

And I think photons would disagree with the bit about their travel not being instant: as I understand special relativity (barely, did a unit about it in high school) it would seem to me photons observe the universe as standing still in time and being perfectly flat (with the plane perpendicular to the direction of travel). And infinitely heavy, I think? Or at least those are limit cases, as v approaches c from below, for a function that is ill-defined for v=c.

Ps. And regarding sense of distance being off or not: I must admit my own sense of distance just gives up for stellar distances, unless I start thinking in "light times" as the base unit of distance, at which point all my reference distances effectively become 0, so I still have no sense of how big space really is. Rules of thumb: however vast you think interstellar space is, it's bigger than that, and however fast you think light is, it's faster than that. And those cancel out. And I wonder how they compare to supernovae.

*hey, a front yard a yard long is really tiny, feet a foot long are huge, and taking a thousand (mille) paces will take you half a mile forward. Imperial system users are USED to units, especially of distance, not making the foggiest bit of sense etymologically. The metric system has it better as far as I know: none of their units seem to refer to any object-derived distance/volume/time/force/energy in their etymology at all.

*edit*: dammit, ninja.
Gil-Galad wrote:
Himself wrote:Yes. That misconception is a bit of a pet peeve. Kinda funny that, given how big the universe is, that people would actually overestimate the distance between things.

They just underestimate the speed of light. Everything in Space is huge, so a couple (hundred) lightyears doesn’t sound much.


Perhaps it is the speed of light they underestimate. Either way, I'd be interesting to see how many people think that the stars we see are millions of light years away, or that Mars is light years away.

I stumbled across this image a while back.
Image
I found it interesting that everyone seemed to comment on how a light year is a unit of distance, not time, and did not seem to notice the few orders of magnitude of error.
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Re: 1440: Geese

Postby Flumble » Wed Oct 29, 2014 9:14 pm UTC

Jumping to that topic again: are the objects, that are visible to the naked eye in the night sky, only stars (within a few hundred lightyears) or are there also vast galaxies (millions of lightyears away, like the image above reads, but not actually a star) that show up as a bright dot?

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Re: 1440: Geese

Postby ahammel » Wed Oct 29, 2014 9:18 pm UTC

Technically they're only called "geese" when they're on the ground. When they're flying they're called "jetsam".
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Re: 1440: Geese

Postby Himself » Wed Oct 29, 2014 9:24 pm UTC

Flumble wrote:Jumping to that topic again: are the objects, that are visible to the naked eye in the night sky, only stars (within a few hundred lightyears) or are there also vast galaxies (millions of lightyears away, like the image above reads, but not actually a star) that show up as a bright dot?

Galaxies look smudge-like. From what I understand astronomers referred to them as clouds before they figured out what they were. A supernova in a relatively close galaxy such as Andromeda might be visible as a point of light, but not for very long.
Astronomy people correct me if I am wrong.
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Re: 1440: Geese

Postby 7lions » Wed Oct 29, 2014 10:54 pm UTC

NMcCoy wrote:
7lions wrote:All that is well and good, but why are the geese flying backwards!?

They're not, it's just that the earth is rotating beneath them, like how the moon rises in the east even though it actually orbits in an eastward direction.

Even if we allow for arbitrary camera motion, that is clearly a goose butt at the point of the V, where I'd expect to see a goose head.


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