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(io9)   What would happen if the sun vanished?   (io9.com) divider line 116
    More: Cool, reflected light  
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6448 clicks; posted to Geek » on 01 Apr 2013 at 4:22 AM (1 year ago)   |  Favorite    |   share:  Share on Twitter share via Email Share on Facebook   more»



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2013-03-31 11:43:36 PM
It'd be dark and stuff.
 
2013-03-31 11:47:19 PM
Black Hole Sun.
 
2013-03-31 11:56:09 PM
We'd all be dead in hours or days. Those idiot preppers would be first.
 
2013-04-01 12:07:30 AM
The Sun isn't there.
 
2013-04-01 12:11:33 AM
Rupert Murdock would cry.
 
2013-04-01 12:12:59 AM
Goddam, that guy's annoying. Couldn't stand it past 2 minutes.
 
2013-04-01 12:21:25 AM
Like an old oak table?

Oh, vanished.
 
2013-04-01 12:49:24 AM

Generation_D: We'd all be dead in hours or days. Those idiot preppers would be first.


Not people who stockpiled fuel, water and a generator.
 
Actually, people in cities would be first once the electricity shut off.  They wouldn't even have transportation to leave.  Suburbs would be a close second because water and food wouldn't be available.  Anyone with self-sufficient power and water who was well isolated from the rest of the world (rural) would last until the food ran out, which would be shortly thereafter.
 
Winners?  Anyone in Afghanistan or the mountains near Pakistan, at least short term.
 
2013-04-01 01:15:18 AM

Lsherm:  Anyone with self-sufficient power and water who was well isolated from the rest of the world (rural) would last until the food ran out,

 
I would bet the food would still be there once Earth's surface reached ambient background temperature of 0.^A Kelvin. Only ones likely to survive much beyond a few days would be those in nuclear subs.
 
2013-04-01 01:15:37 AM

Godscrack: Black Hole Sun.


No, there's a difference. We would still happily orbit a black hole.
 
2013-04-01 01:24:13 AM
We'd be hoping there wasn't a mine shaft gap.
 
2013-04-01 01:34:16 AM

Speaker2Animals: Lsherm:  Anyone with self-sufficient power and water who was well isolated from the rest of the world (rural) would last until the food ran out,
 
I would bet the food would still be there once Earth's surface reached ambient background temperature of 0.^A Kelvin. Only ones likely to survive much beyond a few days would be those in nuclear subs.


Thank you.  The longer he went on, the more stabby I was getting about ambient temperature.
 
2013-04-01 01:40:11 AM

Benevolent Misanthrope: Speaker2Animals: Lsherm:  Anyone with self-sufficient power and water who was well isolated from the rest of the world (rural) would last until the food ran out,
 
I would bet the food would still be there once Earth's surface reached ambient background temperature of 0.^A Kelvin. Only ones likely to survive much beyond a few days would be those in nuclear subs.

Thank you.  The longer he went on, the more stabby I was getting about ambient temperature.


Geothermal might be able to provide enough heat for survival if you're lucky enough to be near a source (deep mine, volcano, etc.), but starvation would follow unless by some miracle underground farms of some kind were successfully cultivated (obviously using lifeforms not dependent on the sun).
 
2013-04-01 01:51:14 AM
I'd have to switch to the Daily Fail as my primary source for English celebrity news?
 
2013-04-01 01:57:07 AM

Sid_6.7: Benevolent Misanthrope: Speaker2Animals: Lsherm:  Anyone with self-sufficient power and water who was well isolated from the rest of the world (rural) would last until the food ran out,
 
I would bet the food would still be there once Earth's surface reached ambient background temperature of 0.^A Kelvin. Only ones likely to survive much beyond a few days would be those in nuclear subs.

Thank you.  The longer he went on, the more stabby I was getting about ambient temperature.

Geothermal might be able to provide enough heat for survival if you're lucky enough to be near a source (deep mine, volcano, etc.), but starvation would follow unless by some miracle underground farms of some kind were successfully cultivated (obviously using lifeforms not dependent on the sun).


How long would it take for the earth to cool to a temperature that would not support life, though?
 
2013-04-01 02:06:10 AM

Benevolent Misanthrope: How long would it take for the earth to cool to a temperature that would not support life, though?


Billions of years? Probably at least millions. I believe the tidal action of the sun helps keep the middle churning, but it should still take a very long time to cool off. We're talking about the thermal inertia of the entire earth. And at least some of the heat is from radioactive decay, which would not be affected by the presence of the sun.
 
The simple lifeforms living around the black smokers in the abysses of the oceans should be fine for a very long time.
 
2013-04-01 03:09:06 AM

Benevolent Misanthrope: How long would it take for the earth to cool to a temperature that would not support life, though?


Macrobiotic life? Not as long as you'd think. Microbes? I don't think some microbes can be killed by cold.
 
2013-04-01 04:46:34 AM
Clearly, it's April Fool's day because that article is a joke. Here is the video.
 
2013-04-01 04:51:29 AM
The exploding Tardis would keep us warm for a couple thousand years without the sun.
 
2013-04-01 05:15:46 AM

BarkingUnicorn: Goddam, that guy's annoying. Couldn't stand it past 2 minutes.


THIS.
I was half-expecting him to start pulling out puppets.
 
2013-04-01 05:24:05 AM

Benevolent Misanthrope: How long would it take for the earth to cool to a temperature that would not support life, though?

 
Billions of years. The interior of the earth is not warmed by the sun.
 
2013-04-01 05:29:04 AM

Sid_6.7: Benevolent Misanthrope: How long would it take for the earth to cool to a temperature that would not support life, though?

Billions of years? Probably at least millions. I believe the tidal action of the sun helps keep the middle churning

 
You're thinking Io or Enceladus. The moon exerts more tidal friction on the earth than the sun does. Most of heat in the interior comes from radioactive decay. The rest of it comes from leftover heat from the formation of the earth.
 
2013-04-01 05:40:18 AM

Ed Grubermann: Benevolent Misanthrope: How long would it take for the earth to cool to a temperature that would not support life, though?
 
Billions of years. The interior of the earth is not warmed by the sun.


and the exterior of the earth is not warmed by the interior. 
 
Sure some hot spots would still exist, but the a huge majority of the earths surface would be unlivable in a much shorter amount of time than that. I'm guessing more like days or weeks.
 
2013-04-01 05:57:59 AM
We wouldn't have to worry about daylight saving time?
 
2013-04-01 06:19:05 AM
Ants living near an elementary schools would no longer be terrorized by blinding beams of hot death?
 
2013-04-01 06:35:25 AM
 
2013-04-01 06:37:05 AM
THIS IS WHY WE NEED GLOBAL WARMING
 
2013-04-01 06:58:18 AM
 

Dancis_Frake: BarkingUnicorn: Goddam, that guy's annoying. Couldn't stand it past 2 minutes.

THIS.
I was half-expecting him to start pulling out puppets.

 
I barely made it to 20 seconds. Which is a pity because I kinda wanted to hear about all the dying.
 
2013-04-01 07:03:28 AM

Lsherm: Actually, people in cities would be first once the electricity shut off. They wouldn't even have transportation to leave.


Um, most transportation runs on fossil fuels.  You're thinking zombocalypse.  Most people will be fending off an increasing cold unless the food runs out first.  The result is likely to be mass pandemonium, but if someone could gather plant lights, crops, enough fuel and a generator and set up a hydroponic farm deep underground, one could subsist on fossil fuels for a while.  But such a hopeless existence is likely to result in suicide.  Otherwise, in this case humans will potentially be among the last species to go because of their dependence on fossil fuels.  If we don't annihilate ourselves with derp, probably only the critters around the aforementioned black smokers would beat us, as well as underground bacteria.
 
2013-04-01 07:12:14 AM

log_jammin: Ed Grubermann: Benevolent Misanthrope: How long would it take for the earth to cool to a temperature that would not support life, though?
 
Billions of years. The interior of the earth is not warmed by the sun.

and the exterior of the earth is not warmed by the interior. 
 
Sure some hot spots would still exist, but the a huge majority of the earths surface would be unlivable in a much shorter amount of time than that. I'm guessing more like days or weeks.


I'm thinking temps globally would take a sharp and sudden drop for the first few hours/days until we got to something relative and then it would be a slow steady decline.
 
2013-04-01 07:43:04 AM
Superman would be a giant pussy?
 
2013-04-01 07:54:24 AM

Benevolent Misanthrope: Sid_6.7: Benevolent Misanthrope: Speaker2Animals: Lsherm:  Anyone with self-sufficient power and water who was well isolated from the rest of the world (rural) would last until the food ran out,
 
I would bet the food would still be there once Earth's surface reached ambient background temperature of 0.^A Kelvin. Only ones likely to survive much beyond a few days would be those in nuclear subs.

Thank you.  The longer he went on, the more stabby I was getting about ambient temperature.

Geothermal might be able to provide enough heat for survival if you're lucky enough to be near a source (deep mine, volcano, etc.), but starvation would follow unless by some miracle underground farms of some kind were successfully cultivated (obviously using lifeforms not dependent on the sun).

How long would it take for the earth to cool to a temperature that would not support life, though?


The cooling temperatures are only part of the problem.  Most life on earth depends on the sun for energy, either directly or indirectly, and that's not 'heat' energy.  Plant life would perish, and there goes our primary producers of food and oxygen.  I don't think human production with sunlamps would adequately offset that loss.
 
2013-04-01 08:56:35 AM
media.comicvine.com
 
I thought this was pretty thoroughly covered in a research paper a few years ago...
 
2013-04-01 09:14:20 AM
I would LOVE it if the Sun vanished.  What a crap assed tabloid.
 
2013-04-01 09:19:54 AM
vanished or blocked out?
 
1.bp.blogspot.com
 
2013-04-01 09:26:13 AM
Depends on if conservation of mass/energy is observed during this "disappearance" event.
 
2013-04-01 09:38:08 AM
came for Sunshine references....
 
2013-04-01 09:42:13 AM
Fark would lose a running joke. Duke would still suck though.
 
2013-04-01 09:47:22 AM
 
2013-04-01 09:50:54 AM
Then we'd switch to The Daily Mail. Duh.
 
2013-04-01 09:51:16 AM
It would be weird that the night would then be brighter than the "day" thanks to the Moon.
 
2013-04-01 09:54:43 AM
 
2013-04-01 09:56:23 AM

dragonchild: Lsherm: Actually, people in cities would be first once the electricity shut off. They wouldn't even have transportation to leave.

 
Um, most transportation runs on fossil fuels.  You're thinking zombocalypse.  Most people will be fending off an increasing cold unless the food runs out first.  The result is likely to be mass pandemonium, but if someone could gather plant lights, crops, enough fuel and a generator and set up a hydroponic farm deep underground, one could subsist on fossil fuels for a while.  But such a hopeless existence is likely to result in suicide.  Otherwise, in this case humans will potentially be among the last species to go because of their dependence on fossil fuels.  If we don't annihilate ourselves with derp, probably only the critters around the aforementioned black smokers would beat us, as well as underground bacteria.
 
The zombocalypse would be great. You could do anything, the only limit would be your self.
 
2013-04-01 09:56:43 AM

Lord Dimwit: It would be weird that the night would then be brighter than the "day" thanks to the Moon.


Except that night and day is not defined by the moon, but technically by the amount of light in the sky.
So moonrise would become the beginning of "night" and moonset would be the beginning of "day."
 
lol
 
2013-04-01 10:01:15 AM

dragonchild: Most people will be fending off an increasing cold unless the food runs out first.


hmmmm
how long would it take to cool?
A huge amount of heat is generated from within the planet itself. As long as there is enough heat to keep the atmosphere vapor ... probably isnt.
 

dragonchild: Otherwise, in this case humans will potentially be among the last species to go because of their dependence on fossil fuels.


please.
all of the life which lives outside of the reach of the sun would still continue unabated. ocean thermal vents ecologies are oblivious to the rest of the solar-driven ecosystem.
 
plus in theory, we would have plenty of time ...
nah you are right, the mass panic would kill all the humans pretty quickly
 
2013-04-01 10:08:36 AM

Lord Dimwit: It would be weird that the night would then be brighter than the "day" thanks to the Moon.


*chomp*

Since the moon reflects the sun, if the sun vanishes, the moon will also cease to shine.
 
2013-04-01 10:11:02 AM

qorkfiend: Lord Dimwit: It would be weird that the night would then be brighter than the "day" thanks to the Moon.

*chomp*

Since the moon reflects the sun, if the sun vanishes, the moon will also cease to shine.


what was being referred to was that the moon would effectively block "some" starlight. causing it to be brighter when the moonset rather than the current brighter at night with the moon in the sky....
 
2013-04-01 10:16:57 AM

namatad: qorkfiend: Lord Dimwit: It would be weird that the night would then be brighter than the "day" thanks to the Moon.

*chomp*

Since the moon reflects the sun, if the sun vanishes, the moon will also cease to shine.

what was being referred to was that the moon would effectively block "some" starlight. causing it to be brighter when the moonset rather than the current brighter at night with the moon in the sky....


I don't think so.

In any case, the moon would not block an appreciable amount of starlight, certainly not enough to draw a day vs. night distinction.
 
2013-04-01 10:20:48 AM
So, life on Earth would survive for billions of years because of the geothermal vents at the bottom of the oceans and the heat from the Earth's core. If the sun disappeared without warning humanity would die out although people living in nuclear subs and in the ISS might be able to hold out for a little while. However, if we had advanced warning manufacturing facilities could be moved to areas with easy access to geothermal energy (e.g. Iceland, Yellowstone) and humanity could survive underground indefinitely.
 
2013-04-01 10:23:04 AM
It seems to me that there would be about a 50/50 chance that our Moon would end up crashing into Earth at some point if the Earth was gravitationally let go from its orbit around the Sun. If the Moon was behind the Earth, then it seems like it would fly off on its own. If the Moon was ahead of the Earth when the Earth went off tangentially, then it seems like the Moon would end up running into the Earth.
 
2013-04-01 10:29:08 AM

Befuddled: It seems to me that there would be about a 50/50 chance that our Moon would end up crashing into Earth at some point if the Earth was gravitationally let go from its orbit around the Sun. If the Moon was behind the Earth, then it seems like it would fly off on its own. If the Moon was ahead of the Earth when the Earth went off tangentially, then it seems like the Moon would end up running into the Earth.


The Sun's gravity doesn't do much to prevent the Moon from crashing into the Earth as it stands, so I don't think the sudden absence of the Sun would have an effect there.
 
2013-04-01 10:33:16 AM

Lord Dimwit: It would be weird that the night would then be brighter than the "day" thanks to the Moon.


Uhhh, you're missing the fact that moonlight is reflected sunshine, yo. It'll ALL be dark, son!
 
2013-04-01 10:33:55 AM

Jurodan: Fark would lose a running joke. Duke would still suck though.

 
DUKE ROCKS !!!
 
 
danielclavery.com
 
2013-04-01 10:55:42 AM
The funny thing is, if this were to happen, life on Earth would persist longer than it's actually going to. We have little more than a billion years before the Sun heats to the point that life is no longer possible, but if the Earth became a freerange planet life could continue on the ocean floor almost indefinitely.
Also, has anyone else read The Night Land, by William Hope Hodgson? It had a similar sort of plot, with the Sun dead and all humanity living in a single enormous pyramid.
 
2013-04-01 11:00:37 AM
Besides the fact that most of the plant life would die and the atmosphere would probably change to one not suited to life as we know it, you don't think that the planet souring off into outer space as a rogue planet wouldn't pretty much cause it's temperatures to freeze, including the oceans?
 
Even with the sun in place, the planet has had ice ages where the northern and southern pole froze up and glaciers creeped towards the equator.
 
So why wouldn't the entire planet freeze into one big ice cube as we whip out into space with no outside energy sources to help regulate it?
 
2013-04-01 11:07:35 AM

PC LOAD LETTER: Godscrack: Black Hole Sun.

No, there's a difference. We would still happily orbit a black hole.


Wrong. 
 
Everybody knows the black hole sun comes out and washes away the rain.
 
2013-04-01 12:06:42 PM

qorkfiend: namatad: qorkfiend: Lord Dimwit: It would be weird that the night would then be brighter than the "day" thanks to the Moon.

*chomp*

Since the moon reflects the sun, if the sun vanishes, the moon will also cease to shine.

what was being referred to was that the moon would effectively block "some" starlight. causing it to be brighter when the moonset rather than the current brighter at night with the moon in the sky....

I don't think so.

In any case, the moon would not block an appreciable amount of starlight, certainly not enough to draw a day vs. night distinction.


what part of "SOME" was confusing?
and yes it is a tiny part
On average, the Moon covers an area of0.21078 square degrees on the night sky.
or 1 x10-5 of the sky (assuming a full sky was visible, which it isnt, but we are talking orders of magnitude)
 
2013-04-01 12:07:24 PM

KellyX: Besides the fact that most of the plant life would die and the atmosphere would probably change to one not suited to life as we know it, you don't think that the planet souring off into outer space as a rogue planet wouldn't pretty much cause it's temperatures to freeze, including the oceans?
 
Even with the sun in place, the planet has had ice ages where the northern and southern pole froze up and glaciers creeped towards the equator.
 
So why wouldn't the entire planet freeze into one big ice cube as we whip out into space with no outside energy sources to help regulate it?


It would do just that, on the surface.  Underground it would be possible for humankind to survive.  It's heat comes from the earth, but you'd need power to help plantlife thrive for co2 conversion and food.

Whether we're set up for that is another story.  Surely there are some government bunkers set up for just such a thing, but they'll die out within decades due to small overlooked things or faults in design.

For humans to survive perpetually, you'd need some setup which was constructed and utilized before hand so that all the kinks were ironed out.  Would need to account for inbreeding as well I'm sure.

And that's all IF we don't get smashed into by another planet or something shortly after the sun lost it's gravitational influence.
 
2013-04-01 12:16:33 PM

omeganuepsilon: KellyX: Besides the fact that most of the plant life would die and the atmosphere would probably change to one not suited to life as we know it, you don't think that the planet souring off into outer space as a rogue planet wouldn't pretty much cause it's temperatures to freeze, including the oceans?
 
Even with the sun in place, the planet has had ice ages where the northern and southern pole froze up and glaciers creeped towards the equator.
 
So why wouldn't the entire planet freeze into one big ice cube as we whip out into space with no outside energy sources to help regulate it?

It would do just that, on the surface.  Underground it would be possible for humankind to survive.  It's heat comes from the earth, but you'd need power to help plantlife thrive for co2 conversion and food.

Whether we're set up for that is another story.  Surely there are some government bunkers set up for just such a thing, but they'll die out within decades due to small overlooked things or faults in design.

For humans to survive perpetually, you'd need some setup which was constructed and utilized before hand so that all the kinks were ironed out.  Would need to account for inbreeding as well I'm sure.

And that's all IF we don't get smashed into by another planet or something shortly after the sun lost it's gravitational influence.


I actually only just watched the video and saw he covered a lot of what I mentioned, and yea, short of humans having something planned, I don't think we could build anything in time that would solve our issues, we'd be pretty farked.
 
2013-04-01 12:24:52 PM

KellyX: So why wouldn't the entire planet freeze into one big ice cube as we whip out into space with no outside energy sources to help regulate it?


so at some point, it would get cold enough that ice would form, covering the oceans from pole to pole. one giant snowball. (Before the oceans freeze over, the "warm" ocean would keep the atmosphere from freezing.)

Once that happened, it would be easier for the atmosphere to freeze out and fall in layers.
First water, then co2, then methane, etc ... (dont get me started about the freezing point changing as the air pressure changed.)

H2O 273k
CO2 195k
CH4 90k
Ar 84kN2 77k
O2 50k

BUT, going down in the ocean and land is a different story. The frozen layers would act as insulation and prevent the ocean from freezing all the way down. But that is only part of the story. The reason that it could not freeze solid is thorium (and to a lesser degree uranium). The earth's core is hot and the decay of thorium will keep the core and crust from freezing solid, at least until all of the thorium has decayed.

Until that happens there will be an equilibrium. Certain thickness of ice, certain amount of liquid water.

/A slightly different process keeps the liquid (they are pretty certain that it is water) on Europa from freezing solid under the ice. The tidal forces from Jupiter produce a ton of heat.
/Strangely enough, the tidal forces of the Moon do the same thing on earth.
 
2013-04-01 12:27:55 PM
I already subscribe to Vsauce, thanks though.
 
2013-04-01 12:31:35 PM
I have yet to watch it, but I love v-sauce.  Yeah he's a big dork, even annoying at times, but he grows on ya.

He's also wrong on occasion but a lot of that is oversight because his videos are pumped out so fast he just takes idea's and runs with them. I would like to see him come out with re-visits of some of his more questionable work, but i get the impression once he posts it he promptly forgets about it altogether.

I think some of the hate comes from people who can't keep with his typical pacing.  He's a good ADD generation teacher, but loses some slow and steady types as well as people who are judgmental of personality.

Between him and ViHart, a person can fill quite a lot of time, I'd say waste, but if it's stimulating the mind it's never really a waste.

/laid up with a broken foot
//have lots of time to fill
 
2013-04-01 12:35:28 PM
Back of the envelope, the temperature drops 5 °C overnight.  So with no sun, that's 10 °C every 24 hours.

The average temperature of the Earth is 15 °C.  After 36 hours, the average drops below the freezing point of water.  After one week, carbon dioxide snow starts falling.  At about three weeks, oxygen starts to rain out of the atmosphere.


Answer: It gets cold.
 
2013-04-01 12:39:26 PM

omeganuepsilon: And that's all IF we don't get smashed into by another planet or something shortly after the sun lost it's gravitational influence.


I thought about this for about 10 seconds. We would smash into other things as we overtook them rather than the other way around. There are vastly more objects, orbiting slower than the earth, further out from us, than there are inward moving faster than us.

Somewhere out beyond where the current asteroid belt is, we would have to start worrying about running into slower moving asteroids. (think a whirlpool, as we whipped out from the middle, we would run into the slow moving bits)

The only risk to stuff hit us would mercury, venus and the small number of asteroids between us and the sun.

/yes, I know, it would be possible for some of the asteroids to hit us, but it is a much smaller number than the amount of stuff which we would be over taking.
 
2013-04-01 12:43:52 PM

idsfa: Back of the envelope, the temperature drops 5 °C overnight.  So with no sun, that's 10 °C every 24 hours.

The average temperature of the Earth is 15 °C.  After 36 hours, the average drops below the freezing point of water.  After one week, carbon dioxide snow starts falling.  At about three weeks, oxygen starts to rain out of the atmosphere.


Answer: It gets cold.


left out the ocean
until the ocean freezes over, TONS of heat get dumped into the atmosphere.
http://www.last-word.com/content_handling/show_tree/tree_id/1517.htm l
They say about 45 days, ... not much longer than your first guess 21 days. So not too bad.
 
2013-04-01 01:10:54 PM
So, TFA implies that the effects of gravity travel at the speed of light. Do we have any evidence of that?
 
2013-04-01 01:14:39 PM

AdrienVeidt: Lord Dimwit: It would be weird that the night would then be brighter than the "day" thanks to the Moon.

Uhhh, you're missing the fact that moonlight is reflected sunshine, yo. It'll ALL be dark, son!


I think you need to adjust your sarcasm detector.

Or I need to adjust my sarcasm emitter.

Either way, something needs to be adjusted.
 
2013-04-01 01:42:44 PM

TopoGigo: So, TFA implies that the effects of gravity travel at the speed of light. Do we have any evidence of that?


yes
 
2013-04-01 01:45:07 PM

namatad: TopoGigo: So, TFA implies that the effects of gravity travel at the speed of light. Do we have any evidence of that?

yes


http://en.wikipedia.org/wiki/Speed_of_gravity
so really yes, by definition, with little evidence of that not being true
 
2013-04-01 01:48:20 PM
Wait, does gravity have a speed?
 
2013-04-01 02:00:10 PM

namatad: namatad: TopoGigo: So, TFA implies that the effects of gravity travel at the speed of light. Do we have any evidence of that?

yes

http://en.wikipedia.org/wiki/Speed_of_gravity
so really yes, by definition, with little evidence of that not being true


This seems to specifically deal with the speed of gravitational waves. Now, I don't have the physics chops to say for certain, but that doesn't seem like it's exactly equivalent to the speed at which the earth would "notice" the absence of the sun's gravity.
 
2013-04-01 02:15:49 PM
I've got a pretty sweet North Face jacket, so I figure I'm good
 
2013-04-01 02:24:29 PM

TopoGigo: namatad: namatad: TopoGigo: So, TFA implies that the effects of gravity travel at the speed of light. Do we have any evidence of that?

yes

http://en.wikipedia.org/wiki/Speed_of_gravity
so really yes, by definition, with little evidence of that not being true

This seems to specifically deal with the speed of gravitational waves. Now, I don't have the physics chops to say for certain, but that doesn't seem like it's exactly equivalent to the speed at which the earth would "notice" the absence of the sun's gravity.


Hovering slinky phenomenon.
 
2013-04-01 03:28:32 PM

TopoGigo: namatad: namatad: TopoGigo: So, TFA implies that the effects of gravity travel at the speed of light. Do we have any evidence of that?

yes

http://en.wikipedia.org/wiki/Speed_of_gravity
so really yes, by definition, with little evidence of that not being true

This seems to specifically deal with the speed of gravitational waves. Now, I don't have the physics chops to say for certain, but that doesn't seem like it's exactly equivalent to the speed at which the earth would "notice" the absence of the sun's gravity.


LOL

this is where the magic of the thought experiment gets "silly"
how do you make the sun disappear?
If it doesnt magically disappear, and just moved instead, well the earth would just follow.

so fine MAGIC! POOF it is goon. in less than planck time (really really fast). GONE.
nothing in the physical world travels faster than light (currently accepted theory).
Therefore it would take c*d for you to notice the disappearance of a mass. about 8 mins for the sun going missing.

another way to "look" at it is, the SUN is pulling on the earth. ti would take us 8 mins for the pull to go away once the sun disappeared. another way is that the earth would continue traveling in its circular orbit for 8 mins and then shoot off on a tangent once it "noticed" that the sun was gone.
 
2013-04-01 03:30:47 PM

narocroc: Hovering slinky phenomenon.


center of mass is funny. or is it?
/yes I know it looks wrong because the spring is also contracting while falling. lol
 
2013-04-01 03:46:15 PM

narocroc: TopoGigo: namatad: namatad: TopoGigo: So, TFA implies that the effects of gravity travel at the speed of light. Do we have any evidence of that?

yes

http://en.wikipedia.org/wiki/Speed_of_gravity
so really yes, by definition, with little evidence of that not being true

This seems to specifically deal with the speed of gravitational waves. Now, I don't have the physics chops to say for certain, but that doesn't seem like it's exactly equivalent to the speed at which the earth would "notice" the absence of the sun's gravity.

Hovering slinky phenomenon.


That has nothing to do with the speed of gravity and is rather because of the propagation of forces within a material.
 
2013-04-01 03:48:47 PM

namatad: TopoGigo: namatad: namatad: TopoGigo: So, TFA implies that the effects of gravity travel at the speed of light. Do we have any evidence of that?

yes

http://en.wikipedia.org/wiki/Speed_of_gravity
so really yes, by definition, with little evidence of that not being true

This seems to specifically deal with the speed of gravitational waves. Now, I don't have the physics chops to say for certain, but that doesn't seem like it's exactly equivalent to the speed at which the earth would "notice" the absence of the sun's gravity.

LOL

this is where the magic of the thought experiment gets "silly"
how do you make the sun disappear?
If it doesnt magically disappear, and just moved instead, well the earth would just follow.

so fine MAGIC! POOF it is goon. in less than planck time (really really fast). GONE.
nothing in the physical world travels faster than light (currently accepted theory).
Therefore it would take c*d for you to notice the disappearance of a mass. about 8 mins for the sun going missing.

another way to "look" at it is, the SUN is pulling on the earth. ti would take us 8 mins for the pull to go away once the sun disappeared. another way is that the earth would continue traveling in its circular orbit for 8 mins and then shoot off on a tangent once it "noticed" that the sun was gone.


Did we discover the graviton while I wasn't looking? We don't know what, if anything, transmits gravitational attraction. We don't have any solid theory on how the Higgs boson actually relates to attraction AFAIK. We don't know if a theoretical graviton, or another undiscovered particle or force, moves at c, slower than c, or (massively unlikely if not impossible) faster than c. If we take the high school physics of relativity literally, would the sudden magical absence of the sun cause the "dent" in the "rubber sheet" to bounce back, pushing us violently away from where the sun was? If so, then the speed of a gravitational wave would seem to apply, but the earth wouldn't just move off in a tangent due to the absence of the sun; it would be flung away at alarming speeds. I'm just saying that for someone to state authoritatively that we would feel the sudden, magical absence of the sun 9 seconds later is stupid. I don't even know how one could test such a thing before we find, and can measure, a graviton or a similar particle or force.
 
2013-04-01 04:09:22 PM

TopoGigo: namatad: TopoGigo: namatad: namatad: TopoGigo: So, TFA implies that the effects of gravity travel at the speed of light. Do we have any evidence of that?

yes

http://en.wikipedia.org/wiki/Speed_of_gravity
so really yes, by definition, with little evidence of that not being true

This seems to specifically deal with the speed of gravitational waves. Now, I don't have the physics chops to say for certain, but that doesn't seem like it's exactly equivalent to the speed at which the earth would "notice" the absence of the sun's gravity.

LOL

this is where the magic of the thought experiment gets "silly"
how do you make the sun disappear?
If it doesnt magically disappear, and just moved instead, well the earth would just follow.

so fine MAGIC! POOF it is goon. in less than planck time (really really fast). GONE.
nothing in the physical world travels faster than light (currently accepted theory).
Therefore it would take c*d for you to notice the disappearance of a mass. about 8 mins for the sun going missing.

another way to "look" at it is, the SUN is pulling on the earth. ti would take us 8 mins for the pull to go away once the sun disappeared. another way is that the earth would continue traveling in its circular orbit for 8 mins and then shoot off on a tangent once it "noticed" that the sun was gone.

Did we discover the graviton while I wasn't looking? We don't know what, if anything, transmits gravitational attraction. We don't have any solid theory on how the Higgs boson actually relates to attraction AFAIK. We don't know if a theoretical graviton, or another undiscovered particle or force, moves at c, slower than c, or (massively unlikely if not impossible) faster than c. If we take the high school physics of relativity literally, would the sudden magical absence of the sun cause the "dent" in the "rubber sheet" to bounce back, pushing us violently away from where the sun was? If so, then the speed of a gravitational wave would seem to apply, but the earth woul ...


All the experimental evidence to date indicates that the speed of gravity is the same as the speed of light.
 
2013-04-01 04:18:51 PM

omeganuepsilon: And that's all IF we don't get smashed into by another planet or something shortly after the sun lost it's gravitational influence.


Totally THIS. That was my only problem with the video. He entirely neglected the fact that as we zip off into the unknown we could crash into all sorts of stuff before the possibility of getting pulled into another orbit happened. Other than that it was an entirely fascinating video, and I don't understand people's annoyance. Although he did remind me an awful lot of The Dean from Community.

Humans would find a way to survive. We survived an Ice Age before the advent of technology. Granted this would be an extreme ice age, but isn't like life hasn't survived without the sun before. We could find ways to create artifical light so keep plants going for a short time. He even states that large trees could survive a very long time; so long, in fact, that they'd freeze to death before starving to death. Also says that the vast majority of us wouldn't make it a year. It isn't the insta-death I imagined it would be.
 
2013-04-01 05:09:25 PM

namatad: how long would it take to cool?


I don't know, and I'm too far removed from my physics background to calculate.  But we can apply deductive reasoning here.  If geothermal was that influential, Antarctica shouldn't have a permanent ice cap.  Nor would there ever be Ice Ages.  The surface gets almost all its heat from the Sun.

namatad: all of the life which lives outside of the reach of the sun would still continue unabated. ocean thermal vents ecologies are oblivious to the rest of the solar-driven ecosystem.


Actually, I've heard they're not well understood yet, as they've only been recently discovered.  That said, it's not like they're "oblivious" to the Sun because there's always dead microorganism "snow" that continually falls onto the ocean bottom.  Without the Sun, eventually that would stop when the oceans freeze over.  If it provides a crucial chemical input, its cessation would disrupt the ecosystem.
 
2013-04-01 05:11:28 PM

clambam: http://en.wikipedia.org/wiki/A_Pail_of_Air


It was annoying the heck out of me that I couldn't remember the name of this story. Thanks!
 
2013-04-01 05:26:53 PM

give me doughnuts: TopoGigo: namatad: TopoGigo: namatad: namatad: TopoGigo: So, TFA implies that the effects of gravity travel at the speed of light. Do we have any evidence of that?

yes

http://en.wikipedia.org/wiki/Speed_of_gravity
so really yes, by definition, with little evidence of that not being true

This seems to specifically deal with the speed of gravitational waves. Now, I don't have the physics chops to say for certain, but that doesn't seem like it's exactly equivalent to the speed at which the earth would "notice" the absence of the sun's gravity.

LOL

this is where the magic of the thought experiment gets "silly"
how do you make the sun disappear?
If it doesnt magically disappear, and just moved instead, well the earth would just follow.

so fine MAGIC! POOF it is goon. in less than planck time (really really fast). GONE.
nothing in the physical world travels faster than light (currently accepted theory).
Therefore it would take c*d for you to notice the disappearance of a mass. about 8 mins for the sun going missing.

another way to "look" at it is, the SUN is pulling on the earth. ti would take us 8 mins for the pull to go away once the sun disappeared. another way is that the earth would continue traveling in its circular orbit for 8 mins and then shoot off on a tangent once it "noticed" that the sun was gone.

Did we discover the graviton while I wasn't looking? We don't know what, if anything, transmits gravitational attraction. We don't have any solid theory on how the Higgs boson actually relates to attraction AFAIK. We don't know if a theoretical graviton, or another undiscovered particle or force, moves at c, slower than c, or (massively unlikely if not impossible) faster than c. If we take the high school physics of relativity literally, would the sudden magical absence of the sun cause the "dent" in the "rubber sheet" to bounce back, pushing us violently away from where the sun was? If so, then the speed of a gravitational wave would seem to apply, but the ...


I used to annoy all my science teachers w/ this very same question when discussing the speed of light.  Their answer was always that gravity was a "Force" and didn't travel, just existed. That my hypothetical disappearing sun wouldn't happen in reality didn't help.
 
2013-04-01 06:31:52 PM

FC Exile: Their answer was always that gravity was a "Force" and didn't travel, just existed.


It's a cop-out answer.  Changes in gravity propagate at the speed of light, but it takes a very profound interaction -- like orbiting neutron stars -- to notice such an effect.  What seems to be an immediate interaction with gravity is your own behavior as an observer within a static field (well, effectively static because significant sources of gravity tend to be pretty stable).  Every gravitational field basically extends to infinity, so no matter where you go or what you do, you're interacting with the field.  There's no propagation because the point of interaction is you.

ParagonComplex: He entirely neglected the fact that as we zip off into the unknown we could crash into all sorts of stuff before the possibility of getting pulled into another orbit happened.


As would I, if I hypothesized the disappearance of the Sun.  Space is very, VERY sparsely populated.
 
2013-04-01 06:45:03 PM

log_jammin: Ed Grubermann: Benevolent Misanthrope: How long would it take for the earth to cool to a temperature that would not support life, though?
 
Billions of years. The interior of the earth is not warmed by the sun.

and the exterior of the earth is not warmed by the interior. 
 
Sure some hot spots would still exist


Yes, that was the point. Watch the video?
 
2013-04-01 06:46:19 PM

ParagonComplex: omeganuepsilon: And that's all IF we don't get smashed into by another planet or something shortly after the sun lost it's gravitational influence.

Totally THIS. That was my only problem with the video. He entirely neglected the fact that as we zip off into the unknown we could crash into all sorts of stuff before the possibility of getting pulled into another orbit happened.


Well, for one thing, space is very, very empty. Consider the Oort cloud, which may have as little as 10 earth-masses in its entirety. (The Kuiper belt in its entirety doesn't even have a Moon's worth of stuff in it.) And those are the  dense parts of the solar system map. Let's assume, not for any good reason, that those things stay roughly where they are now, instead of being flung off into space like the planets. That's five earth-masses spread out over... carry the three... times pi... I get  five quadrillion cubic AU (ha, there's a goofy unit) or about 4 cubic light years. Plus, the cloud is a spheroid thing, and the earth would only going through the part that lined up with its former orbital plane. All things considered, that's  really empty.

Now, that being said, even a tiny chunk of mass the size of Delaware can pretty much ruin your planet... except in this scenario, the earth is already pretty farked. We're down to a few extremophile bacteria living under several miles of ice, so what used to be a civilization-ending nightmare rock from the skies is just going to make a big crater on the ice-shield. The bacteria wouldn't even notice. For those things to die, the planet would have to hit something damn near its own size (like the impactor that created the Moon) and there's just no such animal in the Oort cloud, so far as we know.

The only problem with his "spaceship earth" hypothesis is that I think we're less likely to be gently captured in a nice Goldilocks orbit by another star than we are to be eaten by it, or one of its gas giants.
 
2013-04-01 06:47:46 PM

namatad: qorkfiend: Lord Dimwit: It would be weird that the night would then be brighter than the "day" thanks to the Moon.

*chomp*

Since the moon reflects the sun, if the sun vanishes, the moon will also cease to shine.

what was being referred to was that the moon would effectively block "some" starlight. causing it to be brighter when the moonset rather than the current brighter at night with the moon in the sky....


If you say so, champ.
 
2013-04-01 06:53:42 PM
I love the fact that people keep asking questions that were answered in the video. Way to pay attention, guys.
 
2013-04-01 06:58:15 PM
Since the article acknowledges that the gravitation front will travel outward at a finite speed, it is strange that it doesn't also mention the earth would be torn apart b the tidal forces.   All the speculation in this thread about how long heat would last etc is pointless.

As the gravitational effect passes through the diameter of the earth there will be roughl 42 milliseconds where part of the earth is travelling along the orbital trajector, and part is traveling along a straight tangent.  (Large parts of the earth would be travelling in two different directions.)   The amount of force this would exert on all parts of the earth would be about the same magnitude as being impacted b a planet sized object.  And these forces would be exerted on all parts of the earth, inside and out (instead of on just one side).

M best semi-educated guess is that what used to be earth would be absolutel sterilized, down to the last subterranean microbe, within 42 milliseconds (give or take a few milliseconds) of the wavefront reaching the sunward side.
 
2013-04-01 07:11:11 PM
Aaaand my 'y' key apparently stopped working for the duration of typing that post.
 
2013-04-01 07:22:36 PM

ThrobblefootSpectre: Aaaand my 'y' key apparently stopped working for the duration of typing that post.


Fark's April Fools joke for this year seems to be that some posts have a specific letter completely disappear from them.
 
2013-04-01 07:24:52 PM

anfrind: Fark's April Fools joke for this year seems to be that some posts have a specific letter completely disappear from them.


Ah, okay.  Good one.  I didn't make the connection, lol.
 
2013-04-01 07:28:18 PM

anfrind: ThrobblefootSpectre: Aaaand my 'y' key apparently stopped working for the duration of typing that post.

Fark's April Fools joke for this year seems to be that some posts have a specific letter completely disappear from them.


I actually saw it yesterday as well but that doesn't mean much.

I was wondering what that was, seen A and C go missing in different posts by different users, thought it was people screwing around like maybe a troll outing his alt or something.  Surely someone with a bad letter on their keyboard would make a note of it.

Never put the two together, so thanks for the observation.
 
2013-04-01 07:47:56 PM

ThrobblefootSpectre: Since the article acknowledges that the gravitation front will travel outward at a finite speed, it is strange that it doesn't also mention the earth would be torn apart b the tidal forces.   All the speculation in this thread about how long heat would last etc is pointless.

As the gravitational effect passes through the diameter of the earth there will be roughl 42 milliseconds where part of the earth is travelling along the orbital trajector, and part is traveling along a straight tangent.  (Large parts of the earth would be travelling in two different directions.)   The amount of force this would exert on all parts of the earth would be about the same magnitude as being impacted b a planet sized object.  And these forces would be exerted on all parts of the earth, inside and out (instead of on just one side).

M best semi-educated guess is that what used to be earth would be absolutel sterilized, down to the last subterranean microbe, within 42 milliseconds (give or take a few milliseconds) of the wavefront reaching the sunward side.


I don't know if you're right about that, but it has the look and feel of something extremely intelligent and physics knowledgeable, so this is me stroking my chin and saying "ah, yes, indeed, gravitational shear, quite so."
 
2013-04-01 07:49:06 PM

Ed Grubermann: I love the fact that people keep asking questions that were answered in the video. Way to pay attention, guys.


Well I know my phone doesn't really play embedded videos aside from a couple of porn sites--- and then maybe after 20 minutes of downloading in its own window. So although I haven't posted before this comment, I am relying entirely on the content of the thread.

This is pretty much true of any Gawker-type sites even if the link doesn't have video. I imagine I'm not the only one using phones like this so whenever you have articles from i09 or some other overly-encoded website you'll have a percent of Farkers literally unable to RTFA. I have a whole list of websites that I just don't click on because of mobile difficulties.
 
2013-04-01 07:57:27 PM

dragonchild: As would I, if I hypothesized the disappearance of the Sun. Space is very, VERY sparsely populated.


When one runs through a hypothetical scenario one generally contemplates all the possibilities. The thought that the sun would simply vanish is nowhere near as far-fetched as the Earth getting belted by something. So that doesn't work for me. You can't think of the most outrageous thing ever happening, and then dismiss something else more likely than said outrageousness.

semiotix: Well, for one thing, space is very, very empty. Consider the Oort cloud, which may have as little as 10 earth-masses in its entirety. (The Kuiper belt in its entirety doesn't even have a Moon's worth of stuff in it.) And those are the dense parts of the solar system map. Let's assume, not for any good reason, that those things stay roughly where they are now, instead of being flung off into space like the planets. That's five earth-masses spread out over... carry the three... times pi... I get five quadrillion cubic AU (ha, there's a goofy unit) or about 4 cubic light years. Plus, the cloud is a spheroid thing, and the earth would only going through the part that lined up with its former orbital plane. All things considered, that's really empty.

Now, that being said, even a tiny chunk of mass the size of Delaware can pretty much ruin your planet... except in this scenario, the earth is already pretty farked. We're down to a few extremophile bacteria living under several miles of ice, so what used to be a civilization-ending nightmare rock from the skies is just going to make a big crater on the ice-shield. The bacteria wouldn't even notice. For those things to die, the planet would have to hit something damn near its own size (like the impactor that created the Moon) and there's just no such animal in the Oort cloud, so far as we know.

The only problem with his "spaceship earth" hypothesis is that I think we're less likely to be gently captured in a nice Goldilocks orbit by another star than we are to be eaten by it, or one of its gas giants.


See above.
 
2013-04-01 08:28:36 PM

BolloxReader: Ed Grubermann: I love the fact that people keep asking questions that were answered in the video. Way to pay attention, guys.

Well I know my phone doesn't really play embedded videos aside from a couple of porn sites--- and then maybe after 20 minutes of downloading in its own window. So although I haven't posted before this comment, I am relying entirely on the content of the thread.

This is pretty much true of any Gawker-type sites even if the link doesn't have video. I imagine I'm not the only one using phones like this so whenever you have articles from i09 or some other overly-encoded website you'll have a percent of Farkers literally unable to RTFA. I have a whole list of websites that I just don't click on because of mobile difficulties.


You can watch it directly on YouTube, without dealing with Gawker or i09.  I think someone posted the link earlier in the thread, and at least on Android I'm pretty sure that the browser is smart enough to offer to open YouTube links in the YouTube app.
 
2013-04-01 08:42:12 PM
I'd probably put on a sweater. Man up already... Yeesh!
 
2013-04-01 08:54:55 PM

ParagonComplex: When one runs through a hypothetical scenario one generally contemplates all the possibilities. The thought that the sun would simply vanish is nowhere near as far-fetched as the Earth getting belted by something.


I took it as the opposite; if we're going through a crazy thought experiment we need to limit the magic to exactly one thing.  Otherwise we might as well be talking rainbow farts here.
 
2013-04-01 08:55:07 PM

anfrind: BolloxReader: Ed Grubermann: I love the fact that people keep asking questions that were answered in the video. Way to pay attention, guys.

Well I know my phone doesn't really play embedded videos aside from a couple of porn sites--- and then maybe after 20 minutes of downloading in its own window. So although I haven't posted before this comment, I am relying entirely on the content of the thread.

This is pretty much true of any Gawker-type sites even if the link doesn't have video. I imagine I'm not the only one using phones like this so whenever you have articles from i09 or some other overly-encoded website you'll have a percent of Farkers literally unable to RTFA. I have a whole list of websites that I just don't click on because of mobile difficulties.

You can watch it directly on YouTube, without dealing with Gawker or i09.  I think someone posted the link earlier in the thread, and at least on Android I'm pretty sure that the browser is smart enough to offer to open YouTube links in the YouTube app.


youtube user is Vsause, got to his youtube  page, it's the latest upload
 
2013-04-01 08:55:44 PM
vsauce


/damnit
 
2013-04-01 09:13:25 PM

ParagonComplex: You can't think of the most outrageous thing ever happening, and then dismiss something else more likely than said outrageousness.


I can and I have. Now if you'll excuse me, I'm off to open diplomatic relations with the extremophile bacteria who colonize volcanic vents at the bottom of the ocean. GOOD DAY SIR.
 
2013-04-01 10:12:34 PM

malaktaus: The funny thing is, if this were to happen, life on Earth would persist longer than it's actually going to. We have little more than a billion years before the Sun heats to the point that life is no longer possible, but if the Earth became a freerange planet life could continue on the ocean floor almost indefinitely.
Also, has anyone else read The Night Land, by William Hope Hodgson? It had a similar sort of plot, with the Sun dead and all humanity living in a single enormous pyramid.


Me, I've read it. It's pretty fascinating.
 
2013-04-02 12:26:31 AM
The article makes the assumption that the gravitational effect moves at the speed of light.  What if it's faster (as postulated in a number of sci fi books)?  What if it's several magnitudes faster.  If we settle for 100 times faster, then instead of just over eight minutes, the earth would react in five seconds.  We would still see the sun as we suddenly left our orbit.  It's been far too long since I took physics and astronomy for me to even attempt to calculate how long it would take for us to all die from the temperature change (and probably massive tidal surges).  Would we live long enough to see the sun disappear?
 
2013-04-02 12:43:45 AM

Ed Grubermann: I love the fact that people keep asking questions that were answered in the video. Way to pay attention, guys.


Not many people were able to handle that annoying douche for more than 60 seconds tops.
 
2013-04-02 12:49:38 AM
Fark would link to The Daily Mail that much more?
 
2013-04-02 12:51:15 AM

quatchi: I'd have to switch to the Daily Fail as my primary source for English celebrity news?


Damn it. I can't expect to come to the party late and crack a new joke... Ho hum...
 
2013-04-02 02:18:34 AM
If we're nit picking the hypothetical about the effects of being released from our orbit, why hasn't anyone mentioned the likely geological effects such as massive earthquakes as our tectonic plates balance out? I wouldn't imagine tsunamis, but huge volumes of water will be flowing between the hemispheres too
 
2013-04-02 02:46:18 AM

OgreMagi: The article makes the assumption that the gravitational effect moves at the speed of light.  What if it's faster (as postulated in a number of sci fi books)?  What if it's several magnitudes faster.  If we settle for 100 times faster, then instead of just over eight minutes, the earth would react in five seconds.  We would still see the sun as we suddenly left our orbit.


I don't know offhand what sci-fi books you're talking about, but you've basically described one reason we know it can't be faster than the speed of light in reality: because that would mean faster-than-light information transfer (e.g., we feel the sun's nonexistence gravitationally faster than the sight of it disappearing reaches us), which is tantamount under relativity theory to time travel. And we don't observe a lot of time travel.

Put another way, if you're still on board with general relativity, you're basically committing to gravity waves that travel at the speed of light. I'm not suggesting that relativity theory as presently elaborated is some kind of sacred relic that can never be challenged; I'm just saying that because it's stood up pretty well to a century of seriously badass physics already, it's probably a good reason not to go assuming things that it directly contradicts and then saying "you can't prove otherwise!"

In other words, if you have an issue with relativity, then measuring the speed of gravity waves would be a smart thing to do. (Which has been done using astronomical observations, obviously with some error bars, but always with  c right smack in the middle of them.) But if you're comfortable with relativity and the physical validity of the kinds of predictions it makes, then you're basically already saying you don't have a problem with that assumption about gravity.
 
2013-04-02 03:47:47 AM

American Decency Association: If we're nit picking the hypothetical about the effects of being released from our orbit, why hasn't anyone mentioned the likely geological effects such as massive earthquakes as our tectonic plates balance out? I wouldn't imagine tsunamis, but huge volumes of water will be flowing between the hemispheres too


Good call.

Any underground bunkers would be at stake, as well as the sea life that lives by heat vents. Though unlikely all would get crushed or otherwise lost, but a severe knock nonetheless.
 
2013-04-02 07:54:07 AM
i.imgur.com
 
2013-04-02 09:33:26 AM

omeganuepsilon: American Decency Association: If we're nit picking the hypothetical about the effects of being released from our orbit, why hasn't anyone mentioned the likely geological effects such as massive earthquakes as our tectonic plates balance out? I wouldn't imagine tsunamis, but huge volumes of water will be flowing between the hemispheres too

Good call.

Any underground bunkers would be at stake, as well as the sea life that lives by heat vents. Though unlikely all would get crushed or otherwise lost, but a severe knock nonetheless.


yes, if event planning was possible, some would survive even this.  i wonder in what year would we be capable of such a feat?  perhaps now, with enough conviction
 
2013-04-02 12:12:39 PM

semiotix: OgreMagi: The article makes the assumption that the gravitational effect moves at the speed of light.  What if it's faster (as postulated in a number of sci fi books)?  What if it's several magnitudes faster.  If we settle for 100 times faster, then instead of just over eight minutes, the earth would react in five seconds.  We would still see the sun as we suddenly left our orbit.

I don't know offhand what sci-fi books you're talking about, but you've basically described one reason we know it can't be faster than the speed of light in reality: because that would mean faster-than-light information transfer (e.g., we feel the sun's nonexistence gravitationally faster than the sight of it disappearing reaches us), which is tantamount under relativity theory to time travel. And we don't observe a lot of time travel.

Put another way, if you're still on board with general relativity, you're basically committing to gravity waves that travel at the speed of light. I'm not suggesting that relativity theory as presently elaborated is some kind of sacred relic that can never be challenged; I'm just saying that because it's stood up pretty well to a century of seriously badass physics already, it's probably a good reason not to go assuming things that it directly contradicts and then saying "you can't prove otherwise!"

In other words, if you have an issue with relativity, then measuring the speed of gravity waves would be a smart thing to do. (Which has been done using astronomical observations, obviously with some error bars, but always with  c right smack in the middle of them.) But if you're comfortable with relativity and the physical validity of the kinds of predictions it makes, then you're basically already saying you don't have a problem with that assumption about gravity.


General relativity has been measured directly at least as long ago as 1976, and to an even higher degree of precision in 2005.
 
2013-04-02 12:24:02 PM

USCLaw2010: vanished or blocked out?

[1.bp.blogspot.com image 287x239]


Then we'd all get the damn rickets.

25.media.tumblr.com
 
2013-04-02 12:36:19 PM

American Decency Association: omeganuepsilon: American Decency Association: If we're nit picking the hypothetical about the effects of being released from our orbit, why hasn't anyone mentioned the likely geological effects such as massive earthquakes as our tectonic plates balance out? I wouldn't imagine tsunamis, but huge volumes of water will be flowing between the hemispheres too

Good call.

Any underground bunkers would be at stake, as well as the sea life that lives by heat vents. Though unlikely all would get crushed or otherwise lost, but a severe knock nonetheless.

yes, if event planning was possible, some would survive even this.  i wonder in what year would we be capable of such a feat?  perhaps now, with enough conviction


We should totally get on that, you know, just in case the sun just magically disappears in an instant and we float out in whatever direction the planet was going at the time of this instant disappearance!!

=)
 
2013-04-02 01:42:49 PM

namatad: namatad: TopoGigo: So, TFA implies that the effects of gravity travel at the speed of light. Do we have any evidence of that?

yes

http://en.wikipedia.org/wiki/Speed_of_gravity
so really yes, by definition, with little evidence of that not being true


Your citation used a lot of "measurement against a theory" stuff, which means they could be completely wrong.  You say there's little evidence of it not being true.  Yep, and there's little evidence of it not being false.  This is one of those weird physics fields that is way beyond my pay grade, though, so I'll let the experts argue about it for a few decades (or centuries).
 
2013-04-02 04:54:21 PM

anfrind: General relativity has been measured directly at least as long ago as 1976, and to an even higher degree of precision in 2005.


It got pretty solid observational confirmation in 1919, for that matter. Which is, um, why I don't think people should say we don't have any evidence for gravity waves propagating at the speed of light.
 
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