What is the difference between an astronaut in the ISS and a freediver in perfect neutral buoyancy?How are the symptoms of long-term exposure to microgravity similar to those of bedridden patients?Would the blast clearing technique used in snorkeling work in an EVA situation?Can you take a bath on Mars?How long can an astronaut stay in space and later have children?Nudism in space: Why wear clothes anyway?What is Astronaut Sunita Williams wearing on her wrist?What was the colour of the shoes used by the Apollo astronauts in moon landing?What exactly makes it difficult for astronauts to walk immediately after landing after extended stays in space?
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What is the difference between an astronaut in the ISS and a freediver in perfect neutral buoyancy?
How are the symptoms of long-term exposure to microgravity similar to those of bedridden patients?Would the blast clearing technique used in snorkeling work in an EVA situation?Can you take a bath on Mars?How long can an astronaut stay in space and later have children?Nudism in space: Why wear clothes anyway?What is Astronaut Sunita Williams wearing on her wrist?What was the colour of the shoes used by the Apollo astronauts in moon landing?What exactly makes it difficult for astronauts to walk immediately after landing after extended stays in space?
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For example, does the blood of the freediver accumulates in his/her head while being upside down, as it would on land, or not, as it would in microgravity environment ?
astronauts water
asked 11 hours ago
Arnaud PROSTArnaud PROST
1134 bronze badges
$endgroup$
add a comment
|
$begingroup$
For example, does the blood of the freediver accumulates in his/her head while being upside down, as it would on land, or not, as it would in microgravity environment ?
astronauts water
asked 11 hours ago
Arnaud PROSTArnaud PROST
1134 bronze badges
$endgroup$
add a comment
|
$begingroup$
For example, does the blood of the freediver accumulates in his/her head while being upside down, as it would on land, or not, as it would in microgravity environment ?
astronauts water
asked 11 hours ago
Arnaud PROSTArnaud PROST
1134 bronze badges
$endgroup$
For example, does the blood of the freediver accumulates in his/her head while being upside down, as it would on land, or not, as it would in microgravity environment ?
astronauts water
astronauts water
asked 11 hours ago
Arnaud PROSTArnaud PROST
1134 bronze badges
asked 11 hours ago
Arnaud PROSTArnaud PROST
1134 bronze badges
asked 11 hours ago
Arnaud PROSTArnaud PROST
1134 bronze badges
asked 11 hours ago
Arnaud PROSTArnaud PROST
1134 bronze badges
asked 11 hours ago
Arnaud PROSTArnaud PROST
1134 bronze badges
1134 bronze badges
add a comment
|
add a comment
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2 Answers
2
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oldest
votes
$begingroup$
A freediver could not be in perfect neutral buoyancy. The air in his lungs causes his chest to be more buoyant than his legs. So he would be turned chest up, legs down. Been there, done that.
But blood does not accumulate in the head while being upside down. Rising blood pressure is compensated by rising water pressure when going down from feet to head.
answered 11 hours ago
UweUwe
15.8k3 gold badges43 silver badges73 bronze badges
$endgroup$
$begingroup$
So let's say you put on the freediver a tight suit which is weighted in such a way that the specific gravity of the freediver is 1 with full lungs. The bloodflow of this diver would then be the same than the blood flow of an astronaut in weightlessness ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
You may try to compensate buoyancy of the body with weights, but you will get neutral buoyancy only for a certain depth of water and a certain air content of the lungs. Going down or up some meters and the neutral buoyancy is gone.
$endgroup$
– Uwe
11 hours ago
$begingroup$
Yes it's fundamentally an unstable equilibrium, and the amplitude of this instability is affected by many different factors. But let's focus on the question putting this aside with the thought experiment of a neutral buoyancy. So the hydrostatic gradient counteracts rising blood pressure from feet to head. Does it compensate it exactly ? I.e. is the bloodflow the same than in microgravity ?
$endgroup$
– Arnaud PROST
11 hours ago
add a comment
|
$begingroup$
An astronaut practicing an EVA in the Neutral Buoyancy Laboratory (a large swimming-pool like facility) is still affected by gravity. They are pulled down relative to the suit - which is buoyed up by its internal air volume and attached flotation devices. If they are upside down, the blood would tend to accumulate in their head.
Buoyant forces do not remove the effect of gravity on the internals of a floating object. Crewmembers do not fly/float about within submarines and an object dropped in a submarine falls as normal.
An astronaut doing an EVA in space is not affected relative to the suit. There is no buoyancy force and the same inertial forces affect the astronaut and suit.
answered 11 hours ago
Organic MarbleOrganic Marble
79.9k4 gold badges241 silver badges344 bronze badges
$endgroup$
$begingroup$
I agree with you about EVA simulations but could you elaborate on "the same is true for a freediver" ? Would blood in a closed plastic bag accumulate at the bottom of the bag if it is neutrally buoyant ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
Sure. See my added comments about dropping objects in a submarine.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It seems different to me, as in a submarine there is a rigid barriere protecting you inside from the water hydrostatic pressure. I agree submarine analogy is relevant according to EVA simulations, but not convinced yet about a freediver
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
@Uwe's answer mentions some considerations about hydrostatic pressure, so maybe it's more what you are looking for. If your "bag of blood" had a volume of air inside it above the blood, it would have to be at or above the pressure of the surrounding water (or it would collapse) so I don't see much difference from the submarine case.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It's actually the crux of the question and maybe I did not make myself clear, I'm sorry. I picture gravity as an intensive force field acting on every single particle of the body, whereas buoyancy acts "in total" if you take the submarine case, but for a freediver or a bag with flexible interfaces, the hydrostatic pressure can be "transmitted" throughout body layers.
$endgroup$
– Arnaud PROST
11 hours ago
add a comment
|
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
A freediver could not be in perfect neutral buoyancy. The air in his lungs causes his chest to be more buoyant than his legs. So he would be turned chest up, legs down. Been there, done that.
But blood does not accumulate in the head while being upside down. Rising blood pressure is compensated by rising water pressure when going down from feet to head.
answered 11 hours ago
UweUwe
15.8k3 gold badges43 silver badges73 bronze badges
$endgroup$
$begingroup$
So let's say you put on the freediver a tight suit which is weighted in such a way that the specific gravity of the freediver is 1 with full lungs. The bloodflow of this diver would then be the same than the blood flow of an astronaut in weightlessness ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
You may try to compensate buoyancy of the body with weights, but you will get neutral buoyancy only for a certain depth of water and a certain air content of the lungs. Going down or up some meters and the neutral buoyancy is gone.
$endgroup$
– Uwe
11 hours ago
$begingroup$
Yes it's fundamentally an unstable equilibrium, and the amplitude of this instability is affected by many different factors. But let's focus on the question putting this aside with the thought experiment of a neutral buoyancy. So the hydrostatic gradient counteracts rising blood pressure from feet to head. Does it compensate it exactly ? I.e. is the bloodflow the same than in microgravity ?
$endgroup$
– Arnaud PROST
11 hours ago
add a comment
|
$begingroup$
A freediver could not be in perfect neutral buoyancy. The air in his lungs causes his chest to be more buoyant than his legs. So he would be turned chest up, legs down. Been there, done that.
But blood does not accumulate in the head while being upside down. Rising blood pressure is compensated by rising water pressure when going down from feet to head.
answered 11 hours ago
UweUwe
15.8k3 gold badges43 silver badges73 bronze badges
$endgroup$
$begingroup$
So let's say you put on the freediver a tight suit which is weighted in such a way that the specific gravity of the freediver is 1 with full lungs. The bloodflow of this diver would then be the same than the blood flow of an astronaut in weightlessness ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
You may try to compensate buoyancy of the body with weights, but you will get neutral buoyancy only for a certain depth of water and a certain air content of the lungs. Going down or up some meters and the neutral buoyancy is gone.
$endgroup$
– Uwe
11 hours ago
$begingroup$
Yes it's fundamentally an unstable equilibrium, and the amplitude of this instability is affected by many different factors. But let's focus on the question putting this aside with the thought experiment of a neutral buoyancy. So the hydrostatic gradient counteracts rising blood pressure from feet to head. Does it compensate it exactly ? I.e. is the bloodflow the same than in microgravity ?
$endgroup$
– Arnaud PROST
11 hours ago
add a comment
|
$begingroup$
A freediver could not be in perfect neutral buoyancy. The air in his lungs causes his chest to be more buoyant than his legs. So he would be turned chest up, legs down. Been there, done that.
But blood does not accumulate in the head while being upside down. Rising blood pressure is compensated by rising water pressure when going down from feet to head.
answered 11 hours ago
UweUwe
15.8k3 gold badges43 silver badges73 bronze badges
$endgroup$
A freediver could not be in perfect neutral buoyancy. The air in his lungs causes his chest to be more buoyant than his legs. So he would be turned chest up, legs down. Been there, done that.
But blood does not accumulate in the head while being upside down. Rising blood pressure is compensated by rising water pressure when going down from feet to head.
answered 11 hours ago
UweUwe
15.8k3 gold badges43 silver badges73 bronze badges
edited 11 hours ago
answered 11 hours ago
UweUwe
15.8k3 gold badges43 silver badges73 bronze badges
answered 11 hours ago
UweUwe
15.8k3 gold badges43 silver badges73 bronze badges
answered 11 hours ago
UweUwe
15.8k3 gold badges43 silver badges73 bronze badges
15.8k3 gold badges43 silver badges73 bronze badges
$begingroup$
So let's say you put on the freediver a tight suit which is weighted in such a way that the specific gravity of the freediver is 1 with full lungs. The bloodflow of this diver would then be the same than the blood flow of an astronaut in weightlessness ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
You may try to compensate buoyancy of the body with weights, but you will get neutral buoyancy only for a certain depth of water and a certain air content of the lungs. Going down or up some meters and the neutral buoyancy is gone.
$endgroup$
– Uwe
11 hours ago
$begingroup$
Yes it's fundamentally an unstable equilibrium, and the amplitude of this instability is affected by many different factors. But let's focus on the question putting this aside with the thought experiment of a neutral buoyancy. So the hydrostatic gradient counteracts rising blood pressure from feet to head. Does it compensate it exactly ? I.e. is the bloodflow the same than in microgravity ?
$endgroup$
– Arnaud PROST
11 hours ago
add a comment
|
$begingroup$
So let's say you put on the freediver a tight suit which is weighted in such a way that the specific gravity of the freediver is 1 with full lungs. The bloodflow of this diver would then be the same than the blood flow of an astronaut in weightlessness ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
You may try to compensate buoyancy of the body with weights, but you will get neutral buoyancy only for a certain depth of water and a certain air content of the lungs. Going down or up some meters and the neutral buoyancy is gone.
$endgroup$
– Uwe
11 hours ago
$begingroup$
Yes it's fundamentally an unstable equilibrium, and the amplitude of this instability is affected by many different factors. But let's focus on the question putting this aside with the thought experiment of a neutral buoyancy. So the hydrostatic gradient counteracts rising blood pressure from feet to head. Does it compensate it exactly ? I.e. is the bloodflow the same than in microgravity ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
So let's say you put on the freediver a tight suit which is weighted in such a way that the specific gravity of the freediver is 1 with full lungs. The bloodflow of this diver would then be the same than the blood flow of an astronaut in weightlessness ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
So let's say you put on the freediver a tight suit which is weighted in such a way that the specific gravity of the freediver is 1 with full lungs. The bloodflow of this diver would then be the same than the blood flow of an astronaut in weightlessness ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
You may try to compensate buoyancy of the body with weights, but you will get neutral buoyancy only for a certain depth of water and a certain air content of the lungs. Going down or up some meters and the neutral buoyancy is gone.
$endgroup$
– Uwe
11 hours ago
$begingroup$
You may try to compensate buoyancy of the body with weights, but you will get neutral buoyancy only for a certain depth of water and a certain air content of the lungs. Going down or up some meters and the neutral buoyancy is gone.
$endgroup$
– Uwe
11 hours ago
$begingroup$
Yes it's fundamentally an unstable equilibrium, and the amplitude of this instability is affected by many different factors. But let's focus on the question putting this aside with the thought experiment of a neutral buoyancy. So the hydrostatic gradient counteracts rising blood pressure from feet to head. Does it compensate it exactly ? I.e. is the bloodflow the same than in microgravity ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
Yes it's fundamentally an unstable equilibrium, and the amplitude of this instability is affected by many different factors. But let's focus on the question putting this aside with the thought experiment of a neutral buoyancy. So the hydrostatic gradient counteracts rising blood pressure from feet to head. Does it compensate it exactly ? I.e. is the bloodflow the same than in microgravity ?
$endgroup$
– Arnaud PROST
11 hours ago
add a comment
|
$begingroup$
An astronaut practicing an EVA in the Neutral Buoyancy Laboratory (a large swimming-pool like facility) is still affected by gravity. They are pulled down relative to the suit - which is buoyed up by its internal air volume and attached flotation devices. If they are upside down, the blood would tend to accumulate in their head.
Buoyant forces do not remove the effect of gravity on the internals of a floating object. Crewmembers do not fly/float about within submarines and an object dropped in a submarine falls as normal.
An astronaut doing an EVA in space is not affected relative to the suit. There is no buoyancy force and the same inertial forces affect the astronaut and suit.
answered 11 hours ago
Organic MarbleOrganic Marble
79.9k4 gold badges241 silver badges344 bronze badges
$endgroup$
$begingroup$
I agree with you about EVA simulations but could you elaborate on "the same is true for a freediver" ? Would blood in a closed plastic bag accumulate at the bottom of the bag if it is neutrally buoyant ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
Sure. See my added comments about dropping objects in a submarine.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It seems different to me, as in a submarine there is a rigid barriere protecting you inside from the water hydrostatic pressure. I agree submarine analogy is relevant according to EVA simulations, but not convinced yet about a freediver
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
@Uwe's answer mentions some considerations about hydrostatic pressure, so maybe it's more what you are looking for. If your "bag of blood" had a volume of air inside it above the blood, it would have to be at or above the pressure of the surrounding water (or it would collapse) so I don't see much difference from the submarine case.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It's actually the crux of the question and maybe I did not make myself clear, I'm sorry. I picture gravity as an intensive force field acting on every single particle of the body, whereas buoyancy acts "in total" if you take the submarine case, but for a freediver or a bag with flexible interfaces, the hydrostatic pressure can be "transmitted" throughout body layers.
$endgroup$
– Arnaud PROST
11 hours ago
add a comment
|
$begingroup$
An astronaut practicing an EVA in the Neutral Buoyancy Laboratory (a large swimming-pool like facility) is still affected by gravity. They are pulled down relative to the suit - which is buoyed up by its internal air volume and attached flotation devices. If they are upside down, the blood would tend to accumulate in their head.
Buoyant forces do not remove the effect of gravity on the internals of a floating object. Crewmembers do not fly/float about within submarines and an object dropped in a submarine falls as normal.
An astronaut doing an EVA in space is not affected relative to the suit. There is no buoyancy force and the same inertial forces affect the astronaut and suit.
answered 11 hours ago
Organic MarbleOrganic Marble
79.9k4 gold badges241 silver badges344 bronze badges
$endgroup$
$begingroup$
I agree with you about EVA simulations but could you elaborate on "the same is true for a freediver" ? Would blood in a closed plastic bag accumulate at the bottom of the bag if it is neutrally buoyant ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
Sure. See my added comments about dropping objects in a submarine.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It seems different to me, as in a submarine there is a rigid barriere protecting you inside from the water hydrostatic pressure. I agree submarine analogy is relevant according to EVA simulations, but not convinced yet about a freediver
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
@Uwe's answer mentions some considerations about hydrostatic pressure, so maybe it's more what you are looking for. If your "bag of blood" had a volume of air inside it above the blood, it would have to be at or above the pressure of the surrounding water (or it would collapse) so I don't see much difference from the submarine case.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It's actually the crux of the question and maybe I did not make myself clear, I'm sorry. I picture gravity as an intensive force field acting on every single particle of the body, whereas buoyancy acts "in total" if you take the submarine case, but for a freediver or a bag with flexible interfaces, the hydrostatic pressure can be "transmitted" throughout body layers.
$endgroup$
– Arnaud PROST
11 hours ago
add a comment
|
$begingroup$
An astronaut practicing an EVA in the Neutral Buoyancy Laboratory (a large swimming-pool like facility) is still affected by gravity. They are pulled down relative to the suit - which is buoyed up by its internal air volume and attached flotation devices. If they are upside down, the blood would tend to accumulate in their head.
Buoyant forces do not remove the effect of gravity on the internals of a floating object. Crewmembers do not fly/float about within submarines and an object dropped in a submarine falls as normal.
An astronaut doing an EVA in space is not affected relative to the suit. There is no buoyancy force and the same inertial forces affect the astronaut and suit.
answered 11 hours ago
Organic MarbleOrganic Marble
79.9k4 gold badges241 silver badges344 bronze badges
$endgroup$
An astronaut practicing an EVA in the Neutral Buoyancy Laboratory (a large swimming-pool like facility) is still affected by gravity. They are pulled down relative to the suit - which is buoyed up by its internal air volume and attached flotation devices. If they are upside down, the blood would tend to accumulate in their head.
Buoyant forces do not remove the effect of gravity on the internals of a floating object. Crewmembers do not fly/float about within submarines and an object dropped in a submarine falls as normal.
An astronaut doing an EVA in space is not affected relative to the suit. There is no buoyancy force and the same inertial forces affect the astronaut and suit.
answered 11 hours ago
Organic MarbleOrganic Marble
79.9k4 gold badges241 silver badges344 bronze badges
edited 11 hours ago
answered 11 hours ago
Organic MarbleOrganic Marble
79.9k4 gold badges241 silver badges344 bronze badges
answered 11 hours ago
Organic MarbleOrganic Marble
79.9k4 gold badges241 silver badges344 bronze badges
answered 11 hours ago
Organic MarbleOrganic Marble
79.9k4 gold badges241 silver badges344 bronze badges
79.9k4 gold badges241 silver badges344 bronze badges
$begingroup$
I agree with you about EVA simulations but could you elaborate on "the same is true for a freediver" ? Would blood in a closed plastic bag accumulate at the bottom of the bag if it is neutrally buoyant ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
Sure. See my added comments about dropping objects in a submarine.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It seems different to me, as in a submarine there is a rigid barriere protecting you inside from the water hydrostatic pressure. I agree submarine analogy is relevant according to EVA simulations, but not convinced yet about a freediver
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
@Uwe's answer mentions some considerations about hydrostatic pressure, so maybe it's more what you are looking for. If your "bag of blood" had a volume of air inside it above the blood, it would have to be at or above the pressure of the surrounding water (or it would collapse) so I don't see much difference from the submarine case.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It's actually the crux of the question and maybe I did not make myself clear, I'm sorry. I picture gravity as an intensive force field acting on every single particle of the body, whereas buoyancy acts "in total" if you take the submarine case, but for a freediver or a bag with flexible interfaces, the hydrostatic pressure can be "transmitted" throughout body layers.
$endgroup$
– Arnaud PROST
11 hours ago
add a comment
|
$begingroup$
I agree with you about EVA simulations but could you elaborate on "the same is true for a freediver" ? Would blood in a closed plastic bag accumulate at the bottom of the bag if it is neutrally buoyant ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
Sure. See my added comments about dropping objects in a submarine.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It seems different to me, as in a submarine there is a rigid barriere protecting you inside from the water hydrostatic pressure. I agree submarine analogy is relevant according to EVA simulations, but not convinced yet about a freediver
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
@Uwe's answer mentions some considerations about hydrostatic pressure, so maybe it's more what you are looking for. If your "bag of blood" had a volume of air inside it above the blood, it would have to be at or above the pressure of the surrounding water (or it would collapse) so I don't see much difference from the submarine case.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It's actually the crux of the question and maybe I did not make myself clear, I'm sorry. I picture gravity as an intensive force field acting on every single particle of the body, whereas buoyancy acts "in total" if you take the submarine case, but for a freediver or a bag with flexible interfaces, the hydrostatic pressure can be "transmitted" throughout body layers.
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
I agree with you about EVA simulations but could you elaborate on "the same is true for a freediver" ? Would blood in a closed plastic bag accumulate at the bottom of the bag if it is neutrally buoyant ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
I agree with you about EVA simulations but could you elaborate on "the same is true for a freediver" ? Would blood in a closed plastic bag accumulate at the bottom of the bag if it is neutrally buoyant ?
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
Sure. See my added comments about dropping objects in a submarine.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
Sure. See my added comments about dropping objects in a submarine.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It seems different to me, as in a submarine there is a rigid barriere protecting you inside from the water hydrostatic pressure. I agree submarine analogy is relevant according to EVA simulations, but not convinced yet about a freediver
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
It seems different to me, as in a submarine there is a rigid barriere protecting you inside from the water hydrostatic pressure. I agree submarine analogy is relevant according to EVA simulations, but not convinced yet about a freediver
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
@Uwe's answer mentions some considerations about hydrostatic pressure, so maybe it's more what you are looking for. If your "bag of blood" had a volume of air inside it above the blood, it would have to be at or above the pressure of the surrounding water (or it would collapse) so I don't see much difference from the submarine case.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
@Uwe's answer mentions some considerations about hydrostatic pressure, so maybe it's more what you are looking for. If your "bag of blood" had a volume of air inside it above the blood, it would have to be at or above the pressure of the surrounding water (or it would collapse) so I don't see much difference from the submarine case.
$endgroup$
– Organic Marble
11 hours ago
$begingroup$
It's actually the crux of the question and maybe I did not make myself clear, I'm sorry. I picture gravity as an intensive force field acting on every single particle of the body, whereas buoyancy acts "in total" if you take the submarine case, but for a freediver or a bag with flexible interfaces, the hydrostatic pressure can be "transmitted" throughout body layers.
$endgroup$
– Arnaud PROST
11 hours ago
$begingroup$
It's actually the crux of the question and maybe I did not make myself clear, I'm sorry. I picture gravity as an intensive force field acting on every single particle of the body, whereas buoyancy acts "in total" if you take the submarine case, but for a freediver or a bag with flexible interfaces, the hydrostatic pressure can be "transmitted" throughout body layers.
$endgroup$
– Arnaud PROST
11 hours ago
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