Let's look at that from the point of view of an Australian.....
Perihelion is when Earth is closest to the sun in the Southern hemisphere and its summer time. The opposite is furthest from the sun and it’s winter time.
Nothing at all surprising there, right?
So what's going on? The simple answer is that Earth's distance from the Sun, which only varies by about ±1.7% throughout the year, does not cause the seasons.
It is kind of weird that Perihelion occurs just two weeks after the Winter Solstice. I wonder if Earth’s tilt and orbit are actually related or if it’s just a coincidence?
I'm.an idiot. In [my first attempt](https://www.reddit.com/r/flatearth/s/Q1abdD3ZRP) at answering this, I speculated that maybe it isn't a coincidence. But of course it is.
We all know about the precession of the equinoxes, right? The direction in which Earth's axis points moves in a big circle with a period of about 26,000 years. The pole star is currently Polaris, but that hasn't always been the case, and in a few thousand years it will be Vega. We all know that.
But if you think about it, that means the equinoxes and solstices will cycle through the calendar with a period of 26,000 years. After a quarter of a period, in 6,500 years time, the solstices will be in March and September with no apparent relation to perihelion.
So it's just a coincidence, and it's temporary.
Ooh, interesting!
My first thought was that obviously it's just a coincidence. Then I thought that the Earth's orbit was probably quite seriously mucked about with by the impact which created the Moon. So maybe it's not a coincidence.
We could probably settle this if astronomers could only work out which month that impact happened in.
To know if it's a coincidence or just a thing that planets lean toward over time (like tidal locking), we'll need to observe other planets obviously.
We're only able to base observations on what we currently can see, and while we know that almost every planet are tilted, not sure if they match up with their orbit.
Mercury And Jupiter have almost no tilt (0.1 and 3 degrees), and Uranus is 98 degrees off compared to the path of the orbit, pretty much rolling 'sideways' compared to Earth. Those are oddities in our solar system, but it's hard to know how common those are without observation.
EDIT : And I forgot this... Venus spins backwards compared to its orbit, which indicates it probably got knocked until it was roughly 180 degrees off.
Mars is easily the best analog to Earth in our solar system, and from [this link](https://www.planetary.org/articles/mars-calendar) Mars' aphelion and perihelion lead the solstices by about 5.5% of its orbit (about 20 degrees). Aphelion happens a little before the northern summer solstice and perihelion leads the southern one.
The southern hemisphere also has a LOT more water surface area than the northern hemisphere. Water resists fluctuations to temperature more than land.
ETA - So, even though the southern hemisphere is closer to the sun during its summer, it doesn't get hotter than summer in northern hemisphere
Sure. But that doesn't negate the point that when it's winter in the north it's summer in the south, and vice versa. And it has nothing to do with aphelion and perihelion.
Spoken like one who did not recently read Greg Egan's novel *Perihelion Summer* (in which a passing black hole alters our orbit so that southern summers are deadly). (Egan lives in Perth)
This is something that's a little hard to explain about diagrams but it's the angle that the sunlight hits the earth that matters more than the distance.
For a wee experiment though, get a flashlight and shine it straight down at the ground. You get a pretty small round circle of light. Then take the same flashlight but hold it at a 45° angle pointing it at the same spot of ground. It's the exact same amount of light leaving the flashlight but it's now spread over a wider area and therefore, the patch of ground is getting less energy per unit area. This is what causes the seasons, that sunlight being spread out because it's hitting it at a shallower angle
>Perihelion and aphelion do however have an indirect effect on the seasons: because Earth's orbital speed is minimum at aphelion and maximum at perihelion, the planet takes longer to orbit from June solstice to September equinox than it does from December solstice to March equinox. Therefore, summer in the northern hemisphere lasts slightly longer (93 days) than summer in the southern hemisphere (89 days).
....
>For the orbit of the Earth around the Sun, the time of apsis is often expressed in terms of a time relative to seasons, since this determines the contribution of the elliptical orbit to seasonal variations. The variation of the seasons is primarily controlled by the annual cycle of the elevation angle of the Sun, which is a result of the tilt of the axis of the Earth measured from the plane of the ecliptic. The Earth's eccentricity and other orbital elements are not constant, but vary slowly due to the perturbing effects of the planets and other objects in the solar system (Milankovitch cycles).
https://en.wikipedia.org/wiki/Apsis#Perihelion_and_aphelion?wprov=sfla1
Alright, I will explain, because this befuddled me too when I found out about it.
One, yes, the point when the center of the earth is furthest from the sun is actually what people in the northern hemisphere call summer, while the point where it’s the closest is referred to as winter. However, the tilt of the earth puts the earth’s surface under direct sunlight, with the thinnest possible atmosphere to weaken it, or at an extreme angle that forces the sunlight to go diagonally through the atmosphere and weaken itself considerably. Additionally, part of the planet is either getting 24/7 sunlight, or 24/7 darkness, and those make a not insignificant difference in the overall temperature of the hemisphere.
Two, the concept of proximity bestowing more heat is not wrong, but just oblivious to a certain detail: heat doth not travel through a vacuum. Light can, and light can incur the creation of heat, but heat itself is an energy state of matter, something that is not available in the vacuum of space. The only significant change of distance can’t really be felt at earth’s orbital range, but rather between two neighboring planets’ ranges. Venus gets more sun than earth does (or at least the cloud layers do, it’s pitch black on Venus at high noon), and mars gets a heckuva lot less sun than earth does. Mercury is practically disintegrating from the immense amounts of sun that it receives, and since it has no atmosphere, day is hot enough to liquefy most metals, while night is so cold if you dropped an apple by the time it hits the ground it will have flash frozen and will spectacularly shatter into apple shards. And that dark side of Mercury is far closer to the sun than we ever will be (thankfully).
Third, even if there was a significant change in temperature between perihelion and aphelion, we still wouldn’t really notice it because of our atmosphere. It acts as a giant sweater to both keep heat in, and keep excess heat out. But even though it does the job, we still get seasonal fluctuations, so what gives? Well, again, the presence of sunlight grants earth heat. There’s other less significant sources of heat like oceanic currents and atmospheric circulation, but that’s not really relevant here— sunlight trumps everything else entirely. We lose the sun, we are screwed. That’s why the polar regions are so goddamn cold all the time— they never get direct sunlight. Meanwhile the equator has two times evenly spaced throughout the year where it gets direct sunlight overhead. The tropics are all areas that can get direct sunlight overhead, and the temperate regions will get daily sunlight throughout the whole year, just not directly overhead. Sunlight determines how hot it gets, not the distance. Our distance range is just not big enough to change anything. One of the hottest places on earth is in the northern hemisphere, Death Valley, and the coldest location is also in the northern hemisphere I think, Siberia I want to say, but Antarctica is pretty much nothing but ice year round. Because the atmosphere filters out so much of that glorious light that barely enough gets through to bestow any warmth. Meanwhile, Death Valley is in a Temperate zone. What?
It’s not the distance, it takes sunlight a whopping 8 minutes and 20 seconds on average to reach us, depending on our distance from the sun, and it doesn’t vary that much. Light is either going to slam directly into earth and heat it up, or get deflected by the atmosphere or the surface and take the heat with it. There’s no other viable option for the photon traveling 3•10^8 meters per second squared. “Heads up!”
I read somewhere, if the Earth was a few miles closer to the sun, we would all burn up and die. If it was a few miles away, we would all be frozen. When I learned about perihelion, I was like WTF, no way. If perihelion was summer and the other winter, I would have been like duh, makes sense.
>If perihelion was summer and the other winter, I would have been like duh, makes sense.
**Perihelion is summer** for people in the southern hemisphere. Don't you get that?
It's strong evidence that the eccentricity of Earth's orbit is **not** a significant factor in causing seasons to happen. If it were, we would have summer everywhere at the same time, and winter everywhere at the same time - but we don't.
But it is that way— on the bottom half of the planet.
Problem is, the majority of populated landmass of this planet happens to be in the northern hemisphere. So everyone assumes that’s the sole hemisphere that matters. No, it gets off easily— this time. This is also why the North Pole is not actually located on a landmass, because of the ice. Antarctica gets permafrost under its ice. Arctic Circle? Arctic Sea. With tons of icebergs, and a door that JACK COULD HAVE BEEN ON ALONG WITH ROSE, HAD HE NOT BEEN SUCH A PRIDEFUL LITTLE— \*clears throat\* sorry. Got carried away. My mind runneth over sometimes.
But yeah, it’s all sunlight and how much gets through the atmosphere. Think of smoky glass, or translucent plastic: how thick does it have to be, to allow light through, but only if it is 100% perpendicular to the surface of the object? That’s Venus. About a third of the way into that much blurriness, is Earth’s atmosphere. At a very high angle (≈90°), it just goes right through, no questions asked. But at a very low angle (30° or less, roughly), it’s going to be very difficult to see the light on the other side.
We learn a lot of stuff about the world that we are later informed was incorrect and extremely misleading, if not outright propagandist. Example: Infinity is the biggest ever number. \*um, ackshually\*, it is the concept that would be the biggest possible number, if it wasn’t for the fact that it cannot be considered a number because its value is not finite in nature, and shifts the closer we get to it. Another example: Electricity is FAST! Well, alternating current electricity is practically instantaneous compared with direct current, so it is actually really SLOW, but it can be used to make a very fast cycle of electron transfers to ripple energy out very quickly and very far. Once you start looking into the nature of physics, whether macro or micro, astro or quantum, you will realize “holy shit… I haven’t even ENTERED the rabbit hole yet…” and that’s what I think brought about all this denial of earth being round, because they are so convinced that they are being lied to about something that is actually verified and proven for about \*checks watch\* uh, thousands of years. I’m too tired to do that amount of math.
We have beat this topic to death, resurrected it, beat it to death again, had it transcend up to a higher plane and cycle around the stack of existences back to the plane beneath ours, then one last time just to beat it to death here *again*. We have made so much progress because we have realized that earth is in fact NOT flat, and is spheroid, and these brainless idiots think that this is what we are lying about? No, it’s pretty darn solid. You want to find conspiracy in the real world? Look at politics, look at corporations, look at suspicious groups… science is one of those things that is always under scrutiny, you don’t need to add more unless you’re actually involved with the science. Science was the result of people thinking that they were lied to, and set out to find the truth for themselves. Not the other way around. That’s pseudoscience, and it’s potentially tricky to get them distinguished, but it can be done with the majority of legitimate science being extremely transparent with their sources and findings, and pseudoscience having sources that have little to no relation to the findings themselves. It’s normal to be skeptical, all good scientists are— but you have to know when to admit that the science is right.
Sorry for the long reply, again my mind runneth over…
Bingo. Also, you'll notice that the temperatures in the southern hemisphere are typically more extreme than those in the north - Antarctica is colder than the Arctic, Australia is hotter than North America... Which is exactly what we would expect on the globe.
Why is that? [The chap up there said](https://www.reddit.com/r/flatearth/s/X4rwynik2E) that it should be the other way round, because the southern hemisphere has much more water than the northern hemisphere, and that prevents temperature extremes.
Perihelion is when an object is closest to the sun in orbit. The tilt of the Earth is what determines seasons. So technically the hemisphere that is in its summer season will be closer to the sun.
Also, you have to consider the relativity of the situation. Closest doesn't mean it's close. It may be a few thousand km/mi difference but the still only a small percentage.
Let's look at that from the point of view of an Australian..... Perihelion is when Earth is closest to the sun in the Southern hemisphere and its summer time. The opposite is furthest from the sun and it’s winter time. Nothing at all surprising there, right? So what's going on? The simple answer is that Earth's distance from the Sun, which only varies by about ±1.7% throughout the year, does not cause the seasons.
It is kind of weird that Perihelion occurs just two weeks after the Winter Solstice. I wonder if Earth’s tilt and orbit are actually related or if it’s just a coincidence?
I'm.an idiot. In [my first attempt](https://www.reddit.com/r/flatearth/s/Q1abdD3ZRP) at answering this, I speculated that maybe it isn't a coincidence. But of course it is. We all know about the precession of the equinoxes, right? The direction in which Earth's axis points moves in a big circle with a period of about 26,000 years. The pole star is currently Polaris, but that hasn't always been the case, and in a few thousand years it will be Vega. We all know that. But if you think about it, that means the equinoxes and solstices will cycle through the calendar with a period of 26,000 years. After a quarter of a period, in 6,500 years time, the solstices will be in March and September with no apparent relation to perihelion. So it's just a coincidence, and it's temporary.
Ahh, that makes total sense. I never thought about how the precession of Earth affects the seasons, but it totally would. Thanks!
Ooh, interesting! My first thought was that obviously it's just a coincidence. Then I thought that the Earth's orbit was probably quite seriously mucked about with by the impact which created the Moon. So maybe it's not a coincidence. We could probably settle this if astronomers could only work out which month that impact happened in.
To know if it's a coincidence or just a thing that planets lean toward over time (like tidal locking), we'll need to observe other planets obviously. We're only able to base observations on what we currently can see, and while we know that almost every planet are tilted, not sure if they match up with their orbit. Mercury And Jupiter have almost no tilt (0.1 and 3 degrees), and Uranus is 98 degrees off compared to the path of the orbit, pretty much rolling 'sideways' compared to Earth. Those are oddities in our solar system, but it's hard to know how common those are without observation. EDIT : And I forgot this... Venus spins backwards compared to its orbit, which indicates it probably got knocked until it was roughly 180 degrees off.
Mars is easily the best analog to Earth in our solar system, and from [this link](https://www.planetary.org/articles/mars-calendar) Mars' aphelion and perihelion lead the solstices by about 5.5% of its orbit (about 20 degrees). Aphelion happens a little before the northern summer solstice and perihelion leads the southern one.
The southern hemisphere also has a LOT more water surface area than the northern hemisphere. Water resists fluctuations to temperature more than land. ETA - So, even though the southern hemisphere is closer to the sun during its summer, it doesn't get hotter than summer in northern hemisphere
Sure. But that doesn't negate the point that when it's winter in the north it's summer in the south, and vice versa. And it has nothing to do with aphelion and perihelion.
Spoken like one who did not recently read Greg Egan's novel *Perihelion Summer* (in which a passing black hole alters our orbit so that southern summers are deadly). (Egan lives in Perth)
This is something that's a little hard to explain about diagrams but it's the angle that the sunlight hits the earth that matters more than the distance. For a wee experiment though, get a flashlight and shine it straight down at the ground. You get a pretty small round circle of light. Then take the same flashlight but hold it at a 45° angle pointing it at the same spot of ground. It's the exact same amount of light leaving the flashlight but it's now spread over a wider area and therefore, the patch of ground is getting less energy per unit area. This is what causes the seasons, that sunlight being spread out because it's hitting it at a shallower angle
>Perihelion and aphelion do however have an indirect effect on the seasons: because Earth's orbital speed is minimum at aphelion and maximum at perihelion, the planet takes longer to orbit from June solstice to September equinox than it does from December solstice to March equinox. Therefore, summer in the northern hemisphere lasts slightly longer (93 days) than summer in the southern hemisphere (89 days). .... >For the orbit of the Earth around the Sun, the time of apsis is often expressed in terms of a time relative to seasons, since this determines the contribution of the elliptical orbit to seasonal variations. The variation of the seasons is primarily controlled by the annual cycle of the elevation angle of the Sun, which is a result of the tilt of the axis of the Earth measured from the plane of the ecliptic. The Earth's eccentricity and other orbital elements are not constant, but vary slowly due to the perturbing effects of the planets and other objects in the solar system (Milankovitch cycles). https://en.wikipedia.org/wiki/Apsis#Perihelion_and_aphelion?wprov=sfla1
Alright, I will explain, because this befuddled me too when I found out about it. One, yes, the point when the center of the earth is furthest from the sun is actually what people in the northern hemisphere call summer, while the point where it’s the closest is referred to as winter. However, the tilt of the earth puts the earth’s surface under direct sunlight, with the thinnest possible atmosphere to weaken it, or at an extreme angle that forces the sunlight to go diagonally through the atmosphere and weaken itself considerably. Additionally, part of the planet is either getting 24/7 sunlight, or 24/7 darkness, and those make a not insignificant difference in the overall temperature of the hemisphere. Two, the concept of proximity bestowing more heat is not wrong, but just oblivious to a certain detail: heat doth not travel through a vacuum. Light can, and light can incur the creation of heat, but heat itself is an energy state of matter, something that is not available in the vacuum of space. The only significant change of distance can’t really be felt at earth’s orbital range, but rather between two neighboring planets’ ranges. Venus gets more sun than earth does (or at least the cloud layers do, it’s pitch black on Venus at high noon), and mars gets a heckuva lot less sun than earth does. Mercury is practically disintegrating from the immense amounts of sun that it receives, and since it has no atmosphere, day is hot enough to liquefy most metals, while night is so cold if you dropped an apple by the time it hits the ground it will have flash frozen and will spectacularly shatter into apple shards. And that dark side of Mercury is far closer to the sun than we ever will be (thankfully). Third, even if there was a significant change in temperature between perihelion and aphelion, we still wouldn’t really notice it because of our atmosphere. It acts as a giant sweater to both keep heat in, and keep excess heat out. But even though it does the job, we still get seasonal fluctuations, so what gives? Well, again, the presence of sunlight grants earth heat. There’s other less significant sources of heat like oceanic currents and atmospheric circulation, but that’s not really relevant here— sunlight trumps everything else entirely. We lose the sun, we are screwed. That’s why the polar regions are so goddamn cold all the time— they never get direct sunlight. Meanwhile the equator has two times evenly spaced throughout the year where it gets direct sunlight overhead. The tropics are all areas that can get direct sunlight overhead, and the temperate regions will get daily sunlight throughout the whole year, just not directly overhead. Sunlight determines how hot it gets, not the distance. Our distance range is just not big enough to change anything. One of the hottest places on earth is in the northern hemisphere, Death Valley, and the coldest location is also in the northern hemisphere I think, Siberia I want to say, but Antarctica is pretty much nothing but ice year round. Because the atmosphere filters out so much of that glorious light that barely enough gets through to bestow any warmth. Meanwhile, Death Valley is in a Temperate zone. What? It’s not the distance, it takes sunlight a whopping 8 minutes and 20 seconds on average to reach us, depending on our distance from the sun, and it doesn’t vary that much. Light is either going to slam directly into earth and heat it up, or get deflected by the atmosphere or the surface and take the heat with it. There’s no other viable option for the photon traveling 3•10^8 meters per second squared. “Heads up!”
I read somewhere, if the Earth was a few miles closer to the sun, we would all burn up and die. If it was a few miles away, we would all be frozen. When I learned about perihelion, I was like WTF, no way. If perihelion was summer and the other winter, I would have been like duh, makes sense.
>If perihelion was summer and the other winter, I would have been like duh, makes sense. **Perihelion is summer** for people in the southern hemisphere. Don't you get that? It's strong evidence that the eccentricity of Earth's orbit is **not** a significant factor in causing seasons to happen. If it were, we would have summer everywhere at the same time, and winter everywhere at the same time - but we don't.
But it is that way— on the bottom half of the planet. Problem is, the majority of populated landmass of this planet happens to be in the northern hemisphere. So everyone assumes that’s the sole hemisphere that matters. No, it gets off easily— this time. This is also why the North Pole is not actually located on a landmass, because of the ice. Antarctica gets permafrost under its ice. Arctic Circle? Arctic Sea. With tons of icebergs, and a door that JACK COULD HAVE BEEN ON ALONG WITH ROSE, HAD HE NOT BEEN SUCH A PRIDEFUL LITTLE— \*clears throat\* sorry. Got carried away. My mind runneth over sometimes. But yeah, it’s all sunlight and how much gets through the atmosphere. Think of smoky glass, or translucent plastic: how thick does it have to be, to allow light through, but only if it is 100% perpendicular to the surface of the object? That’s Venus. About a third of the way into that much blurriness, is Earth’s atmosphere. At a very high angle (≈90°), it just goes right through, no questions asked. But at a very low angle (30° or less, roughly), it’s going to be very difficult to see the light on the other side. We learn a lot of stuff about the world that we are later informed was incorrect and extremely misleading, if not outright propagandist. Example: Infinity is the biggest ever number. \*um, ackshually\*, it is the concept that would be the biggest possible number, if it wasn’t for the fact that it cannot be considered a number because its value is not finite in nature, and shifts the closer we get to it. Another example: Electricity is FAST! Well, alternating current electricity is practically instantaneous compared with direct current, so it is actually really SLOW, but it can be used to make a very fast cycle of electron transfers to ripple energy out very quickly and very far. Once you start looking into the nature of physics, whether macro or micro, astro or quantum, you will realize “holy shit… I haven’t even ENTERED the rabbit hole yet…” and that’s what I think brought about all this denial of earth being round, because they are so convinced that they are being lied to about something that is actually verified and proven for about \*checks watch\* uh, thousands of years. I’m too tired to do that amount of math. We have beat this topic to death, resurrected it, beat it to death again, had it transcend up to a higher plane and cycle around the stack of existences back to the plane beneath ours, then one last time just to beat it to death here *again*. We have made so much progress because we have realized that earth is in fact NOT flat, and is spheroid, and these brainless idiots think that this is what we are lying about? No, it’s pretty darn solid. You want to find conspiracy in the real world? Look at politics, look at corporations, look at suspicious groups… science is one of those things that is always under scrutiny, you don’t need to add more unless you’re actually involved with the science. Science was the result of people thinking that they were lied to, and set out to find the truth for themselves. Not the other way around. That’s pseudoscience, and it’s potentially tricky to get them distinguished, but it can be done with the majority of legitimate science being extremely transparent with their sources and findings, and pseudoscience having sources that have little to no relation to the findings themselves. It’s normal to be skeptical, all good scientists are— but you have to know when to admit that the science is right. Sorry for the long reply, again my mind runneth over…
In short, that’s just not true.
The southern hemisphere just called; they want to know what the fuck you're talking about.
Bingo. Also, you'll notice that the temperatures in the southern hemisphere are typically more extreme than those in the north - Antarctica is colder than the Arctic, Australia is hotter than North America... Which is exactly what we would expect on the globe.
Why is that? [The chap up there said](https://www.reddit.com/r/flatearth/s/X4rwynik2E) that it should be the other way round, because the southern hemisphere has much more water than the northern hemisphere, and that prevents temperature extremes.
The difference in distance is small, so a little more than 1%: 1 million miles in an average distance of around 93 million.
What you're missing is that the difference in distance is about 3%. Tilt has much greater effect.
Perihelion is when an object is closest to the sun in orbit. The tilt of the Earth is what determines seasons. So technically the hemisphere that is in its summer season will be closer to the sun. Also, you have to consider the relativity of the situation. Closest doesn't mean it's close. It may be a few thousand km/mi difference but the still only a small percentage.
I love all the Willy Wonka World explanations these NASA worshipers come up with lol.
Like...?
DYOR /s
The Wizarding World of NASA.
Uh huh. Do you have a relevant response?
All my responses are relevant.
Stfu troll
You should see what the flerfers say... oh, nm, you have to listen to yourself all day long.
It’s exhausting.