Can anyone answer this question.

I'll explain why I'm asking after some people have answered.

Let's assume that the earth is what you roundies say it is and everything is how you say it is, EXCEPT, the sun.
Instead of the sun being as big as it is, let us assume that the sun is only 20,000 miles in diameter. How much of the earth would it light up as opposed to what it's supposed to be doing right now?

Quote from: sceptimatic on October 13, 2013, 10:07:05 AM

I'll explain why I'm asking after some people have answered.

Let's assume that the earth is what you roundies say it is and everything is how you say it is, EXCEPT, the sun.
Instead of the sun being as big as it is, let us assume that the sun is only 20,000 miles in diameter. How much of the earth would it light up as opposed to what it's supposed to be doing right now?

Depends more on the Sun's mass.
If it were to stay the same with nothing changed besides diameter, then it would have no other effect than appearing smaller in the sky.
This is assuming that the mass-energy relation is still applicable in this crazy universe.
If the mass was scaled down with the volume, it would have to be about 2,150,000 miles away, or we wouldn't be here to discuss hypothetical questions.
The energy output would be far less than it is in the real world.
Clarify your question!

The sunlight would still reach us in the same amount of time and the same area of earth would be receiving that light but the light would be much less radiant and thus would have caused many different things to happen for the development of Earth. First of all I'm not so sure that such a small Sun would have been able to even keep us all in orbit to develop the solar system in the first place and if it had then our orbit around the sun would be much different that it currently is. We'd be likely to be much closer to the sun and it would probably be that the sun would revolve around us instead which would change the dynamics of the whole solar system. The less radiant sun would also not allow for evolution to occur on the level that it has and we might not exist.

Quote from: rottingroom on October 13, 2013, 10:30:43 AM

The sunlight would still reach us in the same amount of time and the same area of earth would be receiving that light but the light would be much less radiant and thus would have caused many different things to happen for the development of Earth. First of all I'm not so sure that such a small Sun would have been able to even keep us all in orbit to develop the solar system in the first place and if it had then our orbit around the sun would be much different that it currently is. We'd be likely to be much closer to the sun and it would probably be that the sun would revolve around us instead which would change the dynamics of the whole solar system. The less radiant sun would also not allow for evolution to occur on the level that it has and we might not exist.

Oh brother.  Don't bring evolution into this.

I'll explain why I'm asking after some people have answered.

Let's assume that the earth is what you roundies say it is and everything is how you say it is, EXCEPT, the sun.
Instead of the sun being as big as it is, let us assume that the sun is only 20,000 miles in diameter. How much of the earth would it light up as opposed to what it's supposed to be doing right now?

Quote from: sceptimatic on October 13, 2013, 10:07:05 AM

I'll explain why I'm asking after some people have answered.

Let's assume that the earth is what you roundies say it is and everything is how you say it is, EXCEPT, the sun.
Instead of the sun being as big as it is, let us assume that the sun is only 20,000 miles in diameter. How much of the earth would it light up as opposed to what it's supposed to be doing right now?

It would be a same "part" of the earth that is lit up, but the light would have less luminosity, i.e. it would look much dimmer. But that isn't the main problem, if the sun wasn't as big as it is, we would not be in orbit around it, earth would be significantly colder, there would be no liquid water, and we wouldn't have existed 

Ok, I've took your answers on board. Now I'd like to go the opposite way.

If the sun was the size you roundies say it is (approx. one million, plus km in diameter) but was 500 million miles away, what earth effects would change, assuming that only distance has changed and nothing else?

Quote from: sceptimatic on October 13, 2013, 11:55:36 PM

Ok, I've took your answers on board. Now I'd like to go the opposite way.

If the sun was the size you roundies say it is (approx. one million, plus km in diameter) but was 500 million miles away, what earth effects would change, assuming that only distance has changed and nothing else?

Are we still in orbit around it? That's about 5 times farther than our avg distance to the sun as of now. That's about as far as the distance to Jupiter. So it is safe to say we wouldn't even exist due to no liquid water, temperatures hundreds of degrees colder than earth now, life probably couldn't exist.

Ok, I've took your answers on board. Now I'd like to go the opposite way.

If the sun was the size you roundies say it is (approx. one million, plus km in diameter) but was 500 million miles away, what earth effects would change, assuming that only distance has changed and nothing else?

Quote from: Almostaphysicsmajor on October 14, 2013, 12:08:46 AM

Quote from: sceptimatic on October 13, 2013, 11:55:36 PM

Ok, I've took your answers on board. Now I'd like to go the opposite way.

If the sun was the size you roundies say it is (approx. one million, plus km in diameter) but was 500 million miles away, what earth effects would change, assuming that only distance has changed and nothing else?

It has to do with the amount of energy that reaches Earth. The sun radiates the same power in every direction, so more of it hits the earth when it is closer, and farther away more if it misses and gets sent into space.
Are we still in orbit around it? That's about 5 times farther than our avg distance to the sun as of now. That's about as far as the distance to Jupiter. So it is safe to say we wouldn't even exist due to no liquid water, temperatures hundreds of degrees colder than earth now, life probably couldn't exist.

Everything is the same. The only difference is the sun would be over 5 times the distance, nothing else.
So why would anything change on earth due to this?
It's a vacuum of space isn't it and by your accounts the only difference should be the time it takes for the heat and light to hit earth, as in, instead of this supposed 8 minutes, it would be something like 40 something minutes. I'd just like to get to the bottom of this, so what's the difference?

Quote from: sceptimatic on October 13, 2013, 11:55:36 PM

Ok, I've took your answers on board. Now I'd like to go the opposite way.

If the sun was the size you roundies say it is (approx. one million, plus km in diameter) but was 500 million miles away, what earth effects would change, assuming that only distance has changed and nothing else?

The sun would have to be 4,655,543 or so miles in diameter for it to appear the same size in the sky.
Otherwise, it would look much further away / smaller in the sky.
Answer the question about mass?
Mass is more relevant.

Quote from: th3rm0m3t3r0 on October 14, 2013, 12:19:13 AM

Quote from: sceptimatic on October 13, 2013, 11:55:36 PM

Ok, I've took your answers on board. Now I'd like to go the opposite way.

If the sun was the size you roundies say it is (approx. one million, plus km in diameter) but was 500 million miles away, what earth effects would change, assuming that only distance has changed and nothing else?

The sun would have to be 4,655,543 or so miles in diameter for it to appear the same size in the sky.
Otherwise, it would look much further away / smaller in the sky.
Answer the question about mass?
Mass is more relevant.

This isn't a question about what it would look like to our eyes. It's a question on how the sun would act upon the earth inside this vacuum of space.

At 5 times the distance, we would receive only 4% of the energy that we receive at this distance (inverse square law). This would not be sufficient to sustain life.

Quote from: Scintific Method on October 14, 2013, 12:22:33 AM

At 5 times the distance, we would receive only 4% of the energy that we receive at this distance (inverse square law). This would not be sufficient to sustain life.

4% of the energy in such a small so called space distance? How does that work out then, inside a vacuum?
If the energy travels to earth, it should travel to earth with no hindrance, other than the time difference.

Quote from: Scintific Method on October 14, 2013, 12:22:33 AM

At 5 times the distance, we would receive only 4% of the energy that we receive at this distance (inverse square law). This would not be sufficient to sustain life.

4% of the energy in such a small so called space distance? How does that work out then, inside a vacuum?
If the energy travels to earth, it should travel to earth with no hindrance, other than the time difference.

Sorry scepti, I wrote a long answer explaining it but im on mobile and it messed up pretty much yeah only a fraction hits the earth, and much less of that fraction at a greater distance, power from the sun is distilributed radially.

Quote from: sceptimatic on October 14, 2013, 12:26:33 AM

Quote from: Scintific Method on October 14, 2013, 12:22:33 AM

At 5 times the distance, we would receive only 4% of the energy that we receive at this distance (inverse square law). This would not be sufficient to sustain life.

4% of the energy in such a small so called space distance? How does that work out then, inside a vacuum?
If the energy travels to earth, it should travel to earth with no hindrance, other than the time difference.

You're not familiar with the inverse square law are you? It's why your ears don't burst when there's an explosion a mile away that turns a cement truck into scrap metal.

#" class="bbc_link" target="_blank" rel="noopener noreferrer">Mythbusters - Cement Truck Explosion

And yes, it does work the same with EM radiation in a vacuum.

Quote from: Almostaphysicsmajor on October 14, 2013, 12:28:16 AM

Sorry scepti, I wrote a long answer explaining it but im on mobile and it messed up pretty much yeah only a fraction hits the earth, and much less of that fraction at a greater distance, power from the sun is distilributed radially.

So at this distance, what would the sun look like to your eye view, compared to how it looks now, as we see it?

Quote from: sceptimatic on October 14, 2013, 12:33:44 AM

Quote from: Almostaphysicsmajor on October 14, 2013, 12:28:16 AM

Sorry scepti, I wrote a long answer explaining it but im on mobile and it messed up pretty much yeah only a fraction hits the earth, and much less of that fraction at a greater distance, power from the sun is distilributed radially.

So at this distance, what would the sun look like to your eye view, compared to how it looks now, as we see it?

much smaller and not as bright. Its the same way that stars are very dim compared to our sun, they are simply much farther away!

Quote from: Scintific Method on October 14, 2013, 12:29:59 AM

Quote from: sceptimatic on October 14, 2013, 12:26:33 AM

Quote from: Scintific Method on October 14, 2013, 12:22:33 AM

At 5 times the distance, we would receive only 4% of the energy that we receive at this distance (inverse square law). This would not be sufficient to sustain life.

4% of the energy in such a small so called space distance? How does that work out then, inside a vacuum?
If the energy travels to earth, it should travel to earth with no hindrance, other than the time difference.

You're not familiar with the inverse square law are you? It's why your ears don't burst when there's an explosion a mile away that turns a cement truck into scrap metal.

#" class="bbc_link" target="_blank" rel="noopener noreferrer">Mythbusters - Cement Truck Explosion

And yes, it does work the same with EM radiation in a vacuum.

Let's leave the bull crap myth buster crew out and happenings in an atmosphere here, as I'm not dealing with that.

Quote from: sceptimatic on October 14, 2013, 12:36:04 AM

Quote from: Scintific Method on October 14, 2013, 12:29:59 AM

Quote from: sceptimatic on October 14, 2013, 12:26:33 AM

Quote from: Scintific Method on October 14, 2013, 12:22:33 AM

At 5 times the distance, we would receive only 4% of the energy that we receive at this distance (inverse square law). This would not be sufficient to sustain life.

4% of the energy in such a small so called space distance? How does that work out then, inside a vacuum?
If the energy travels to earth, it should travel to earth with no hindrance, other than the time difference.

You're not familiar with the inverse square law are you? It's why your ears don't burst when there's an explosion a mile away that turns a cement truck into scrap metal.

#" class="bbc_link" target="_blank" rel="noopener noreferrer">Mythbusters - Cement Truck Explosion

And yes, it does work the same with EM radiation in a vacuum.

Let's leave the bull crap myth buster crew out and happenings in an atmosphere here, as I'm not dealing with that.

Okay, fine, I was trying to give you a nice, simple example, but now I'm going to have to use maths. We're talking in terms of round earth physics here, so I'm going to use that in my explanation.

The sun is roughly spherical, and it emits it's energy in a spherical pattern. To picture that, picture a slightly inflated balloon. That's the energy that the sun emitted in the last microsecond. Now blow that balloon up. That's the energy moving out into space, but do you notice how it's spreading out? getting thinner? The amount of energy is the same, just like the amount of rubber in the skin of the balloon is the same, but now it's covering more area, and it's spread more thinly. Here comes the maths:

The surface area of a sphere is 4πr², so the surface area of the sun is about 12,000,000,000,000 square miles. At the distance of the earth, the energy is spread over an area of 120,000,000,000,000,000 square miles. At the distance you proposed, the same amount of energy would be spread over an area of about 3,100,000,000,000,000,000 square miles.

Now do you see what I mean? Or are you going to call "bullshit" again because you can't be bothered understanding what's going on?

I'm not going to call anything. I'm trying to work stuff out. Not by your maths by the way, but anyway, let's get back to basics.

Once the sun has emitted it's heat/radiation or whatever you want to call it, in the direction it is going. Why should it dissipate when it's in this vacuum that you and others say cannot change anything, so how and why would it dissipate. It's not like it's a hair dryer on earth is it, that dissipates because the air makes it happen by creating a barrier against the hot air.
There's no such thing in your vacuum, so what's going on?

Okay, fine, I was trying to give you a nice, simple example, but now I'm going to have to use maths. We're talking in terms of round earth physics here, so I'm going to use that in my explanation.

The sun is roughly spherical, and it emits it's energy in a spherical pattern. To picture that, picture a slightly inflated balloon. That's the energy that the sun emitted in the last microsecond. Now blow that balloon up. That's the energy moving out into space, but do you notice how it's spreading out? getting thinner? The amount of energy is the same, just like the amount of rubber in the skin of the balloon is the same, but now it's covering more area, and it's spread more thinly. Here comes the maths:

The surface area of a sphere is 4πr², so the surface area of the sun is about 12,000,000,000,000 square miles. At the distance of the earth, the energy is spread over an area of 120,000,000,000,000,000 square miles. At the distance you proposed, the same amount of energy would be spread over an area of about 3,100,000,000,000,000,000 square miles.

Now do you see what I mean? Or are you going to call "bullshit" again because you can't be bothered understanding what's going on?

Just realised I used the sun's diameter in the formula instead of it's radius... Oops! I'll redo those numbers, using more accurate numbers for the sun's radius and the orbital distance of the earth (I was using approximations pulled from memory before).

Surface area of sun (more accurate): 2,400,000,000,000 square miles
Area covered at distance of earth: 110,000,000,000,000,000 square miles
Area covered at scepti's orbital distance: 2,700,000,000,000,000,000 square miles

Sorry about that folks!

Anyway, lets knock 11 0's off those numbers, and pretend they're square centimetres instead of square miles:
Energy emitted by 24cm² of the sun's surface has spread out to cover 1,100,000cm² by the time it gets to earth, and 27,000,000cm² by the time it's reached scepti's orbital distance (assuming I haven't cocked up my maths this time).

How about explaining it in kindergarten type stuff then, instead of putting out stupid numbers.
I'm asking a basic question, so answer it with a simple basic answer, I don't need all this number clap trap.

My question is:
What dissipates the heat once it immediately emits from the sun in one direction, as in earth.

Try this: get a balloon, blow it up a little bit, draw a square on it with sides of 1cm. Now blow the balloon up to twice it's size and measure the square. It should be about 2cm each side, with a total area of 4cm². If you can't get your head around that, then I fear there may be no hope for you.