Our Universe

[Mike]

Just did the math. If earth was the size of a grain of salt (1/10th of a millimeter or 1/32 of an inch), the largest star shown there, VY Canis, would be 2.5 km or 1.5 miles wide.

In the same scale, the sun would only be 11 millimeters (or about half an inch) wide.

[Philip]

Oh, btw

Apparantly the 12th of august is 'the night of the shooting stars'
While I was on vacation in croatia I must've seen over 50 of them in just a few hours, and I had only seen 4 before that.


So yeah, you might wanna remember that, 'cause it's really impressive

I was in Croatia aswell, what part of Croatia you go?

[Mike]

Oh, btw

Apparantly the 12th of august is 'the night of the shooting stars'
While I was on vacation in croatia I must've seen over 50 of them in just a few hours, and I had only seen 4 before that.


So yeah, you might wanna remember that, 'cause it's really impressive

My birthday.

[Tnext]

lol ;D

[Sean3]

Not sure if this was referenced, but below is a more detailed size comparison. Its a gif and i forgot to increase the speed. but u can download it and use a gif editor to go through it quicker.

I dont know if i should believe it or not, but for now, ill say no due to lack of proof that planets could actually be that big.

[Alpha]

this shit sends shivers down my spine, but still amazing how big our universe is.

[Maddolis]

I dont know if i should believe it or not, but for now, ill say no due to lack of proof that planets could actually be that big.

Aye, planets can't be, but stars can.
...that being said, yes it is hard to believe.
I can imagine (using Mike's scale) the sun being 11mm in diameter and VY Canis being 2.5 metres in diameter (which'd still be thousands of times bigger), but 214.5 metres is pretty crazy.

Just did the math. If earth was the size of a grain of salt (1/10th of a millimeter or 1/32 of an inch), the largest star shown there, VY Canis, would be 2.5 km or 1.5 miles wide.

In the same scale, the sun would only be 11 millimeters (or about half an inch) wide.

Thanks for that, I can almost wrap my head around it.

Edit: Actually it's 214.5 metres in diameter, not 2.5km (assuming VY Canis Majoris is 1950 solar radii) in comparison to our Sun being 11mm in diameter.
The Earthun 1/10mm : 11mm ratio is correct.

But then that last picture, that star must be billions of light years away not to be seen by the naked eye if it's that big?

It is located about 1.5 kiloparsecs (4.6×1016 km) or about 4,900 light years away from Earth.

Considering the sun is 0.00001585 light years away from earth (on average), 4900 light years is quite a while away.

[Mike]

Edit: Actually it's 214.5 metres in diameter, not 2.5km (assuming VY Canis Majoris is 1950 solar radii) in comparison to our Sun being 11mm in diameter.

I used 2100 AU for the diameter of VY Canis Majoris. Goes to show we really don't know how big it is, only that it's really big. 

Edit: Even if you did use 1950 AU for the diameter, it would be ~2.28685737 km.

((Diameter of Canis in km)/(Diameter of Earth in km))*(Diameter of salt granule in km) is what I used.

[Maddolis]

I used 1950 Solar radii (1950 * ), not 1950 AU.
= 0.004652 AU.
VY Canis Majoris is 19 AU in diameter (on average), or 1800-2100 Solar Radii (as is the most widely accepted size).

= The radius of the sun;
hence the radius of VY CMa =~1950*radius of the sun;
hence the diameter of VY CMa =~1950*diameter of the sun.

Let the diameter of the sun = 11mm;
hence Diameter of VY CMa = 1950*11mm = 21450mm
=2145cm
=214.5 metres


You were just using the wrong unit, whether or not the calculations from that point on were correct or not.

[Mike]

Ahh, should have done my own research rather than relying on what my astronomy teacher taught me in high school.  So it being only 214 meters puts it into a bit of a better perspective.

So it would be a grain of salt next to the tallest building in this picture: