Orbiter-Forum  

Go Back   Orbiter-Forum > Far Side of the Moon > Brighton Lounge
Register Blogs Orbinauts List Social Groups FAQ Projects Mark Forums Read

Brighton Lounge General off-topic discussions. Political or religious topics may only be posted in The Basement forum.

Reply
 
Thread Tools
Old 07-16-2019, 09:12 AM   #1
Notebook
Donator
 
Notebook's Avatar


Default If the Sun dissapeared...?

Was wondering if we could be hit by Mercury if the Sun disappeared.

I'm assuming as soon as the Sun's gravity is removed Mercury continues at its orbital velocity in whichever direction its moving then?

There are 5 light-minutes between Earth and Mercury, and Mercury average orbital velocity is about 47km/s, 2820km per minute.
So Mercury travels about 14000 km before the Earth starts moving at a tangent. Average distance between Mercury and Earth is 77 Million km.

I think we'll be all right, but I can't promise anything.

N.
Notebook is online now   Reply With Quote
Old 07-16-2019, 10:19 AM   #2
martins
Orbiter Founder
Default

Logic can be a funny thing. If we formally define the conditional statement "If the sun suddenly disappears, then Mercury will hit the Earth" as

p: the sun suddenly disappears
q: Mercury hits Earth
p -> q

then the statement p -> q is only false if p is true and q is false.(ex falso quod libet).
https://en.wikipedia.org/wiki/Material_conditional
https://www.mathgoodies.com/lessons/vol9/conditional

From all we know about physics, p is false. Therefore, p -> q is true. If the sun were to disappear, then we will indeed be struck by Mercury!
martins is offline   Reply With Quote
Thanked by:
Old 07-16-2019, 10:32 AM   #3
Notebook
Donator
 
Notebook's Avatar


Default

Yes, I was going to phrase it like that....
Notebook is online now   Reply With Quote
Reply

  Orbiter-Forum > Far Side of the Moon > Brighton Lounge


Thread Tools

Posting Rules
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
Forum Jump


All times are GMT. The time now is 09:56 AM.

Quick Links Need Help?


About Us | Rules & Guidelines | TOS Policy | Privacy Policy

Orbiter-Forum is hosted at Orbithangar.com
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Copyright 2007 - 2017, Orbiter-Forum.com. All rights reserved.