Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

stargazine_ep34_banner.thumb.jpg.28dd32d9305c7de9b6591e6bf6600b27.jpg

Corkeyno2

An Impact at a Relativistic Speed

Recommended Posts

4 minutes ago, ollypenrice said:

Yes, but since no massive body can get anywhere near 0.999C the question is rather academic!

Olly

They might be able to, but it would require an ENORMOUS amount of energy

Share this post


Link to post
Share on other sites
2 minutes ago, Alien 13 said:

The online calculators I saw wont let you input C the best I could get was 0.9999999999999999 C, the energy released compared to 0.99999999999999 C was huge.

Alan

Yes, it increases more dramatically as you get closer to c

Share this post


Link to post
Share on other sites
4 minutes ago, Corkeyno2 said:

Yes, it increases more dramatically as you get closer to c

'Dramatically' mght be the understatement of the year...

Olly

Edit: Even in dramas like Macbeth and Hamlet  not everyone is dead at the end. :D

Edited by ollypenrice
  • Like 1

Share this post


Link to post
Share on other sites
Just now, ollypenrice said:

'Dramatically' mght be the understement of the year...

Lol

  • Like 1

Share this post


Link to post
Share on other sites

I you could achieve C would the energy from a gram of matter or even a single neutron be infinite? that was the feeling I got using the calculator.

Alan

  • Like 1

Share this post


Link to post
Share on other sites

I made a video on this on my Youtube account called 'how could we get to proxima b'

Share this post


Link to post
Share on other sites
6 minutes ago, ollypenrice said:

 no massive body can get anywhere near 0.999C

Ummmm, I dont wish to nit pick (do I, harhar !) but any body with a non-zero rest mass is in fact massive, by definition, soooo many massive particles do regular get well up into the 0.99999etc region many places including CERN.

 

  • Like 1

Share this post


Link to post
Share on other sites
Just now, Alien 13 said:

I you could achieve C would the energy from a gram of matter or even a single neutron be infinite? that was the feeling I got using the calculator.

Alan

it would be, but at the speed of light, the entire length of the universe would be decreased to zero. so hitting a particle would be the least of your problems XD

Share this post


Link to post
Share on other sites
2 minutes ago, Alien 13 said:

I you could achieve C

be infinite?

You cant,,,, end of !  and the infinite bit is why :)

 

  • Like 1

Share this post


Link to post
Share on other sites
1 minute ago, SilverAstro said:

You cant,,,, end of !  and the infinite bit is why :)

 

its because of mass increase isn't it? you'd need infinite energy to move when you have infinite mass

Share this post


Link to post
Share on other sites

I know that any particle with mass cant accelerate to C but isn't there the possibility that if by what ever means in the early universe some particle were already in excess of that speed then it wouldn't break any rules.

Alan

Edited by Alien 13
  • Like 1

Share this post


Link to post
Share on other sites
1 minute ago, Corkeyno2 said:

its because of mass increase isn't it? you'd need infinite energy to move when you have infinite mass

Yes sort of in the vernacular I suppose, but one should not talk about if,  when and needing, at, etc. because you cant ever. To be rigorous you need to approach it in little bits and talk asymptotically.

  • Like 1

Share this post


Link to post
Share on other sites
3 minutes ago, SilverAstro said:

Ummmm, I dont wish to nit pick (do I, harhar !) but any body with a non-zero rest mass is in fact massive, by definition, soooo many massive particles do regular get well up into the 0.99999etc region many places including CERN.

 

I meant ( well I didn't but harhar :D:blob6:) a human body. Or at least a 'body' such as might be sojourning in the OP's hypothetical spacecraft. One wth more pointed ears, that kind of thing. The body that is, not the spacecraft...

Having suffered the consequences (permanet) of hitting the tarmac while falling off my bike at an entirely non-relativistic velocity I firmly counsel the spacecraft pilot to slow down.

:confused2:lly

  • Like 2

Share this post


Link to post
Share on other sites
1 minute ago, ollypenrice said:

I meant

:D  yes I knew well what you meant, massive in the English sense, you being, in a previous life, a being, a species even, that I used to hate ( an English teacher for the info of everyone else :) )

Oh what jolly fun :thumbsup:

  • Like 1

Share this post


Link to post
Share on other sites

On this vexed matter ( did I just say matter !) of E and mc^2 just to illustrate the enormity of c^2 it is interesting to estimate how much mass LittleBoy ( the Hiroshima bomb) lost. I say 'estimate' cos no one actually measured the energy released.

,

,

,

,

some authorities suggest only 0.6 of a gram of matter was consumed :(

 

  • Like 1

Share this post


Link to post
Share on other sites
5 minutes ago, SilverAstro said:

:D  yes I knew well what you meant, massive in the English sense, you being, in a previous life, a being, a species even, that I used to hate ( an English teacher for the info of everyone else :) )

Oh what jolly fun :thumbsup:

How can you possibly hate English teachers? Let me tell you about J.... She was gorgeo- oh damn that C of C!!!

Olly

  • Like 1

Share this post


Link to post
Share on other sites
1 minute ago, ollypenrice said:

Let me tell you about J.... She was gorgeo-

:thumbsup:  :angel9: I'll use my imagination :)

  • Like 1

Share this post


Link to post
Share on other sites
8 minutes ago, SilverAstro said:

On this vexed matter ( did I just say matter !) of E and mc^2 just to illustrate the enormity of c^2 it is interesting to estimate how much mass LittleBoy ( the Hiroshima bomb) lost. I say 'estimate' cos no one actually measured the energy released.

,

,

,

,

some authorities suggest only 0.6 of a gram of matter was consumed :(

 

This puzzles me because even 0.6 grams at the speed of light the energy would have been infinite consuming the solar system but it didn't so the actual speed must have been a lot slower.

Alan

  • Like 1

Share this post


Link to post
Share on other sites
29 minutes ago, ollypenrice said:

How can you possibly hate English teachers? Let me tell you about J.... She was gorgeo- oh damn that C of C!!!

Olly you are a genius, finally I now know why I never enjoyed Eng.lit and Eng.lang , , , wrong type of teacher !

 

  • Like 1

Share this post


Link to post
Share on other sites
29 minutes ago, Alien 13 said:

This puzzles me because even 0.6 grams at the speed of light the energy would have been infinite consuming the solar system but it didn't so the actual speed must have been a lot slower.

Only the energy released was travelling at the speed of light.

  • Like 1

Share this post


Link to post
Share on other sites
3 hours ago, ollypenrice said:

Yes, but since no massive body can get anywhere near 0.999C the question is rather academic!

Olly

Your forgetting this is all relative Olly. if say a cosmic ray is approaching you at 0.999c the from it's perspective you are approaching it (along with the earth and everything on it) at 0.999c.

Kinetic energy is not conserved when swapping views between inertial frames.

Regards Andrew

 

  • Like 1

Share this post


Link to post
Share on other sites
10 hours ago, andrew s said:

Your forgetting this is all relative Olly. if say a cosmic ray is approaching you at 0.999c the from it's perspective you are approaching it (along with the earth and everything on it) at 0.999c.

Kinetic energy is not conserved when swapping views between inertial frames.

Regards Andrew

 

Yes, but in the OP's scenario a rock 'of a few kilograms' and a spacecraft are approaching each other. How could two such massive bodies find themselves with a relative velocity approaching C?

Olly

  • Like 1

Share this post


Link to post
Share on other sites
2 hours ago, ollypenrice said:

 scenario  =

= a gedanken experiment in the style of the master himself ? And anyway "spaceship" "c" and "relativity" when appearing in the same post on a popular forum are, errrr, ummmm.

But it is a good vehicle device with which to pick up some hints about the workings of the great thinkers :) like what happens with kinetic energy :) Thank you Andrew I hadnt considered it that way round.

A gedanken, not an engineering blueprint.

Did you hear about the Bussard Ram thast scoops up interstellar hydrogen as fuel. Goes faster and faster and gets relativistically bigger and bigger and scoops more and more hydrogen till it starts scooping up whole stars and then star clusters - -  more and more hydrogen - - it goes so fast and grows so big that it starts gulping up intergalactic hydrogen - - and then whole galaxies - - and gets really really big and fast.

continued after the big crunch , , ,

 

Edited by SilverAstro
  • Like 1

Share this post


Link to post
Share on other sites
8 hours ago, ollypenrice said:

Yes, but in the OP's scenario a rock 'of a few kilograms' and a spacecraft are approaching each other. How could two such massive bodies find themselves with a relative velocity approaching C?

Olly

You can go as near to c as you want, but never c itself. Obviously, humans will never be able to do this, as due to mass increase, the ship would require a crazily humongous wacky vast amount of energy to move.

Share this post


Link to post
Share on other sites
10 minutes ago, Corkeyno2 said:

You can go as near to c as you want, but never c itself. Obviously, humans will never be able to do this, as due to mass increase, the ship would require a crazily humongous wacky vast amount of energy to move.

What your scenario needs, though, is a mechanism by which the craft would reach O.5C and the rock the same, minus the infinity-dodging digit. If we interpreted your initial description of the rock as 'stationary' as its having a history without acceleration then the acceleration history would need to belong to the craft and be almost C.

Olly

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.