# Macroscopic objects traveling at relativistic speed **URL:** \ **Category:** Factual Questions\ **Created:** [March 2, 2015, 6:30am UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991 "2015-03-02T06:30:39Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![cjackson](https://avatars.discourse-cdn.com/v4/letter/c/a3d4f5/32.png) [@cjackson](https://boards.straightdope.com/u/cjackson)\ **Post date:** [March 2, 2015, 6:30am UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/1 "2015-03-02T06:30:39Z")
How much energy would be required to accelerate something the size of the space station to the same speed as protons colliding at the LHC? ---
**Author:** ![TonySinclair](https://avatars.discourse-cdn.com/v4/letter/t/49beb7/32.png) [@TonySinclair](https://boards.straightdope.com/u/TonySinclair)\ **Post date:** [March 2, 2015, 6:49am UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/2 "2015-03-02T06:49:01Z")
> [@cjackson](#): > > How much energy would be required to accelerate something the size of the space station to the same speed as protons colliding at the LHC? [![](https://upload.wikimedia.org/math/b/2/5/b257bfb672ad4c1d718c8b51489089e8.png) ](https://upload.wikimedia.org/math/b/2/5/b257bfb672ad4c1d718c8b51489089e8.png) > **[Kinetic energy](https://en.wikipedia.org/wiki/Kinetic_energy#Relativistic_kinetic_energy_of_rigid_bodies)** > > In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. > In classical mechanics, the kinetic energy of a non-rotating object of mass m traveling at a speed v is > > > > > > 1 > 2 > > > m > > v > > 2 > > > > > {\\textstyle {\\frac {1}{2}}mv^{2}} > > . > The kinetic energy of an object is equal to the work, force (F) times disp... Plug in the appropriate values for v and m. ---
**Author:** ![jezzaOZ](https://avatars.discourse-cdn.com/v4/letter/j/a9a28c/32.png) [@jezzaOZ](https://boards.straightdope.com/u/jezzaOZ)\ **Post date:** [March 2, 2015, 7:04am UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/3 "2015-03-02T07:04:14Z")
Many objects already travel at ‘relativistic’ speed. In particular GPS and GLONASS satellites whose signals have to have relativistic compensation applied before they can be used in your GPS unit. They also have to have ‘General Relativity’ corrections but these are essentially fudge-factors to make the numbers work out and they happen to coincide roughly with GR predictions. ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [March 2, 2015, 8:02am UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/4 "2015-03-02T08:02:56Z")
> [@](#): > > They also have to have ‘General Relativity’ corrections but these are essentially fudge-factors to make the numbers work out and they happen to coincide roughly with GR predictions. As I understand it, GR works exactly as predicted on those satellites. ---
**Author:** ![cjackson](https://avatars.discourse-cdn.com/v4/letter/c/a3d4f5/32.png) [@cjackson](https://boards.straightdope.com/u/cjackson)\ **Post date:** [March 2, 2015, 8:13am UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/5 "2015-03-02T08:13:01Z")
> [@TonySinclair](#): > > [https://upload.wikimedia.org/math/b/2/5/b257bfb672ad4c1d718c8b51489089e8.png](https://upload.wikimedia.org/math/b/2/5/b257bfb672ad4c1d718c8b51489089e8.png) > > [Kinetic energy - Wikipedia](https://en.wikipedia.org/wiki/Kinetic_energy#Relativistic_kinetic_energy_of_rigid_bodies) > > Plug in the appropriate values for v and m. I have no idea how to do that. ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [March 2, 2015, 11:18am UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/6 "2015-03-02T11:18:03Z")
I used my old calculator to do it for you, and I got the result: about 3\*10^26 J. _How much is that?_ It’s a lot. _How much of a lot?_ It’s, by chance, almost exactly the same amount of energy the sun generates in a second. _That is hard to relate to._ Admittedly; let me try another one: it’s about 10 000 times the estimated energy of all known fossil fuel reserves on Earth. _Again, that is hard to relate to._ Let’s try one more: it’s close to a million times the annual energy production on Earth. If we started today, and used all our energy for that purpose, it would take us a million years to accelerate that spacecraft to such a ludicrous speed, provided we could keep energy production at its’ present. _How much is a million years?_ It’s been like a million years since our ancestors lit the first fires. ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [March 2, 2015, 12:23pm UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/7 "2015-03-02T12:23:50Z")
> [@Ignotus](#): > > I used my old calculator to do it for you, and I got the result: about 3\*10^26 J. > > _How much is that?_ > > It’s a lot. > > _How much of a lot?_ > > It’s, by chance, almost exactly the same amount of energy the sun generates in a second. > > _That is hard to relate to._ > > Admittedly; let me try another one: it’s about 10 000 times the estimated energy of all known fossil fuel reserves on Earth. > > _Again, that is hard to relate to._ > > Let’s try one more: it’s close to a million times the annual energy production on Earth. If we started today, and used all our energy for that purpose, it would take us a million years to accelerate that spacecraft to such a ludicrous speed, provided we could keep energy production at its’ present. > > _How much is a million years?_ > > It’s been like a million years since our ancestors lit the first fires. Or if we employ a constant acceleration of 1 g, we will get to c in about a year. ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [March 2, 2015, 6:31pm UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/8 "2015-03-02T18:31:19Z")
> [@cjackson](#): > > How much energy would be required to accelerate something the size of the space station to the same speed as protons colliding at the LHC? Energy as per **Ignotus** = a lot. Acceleration as per **K84** = energy to do this, an even bigger ‘a lot’ :eek: ---
**Author:** ![Washoe](https://avatars.discourse-cdn.com/v4/letter/w/ecae2f/32.png) [@Washoe](https://boards.straightdope.com/u/Washoe)\ **Post date:** [March 2, 2015, 6:53pm UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/9 "2015-03-02T18:53:07Z")
> [@cjackson](#): > > How much energy would be required to accelerate something the size of the space station to the **same speed as protons colliding at the LHC?** Exactly how fast are those bad boys zipping around? I’ll calculate the Lorentz factor myself. ---
**Author:** ![rsa](https://avatars.discourse-cdn.com/v4/letter/r/839c29/32.png) [@rsa](https://boards.straightdope.com/u/rsa)\ **Post date:** [March 3, 2015, 4:58am UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/10 "2015-03-03T04:58:15Z")
> [@Washoe](#): > > Exactly how fast are those bad boys zipping around? I’ll calculate the Lorentz factor myself. [From here](http://journal.batard.info/post/2008/09/12/lhc-how-fast-do-these-protons-go): With E = 7 TeV: v = 99.9999991% times the speed of light The Lorentz factor has a value of about 7460 ---
**Author:** ![Suburban\_Plankton](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/suburban_plankton/32/219_2.png) [@Suburban\_Plankton](https://boards.straightdope.com/u/Suburban_Plankton)\ **Post date:** [March 3, 2015, 5:39am UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/11 "2015-03-03T05:39:35Z")
> [@Ignotus](#): > > Let’s try one more: it’s close to a million times the annual energy production on Earth. If we started today, and used all our energy for that purpose, it would take us a million years to accelerate that spacecraft to such a ludicrous speed, provided we could keep energy production at its’ present. That’s quite a lot, but how much energy would it take to get the ship go to plaid? ---
**Author:** ![Pasta](https://avatars.discourse-cdn.com/v4/letter/p/ecccb3/32.png) [@Pasta](https://boards.straightdope.com/u/Pasta)\ **Post date:** [March 3, 2015, 7:42pm UTC](https://boards.straightdope.com/t/macroscopic-objects-traveling-at-relativistic-speed/713991/12 "2015-03-03T19:42:40Z")
It’s worth pointing out that the protons in the LHC are moving more slowly than did the electrons and positrons in the earlier LEP collider, though the latter particles did have lower energy. LEP particle speeds reached 99.9999999988% _c_.