# Oh-my-god particle

1. Jun 4, 2011

### 1MileCrash

http://www.fourmilab.ch/documents/ohmygodpart.html/

"At a velocity of 1516 c, traveling to the centre of the galaxy would take, as perceived by the life forms on board, a little more than 21 years."

I know they're making a comparison to sci-fi (which really grinds my hears but I won't go into that) but WHAT are they talking about???

At 1516 times the speed of light, the trip takes 21 years?? How did they perform that calculation? I'm so annoyed that this is in an actual science article.

2. Jun 4, 2011

### phinds

Could it be that what was intended was .1516 ? Seems like an oddly precise number in any event. Maybe that's some round number of zillions of miles per hour or km/sec or something.
I'm too lazy to do the math.

3. Jun 4, 2011

### 1MileCrash

No,

"It is interesting to observe that a real particle, in our universe, subject to all the laws of physics we understand, is a rather better interstellar voyager than the best fielded in the 24th century by the United Federation of Planets. Their much-vaunted Galaxy Class starships are capable of speeds slightly in excess of Warp Factor 9, an apparent velocity of 1516 cochranes (or 1516 times the speed of light).[4] At a velocity of 1516 c, traveling to the centre of the galaxy would take, as perceived by the life forms on board, a little more than 21 years. By contrast, an observer on board the Oh-My-God particle would arrive at the nucleus of the Milky Way, according to his clock, just about 3 seconds after leaving Starbase Terra. That's more than 9,700,000 times faster than the starship. In the time the starship spends vacuum-whooshing and rumbling its way to the nearby star Aldebaran, the particle could travel to the edge of the visible universe."

4. Jun 4, 2011

### Zorba

Note the use of "according to his clock" so time dilation comes into effect.

According to the article the 1516c figure refers to star trek (I think?) spaceship drives, and using wikipedia (d=24,900 ± 1,000 ly to centre of milky way) and obviously neglecting all relativistic effects I get a figure of 16.5y which is pretty close.

5. Jun 4, 2011

### 1MileCrash

So they are comparing the speed of the oh-my-god particle taking into account relativistic effects to the speed of a fictional spaceship without taking into account relativistic effects?

Whoever decided to throw that paragraph in there needs a swift kick in the jaw.

6. Jun 4, 2011

### Staff: Mentor

Seems like they are saying "In the fictional Star Trek TV show a ship could get to the centre of the galaxy in X time as measured by both the ship's crew and an individual who stayed at departure. IRL a near C object could get to the centre of the galaxy in <X time according to the object but 1000s of X as measured by an individual who stayed at departure"

Stupid way of discussing relativity.