Planets Zooming at a Fraction of Light-Speed

[Waspie_Dwarf]

Seven years ago, astronomers boggled when they found the first runaway star flying out of our Galaxy at a speed of 1.5 million miles per hour. The discovery intrigued theorists, who wondered: If a star can get tossed outward at such an extreme velocity, could the same thing happen to planets?

New research shows that the answer is yes.Not only do runaway planets exist, but some of them zoom through space at a few percent of the speed of light - up to 30 million miles per hour.

"These warp-speed planets would be some of the fastest objects in our Galaxy.

Read more...

Edited June 9, 2012 by Waspie_Dwarf
Added tags

[JayMark]

Quite facinating!

"Other than subatomic particles, I don't know of anything leaving our galaxy as fast [...]" added lead author Idan Ginsburg of Dartmouth College.

That was quite indeed one of the first thing I thought.

Isn't it a good example of what was arleady theorised about using a black hole to propel crafts at these kind of velocities? Wasen't it Hawking who thought about this?

[Taun]

That means a hypervelocity planet would only take about 782,000 years to get from our Solar system to Alpha Centauri (if my math is right)... That's still insanely faster than we could do it...

Edit: my bad... re-did my math and it seems it's only 88 years... oops...

Edited March 23, 2012 by Taun

[JayMark]

Edit: my bad... re-did my math and it seems it's only 88 years... oops...

Just blame it on the calculator.

[Taun]

Just blame it on the calculator.

Nah it was me... I did it in Excel and squirreled up the formula...

[8th_wall]

That means a hypervelocity planet would only take about 782,000 years to get from our Solar system to Alpha Centauri (if my math is right)... That's still insanely faster than we could do it...

Edit: my bad... re-did my math and it seems it's only 88 years... oops...

Well, if you were on the actual planet it would take less than 88 years as far as you were concerned. It would take 88 years for the people observing you but far less for you. (I.e time is relative)

[27vet]

The recent Nat Geo article poses the question on what one would observe if one was on such a planet. No sun, rapidly changing cosmos etc

More here....

[Taun]

Well, if you were on the actual planet it would take less than 88 years as far as you were concerned. It would take 88 years for the people observing you but far less for you. (I.e time is relative)

True, but I'm way too lazy to try and calculate that...

[pallidin]

No, it would be not be too much more than 88 years. 30 million miles per hour is a fraction of the speed of light. 1/22th to be exact( if I have my math right )

[8th_wall]

No, it would be not be too much more than 88 years. 30 million miles per hour is a fraction of the speed of light. 1/22th to be exact( if I have my math right )

I don't think you understand how relative time works. Assume you hopped on a space ship that can travel at the speed of light. You shoot off and travel at the speed of light. You decide to slow down and stop travelling at the speed of light after 1 second because you forgot something. In that 1 second of time you experienced a presumably infinite amount of time would have past where you left off.

Edit1: The faster you travel towards an object the less time you experience subjectively relative to your 0 speed. (The time you experience won't feel different though) The distance you travel towards the object doesn't change though because the speed of light doesn't change in relation to time.

Edit2:

This may help:

And:

The key here being that objects in time distance are closer than they appear. They're just super hard to get to. (Require enormous amounts of energy)

Edited March 28, 2012 by PsiSeeker

[pallidin]

So, how much time dilation would there be with an object traveling only 1/22th light speed?

[Waspie_Dwarf]

No, it would be not be too much more than 88 years.

At 1/22 the speed of light it would take 88 years to cover 4 light years. The Alpha Centauri system is a little further than that, 4.24 ly for Proxima and 4.37 ly for Alpha Centauri A & B. This gives use journey times at 1/22 c of 93 and 96 years respectively. I give these figures not to show off, but to justify a step in the calculation I will do below.

So, how much time dilation would there be with an object traveling only 1/22th light speed?

The short answer is not a lot. Time dilation is an exponential function and really only becomes significant above about 10% of the speed of light.

For fun (because I had nothing else to do) I decided to do the calculation.

The formula for time dilation is:

t = t

₀

/√(1-v

²

/c

²

)

Where:

t = time observed in the other reference frame

t₀ = time in observers own frame of reference (rest time)

v = the speed of the moving object

c = the speed of light in a vacuum

I am going to round up the journey time to 100 years to make the maths easier (that is why I give the figures to Alpha Centauri above).

We do not need to use the absolute value of c. If we say c=1 then we can use 1/22 (or 0.04545 as a decimal) as the value for v.

This gives us:

t = 100/√(1-0.4545²/1²)

= 100/√(1-2.060x10^-3/1)

= 100.1 years

In other words, from the point of view of an observer on Earth, a traveller on our hypothetical planet would only be a little bitt over one month younger than he would have been.

[8th_wall]

Hmm, if you're travelling at 1/x speed of light (where 'x' is any positive integer) the amount of energy you consume will be exponential increasing as x approaches 1. What actually happens to the energy consumption in terms of distance traveled as time dilation starts taking effect?

I.e you objectively experience less time per unit of distance the closer x gets to 1. Does this mean the energy being consumed also experiences less objective time per unit of distance and as a result travels more distance per unit of energy subjectively relative to 0 velocity?

[Waspie_Dwarf]

My understanding is that as any object with mass approachs the speed of light the energy required to accelerate it further approaches infinite.

This is one of the reasons that no object with mass can reach the speed of light.

[8th_wall]

Edit2: Does it makes sense to say that the closer and closer an object gets to the speed of light the more physical distance is traveled per unit of energy (subjectively and relative to the 0 velocity state) and as a result after the object reaches the speed of light the moment an infinitesimal amount of energy is spent the object will have traveled infinite distance in that moment? (relative to the 0 velocity state)

Edited March 29, 2012 by PsiSeeker

[Waspie_Dwarf]

If I have understood you correctly than I believe the answer is no.

It takes more and more energy to accelerate the same amount the closer you get to the speed of light. For example accelerating fro 99.0% c to 99.1% c would take vastly more energy than accelerating from 10.0% c to 10.1%c.

Reaching 100% c would require an infinite amount of energy and is, therefore, impossible.

As it is impossible to add even an infinitesimal amount of energy to a system which is already using an (impossible) infinite among of energy, then your point about it travelling an infinite distance is largely irrelevant.

An object with mass exceeding the speed of light would not only be using a greater than infinite amont of energy, it would also have a negative length and be traveling backwards in time.

[trancelikestate]

imagine if one of these planets collided with another... Quite the show I would imagine

[8th_wall]

Lmao, I'm so silly. Of course a person would travel farther at a faster speed compared to at a slower speed o.O.. Nfi what was going on in my head last night. Actually, light bulb switching on. Time dilation effects an accelerating object. Time dilation therefore effects the object's energy consumption which in turn effects the object's speed and its distance traveled. YES! That's what I was trying to say! The distance the object travels doesn't only increase based on the object's acceleration. Its distance also increases because of time dilation.

Why was that so hard to say *cries*.

Edit1: @Waspie_Dwarf Haha yeah, I realized like 5 minutes after posting that an infinitesimal amount of energy at the speed of light is still an infinite amount of energy. But yeah, I was trying to understand how the distance traveled was effected by time dilation. My way of wording things occurring in my head is absolutely horrendous >.<.

Edited March 30, 2012 by PsiSeeker

[27vet]

imagine if one of these planets collided with another... Quite the show I would imagine

Planets are colliding all the time. Galaxies are colliding and have been photographed.

[Waspie_Dwarf]

Planets are colliding all the time.

This is true, however when planets collide it is generally during the chaos which ensues during a solar systems formation. These are planets which are all travelling in the same plane and are orbiting the same star.

Space is mostly full of nothing. For one of these free roaming planets to hit another would be phenomenally unlikely... but it's a big universe, it may have happened somewhere.

Galaxies are colliding and have been photographed.

Galactic collisions are another thing altogether. Galaxies are also mostly filled with nothing. There are huge spaces between the stars in them. Two galaxies can collide without any star or planet within them ever hitting each other.

What does happen is disruptions in the gaseous nebulae within the galaxies, causing a dramatic increase in the formation of new stars.