Honey, I Shrunk the Ferrari

Not many people know this, but my dad has a magical garage; it has a door on the front, and a door on the back, and these 2 doors can be opened or closed instantly (within zero seconds).
Since my parents are away and I’m extremely bored, this is how I wanna spend my afternoon:
My friend will open the front door of our 4 meter long garage, and I shall speed with my dad’s 4 meter long Ferrari into the open garage; as soon as the back of the car will go through the front door, my friend will close the door (for a split second the whole car will be trapped inside the closed garage) and then immediately open the back door allowing me to come out from the other side. Since me and my friend both have hyper-sharp reflexes, we should have no problems pulling this off and no explaining to do when my dad gets back home.

Do you know how can we complete this stunt with a 2 meter long garage (and the same 4 meter long Ferrari) without damaging the expensive paint job? Hint: Lorentz Factor. Extra kudos for explaining both points of view (my friend in the garage and me in the car).

* Actually, the truth is that my dad drives a modest Hyundai Accent and I don't live at my parents' house, but I think this riddle sounds cooler as an expensive teenage prank.

EDIT: I've posted the solution as a comment to this post.

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p.s. It’s all about motivation; I say put Angelina Jolie on the fifth row, and Conway’s Soldiers will get there.

A Heretic in the Temple of Saint Albert

I admit it. I’m a huge fan of Einstein’s Theory of Relativity (the parts that I can understand). These ideas from the beginning of the 20th century are so beautiful! Mass-energy equivalence, the speed of light, reference frames, length contraction, time dilation, gravitational space-time curvature, relativity of simultaneity, the Twin Paradox etc. How can you not fall in love with Albert’s mind-blowing elegant ideas?

- Heretic: "But for the last decades we keep on failing merging The Theory of Relativity with Quantum Physics to one unified set of equations. The physicists’ Holy Grail, ‘Quantum Gravity’, ‘The Grand Unified Theory’, ‘The Theory of Everything’ still eludes us."

- Priest: "Damn! Umm… ok, got an idea! Let’s just use one set of equations to describe the very large like cars, planes, stars, galaxies, and a different set to describe the very small like sub-atomic particles. Don’t give me that look, I know what you’re thinking, but surely Einstein can’t possibly be wrong, right?"

- Heretic: "But the mass of the observable matter in the universe is too small to explain its structure and behavior."

- Priest: "Damn! Umm… ok, got an idea! Let’s just invent something with some mysterious name like… umm… dark matter or something, a hypothetical matter of unknown composition that does not emit or reflect enough electromagnetic radiation to be observed directly. Don’t give me that look again, you know Einstein can’t be wrong."

- Heretic: "But the universe is accelerating outwards instead of slowing down like you would expect because of the 'gravity pull' between the galaxies."

- Priest: "Damn! Umm… ok, got an idea! Let’s just invent another something with some another mysterious name like… umm… dark energy or something, a hypothetical form of energy that permeates all of space and tends to increase the rate of expansion of the universe. Enough with the look already! I’m telling you, Einstein can’t be wrong!"

- Heretic: "Should we stop searching for awkward workarounds for all the things that don’t conform to The Theory of Relativity, just because we don’t want to believe Saint Albert could have been wrong? Should we start questioning Einstein? Should we admit we still don’t understand simple gravity?"

- Priest: "Pray 'E=MC2' three times a day and you'll be forgiven for your heresy."

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p.s. Violins have 4 strings, guitars have 6. Damn! Could have been a musician if I didn’t have 5 fingers.

The Day the Sky will Fall - Colliding with the Andromeda Galaxy

Meet Andromeda, a beautiful spiral galaxy (you must see this) bigger than our own, approximately 2 million light-years away. Andromeda is blue-shifted, meaning it’s heading our way, however this does not mean it will definitely collide with our Milky Way, since the galaxy's tangential velocity is unknown. Galaxies colliding is a frequent event within galaxy groups, and there are signs that Andromeda has already swallowed several other galaxies in the past. In Greek mythology, the young princess Andromeda was pretty helpless, needed to be saved by Perseus from the sea monster sent by Posiedon to the coast of Ethiopia. In real life, it seems like this girl can take care of herself pretty well...

If we are on a collision course, this neighbor heading our way at a relative speed of about 140 kilometres per second, should pay us a visit in about 2-3 billion years, even before our sun will start turning into a red giant, boiling our oceans and evaporating our atmosphere in the process. In the aftermath, it is predicted that both galaxies will change beyond recognition, merging to form a new giant elliptical galaxy – sometimes being referred to as the “Milkomeda” galaxy. And what will become of our solar system in the case of a collision? The chances of a physical impact between stars, planets or moons are very low, since the majority of galaxy space is actually empty, but the enormous gravity pull will take its toll for sure. One option is that our solar system will be thrown away to a higher orbit around the new center of Milkomeda. Another option is that we will be totally ejected from the galaxy to drift alone through the vast empty inter-galactic space. Another cheerful option is that we will be thrown toward the core, where a super-massive black hole lurking behind its event horizon will devour us.

No matter how it will end, it will be a spectacular sight to watch. And you thought our current night sky is beautiful… Just think of how it will look in 3 billion years, when Andromeda will stretch its spiral arms to fill the entire black canvas above...

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p.s. If I’ll drop two balls of different weights from the Leaning Tower of Pisa, will I be sued for polluting?

Doomsday Rock Coming Your Way at 15 Miles per Second

Somewhere on December 2004, Bruce Willis and Ben Affleck drilling and blowing up an asteroid in space stopped being amusing. A newly discovered asteroid was thought to be on a collision course with Earth; predicted impact energy: 400 megatons (~30,000 Hiroshimas); ETA: April 13, 2029. This asteroid was named ‘99942 Apophis’ after the evil demon, the deification of darkness and chaos in Egyptian mythology. Although later on, a more precise calculation revealed that this 300 meters (1000 feet) rock will wave us hello from about 25,000 kilometers away (VERY close) but will not impact our beloved blue sphere, it seems like the night sky will never be the same again.

A doomsday meteorite hitting the Earth will release energy many times greater than all the nukes in the world. It will vaporize several countries on impact, melting the Earth’s crust and igniting every flammable material. The survivals will witness world wide volcanic eruptions, earthquakes and firestorms. The oceans’ acidity level will drop to that of a battery acid and the sun’s light will be completely blocked for years. All plants and animals will die, transforming Earth into a lifeless desert. The good news – it should be suitable for life again in a few thousand years.

So what could we do? The one thing you don’t wanna do is nuke it Armageddon-style. If the asteroid is hard, then this will only break it into many smaller now radioactive pieces that will hit Earth on multiple locations. If it is softer, the blast’s energy will be absorbed, so nukes will have almost no effect at all. Some methods suggested are to use a spaceship’s gravity in order to slightly affect the asteroid’s path, use a giant mirror to focus the sun’s heat (to melt one spot of the asteroid to create a jet stream deflecting the asteroid), pull it, push it or ram it. Some of these might actually work, we just need a tiny change in course or speed, but we must have an early warning - decades in advance.

Currently the most dangerous known rock in space is ‘1950 DA’ that should drop by to say hello on March 16, 2880, but there are thousands of unknown asteroids and comets that may impact Earth in the near future. It’s not a question of ‘if’, it’s a question of ‘when’. It can happen in a million years; it can happen by the time you’ll finish reading this post, but eventually - it will happen.

The biggest threat to human race, the one thing that can wipe us out completely and make us extinct, emmm… I’m sure it’s top priority. Or is it? Currently, about 30% of the sky is not even surveyed! To quote astronaut Ed Lu from the Johnson Space Center “The number of people world wide who are working actively on this problem is enough to staff one shift in a McDonald’s”. Good night, sleep well; the planetary defense is in the hands of 4 kids with build-your-own-telescope kits.

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p.s. The Sun will die in 5 billion years. Good! I hate sunscreen!

Time Travelers, Please Proceed to Gate Number 42

Last night while watching Hiro Nakamura and Nathan Petrelli doing their thing on Heroes, I came to the conclusion that strolling through the forth dimension is much more fun than flying through the other three. While time traveling seems like a great way to spend your weekends, is it feasible?

Forward time traveling is relatively simple. It can be achieved by accelerating to extremely high speed or by getting close to an extremely big mass. As predicted by Einstein’s theory of relativity - time is subjective. For example, you can go on a one minute high speed trip only to return to Earth to discover you have just missed a whole decade back at home. A real-life example is the cosmonaut Sergei Avdeyev that spent a total of 748 days on the Russian space station Mir and missed a whole 0.02 seconds on Earth.

Although that DeLorean looked really cool on Marty McFly, backward time traveling may be theoretically or practically impossible. Some claim it can be done using wormholes, black holes or other abnormalities of spacetime, while others claim it exists only in science fiction.

If backward time traveling is possible, where are all the tourists from the future? Even if it will be illegal in the future to go back to the past, I’m sure some would break the law eventually.
Possible explanations are:
1. Backward time travel is not possible.
2. It’s theoretically possible but practically impossible.
3. It can be done, but we will destroy ourselves before achieving this.
4. It will be done in the future, but time machines allow you only to go back as far as the time the machine was created.

A famous problem is the grandfather paradox, where a man travels back in time and kills his own grandfather before the latter met the traveler's grandmother. As a result of this act, the traveler could not have been born, so how can he later travel back in time? Some see this paradox as a death blow to backward time travel possibility, but although definitely weird, I think the only problem here is that it’s not aligned with our intuition. Because human logic was developed by evolutionary process in order to better hide from lions and hunt zebras more effectively, I don’t see a big problem in the fact that 21st century thought experiments regarding traveling through the forth dimension don’t appear logical to us hunter-gatherers.

No need to comment on this post since I have just been back from the future and already read all your comments.

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p.s. Every time a lightning hits the Eiffel Tower there’s a 78% chance your wife’s on the phone.

Relatively Useful Relativity Tips (for you and your relatives)

You know what’s my problem with Einstein’s theory of relativity? Not that it’s inaccurate (like I would know) or inelegant (like I would care), but that it’s god damn useless. OK, sorry, I admit it, there are about ten guys from NASA that must use the Lorentz factor every once in a while, but what about the rest of us 6,599,999,990? Are we not worthy of enjoying uncle Albert’s heritage? I say no more! This ends now! I give you… drum rolls… (snare drum X 16, bass drum, crash cymbal). My tip list!

Tip #1: Make a very fast drive-by-style pass with your car if you wanna catch David Blaine slipping a card up his sleeve. Time on another reference frame (David Blain) will always look slower, depending on the relative speeds between the two frames (Blain and you). This phenomenon is called Time Dilation. Note that you may need to sell your Toyota and buy a faster car. For example, you’ll need to travel at 86.6% of the speed of light in order to delay time by half. So, this tip (as all the others), is theoretically true and magnificently useless.

Tip #2: Accelerating and decelerating your car may be bad for the brake system and fuel consumption, but it will make you look younger. Well, at least younger than everybody else your age. The acceleration will cause your time (everything - your wristwatch, your heart rate, your metabolism…) to move slower than the regular time on the ground. Note that you will not feel like you are living in slow motion (but will probably feel like you wanna puke from all the accelerations and decelerations).

Tip #3: The Twin Paradox. If you’re considering start dating one of the Olsen twins and wonder how she’ll look when she’s old, take her with you on a fast shuttle ride to Alpha Centauri. When you are both back on Earth, look at her sister. If you’re not happy with how her sister looks (this is how your date will look in a few years), take them both to another fast shuttle ride to Alpha Centauri, and just leave them there.

Tip #4: Objects can not travel faster than the speed of light, but allowed to move at any speed below that value. Use this when your kid tells you he came as soon as you called him.

Tip #5: Two events happening in two different locations that occur simultaneously to one observer may occur at different times to another observer. Watching your daughter on her synchronized swimming lesson from a moving airplane can make you wonder where your money went.

Tip #6: Lorentz contraction. Objects appear shorter from another relative speed reference frame. If you wanna be a porn star, don’t move while you’re auditioning.

Tip #7: The lower you go, the stronger the G-force, and gravity slows down time. Choose a low chair for long boring office meetings. To you, they will appear shorter.

Tip #8: Equivalence of mass and energy. If you’re making a home-made super bomb and C4 is hard to get, try using ultra-fat people.

Tip #9: A black hole is an object with gravitational field so powerful that even light cannot escape its pull. Sounds too good to be true, but placing your mother-in-law behind an event horizon might actually work.

Tip #10: As an object's velocity increases, its mass appears to increase. If your wife’s on a moving spaceship, shouting at you “Is this dress making me look fat?” - screw the physics, shout back “No dear, you look exactly like you did on the day we first met!” (to be honest, although her mass will increase, her waistline will shrink due to the Lorentz contraction effect, so she will actually look thinner, but that will kill my joke).

So, there you have it. As promised… theoretically true and magnificently useless. Oops, my bad, sorry again, you ten guys from NASA can still use this list when appropriate, okay?

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p.s. Remember your mistakes so the next time you’ll know you made them all over again. (credit not mine)