After a relatively long news hiatus, the impossible EM
(Electromagnetic) Drive is making a comeback. Researchers from China’s space
agency have released a video through state media earlier this month showing a
supposedly-functional EM Drive. Have the Chinese finally made the impossible
happen? Let’s not be quick to jump to conclusions here, though — at least not
as fast as China did.
First, let’s review where we are with the EM Drive. Prior
to this month’s update, there were two supposed breakthroughs regarding the EM
Drive. One was a NASA peer-reviewed paper that claimed the EM Drive can work,
at least theoretically. The results, however, have been largely contested by
experts and is considered controversial at best. We’ll get to why in a bit.
Then, there was news that China claims to have proven that an EM Drive works
and it began testing one. The latest video, presumably, shows that the tests
have been successful.
So what is an EM Drive? Also
known as a radio frequency resonant cavity thruster, an EM Drive supposedly
generates thrust without the need for a propellant. It’s an electromagnetic
thrust produced by bouncing microwaves inside a cavity — like a person sitting
inside a box and pushing from the inside to make it move. Plus, the total
momentum generated by the EM Drive supposedly increases as it moves.
The appeal of such a technology is understandable. Not
only would it mean cheaper spaceflight costs, it also translates to faster
space travel. Here’s the catch, though. The physics of the EM Drive goes against
Newton’s third law of motion — for every action, there’s an equal and opposite
reaction, which is impossible to generate in space without a propellant.
“Action and reaction is a direct result of the
conservation of momentum,” Brice Cassenti, advanced propulsions system expert
from the University of Connecticut, explained previously. “The violation of
such a basic law as the conservation of momentum would invalidate much of the
basis for all of physics as we know it.”
So, as much as we’d love to have a device that could
revolutionize space travel and make getting to Mars and beyond faster, it
remains very unlikely that it’ll be this EM Drive. Nor would it be a warp drive
— which, incidentally, Yahoo News says is how some describe the EM Drive. No, the
EM Drive is not a warp drive, the two are very different things.
A warp drive, which remains only possible in the realm of
science fiction, refers to a faster-than-light (FTL) form of travel that breaks
the speed of light by warping the fabric of space-time. “The bulk of scientific
knowledge concludes that it’s impossible, especially when considering
Einstein’s Theory of Relativity,” according to NASA.
With no EM Drive and definitely no warp drive in the near
(and maybe even distant) future, we’re left with current rocket propulsion
technology to travel to Mars and beyond. Fret not, however, as NASA and
companies like SpaceX are working on bigger rockets capable of closing the
distance between Earth and Mars. Depending on how Mars and Earth align, one
trip aboard SpaceX’s Interplanetary Transport System could take just 80 days.
CEO and founder Elon Musk thinks rocket technology can improve to cut that down
to just 30 days. While that may not be faster than light, nor supposedly as
fast as an EM Drive, it’s a more realistic travel time that keeps the laws of
physics intact.