I heard about project Breaktrhough on steemit here. I did little Internet research to find out more.

too far too slow

Sails are the only way that might work in the near term. According to this article, there are 5 talked about propulsion ( ex 2 that seem unfeasible)systems:

1. anti-matter drives the fuel is created through super collider but cost $100B to generate a few grams. Next?
2. fusion engine unfortunately we can't even get this to work for energy here on earth. Even if it did work it would be huge! Anyone else?
3. nuclear pulse shoot nukes off just behind the ship. We could do this but it would take 100 years and using them to slow down might lead to flying through radiation.
4. generation ships it sounds feasible to build a ship so big generations could live on it? Battlestar galatica anyone?. However how long did it take to build the space station that holds 4 people?
5. Solar sails - winner! shoot a laser at sails ( though no brakes). I rennet this expiriment in high school physics. It works! We get to build the hard part on earth where we are good at building things.

note I left out ram jets and warp drives. These do not even sound understandable (ran jets) or feasible (warp drives)

so how would sails work?

This New York Times article discusses the proposal by the project Breaktrhough guys.
They would send a fleet of cell phone sized ships to alpha Centauri 4.4 light years away. Apparently the earth based laser could get the cell phone sats up to 20percent of the speed of light with a giant array of lasers.

Already been tested

According to space.com the physics have already been tested

The technology has already been tested in space, with Japan's Ikaros probe deploying a 46-foot-wide (14 meters) sail in June 2010 and NASA launching an even smaller craft called NanoSail-D five months later.

But ...

You'd have to point [the laser] more accurately than we can point anything today to keep it focused on the sail,"

And it would use massive amounts of energy.

They have studied them since the 70s but until now material science was a real constraint. Here is a solar sale that nasa has built in Virginia.

Exciting things happening in space exploration these days