Four ways to break the universe’s speed limit

BI Answers: What can travel faster than the speed of light?

When Albert Einstein first showed that light travels the same speed everywhere in the universe, he essentially stamped a speed limit on our universe: 670,616,629 miles per hour.

But that’s not the entire story. In fact, it’s just the beginning.

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The four they mention are:
1. Light slows in a non-vacuum, so particles in a non-vacuum can travel faster than light in that medium – Cerenkov Radiation
2. Expansion of space, in the inflationary era and beyond the event horizon.
3. Quantum entanglement leads to “spooky action at a distance”.
4. Wormholes.

They miss my favourite one.

5. Superluminal quantum tunneling

Günter Nimtz and his coauthors have been investigating this subject since 1992. Their preferred experimental setup involved microwaves either being sent across two space-separated prisms or through frequency-filtered waveguides. In the latter case either an additional undersized waveguide or a reflective grating structure had been used. In 1994 Günter Nimtz and Horst Aichmann carried out a tunneling experiment at the laboratories of Hewlett-Packard after which Nimtz stated that the frequency modulated (FM) carrier wave transported the 40th symphony of Wolfgang Amadeus Mozart 4.7 times faster than light due to the effect of quantum tunneling.

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I’ve written about all five of these before.
1. This doesn’t “break the universe’s speed limit”.
2. Yes.
3. “Spooky action at a distance” has been confirmed over long distances, but the process may have limitations, such as the need for a single clock to control both ends of the action.
4. Wormholes don’t exist. Travelling faster than light does happen, but only shortly before being crushed into nothingness.