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Slash Tech Live Podcast.

Welcome to Tech News Briefing. It's Wednesday, August 2nd.

I'm Zoe Thomas for the Wall Street Journal.

Uber has big plans to lead the transition to electric vehicle use in London.

But powering that ambitious goal is proving problematic.

Our European Tech reporter, Sam Shekner, will explain where things stand for Uber

and what lessons other companies and cities can learn about setting green goals.

But first, back in March, we told you about a stunning discovery that could make batteries last longer.

A physicist at the University of Rochester, Ranga Diaz,

claimed to have found a superconductor that could work at room temperature and under normal pressure.

That would mean the potential for a lossless and cheaper energy production.

But now, questions are being raised about his findings.

Nidhi Subaraman is a science reporter for the Wall Street Journal, and she joins me now.

Nidhi, what concerns have been raised about this finding?

So, as is typical in science, a couple of labs started trying to synthesize a material

in the way that the group had done.

So, these were labs in China, two of them in particular tried to make a combination of

notishim, this rare earth metal, hydrogen and nitrogen,

and see if it exhibited superconductivity under the conditions that Diaz and his team had done.

...