<div dir="ltr"><span class="gmail_default" style="font-family:arial,helvetica,sans-serif"><font size="4">A new upper bound on the </font></span><font size="4">time it takes for a<span class="gmail_default" style="font-family:arial,helvetica,sans-serif">n</span> electron to get through a barrier by Quantum Tunneling has been <span class="gmail_default" style="font-family:arial,helvetica,sans-serif">found</span>. They found it takes less <span class="gmail_default" style="font-family:arial,helvetica,sans-serif">than</span> 1.8 attoseconds<span class="gmail_default" style="font-family:arial,helvetica,sans-serif">, perhaps 1.8 attoseconds less</span>. They <span class="gmail_default" style="font-family:arial,helvetica,sans-serif">say</span> their experimental results are "in agreement with recent theoretical findings<span class="gmail_default" style="font-family:arial,helvetica,sans-serif">" and "</span>present a compelling argument for instantaneous tunnelling<span class="gmail_default" style="font-family:arial,helvetica,sans-serif">".  One attosecond is to a second as one second is to 32 years.</span></font><div><span class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></span></div><div><span class="gmail_default" style="font-family:arial,helvetica,sans-serif"><a href="https://www.nature.com/articles/s41586-019-1028-3">Tunnelling time in atomic hydrogen</a><br></span></div><div><br></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><font size="4">John K Clark</font></div><br></div></div>