Showing posts with label experiments. Show all posts
Showing posts with label experiments. Show all posts

Wednesday, July 30, 2025

Famous double-slit experiment holds up at the single atom level

Amazing stuff!

"MIT physicists have performed an idealized version of one of the most famous experiments in quantum physics. Their findings demonstrate, with atomic-level precision, the dual yet evasive nature of light. They also happen to confirm that Albert Einstein was wrong about this particular quantum scenario. ...

Scientists have since carried out multiple versions of the double-slit experiment, and they have all, to various degrees, confirmed the validity of the quantum theory formulated by Bohr. Now, MIT physicists have performed the most “idealized” version of the double-slit experiment to date. Their version strips down the experiment to its quantum essentials. They used individual atoms as slits, and used weak beams of light so that each atom scattered at most one photon. By preparing the atoms in different quantum states, they were able to modify what information the atoms obtained about the path of the photons. The researchers thus confirmed the predictions of quantum theory: The more information was obtained about the path (i.e. the particle nature) of light, the lower the visibility of the interference pattern was. ..."

From the abstract:
"We study light scattering of single atoms in free space and discuss the results in terms of atom-photon entanglement and which-way information.
Using ultracold atoms released from an optical lattice, we realize a Gedanken experiment which interferes single photons scattering off of Heisenberg uncertainty-limited wavepackets.
We unify the free-space and trapped-atom pictures by measuring the light scattered during wavepacket expansion and show the coherence properties of the scattered light is independent of the presence of the trap. Our experiment demonstrates the potential of using atomic Mott insulators to create single-atom wavepackets for fundamental studies."

Famous double-slit experiment holds up when stripped to its quantum essentials | MIT News | Massachusetts Institute of Technology "MIT physicists confirm that ... light has two identities that are impossible to see at once."






Wednesday, December 08, 2021

Study can't confirm/reproduce lab results for about 50% of cancer experiments

Very concerning!

Can we expect similar devastating results for other areas of medicine? How about SARS-CoV-2/Covid-19?

The wild west of science! Scientists are all too human!

"Eight years ago, a team of researchers launched a project to carefully repeat early but influential lab experiments in cancer research.

They recreated 50 experiments, the type of preliminary research with mice and test tubes that sets the stage for new cancer drugs. The results reported Tuesday: About half the scientific claims didn’t hold up. ...
For the project, the researchers tried to repeat experiments from cancer biology papers published from 2010 to 2012 in major journals such as Cell, Science and Nature.
Overall, 54% of the original findings failed to measure up to statistical criteria set ahead of time by the Reproducibility Project, according to the team’s study published online Tuesday by eLife. The nonprofit eLife receives funding from the Howard Hughes Medical Institute ...
Often, they couldn’t get help from the scientists who did the original work when they had questions about which strain of mice to use or where to find specially engineered tumor cells.
... it is concerning that about a third of scientists were not helpful, and, in some cases, were beyond not helpful,” ..."

Study can't confirm lab results for many cancer experiments | AP News


Investigating the replicability of preclinical cancer biology (open access, it is not clear whether this study was peer reviewed)