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Leveraging advances in microfluidics and light sheet imaging technology. We developed a water refractive index-matched microneedle to catch embryos for live imaging.

The constancy of the speed of light is the second hypothesis of Einstein’s special relativity theory proposed in 1905. Since then science and technology have advanced very much, which can be used to reexamine the century old hypothesis. We proposed a novel method and implemented an optical system accordingly to compare the speed of starlight with the well-known speed of light from a terrestrial source, c. The system consists of a transmitter and a receiver. The transmitter modulated starlight, terrestrial red and infrared lights into pulses simultaneously. After travelling a distance, these pulses were detected by the receiver. A high speed oscilloscope is used to record the arrival times of these pulses, where the terrestrial infrared pulse and the red pulse are used as the trigger and the reference signals. During the measurement, we employed a terrestrial white light travelling along the exact path of the starlight to calibrate the system. We also carefully reduce the errors during the measurement and the data processing, and get some results in these years. We find that comparing with the terrestrial white light pulse, the starlight pulses arrived at the receiver with various degrees of delays. The values of the time delays are likely related to the relative radial velocities of the stars. The result implies that the measured apparent speed of starlight is not constant.

Ground-based observations at terahertz (THz) frequencies are a newly explorable area of astronomy for the next ten years. We discuss science cases for a first-generation 10-m class THz telescope, focusing on the Greenland Telescope as an example of such a facility. We propose science cases and provide quantitative estimates for each case. The largest advantage of ground-based THz telescopes is their higher angular resolution (~ 4 arcsec for a 10-m dish), as compared to space or airborne THz telescopes. Thus, high-resolution mapping is an important scientific argument. In particular, we can isolate zones of interest for Galactic and extragalactic star-forming regions. The THz windows are suitable for observations of high-excitation CO lines and [N II] 205 um lines, which are scientifically relevant tracers of star formation and stellar feedback. Those lines are the brightest lines in the THz windows, so that they are suitable for the initiation of ground-based THz observations. THz polarization of star-forming regions can also be explored since it traces the dust population contributing to the THz spectral peak. For survey-type observations, we focus on ``sub-THz'' extragalactic surveys, whose uniqueness is to detect galaxies at redshifts z ~ 1--2, where the dust emission per comoving volume is the largest in the history of the Universe. Finally we explore possibilities of flexible time scheduling, which enables us to monitor active galactic nuclei, and to target gamma-ray burst afterglows. For these objects, THz and submillimeter wavelength ranges have not yet been explored., 39 pages, 17 figures, accepted for publication in PASJ (as a review paper)

The speed of light is an important physical parameter. Currently it is a common belief of the constance of the speed of light regardless of the relative velocity between the source and the observer. Because the speed of light is very fast, if the relative velocity is small compared with the speed of light, it is difficult to detect the effect of the relative velocity on the measurement of the speed of light. In this paper we present a method of comparing the speeds of starlight and the light emitting from a terrestrial source. We use a telescope to collect the light from the star having significant relative velocity with respect to the earth, e.g. Capella. Then we modulate the starlight and the light emitted from the local source into pulses i.e. these pulses leave the modulator simultaneously. After travelling 4.2 km, these pulses are detected by a receiver. If the starlight and the terrestrial light have the same speed, then these pulses must arrive at the receiver at the same time. Our results show that the arrival times of the pulses of starlight are different from that of the local light. For example, the Capella is leaving away from the earth. The Capella pulses arrive later than the local light pulses. It indicates that the speed of Capella starlight is slower than the common believed value, c. The presented method uses one clock and one stick, so the clock synchronization problem and any physical unit transformation can be avoided.